Paul and others said >> On Sep 16, 2017, at 4:10 PM, Paul Koning via cctalk <cctalk@classiccmp.org> >> wrote: >> >> >>> On Sep 16, 2017, at 9:52 AM, Noel Chiappa via cctalk >>> <cctalk@classiccmp.org> wrote: >>> >>>> does anyone have any spare "pivot bushings" for the DEC H9xx series >>>> cabinets (H950, H960, etc)? (These are the short pieces with a conical >>>> top which fit over the hinge pins, at the bottom.) >>>> ... >>>> I could also use some more of the pins (particularly the kind with the >>>> hole drilled through them to take a roll pin) >>> >>> Someone asked for an image of these; here: >>> >>> http://ana-3.lcs.mit.edu/~jnc/tech/jpg/H9xxPinBushing.jpg >>> >>> is one. The pin in the picture is the kind without the hole at one end, but >>> they are otherwise identical. (Ignore the retaining ring on the pin; those >>> are easy to get, my local hardware store has them.) >> >> If you have a lathe, this looks like a very nice beginner's project. Start >> with a rod of the right diameter; a simple way to get such a rod is to buy a >> long bolt, because those are mostly not threaded. Failing that, get a >> length of "drill rod" from a metal supply outlet. Then all you need is to grind a tool bit (high speed steel) to form a narrow screwdriver-like tip to cut those grooves. Hold the rod in the lathe, cut the grooves in the right spots, cut the thing to length, done.> > Ok, I read that wrong. You were talking about the short thing. Still, > that's an easy project. Same idea. Start with a rod, grip in the chuck, > drill, cut bevel, cut the two diameters, then cut to length. Elementary > lathe operation books are easy to find; the South Bend Lathe manual that used to be reprinted by Lindsay Publications is very good. It's probably still available even though Lindsay unfortunately retired some years ago.> > paul
Yes I agree they both appear to be simple machining jobs. As a substitute for drill rod (although not the same quality steel) you can use shafts out of old printers and photocopiers, I have a bunch of them I saved for just this sort of purpose. Often they have circlip grooves in them already, so some of the work is saved, but a fine tooth hacksaw will make a circlip groove whilst the lathe is spinning (frowned-upon workshop practice, I know). or just place it in a vice, saw, rotate the pin for the next few degrees and so on. Check the circlip for fir every so often. The bush looks pretty straghtforward. Between the one-off and the full CNC route is the form tool approach where the profile is ground in a piece of tool steel and then fed into the job. For very low runs a piece of drill rod can be cut then hardened, sure saves a lot of effort grinding. If some micrometer or digital caliper measurements of the pin and bush are available I'll draw it up for the list. :) Steve.
