Layout marking and printing methods are discussed here. The arrival of the computer and its associated hardware has added to the choices, but traditional methods are still very useful options. If you got to this file directly from my HOME PAGE, return there by using your browser's back button. BUT if you came to this file as the result of a web search engine, see more than 70 additional files on my home page Machining and Metalworking at Home http://www.janellestudio.com/metal/ SAFETY WARNING BEWARE: DO NOT ASSUME that any subject matter or procedure or process is safe or correct or appropriate just because it was mentioned in a news/user group or was included in these files or on this site or on any other web site or was published in a magazine or book or video. Working with metals and machinery and chemicals and electrical equipment is inherently dangerous. Wear safety devices and clothing as appropriate. Remove watches, rings, and jewellery -- and secure or remove loose clothing -- before operating any machine. Read, understand and follow the latest operating procedures and safety instructions provided by the manufacturer of your machine or tool or product. If you do not have those most recent official instructions, acquire a copy through the manufacturer before operating or using their product. Where the company no longer exists, use the appropriate news or user group to locate an official copy. Be careful -- original instructions may not meet current safety standards. Updated safety information and operating instructions may also be available through a local club, a local professional in the trade, a local business, or an appropriate government agency. In every case, use your common sense before beginning or taking the next step; and do not proceed if you have any questions or doubts about any procedure, or the safety of any procedure. Follow all laws and codes, and employ certified or licenced professionals as required by those laws or codes. Hazardous tasks beyond your competence or expertise should also be contracted to professionals. Let's be really careful out there. (c) Copyright 2003 - 2008 Machining and Metalworking at Home The form of the collected work in this text file (including editing, additions, and notes) is copyrighted and this file is not to be reproduced by any means, including electronic, without written permission except for strictly personal use. ========================================================================== NOTE TO FILE: There are not a great many conversations out there about the basics of marking a project piece for drilling or cutting or whatever. The difficulty of describing such topics in words, without sketches or pictures, is largely to blame for this subject's rarity in forums. One of the best resources to the amateur metal (or wood) worker is the local library, which likely has basic text books intended for high school shop instruction. Layout and marking for projects are normally well covered -- along with priceless tips, pictures, sketches, and diagrams. Also see some of the publications mentioned in the "Metal Publications" text file on this site. ------- Date: Fri, 13 Apr 2001 11:27:53 -0400 From: "Daniel Munoz" Subject: Laser printers and picture transfer Hi, the list is quiet, so I ask a maybe a little off-topic question: I've read (I don't remember where) that it is possible to transfer laser printing back to a support by heating the back of the paper and thus transferring the laser toner drawings to the applied support. I've tried it, with my wife iron (while she was not looking), and it work well! The heated toner is transferred to the support in seconds, even with an old print (the toner don't need to be "fresh"). I wonder if this is used by laser-printer owners, to transfer some drawing marks to an item and draw easily some useful positions. Of course, the drawing as to be printed mirror-like, but I thought using a laser with it's 600 points per inch could be a very accurate way to transfer some drawings, and it could be done on non-flat surfaces too. The toner seem to be very resistant once transferred, although I only tried on plywood. Maybe a simple varnish protection could use this trick to create some accurate rulers on metal items. Or to transfer some decorative drawings for carvers and clockmakers ? Well, what do you think ? Is it something that as been tried before ? Daniel ------- Date: Fri, 13 Apr 2001 08:34:31 -0700 From: "David Goodfellow" Subject: Re: Laser printers and picture transfer Hi Daniel: How good is the transfer? I have to try this! I've just started to fool around with transferring laser images to printed circuit board stock. The toner makes a good etch resist, allowing name plates (builder's plates) to be made with a copper image on blank board stock. It also works well with brass plate. I've been using a special transfer paper that costs more per ounce than gold. It looks like you're saying I can do it with plain printer paper. Dave Goodfellow ------- Date: Fri, 13 Apr 2001 11:51:12 -0400 From: "Daniel Munoz" Subject: RE: Laser printers and picture transfer I didn't even know there was some special transfer paper ;-)) Well, yes I used some plain laser paper, but maybe the "Special" one do a real better job !? Please let me know if you try and compare the results. I quickly tried a few days ago with an iron on a piece of plywood, and the result was ok to spot a mark, but not very good. I guess the more you heat it, the better the ink is transferred. After that, it depend on the support resistance to heat treatment. No transfer on plastic I'm afraid :) My primary idea was to create a custom computer program to print some ruler scales for round items on adhesive paper (given a circumference), but I figured transfer by heat could be a better solution than adhesive paper. Just fooling around too ;-)) Daniel ------- Date: Fri, 13 Apr 2001 12:13:17 -0400 From: "Carol & Jerry Jankura" Subject: RE: Laser printers and picture transfer My experiences with anything using paper is that it does not hold dimensions very well. I can see using this kind of image as a guide to make sure that you don't mill something too far off of the mark, but I would not rely on it for any serious work. Also, I wouldn't locate more than one hole center by this method. Carol & Jerry Jankura Strongsville, Ohio So many toys, so little time ------- Date: Fri, 13 Apr 2001 10:13:29 -0700 From: "Arnold Chord" Subject: Re: Laser printers and picture transfer If I am correct the special paper is a high gloss paper. Regular paper absorbs the toner and ink. The glossy does not, allowing for more ink to be transferred. Arnold ------- Date: Fri, 13 Apr 2001 13:10:45 -0400 From: "Daniel Munoz" Subject: RE: Laser printers and picture transfer For big paper plan, of course.. but for a letter size, used right after you print it, there should be no noticeable hygrometric variations, isn't it ? And there is repeatability, I just print on my laser a 8" length ruler twice, there is no "eye" difference between the beginning and the end of the ruler on both papers. So, a good calibration on the vertical *and* horizontal print result should be acceptable in some case, best than a hand mark with a graver I guess. Of course, if not *very* accurate, that's for sure. But certainly better than 0.004". Please explain why you wouldn't locate more than one hole center by this method? I don't understand but I will be happy to learn. I thought that if more than one holes are positioned at the same time, the error will be the same for all, and is not accumulated by a possible repetitive error measurement. Daniel. ------- Date: Fri, 13 Apr 2001 10:15:35 -0700 From: "Arnold Chord" Subject: Re: Laser printers and picture transfer Actually this is software dependant. A good software program will give a great picture, with some exact tolerances. ------- Date: Fri, 13 Apr 2001 13:17:08 EDT From: Grafspee34x~xxaol.com Subject: Re: Laser printers and picture transfer achord2x~xxhome.com writes: << I've been using a special transfer paper that costs more per ounce than gold. >> Who sells this stuff, and what is the technical name for it? Maybe there is a cheaper place to find it? Sounds like it can be very useful for making small etched parts, if used sparingly it can go a long way too. Thanks! ------- Date: Fri, 13 Apr 2001 13:21:24 -0400 From: "Daniel Munoz" Subject: RE: Laser printers and picture transfer Ah, thanks for the tip Arnold, I will try with glossy paper. Of course, you're right. The less the ink is absorbed, the better it will transfer. I remember using once a paper for business card so glossy the toner was not able to penetrate and