Making a New Degree Scale for the Compound Slide Ted Edwards See also: Deg-Scale1.jpg, Deg-Scale2.jpg and Deg-Scale3.jpg The degree scale on the compound slide of my Smithy was a strip of aluminum marked with a paint that turned out to be slightly soluble in the cutting fluid I use. After several years it became unreadable. I pried out the "rivets" that held it in place, made a new scale, tapped the rivet holes for machine screw and fastened the new scale in place. The point of this post is the making of the scale. I carefully measured the diameter of the circular base, added the thickness of the paper to the radius (half the diameter) and calculated the spacings for a degree scale (1/360th of 2*pi*R per degree). I drew this up in CADD and printed it on my elderly Epson dot matrix printer. I then gave it a few coats of epoxy varnish but unfortunately the solvents in the varnish made the ink run and, while useable, the scale was hard to read. Last week I aquired a buble jet printer and printed a new scale on good quality bond paper. I wrapped a layer of adhesive backed Teflon tape around a suitable diameter can, fastened the printed scale to the can and gave it two coats of epoxy varnish. (If you don't have teflon tape, polyethylene will work fine.) The bubble jet ink was unaffected by the epoxy varnish except that the epoxy made the paper somewhat translucent. This can be seen in photo Deg-Scale1.jpg. I gave it a day to cure thoroughly before doing anything else with it. After the epoxy was cured, I removed the scale from the can and gave the back a coat of white epoxy paint. As well as adding to the protection of the paper, this made the printing stand out much better. See Deg-Scale2.jpg. I cut out the cured scale and cut the notches for the fastening screws in the ends. Next, I set the compound parallel to the ways using a dial gage to check and attached the scale loosely. I aligned the zero of the scale with the index mark on the compound and snugged up the screws. The results may be seen in Deg-Scale3.jpg. The drawing also had a line "exactly" 4" long. Measuring this on the paper with a ten power magnifier and scale in hundredths indicated that the line was indeed 4" within two thou or less. The printer is a Canon and the epoxy is Industrial Formulators Inc S-1, http://www.indform.com/ Notes re accuracy: Dot matrix and bubble jet printers I have tried have given very good accuracy when drawings are printed from CADD. Laser printers I have tried didn't do as well. Presumably because heat is used to set the toner and this affects the paper. One degree is a taper of approximately one in sixty so aligning the compound movement to the ways within 0.01" in 6" travel is parallel within one tenth of a degree. If you can read better than that on such a scale as this, you're a better man than I, Gunga Din.