On Thursday 23 January 2014 12:43:06 Stephen Dubovsky did opine: > Tex & Steve (PMDX) have done a couple ball screw micromills. I go to > the monthly meetings and have seen them;) I think Tex has to machine > the nut a little to fit but they appear to work great. Might want to > drop Steve a line again and see what they're doing if he doesn't pipe > in here first. > Steve sent me an 8mmx5 that I cut down and used for the X screw in my 7x12. I did not modify the nut, but made a one piece cage for it I had to pry open a little to get it wrapped around the nut, squeezed it back shut with my vice, held shut by the mounting screws, and that works well. He had fitted some slightly oversized balls, and said he could supply more at $XX per if I was interested, but a couple more attempts to get that in motion for at least 2 more have faded into the no reply from Steve category. They are only 13" long, and with my bigger tables from LMS fitted, not long enough for the X even with an extension similar to what I did in the lathe. The Y is long enough I would move the motor to the rear to keep me from bruising myself as I walk by, but the X has only enough room for about a .700" tall nut maximum, and those flange less cartridges are .750 in diameter. One might be able to polish about 30-35 thou off the sides and turn the recycle tubes to the side and find room that way. My Z drive is a turning nut design that could be adapted to a 16mm screw fairly easily, but its now a 1/2 10 tpi acme with a pair of nook nuts to adjust the backlash, and since I added ball bearings against the post to triple the bearing length of the sled casting, is now working very well, backlash might be a thou & the stiction seems to be totally gone. Carving a pcb just deep enough to cut the copper without damaging the glass under it is now possible. The lack of some method to do plated holes, or a source of micro rivets to do the same is one of the two of my major impediments to doing good double sided pcb's now. The other is lack of spindle rpms at 2500 max, which is why I asked about those cheap chinese R8 equipt motors that put 12k revs in a 52mm diameter package. But I lagged off on that when somebody mentioned the sloppy run-out of that R8's connection to the motor shaft would guarantee.
Anyway, if Steve is copying the mail here, I'd like 2 more of those. At the moment, I am up to my formerly x-rated things in trying to restore an HP4815A RF Vector Voltmeter, its probe is very fragile electrically, and not HP repairable since back in the '87 time frame. I just bought one, cosmetically brand new but without the probe, I have the docs, and believe myself able to repair one, or make another, but that seems nigh impossible without way better pix than there are in a pdf, where a grad student at Walla Walla University tried to make one with usable but not spectacular results. He didn't take near enough pictures, and the pcb's he did make I would have been tempted to throw away as scrap. Apparently he had no access to a real probe to disect it for ideas. I have no clue what coax was used in the probe cabling either, a real puzzle since the cabling they used was about .3" in diameter, and contained 9 coax cables in that .3", all matched to about 1/16" in length since the whole thing is a sampler with nominally 1.2ns sampling pulses. Making it work right, from scratch, probably needs a P.R. witch doctor waving a specific breed of dead chicken over it. But I'd give it a shot if a had one to disect that I couldn't repair. And I think I could repair one if I could buy a bum one. The problem? A 15 volt static charge will destroy it. See offer of 100 USD for one I can disect in the sig. TBT, ebay needs a WTB section. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> NOTICE: Will pay 100 USD for an HP-4815A defective but complete probe assembly. I selected E5 ... but I didn't hear "Sam the Sham and the Pharoahs"! A pen in the hand of this president is far more dangerous than 200 million guns in the hands of law-abiding citizens. ------------------------------------------------------------------------------ CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments & Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