was fussy when rubbing the printed result... a must for transfer I guess ! ;-) Daniel. ------- Date: Fri, 13 Apr 2001 10:45:14 -0700 From: "David Goodfellow" Subject: Re: Laser printers and picture transfer I've been using a product called "Press-N-Peel" (PNP). It cost me $11.95 for 5 8-1/2x11 sheets. It's intended for making printed circuit boards. It feels like a sort of plastic - maybe mylar - and you print on the "dull" side. They claim it's good for a trace witdth down to 5 mil. Like many things, you have to learn the technique. So far I've gone through 2 sheets and have made a couple of reasonably successful builder's plates but there is still room for a lot of improvement. It will take practice for me to get it right consistently. Dave Goodfellow ------- Date: Fri, 13 Apr 2001 10:52:16 -0700 From: Randy Gordon-Gilmore Subject: RE: Laser printers and picture transfer Silicone-impregnated baking paper has been recommended by several people for toner-transfer use also. For actually etching PCB's, the material of choice is PnP Blue, which is a sturdy plastic backing sheet with an applied thinner plastic sheet, that uses the printed toner as a kind of hot-melt glue when you transfer the image. Some people have reported good results, but I was not able to duplicate them. PnP Blue is made by Techniks and, for anyone interested, is shown step-by-step at http://www.techniks.com/press-n-peel.html Best regards, Randy -------- Date: Fri, 13 Apr 2001 11:12:18 -0700 From: Alan Marconett KM6VV Subject: Re: Laser printers and picture transfer Hi Daniel, I think something like this is done to make PC boards from a transfer paper. available in local electronics shops. Can't remember the name of the stuff. Alan KM6VV ------- Date: Fri, 13 Apr 2001 11:13:04 -0700 From: "David Goodfellow" Subject: Re: Laser printers and picture transfer I just touched on that in a previous message, because I didn't want to be seen as a shill for the company. But since you asked, the product name is PRESS-N-PEEL. I got it from All Electronics -- http://www.allelectronics.com/ The specific page of their on-line catalog in .pdf is -- http://www.allelectronics.com/pdf/74.pdf I went to one of their local stores (Van Nuys, California) to get mine, but they do sell on-line. "... if used sparingly ... I make the image on Corel Draw, which allows me to print it out "mirror image." I cut out a piece of this stuff just slightly larger than the image, and Scotch Tape it to the image on a previously printed copy. This is to make sure the PNP is positioned properly. Then I stuff the whole mess back into the laser printer. The learning experience with this stuff is in two areas: cleanliness and amount of heat. Cleanliness: Perfection in this area is required. I finally got things to transfer properly when I first scrubbed the part with a common soap-filled scouring pad whose name I disremember, then scrubbed some more with scouring powder (another kitchen product whose name I can't remember - maybe I have a problem with kitchens). The point is, you simply cannot get it too clean. A mere finger print will break up the image. Temperature: Too much and the image spreads, losing detail. Too little and the transfer is not consistent. I preheat the part to take the image with a heat gun. Then I place the PNP image-side down on the part. I place a piece of paper over that, and iron the whole package. I use the paper between the PNP and the iron because the PNP tends to stick to the iron otherwise, and smear the image. It's important to iron until the whole package is uniformly hot. I cooled it off with water as directed, but I think I may get better results if I just let it cool off naturally, maybe with a book on it to keep the pressure on while it cools. As you can see, I'm still experimenting. Dave Goodfellow Northridge, California "No problem too small to baffle this expert" -------- Date: Fri, 13 Apr 2001 11:27:24 -0700 From: Dave Martindale Subject: RE: Laser printers and picture transfer Even when freshly printed, the accuracy of a laser printed diagram depends on the mechanism of the printer itself. (Long description of how a laser printer works follows - you've been warned!) In the direction that the paper is fed (usually the long side of a standard page), the positioning accuracy is determined by how evenly the paper moves. This is usually done by a stepper motor and gear train, so it should be pretty even along the length of the page - though probably not exactly 600 DPI. You'd need to calibrate the printer by measuring a known distance scale in order to know the exact DPI value to use. In the other direction, things are more complex and possibly less accurate. The dots are positioned by a motor spinning a mirror. The motor speed is regulated, but like any motor its speed will go slightly above and below the average speed over time, and this will cause dots to appear slightly left or right of their intended position. The dot clock for the pixel data being sent to the laser will be generated from a crystal oscillator, so the dots are spaced a constant amount of *time* apart as they leave the laser. If we assume the motor and mirror rotates at a constant rate, then there is a fixed angular distance between the path of the light for each dot as it leaves the mirror. If the imaging surface was wrapped into a cylinder whose center was located at the axis of the rotating mirror, this would give a constant spacing of the dots across the image. And, in fact, this is how some laser film recorders work - the film is bent into a cylinder. But a laser printer can't do that. The imaging surface is a metal drum that has to be oriented like a roller to the paper path, and the portion that is being written for a single scan line is flat. So the distance from the spinning mirror to the imaging drum is variable - it's closer in the center of the page and further at the edges. This means that there needs to be a lens between the rotating mirror and the drum in order to focus the beam through this changing distance. An ordinary lens can do this, but there's still a problem with the spacing of the dots: the dots will be spaced further apart at the edges of the paper and closer together in the middle. This is because the constant angular spacing between dots at the mirror gives a varying linear spacing of the dots on the drum due to the mirror-drum distance changing. Laser printers solve this problem using a special lens design called a "f theta" lens. This has a specific amount of barrel distortion built into it, so that a constant change in *angle* for the incoming light results in a constant change in *distance* on the imaging surface. This is exactly what you want. But the accuracy of the positioning of the dots depends on how perfectly the lens distortion matches the ideal f-theta curve, which may not be perfect. So, along the width of the paper, you may find that the dot spacing varies between the center and edge of the page. This is more complex than along the length, where the spacing is likely constant. In addition, horizontal lines aren't necessarily exactly at right angles to vertical lines. It all depends on how accurately the spinning mirror's rotation axis is perpendicular to the imaging drum axis, and how accurately the paper feed path is aligned to the imaging drum. Unlike machine tools, there's probably no way to adjust this if it's wrong. The end result of all this is that within a small local area on the paper, the relative dot spacing should be accurate to a fraction of the dot size, but over long distances on the paper dots could potentially be many thousandths of an inch away from their ideal positions. You could measure and compensate for differences in the average horizontal and vertical dot spacing, and the amount that they are out of perpendicular, and this would reduce the size of the errors, but this still wouldn't eliminate the effects of any change in horizontal dot spacing along one horizontal line. So, a laser printer is a useful and neat device, but it's not a precision measuring tool. And it's probably not as accurate as a pen plotter, which has some sort of positioning mechanism that's more linear. Dave ------- Date: Fri, 13 Apr 2001 11:55:01 -0700 From: "Arnold Chord" Subject: Re: Laser printers and picture transfer With the hot melt it is better if you can hold the paper down with something. Some people use a heated roller, in the style of an old wash machine wringer, not as large. One or both rollers are heated. When the press and peel is sent through, the paper is held pretty firm. This will reduce sliding of the paper. Arnold ------- Date: Fri, 13 Apr 2001 14:55:45 -0500 From: