Well after a slight pause of uhhh 5 years I FINALLY completed the ELS for my homemade lathe. For me, where I got hung up was in making the brass plate for a thread table. I was unable to do a good job of that using any type of printer medium as a screen for putting down etching resist. I finally lost patience half a decade ago and simply ran the lathe manually, and continued relying on taps and dies for threading.
This winter's snows and cold here have stopped all my normal casting activity, and put a damper on shop time as well (it's been COLD in there!). Searching for something to do indoors I finally said to myself, finish that ELS threading table plate, test the electronics in place, and finish the damn thing -- you can at least do that indoors!
So out with the printer and various new transparency films, and dry resist film, pieces of scrap test aluminum sheet, a UV blacklight, PC Board etchant, etc and.......nope. I simply could not get a good image of the resist on metal -- there were always bad areas or the exposure was wrong or the contrast wasn't high enough.
I decided finally the problem was probably due to too much of a DIY head on my shoulders. I simply could not get a good enough transparency to expose onto the dry film resist. I had tried every method known to YouTube for this and I could not get their poster's printer results either with an inkjet or laser printer.
I finally thought, what about having it printed at Staples on transparency film? A check online showed this would cost under $2, I could upload the image directly and pick it up in a day. Past experience with the their local printing dept wasn't promising for the other large blueprints I sometimes get, but for two bucks I thought, why not?
Well, the product was perfect. Really solid black. Really clean edges to the admittedly tiny numbers letters I was using. A test run on aluminum showed good masking with the resist film. So I repeated on brass, and all went well! Two bucks. I don't know how much I'd invested over time for special papers inks, toners, etc. to try to get a decent transparency, but it was substantial.
I guess I don't have to DIY
everything.

Well sorry to waste space here with the above long-winded chagrin-ology, but the positive side of all this is: I NOW HAVE THREAD CUTTING CAPABILITY WITH MY (mostly) DIY LATHE!!!
This kinda means my lathe is um, finished....!(ELS unit and thread table lower left:)
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well, maybe not -- I'm thinking about making a new milling attachment...........