Ron Roske Subject: Re: Laser printers and picture transfer Hi, gang! I thought that I'd throw my 2 cents worth to carry the information on this technique a bit further. First as to what's actually happening with this process. The short story is that the toner used in laser printers consists of a fine plastic powder that is coated with carbon (simple explanation, but accurate enuff!). This is laid out on, and stays on, the paper thru the use of positive and negative charges, etc. As the paper goes out of the printer thru the exit rolls, the toner is heated and actually melts into the surface fibers of the paper. To accomplish the type of transfer, that we are talking about here, all you need is something that has a surface that will not allow the toner to melt into it, and that will not melt as it goes thru the exit rollers. There are other parameters that are to be considered such as flexibility and feedability and so forth, but there is room for experimentation in this arena. The non-stick aspect is what is important. With the melted toner applied to whatever type of carrier you have picked, it will readily transfer to where ever you want it to go. And that is accomplished by the application of an even heat, by whatever method, over the entire surface that is sufficient to remelt the toner. Again, there is plenty of room for experimentation. As to the accuracy. If you are using a current technology laser printer, and with the assumption that it's up to snuff and working as it should, I doubt that you will detect .001 difference in horizontal placement from side to side on an eight inch print. If in doubt, do a print and compare it to the original by measuring. This is not meant to disregard anything that Dave M said in his post (copy below)! What he stated is very true and may be applicable in many cases. Each printer has it's own characteristics and what may work on your printer may not work on mine. All I'm trying to get across is that you not be afraid to try it on whatever printer you have available and see what happens. Hope this info proves to be of use to some of you and hope your day goes well... Ron ------- Date: Fri, 13 Apr 2001 13:28:48 -0700 From: Randy Gordon-Gilmore Subject: Re: Laser printers and picture transfer At 02:55 PM 4/13/2001 -0500, Ron Roske wrote: >accuracy. If you are using a current technology laser printer, and with >the assumption that it's up to snuff and working as it should, I doubt that >you will detect .001 difference in horizontal placement from side to side >on an eight inch print. If in doubt, do a print and compare it to the Actually, even with a phototypesetter imaging on Mylar you're doing good to hold .001" accuracy over that size. Paper stretching, drive roller slipping, uneven thermal expansion of the paper while going through the fuser section, non-equilibration of the paper to humidity changes can all affect the accuracy. But the real limit to using a laser printer for direct artwork is the pixel size. The toner, as Ron said, is held to the imaging drum electrostatically, and transfered to the paper where it is fused (melted) on. If you look at a single toner pixel under a microscope, it does not have a sharp edge, but looks almost like a little spray-paint spot. This spreading of the toner spots (analagous to ink spread in halftone printing) is what limits the sharpness and resolution of the output. What was the real problem for me when playing with the thermal transfer for photoetching, was the further smearing of the lines when ironing the toner onto the workpiece (either PCB material or thin brass). Compared to the very good results I have with photoresist, the package of PnP Blue that I went through trying to develop a workable technique was not worth it for me. On the other hand, there is an excellent paper for laser-printing at least trial artwork onto for imaging photoresist. It's called Newscraft LGN (Laser Generated Negative) and is described, and available from: http://www.systemfacilities.com/lgn.htm I use it for artwork where I don't need really fine resolution, and trial versions of artwork I eventually plan to have photoplotted. And, for the final artwork, I have been using Precision Digital Imaging: http://www.precisiondigital.com/ who has the most accurate output I know of, and was recommended to me by a commercial photoetcher. Sorry, this has deviated a ways from Sherline machining. But I do use a combination of photoetched parts along with machined parts in my model building (which has been on hiatus while I CNC'ed my 5400 mill) so it's a subject near and dear to me... :-) Best regards, Randy (couple of photoetching articles on my website for anyone interested) Randy Gordon-Gilmore Rio Vista, CA, USA http://www.rickadee.net/~zephyrus -------- Date: Fri, 13 Apr 2001 18:19:03 -0400 From: "Carol & Jerry Jankura" Subject: RE: Laser printers and picture transfer Because I'd be concerned that the relative distances between the centers may not be exactly what I had designed. I would tend to trust the leadscrew and making sure that I was turning the leadscrew in only one direction. Carol & Jerry Jankura Strongsville, Ohio ------- From: seanc62x~xxy... Date: Mon Jul 30, 2001 6:23 am Subject: Re: Laser printers and picture transfer I was just checking the old messages out and though I'd respond to this. > But a laser printer can't do that. The imaging surface > is a metal drum that has to be oriented > like a roller to the paper path, and the portion > that is being written for a single scan line is flat. > So the distance from the spinning mirror to > the imaging drum is variable - it's closer > in the center of the page and further at the edges > So, a laser printer is a useful and neat device, > but it's not a precision measuring tool. > And it's probably not as accurate as a pen > plotter, which has some sort of positioning mechanism > that's more linear. Dave Most 'laser' printers any more use a light emitting diode bar with an array of LEDs a few high by width of paper wide. I don't believe the laser and mirror mechanism type of laser printer is used any more - the led bars are a lot cheaper to produce and maintain. The main thing to watch out for when using this technique is that most copier/laser printers are designed to blow up an image 101% (at least that was the way it was when I worked on them). Postscript capable laser printers are good for getting 100% image size if memory serves. While you probably won't see any image distortion across the width of the paper, the length is another thing. The feed rate of the paper has to match the roll rate of the drum. Worn feed rollers or paper dust causing slippage can be a problem. The thing to do though is check the distance between two points (spaced about as far apart as a sheet of paper will allow) on a test copy. Any drawing program that allows you to set the distance between grid points and 'snap' objects to a grid should do. If you see that things are slightly larger in both width and length (101% problem), see if you can resize the image to 98-99% through the program or through the 'properties' in the print dialog window. This is a good technique for putting lettering on control panel face plates for electronics boxes (haven't done it myself yet but I recall reading about it somewhere). A careful layer or two of spray laquer could probably be applied over it (it might cause the toner to run, so test this first). I hadn't thought about using it for layout. Acetone will clean the toner from parts. I used to use TCFE (trichloro- fluoro-ethane) but it's no longer available. Maybe my quite liberal use of it back in my copier repair days accounts for some of my questionable thinking. There are a few different toner transfer papers available for the printed circuit board market - 'Toner Transfer System', 'PNP-Wet', and 'PNP-Blue'. My testing of these three has led me to favor the 'PNP-Blue' for my printed circuit board work. Sean ------- From: Pavel Korensky Date: Mon Jul 30, 2001 7:01 pm Subject: Re: [sherline] Re: Laser printers and picture transfer I am using the HP LaserJet 6 for PCB making without any problem. I am printing on the transparent plastic sheets and I am using UW light unit for photoresistive PCBs. I am using the ferric chloride (??? right english translation) for etching. With this method, I am doing two sided boards with a lot of through-the-hole and SMD components without any problem. Even the 208 pins QFP circuits and 12 mils wide traces are not a problem. PavelK ------- From: gizmomakerx~xxb... Date: Tue Jul 31, 2001 5:23 am Subject: Re: Laser printers and picture transfer > Acetone will clean the toner from parts. It is a pity there doesn't seem to be a similar process for inkjets with the ink system not being a heat transfer. Have not seen any post where someone has come up with a reliable method. Though for labels, printing onto clear adhesive backed film is quite good. > I used to use TCFE (trichloro-fluoro-ethane) but it's no longer > available. Maybe my quite liberal use of it back in my copier repair > days accounts for some of my questionable thinking. Count yourself lucky Sean. Friend of mine used trichlorethylene, pre runner of TCFE, and labelled and marketed as a contact cleaner to clean electronic stuff, drag on the fag, do some more cleaning.... killed him inside 3 years. Robert Sydney Australia ------- Date: Thu, 30 Jan 2003 22:49:37 -0500 From: RichD Subject: Re: Layout Pencils for Metalworking Jim Rickenbacker wrote: > These are Sanford Verithin 734 pencils. They are about $6 a dozen from > many suppliers. Jim & all, Having used the white 734, I find the General's TEL-E-MARKER No.1256WWH (white) is better at leaving a mark on dark metal and painted surfaces. Also, black steels marked with the Verithin No.753 (silver) is excellent. A soft grade of graphite pencil works for some things others do not. RichD ------- Date: Sat, 12 Apr 2003 10:48:57 EDT From: toolroomtrusteex~xxaol.com Subject: Vellum and Mylar I suspect as jrwillmsx~xxhal-pc.org posted that those shaper drawings are on vellum. When I worked for NOAA we called it tracing cloth AIR. It was a fabric with a blue sizing on it. It didn't erase that well, though a little judicious work could correct small mistakes. It had the advantage that it could be folded. I worked for what was the Coast and Geodetic Survey, their surveying manual specified a maximum size of cloth and then explained that was based on size of drawers used for storage at headquarters. Mylar is so much better for this work. A lot easier to correct mistakes. Anybody here remember Leroy lettering sets? My oceanographic tech department had 6 sets. I went to a lot of trouble to make the sets complete with the furnished pens even though we were using Rapidograph pens. I went on leave once and when I returned found that my heretofore favorite employee had tossed the old pens since they weren't used. I knew my command wouldn't back me up so stuffed my feelings. A coupla years before I retired we got software to use a plotter for the major drafting we did. I wasn't sorry to see that job obsoleted! I do consider it a privilege to know guys that could spend a couple weeks drafting on a piece of tracing cloth with NO mistakes. These guys were real craftsmen. Larry ------- Date: Sat, 12 Apr 2003 10:25:24 -0500 From: jrw Subject: Re: Vellum and Mylar Larry: It was a great day when the Mylar product arrived in our department and be able to go to the special pencils. I have my old drafting set, including a drawer full of templates, as well as the great LeRoy lettering set that goes along with the K&E drafting machine. JRW ------- Date: Sat, 12 Apr 2003 18:45:21 -0000 From: "Art Volz" Subject: Re: Vellum and Mylar Joe and Larry-- I too still have a large collection of both mine, and my dad's, drafting stuff--all manual--except for a couple of electric-powered erasing machines. The last time I tested my "just enuf" set of Rapidograph pens--at least ten years ago--they all (3) still worked. One college-era Christmas my dad's special present to me was a K&E 6- inch nickle plated compass...which I still have...and in near pristine condition: it was intended to last a life time. I remember I saved enuf coins back in the early '60's to buy two Rapidographs for inking some final drawings made in a mechanical design course at ND, and still have both. I didn't see any (that I can remember) non-paper drawing sheets until I joined the Green Machine in Frozen Chosen (64-65). I was the Assistant S3/Battalion Fire Direction Officer for a 105mm towed howitzer battalion with prepared and occupied firing positions right below the DMZ. We had a few Mylar firing charts with our pre- determined targets and barrages located on them for when "the balloon went up." For training, however, we used paper 1:25,000 scale firing charts. They were OK for training, but would tend to stretch with the Korean humidity and contract so, for the "real" firing charts we used only Mylar...when we could scrounge extra ones. The stretching/contracting of paper charts would vary firing ranges considerably when measured with the range deflection protractor. For the annual Battalion and Battery Tests, only hoarded Mylar firing charts were used. We never used ink on them, only pencil, so they tended to last a while. When one target area would become too "holy" because of the pin holes, we'd just renumber and shift grid as appropriate. (Firing charts have a pre-printed grid, 1:25,000 scale, with the square grid being either 1,000 x 1,000 yards (then) or meters (now).) With a hoard of "100-mile-per-hour" green cloth tape (similar to duct tape), a roll of map board clear acetate, and some Mylar firing charts, one became a real "King Rat" and very "well-liked" on the social circle...40 years ago...in Frozen Chosen...with the First Cav. Art (Houston) ------- Date: Mon, 11 Aug 2003 09:06:53 -1000 (HST) From: Tom Benedict Subject: A mechanical dodge [taigtools] I've been making some parts for work in a desperation machining job, so time has been of the essence. A number of the parts didn't need to be cleanly machined all over, so I'm able to settle for saw cuts. In an effort to save time, I hit on a potentially useful mechanical dodge: Most of the parts are smaller than an 8.5x11 page. After drawing up the parts in CAD, I printed out a 1:1 picture of each part, laminated it, and using a paper cutter, cut out the outline of the part. The lamination makes it stiff enough I could use the template to trace each of the parts onto my material using a scribe. Some band saw work, and the parts were ready to have their hole patterns drilled out on the mill. I've used the 1:1 template idea before when selecting material for parts (it makes it really easy to hold the template up to the material and say, "Yup!" or "Nope...") But this is the first time I've used the template to actually mark out the work. The same trick could be used on parts that are going to receive finish machining. When cutting the template out, just leave extra room on each side. This is likely old hat, but I figure someone might not have used it before, and anyone with a printer can pull the same stunt. Tom ------- Date: Wed, 13 Aug 2003 00:22:48 +0000 From: "steve sc" Subject: Using a printer for quick layout Tom reported on a mechanical dodge using a printer to print a template. I do the same thing, particularly useful in making sheet metal enclosures and front panels for electronics projects. The only different wrinkle is after printing the template, I spray the back with spray adhesive (3M makes a good one) and stick the template to the metal. Then I cut away, through the template. If I am being fussy, I scribe through the stuck on paper template with an Xacto knife to score the metal and I prick punch the holes. The surprising part is how accurate even cheap inkjet printers are! Try printing one to one with your CAD program and scale the resulting drawing. I typically find that I am within a few thou, more than good enough for most sheet metal work. I wrote a short article about this technique a few years ago: Machinist's Workshop Magazine, OCT/NOV 2000. Steve ------- Date: Tue, 19 Jul 2005 09:52:29 -0700 From: "Felice Luftschein and Nicholas Carter" Subject: Re: Layout Advise [taigtools group] "Lynn Livingston" wrote: > I'm in need of some layout advise. I have found that my way of doing > layout work is not accurate enough for some things I'd like to achieve. > Specifically, laying out for holes. > I'm currently using various scaled rules, small squares and scribes. > If the part I'm laying out is smallish, this becomes difficult > equipment to hold securely by hand. Also, my eyes are not what they > used to be and I find I can no longer focus well on my 10th rule. As > well, I can't trust that I can make an accurate mark either on smaller > parts (say 1"x1"X1"), being that I'm sure I'm not locating the rule > precisely on each part. > I have also used the mill to layout parts, and sometimes this is okay. > But, I figure it's time I begin another chapter in this hobby. > What would I use to layout and scribe accurate lines? I've seen height > gages and surface gages in catalogs, but I haven't any idea how to use > them. I mean, I could see how to measure with a height gage, but how > would you mark a part with it? > I'd also appreciate a recommendation if you have one to give on any > books or web sites that explain layout principles in beginner language. > Thanks for any help or advise, Lynn Livingston Unfortunately I don't have any pics of my current layout system up on the web (I'll see about that the next time I do some laying out). Basically the height gage has a sharp (these days carbide tipped, usually) knife edge that is used to scribe the line in the part. Surface gages have the same function but generally use a round scribe. Either of these can be raplaced with a dial indicator or other gage for measuring purposes. I have a Fowler (Chinese Import) 24" electronic height gage which although only accurate to about +/- .001" makes layout very easy, especially when measuring relative to another location. The height gage sits on an 18" x 18" grade A granite surface plate (Do-All, purchased at a surplus sale for $35.00), Granite plates, even new, are inexpensive if you don't have to pay for shipping. The hidden element to the system is a right angle plate, that the work is rested against for scribing the lines. In my case I use a large 4" x 8" Taft-Pierce Box Parallel (bought at auction, again for about $30.00) which is quite square, but any good angle plate will work. It helps to have a second angle plate or 1-2-3 block so that you can make sure the work is not only square to the angle plate but to its side (especially if the end resting on the surface plate is rough). It helps to mark the work for scribing with layout dye or an indelible marker pen. This is probably as clear as mud... Check out our homepage www.cartertools.com/nfhome.html ------- Date: Tue, 19 Jul 2005 17:39:44 -0000 From: "Lynn Livingston" Subject: Re: Layout Advise Well, I can see how you'd use the angle plate or two and maybe a 123 block to rest your work up against to help ensure that the work is at a known relational angle. What I can't see in my minds eye is how at the point you have your part positioned correctly, you take something like a long ruler stood on it's end with a non moving (except up or down) arm and get the part marked. In my mind (and it is a simple one now), marking a part must require some action or movement, and I just don't see yet how a clamped part, and a stationary scribe are going to get together and cause an action?????!!!!! :-) If I'm scribing manually with a square, I move the scribe to cause a mark. What is it I'm not seeing about your setup that causes a mark to be made? Okay, I know that since the gage has the scribe point, it's gonna' be doing the marking. But, being on a fixed base, I assume the gage scribe isn't gonna' be doing any moving? So, that leaves the part that has to move... If it's clamped to plates and blocks, that are setting on a solid surface, and that surface is a piece of granite that is the same thing that is anchoring the gage, what is gonna' move? Yeah, I'm a newbie without experience, and it just keeps catching up with me! Lynn ------- Date: Tue, 19 Jul 2005 10:48:04 -0700 From: "Felice Luftschein and Nicholas Carter" Subject: Re: Re: Layout Advise You can do either one of two things: 1) rotate and slide the height gage along the surface plate, keeping the tip/point in contact with the work. The height is fixed, contact pressure is determined by your on-board computer (your brain) and the surface plate ensures the scribing is done in the same plane. 2) move the work along the surface plate, using it like a fence. This only works if the plate is either clamped to the plate or heavy enough (in the case of my box parallel) to not move, and the work has enough of a surface bearing on the plate to not rock. Check out our homepage www.cartertools.com/nfhome.html ------- Date: Tue, 19 Jul 2005 10:50:01 -0700 (GMT-07:00) From: Larry Richter Subject: Re: Layout Advise Wow. Do I have a notion how this feels. Had real problems recently with large layouts on wood, where the small tools wouldn't suffice and the used mind did not jump up and adapt quick. Machinists I sent drawings to in the old days used the Bridgeport table to do layout, like you have the Taig, if they had one they considered reliable enough. I suppose it sounds funny, but the shop was responsible for usable accuracy, not the machine, and a lot of machines weren't so much reliable as they were inaccurate in a repeatable and predictable manner. The heart of old layout techniques was a big steel compass, though, and a rule it could be set with, and a lot of patience in swinging arcs ala high school geometry and scratching intersections in Dykem blue backgrounds. Still the same in sheet metal outfits, I expect. You did your measuring away from the work under best conditions and transferred it. Block stacking was a big part of it, too. The geometric construction was complicated, and the physical manipulations simple but tedious and unforgiving. It allowed someone who could get consistent results to be somebody. I don't know that anyone ever made the process easy, but, once again, the clear and straightforward examples of explanation come from the teens, twenties, and thirties. And once again Lindsey Publications has about all that are available now. There are also dead serious, no fluff, cut to the bone/cut to the chase books on how to do everything in machine work, from the industrial mobilization in World War Two. These are sort of the grown-up version of the high school texts that explained how every common machine worked and how they broke that were in the high school curriculum during the war. They were written, published, distributed, and used up in just three to four years, the length of the time that the industrial push lasted, and are usually rough in every way, but they have more sense per pound about old style skills than anything else I've seen. Lindsey used to have some of those, a Ford one, mainly, but I wonder if they still have a demand for such hairy-chested information. If you are doing repetitive work without using the electronics, it may be jigs and fixtures that are the real subjects, things that spread the work invested in one monster layout session over a number of resulting work pieces. My apologies if I've missed the point here. ------- Date: Sun, 05 Feb 2006 14:23:19 -0000 From: "sebplb" Subject: After you have laid a part out [beginnerswkshp] I have a question regarding what you do with the lay out lines once you have laid out all the lines on a part and mounted it in the mill. How do you use the lines? Do you just keep milling along until you reach the line, using it as a limit of cut? This would be like when you do wood working. Or, do you use the dials for setting all the distances and just use the lines as a check? Or is it a combination of both, depending on the allowable tolerances for the part? Any one have any good thoughts or reference materials on this matter? I do not recall ever seeing this referenced in any of the books I have read so far. Thanks. ------- Date: Sun, 5 Feb 2006 09:44:29 -0500 From: "Cliff Ward" Subject: RE: After you have laid a part out I'm still learning so perhaps not qualified to provide a "expert" answer....having said that, I use layout line to establish points for centers of radius, drilling locations, etc. Once laid out and center punched, the punches become the reference point and the layout lines are no longer referenced. I also use the advancing knob to move a certain amount across the XY travel when doing milling...I find this more accurate than relying on looking at a layout line when milling to size....just be careful to take up the backlash. Regards, Cliff Cary, North Carolina ------- Date: Sun, 5 Feb 2006 11:59:11 -0800 From: "keith green" Subject: Re: After you have laid a part out For myself, I use the lines to rough out the part (don't go over them) and then use the dials to get the right size from there. On a CNC I use them for setting up the occasional offset in a casting or something. The center-punch marks for holes get used for reference as well: Run the table up to eyeball the hole location, go the rest of the way with the handwheels. You have to note the initial position of the handwheel so that you know what number it will be on when you get to the hole position. This is figured out with a calculator and changes from machine to machine as the handwheels rarely have the same graduations. I work in a jobbing shop and this process speeds things up immensely. On the Bridgeport I use once in a while, we spray bluing on the front of the table where it slides. We scribe a light line in the bluing on the moving part of the slide. At each position where a feature gets machined (the start and stop of the feature) we scribe a light line on the adjacent point on the non-moving part adjacent to the previously scribed line. Note the handwheel readings at each mark and, on subsequent pieces, you can keep an eye on the cutter until two lines start to line up, then scoot around to the end of the machine to watch the dial. You can power-feed almost right up to a mark this way; a big plus in work-hardening stainless and such. On parts that don't need a hell of a lot of precision, the old guys in the shop lay out lines to machine to and then go down each line and prick- punch a small mark every 3/8" or so. This is done very carefully so as to ensure that each punch mark is as close to being on the line as possible. When machining, the lines may become lost in chips and coolant, scratched of during cleaning, etc. The punch-marks remain no matter what. The object then becomes to mill the part so that half the punch-mark is milled off. You can get pretty close to a size working like this. We mill some pretty big weldments and castings in this manner; stuff that can easily absorb a .015 deviation from the drawing. I've seen some old parts come into the shop for repair and you can often still see the old half-punch-marks still there. Kind of like a piece of Shaker furniture with the marking-knife lines still on it. ------- Date: Sun, 05 Feb 2006 04:54:19 -0000 From: Subject: What are the tools on your bench??? [taigtools] Not the Wrenches or maybe pliers... not those kinds of tools, I am speaking more of items on your work bench that make YOUR TAIG TIME easier. I will share some of the items I use regularly, remember most of my work is with woods. Some brass, some bronze...but wood is my thing. First marking... For metals an alcohol based pen. These are often called "Marks All" in America. I apply it like metal workers apply Dykum, all over the surface of metal I am milling. For scribing, (and a multitude of other uses) I have a reground 1/8th inch carbide drill bit, its kept in a quarter inch "hex drive"keyless drill chuck. To sharpen that, and other things, I have three Diamond sharpening stones. Two are "medium fine" and "fine" "credit card size" and the third one is a 1X3X1/4 inch Fishing knife sharpener! That last item has a GROOVE right down its center to sharpen fish hooks. I sharpen my scriber in that groove making both edges x~xx 45 degrees to the perpendicular off the face of the plated diamonds. Nice HUH! The particular carbide bit is from the Printed Circuit Board industry, and is a #80 drill bit in the Drill number index. I use a lot of those doing finger jointing on woods. I don't try to "route with them", I just drill and move an axis 3/4's of the diameter and drill again. They last between one hole and several inches of holes in a row, depending on (mostly) operator skill! One of the more usual tools that I use LOTS of are self-stick mailing labels! I cover wood (and sometimes metals) ala Dykum, and then put my .5 MM pencils to use either with rulers and straight edges, or freehand, depending on what I am doing. I leave that on and just cut through it. For my wood working with the mill OR FREEHAND sawing I can take a line or leave a line... with the mill I can cut that line down the middle. (My thin freehand saw is only .020 wide with kerf.) I also have, in four colors, 3/4 inch "price spots". Self Sticking, the four colors provide me with signals as to what is happening if I have to leave for a while. Yellow: NOTICE! (EASY, RIGHT?) Red: STOP!.... look and remember... Green: (everything is OK, proceed as before) The blue labels.... well I use them to COVER the holes on my HighTechSystems MODULAR VISE. I absolutely love that system, combined with a tooling plate, I have quick control of my clamping needs... EXCEPT all those darn little holes get filled with swarf! Or wood dust...UNTIL... I started covering those holes with the blue dots! Need a hole on the plate, remove the dot; need to move that vise? remove the dot, instant CLEAN HOLE to insert an allen head wrench into! Double stick tapes. Plural as I have three varieties, long term sticking or very small stuff... the two inch wide roll 25 feet long is as expensive as my cheap stuff. I buy six rolls for about 10$US and those six rolls are sixty feet long IIRC. I have foam center double stick tapes that I use occasionally, but I still will mention it. In the attaching area I also use Hot Glue guns, often glueing a piece of wood to an 1X3X.250 inch aluminum plate, so I can clamp THAT into my vise, rather than the wood itself. When I first received my mill, I cut about a dozen of those just for practicing "how to mill". It was a good thing for me. One "regular tool" that is not often known by crafts people is made by Taylor Design Group, Inc -- the item is their rulers. What is special about them, (for general FINE wood working)is that they are designed to be used ONLY with .5MM pencils. They have a series of slots or holes which allow consistant EASY measuring down to 1/64th inch! (Remember saying I split 0.5MM lines? That is why. The ruler is attached to an aluminum edge guide, locking it into a perfect 90 degree angle so a person can draw perpindicular lines to a wood's edge, OR parallel lines TO the edge of the wood! I have no financial interest in their company, except owning maybe five of those little rulers, or HighTechSystemsLLC, other than I will be buying some more of their products, hence investing my $$$ into their company, and of course TAIG itself, other than owning two of their lathes and a CNC mill, which I run MANUALLY! So what are some different tools that are on your work bench???? ------- Date: Sun, 5 Feb 2006 20:31:37 -0000 From: "Ellis Cory" Subject: Re: After you have laid a part out Keith wrote >...the old guys in the shop lay out lines to machine to and then go down each line and prick-punch a small mark every 3/8" or so. < We had to do that when I first learnt about metalwork/engineering at school. The difference was, we had to file to split the lines !!! Ellis ------- Date: Sun, 5 Feb 2006 12:49:54 -0800 From: "keith green" Subject: Re: After you have laid a part out Yup, I've done it that way, too. Time is too expensive for things like that to be done on a regular basis, though. We have this giant slotter that I run sometimes and this method works well for marking out the boundaries for large keys to be slotted out rough and then finished with and on-size cutter. I've done 4 and 5" wide keyways in 3' long bores this way. You stand on top of the machine when cutting these and the dials are down and to the right, facing away from you, so you can't see them anyway. For this, we cut up close to the layout (everything is covered in cutting oil, so you need the center-pops) and then use a magnetic-back dial indicator to go the rest of the way after measuring the roughed depth of the key. They tell me that, years ago, the key depth was a little less critical and they would just cut up to split the center-pops and leave it there. It would be up to the millwrights and fitters to custom fit the key on-site during the installation. Keith ------- Probably an Easy Machinist's Trick [sherline] Posted by: "montanaaardvark" boblombardix~xxcfl.rr.com Date: Fri Aug 4, 2006 6:45 pm (PDT) There's probably an easy trick for this, so I thought I'd ask around. I have a large tube that I need to drill at 120 degree intervals - 1/3 the way around the outside of the tube. It's way too big for my sherline rotary table - it's 12" OD. That would be an easy way, though. So how do I mark up the tube so that it's divided into equal thirds? I'm embarrassed by how badly my first attempt came out. I have slots instead of holes. Bob (yes, I are an engineer, but I wrangle electrons and radio waves, not things I can put a ruler on or an end mill across) ------- Re: Probably an Easy Machinist's Trick Posted by: "Mark Zirinsky" markzyx~xxcovad.net Date: Fri Aug 4, 2006 8:24 pm (PDT) a jewelers trick 1. take a piece of paper, or string. 2. wrap it around the circumference of the tube or pipe. 3. trim length to exactly the circumference, or in your case, about 31.54268 " 4. take string in hand, and by eye, fold until you have 3 equal lengths. 5. mark the 1/3 and 2/3's mark 6. rewrap around tube 7. voila regards mark Zirinsky, Denver ------- Re: Probably an Easy Machinist's Trick Posted by: "David Holloway" davidx~xxyawolloh.fsnet.co.uk Date: Sat Aug 5, 2006 4:01 am (PDT) Bob: You don't say how long the tube is, nor how thick ... but this may be of use if the ends are turned square: - Sit the tube vertically on a flat surface - Take a set of dividers (or whatever you may call them over there) and set the points to the diameter (6") apart - Mark a point on the upper (end) surface. You may need to make a little dink with a centre punch to stop the point wandering - Inscribe a mark on the end 6" away as the crow flies. - Repeat, and you will find that after the 6th the point will be back where you started - you have divided the circle into 6ths. - Just take every 2nd mark and transfer (using a square?) onto the vertical (round) surface of the tube. Well, that's a lot of ifs ... I spent a lot of time drawing 'flowers' in geometry lessons, as a nipper. Hope that's of use. David Henley-on-Thames,UK ------- Re: Probably an Easy Machinist's Trick Posted by: "Alan Marconett" KM6VVx~xxarrl.net Date: Sat Aug 5, 2006 11:54 am (PDT) Hi Bob, Dave, OK, you have a rotary table. How about bolting a 12" square (or a little larger) plate or disk onto it, put your tube (centered) on top of that, and then rotate and mark your points. A surface gage and some prussian blue should take care of that! Second plan, draw a circle on a scrap of sheet metal the same size as the tube with dividers, mark off on the circumference with the dividers (6 even sectors). Then you have your three points. Set the tube over the circle, and copy the points. Alan KM6VV ------- Re: Probably an Easy Machinist's Trick Posted by: "montanaaardvark" boblombardix~xxcfl.rr.com Date: Sat Aug 5, 2006 12:17 pm (PDT) > OK, you have a rotary table. How about bolting a 12" square (or a > little larger) plate or disk onto it, put your tube (centered) on > top of that, and then rotate and mark your points. A surface gage > and some prussian blue should take care of that! I almost did that. The tube is a telescope: 12" OD and 5 feet long, so I need to make a rotisserie for it (so to speak). A plug on both ends, bearings to let it rotate on (wood with some cloth or chamois on it) and put one bearing into a chuck on the rotary table. I think I might do this next time, and make a jig that will hold any size tube. But I did the string method that was suggested a couple of messages back. Worked like a champ. Bob W4 Amateur Telescope Maker ------- Math (etc) problem [sherline] Posted by: "Charles Fox" cafox513x~xxgte.net Date: Sat Apr 12, 2008 8:07 pm ((PDT)) I want to mark off a 12th-scale wheel with seven spokes. The 51.4 degrees doesn't bother me . . . But I want to mark off the width of the spokes, therefore two parallel lines equidistant from the center of each 3-1/2" wide spoke. And that goes way beyond anything I've ever tried. If anyone has a step by step I could follow, or could arrange a partial brain transplant, I'd really appreciate it. Charles Fox ------- Re: Math (etc) problem Posted by: "Ian Newman" ian_newx~xxyahoo.com Date: Sun Apr 13, 2008 2:22 am ((PDT)) Hi Charles: At the centre of the wheel scribe a circle with a diameter the same as the spoke width. Scribe a similar circle at the intersect of the spoke centre line and the wheel diameter. The sides of the spoke are formed by the two lines that are parallel tangents to the circles. This assumes there is no taper on the spokes - if there is, just adjust the appropriate circle dia. Ian ------- Re: Math (etc) problem Posted by: "a3sigma" dcclark111x~xxcomcast.net Date: Sun Apr 13, 2008 3:42 am ((PDT)) Hi Charles: As Ian pointed out: to layout a line parallel to another, draw equal arcs centered on that line and then draw the line tangent to the arcs. However, how are you going to cut this thing? CNC? Do you have a rotary table? Do you need to solve for the coordinates of the offset endpoints of the lines? Tell me you're not contemplating doing this with a jeweler's saw and a file. More Info = More Answers If you're using an RT see http://www.sherline.com/3700inst.htm If you need coordinates, it's an exercise in linear algebra. You must solve the simultaneous equations of lines and arcs. Or, do what everyone else does these days -- draw it in CAD and dimension the points you need. Even the simplest free CAD program is more than adequate for this sort of thing. For more on layout, see if you can find an old textbook on drafting. In principal, everything in Euclidean Geometry can be derived with straightedge and dividers. Layout is a good skill to have. Many of us still layout out parts in Dykem, especially when using the mill manually. Really helps to eliminate errors in counting turns on the handwheels. Even in CNC, it's a big help in knowing where you can place clamps -- also to rough out parts on the bandsaw. I've been known to cut out a CAD drawing and paste it right onto the workpiece. DC ------- Re: Math (etc) problem Posted by: "Charles Fox" cafox513x~xxgte.net Date: Sun Apr 13, 2008 5:26 am ((PDT)) > However, how are you going to cut this thing? Nope, I'm avoiding sweat. I machined a female mold for two spokes, and have cast up a bunch of them. They will lie between circumference and rim (machined separately). That package will be cast four times for my 12th-scale model of my own car. ------- Re: Math (etc) problem Posted by: "Charles Fox" cafox513x~xxgte.net Date: Sun Apr 13, 2008 5:32 am ((PDT)) > At the centre of the wheel scribe a circle with a > diameter the same as the spoke width. Gadzooks, I think I actually understood this! Thank Audi, there is no taper to the spokes. The angled sides, and the slight tilt from rim to center, were enough for me to sweat over, they figured. By the way, I found a Chinese motorized toy in 1/12 that has an excellent body, and tires, and many details. It's close enough to let me think I can recreate my own car by adding some extras like wheels. ------- Re: Math (etc) problem Posted by: "Jerry Glickstein" chieftoolmakerx~xxearthlink.net Date: Sun Apr 13, 2008 8:37 am ((PDT)) Quick reply. Do you have: 1. A lathe? 2. A mill? 3. A Rotary Table? 4. Paper and Pencil? 5. Patience? What material is the wheel made of? If you have all of the above, I suggest you make a spring loaded scriber ... details available. Jerry G (Glickstein) P.S. Please verify that the spokes are three and a half inches wide. ------- Re: Math (etc) problem Posted by: "Charles Fox" cafox513x~xxgte.net Date: Sun Apr 13, 2008 9:07 am ((PDT)) Got all those things. Yes indeed, the spokes are a non-tapering 3.5" wide. I've drawn up the hint I was given by Ian Newman to make the sides of the spokes parallel, and equidistant from the 51.4 degree (sheesh!) center lines. I've cast the spokes. Have to cut them out and make sure they're all even. I will remachine the wheel, meaning a rim, with backing. The backing tapers inward from rim to center -- the spokes actually are a little knock-kneed. But the dome of sorts at the hub is on the same level as the face of the rim. I think my main stumbler here is drawing on the machined wheel the parallel lines that will show me how to orient the spokes so they're evenly spaced from each other. "Spring-loaded scriber" sounds like it might be what I need, mounted in the mill spindle, and using incredibly complex math to move the table, rotate the rotary table and do the scribing. Will my head hurt after? When the spokes are in, and the hub is in and faired into the spokes, and the lug nut holes are drilled . . . then I will cast this up four times. ------- Drafting and Layout [sherline follow up to Math (etc) problem] Posted by: "a3sigma" dcclark111x~xxcomcast.net Date: Sun Apr 13, 2008 4:42 am ((PDT)) Hello Group: Following up on Charles Fox's question: For practically ever, the best text on drafting has been "Technical Drawing" by Giesecke et.al. Most of it is now available free at http://wps.prenhall.com/esm_giesecke_8/ including some "how to" animations, and all of the illustrations zipped by chapter. For an illustration of the answer to Charles' question and much more on geometric construction, go to: http://wps.prenhall.com/esm_giesecke_8/15/3917/1002956.cw/index.html and download Chapter 4. The current edition, new, is over $100USD. However, Amazon has many used copies of older editions for under $10. (The stuff I'm talking about hasn't changed since Euclid, so the edition doesn't matter.) See also your local college bookstore for used copies. Alongside Machinery's Handbook, this is probably my favorite reference work -- highly recommended. DC ------- Re: Math (etc) problem Posted by: "alenz2002" alenzx~xxbellsouth.net Date: Sun Apr 13, 2008 9:22 pm ((PDT)) > Layout is a good skill to have. Many of us still layout out parts in > Dykem, especially when using the mill manually. Really helps to > eliminate errors in counting turns on the handwheels. Even in CNC, > it's a big help in knowing where you can place clamps -- also to rough > out parts on the bandsaw. I've been known to cut out a CAD drawing > and paste it right onto the workpiece. DC I'll pass on a tip that I learned from a past mistake. Sketch out a layout (a felt tip marker is OK if using CNC) on the face of any stock that is very near square in cross-section. It will keep you from accidentialy clamping the work in the vise 90 deg out and cutting the wrong face. Al ------- Re: Math (etc) problem Posted by: "DA Dossin" danatlx~xxyahoo.com Date: Tue Apr 15, 2008 10:27 am ((PDT)) Charles, look here: http://www.precisionmeasure.com/pg20.pdf Dan ------- Re: Math (etc) problem Posted by: "chieftoolmaker" chieftoolmakerx~xxearthlink.net Date: Mon Apr 14, 2008 2:42 am ((PDT)) Ok, Charles, you can go a couple of ways here. Dykem is recommended. I know you have it, so I did not enumerate it. The spring loaded scriber is cool because it can be used for other layout stuff. I made a great one but for a Cincinnatti Toolmaster Vertical mill, to layout complex cams a mite more involved than your spokes. I made it so it could be preset using "Jo" blocks, and was therefore very accurate. You can make a scaled down version for your mill. Jerry G (Glickstein) P.S. Will your head hurt? Possibly, but you will feel great after you are done....... ------- Re: spring loaded scribe [sherline follow up to Math (etc) problem] Posted by: "n2562001" jlkiefferx~xxcharter.net Date: Tue Apr 15, 2008 3:03 pm ((PDT)) To All: If your Sherline mill is properly adjusted the "Z" axis is sensitive enough to easily adjust a spindle mounted scribe to function without spring loading. (Far less practical on a larger Mill.) This eliminates any inaccuracy from moving parts associated with a spring loaded device. Jerry Kieffer ------- Re: Math (etc) problem Posted by: "geneking2001" geneking2001x~xxyahoo.com Date: Wed Apr 16, 2008 5:30 am ((PDT)) Charles, check out the Machinist's Bedside Reader # 2 by Guy Lautard. This book has the drawing on page 127 of this type of scribe. Presently there are three bedside readers and a fourth one being promised. They sell for about $20 each and in my opinion are well worth the price. His web page: http://lautard.com/ GeneK ------- Re: spring loaded scribe Posted by: "chieftoolmaker" chieftoolmakerx~xxearthlink.net Date: Thu Apr 17, 2008 5:05 am ((PDT)) Mr. Kieffer, what you say is true, to a point! (pun intended) However, my mention of a spring loaded scriber was a direct result of devising one to suit the situation, which was a work surface that was not pristine, nor flat. As far as inaccuracy of moving parts, all contact surfaces of the scriber point plunger were encased in drill jig liner bushings and lapped in. There was a SFNS* as specified by the Bulova Engineering Dept. * = Snug Fit No Shake... Mr. Glickstein ------- NOTE TO FILE: There is an interesting conversation in the "Boring" file with message heading "Locating scribe marks" starting Apr 26, 2008. Despite the title, most of the solutions relate to boring setups and techniques hence the reason the conversation was placed there. However, there are some really good tips about layout and marking on a difficult workpiece that will be useful to anyone. The next thread here arose from that "Boring" file conversation. Be sure to see the layout methods detailed in that "Boring" file. ------- More on locating holes and other features. [sherline] Posted by: "a3sigma" dcclark111x~xxcomcast.net Date: Mon Apr 28, 2008 7:36 am ((PDT)) To expand and generalize a bit on the discussion that started out as locating scribed lines: The basic question, as I understand it, involves creating datums. That is, obtaining a consistent 3D coordinate system on a workpiece that may not have enough accessible features to define a coordinate system. The key to the solution is to secure the work to a fixture that defines a coordinate system. Consider the problem of drilling coaxial holes in opposite ends of an irregularly shaped object, such as a rough cast cylinder. Secure the cylinder in a vee block, mount the vee block on the mill, indicate it square to the machine axes, and locate adjacent sides with an edge finder. Machine the top side, then flip the vee block over. Datum (indicate and edge find) the other side of the vee block and you're back in the same coordinate system. Now you can accurately machine features in their correct relation to those on the other end. Another example involving castings: One of the first projects I did on my home Sherlines was one of PM Research's little mill engines. The plane of the crosshead, mounting plane of the cylinder, and bore of the crankshaft must be very accurately machined in the casting of the engine base. These features must be mutually perpendicular and correctly dimensioned for the engine to run well. There is nothing on a rough casting that is flat, straight, or square enough to provide a good reference datum. The solution was to make the bottom of the base flat on a belt sander; then drill the mounting feet and screw the casting to a squared up piece of tooling plate. The sides of the tooling plate became the datums for every feature on the casting. All dimensions and work planes were related to the surfaces of the plate. I could mount it in any position on the mill to work on any feature from any angle, always knowing where every other feature was relative to the spindle. One more from the same project: the cylinder casting. This I held in the independent 4 jaw chuck. I faced off one end, and machined all the features in that end. I then made a fixture, a short aluminum cylinder, that bolted to the finished end of the casting via the tapped holes for the cylinder head. The fixture also had a tooling hole drilled through it, perpendicular to its axis, to provide a rotational datum. With the finished end of the casting bolted to the fixture, I indicated the fixture back in the 4 jaw chuck. I could then face the other end, transfer the chuck and work piece to the mill, datum the fixture to the mill, and machine all the rest of the features in perfect relation to those on the opposite end. Hoping this helps somebody, sometime, DC ------- Re: More on locating holes and other features. Posted by: "Craig Earls" enderw88x~xxgmail.com Date: Mon Apr 28, 2008 8:09 am ((PDT)) This was very helpful. I will need to change the way I think about designing parts so that this is easier to accomplish. In retrospect the part I am making could just as easily have started off from square stock, which would have provide the data required to locate the holes. Craig http://enderw88.wordpress.com ------- Re: More on locating holes and other features. Posted by: "Marcus" marcusx~xximplant-mechanix.com Date: Mon Apr 28, 2008 9:09 am ((PDT)) Hi All: What a great discussion this has turned out to be. We have a whole pile of different methods described from which anyone who needs this kind of information can now draw. We have a good commentary about what kind of results can be expected, and how important stable reference planes are in getting accurate results. We have the input of skilled, experienced people showing the planning process for these kinds of projects, and Craig, the original poster, has come to an important new insight in project design. Very Cool!!! Cheers Marcus ------- Re: More on locating holes and other features. Posted by: "a3sigma" dcclark111x~xxcomcast.net Date: Mon Apr 28, 2008 9:30 am ((PDT)) Glad I could help. As the redoubtable Jerry K. never tires of pointing out: perhaps the greatest key to success in this trade is thorough planning. I used to tell our apprentices; learn to build it in your mind before you ever touch a piece of metal. It's so easy to paint yourself into a corner. Another thing that surprises many of the newer hands is the amount of time you must spend making tools, jigs, and fixtures. There just ain't no way around it; if you can't hold the part right, you can't machine it right. Ditto if you don't have the right tool -- you've got to find it, or make it, or sometimes invent it. The trick there is to make your tooling as well as you can -- accurate, of good material, using standard dimensions. Over time you'll acquire a great collection of tooling that can be used again and again. One of the sure marks of a really experienced old hand was that no matter how strange a new challenge was thrown at them, they always seemed to be able to dive into their bag of tricks and come up with some gizmo they had created over the years that made the job easy. To my mind, creating these gizmos was often the most fun and interesting part of the job. DC ------- Re: More on locating holes and other features. Posted by: "chieftoolmaker" chieftoolmakerx~xxearthlink.net Date: Mon Apr 28, 2008 1:53 pm ((PDT)) Hi DC: You sure got that right! Best regards, Jerry G (Glickstein) -------