On Saturday 28 March 2015 06:27:33 Gregg Eshelman wrote: > On 3/28/2015 3:05 AM, Gene Heskett wrote: > > On Friday 27 March 2015 23:28:12 Gregg Eshelman wrote: > >> I've an idea for a project involving a pair of 9x20 9-speed > >> quickchange gearboxes mounted side by side, with a filler between > >> and three gears to couple the output of one to the input of the > >> second. > >> > >> I'll have the gearbox off my $50 9x20 but need another. > >> > >> 9 speeds on one box feeding a second box with 9 speeds... I wonder > >> if any combinations would be duplicates? > > > > I believe that any combo would be the same as mirroring the combo, > > eg 3rd gear on box 1 and 5th gear on box 2, would be identical to > > 5th gear on box 1 and 3rd gear on box2. So while 1st gear in both > > boxes would be a set stakes and call a surveyer slow, there would > > not be the 81 variations with no dups. > > > > To me, with the capability in LCNC to lock axis motions together, it > > made more sense to put a bigger HP treadmill motor on mine, with a > > fixed 3/1 reduction before it got to the backgear. With a fwd only > > toroid mod to one of Jons servo amps, and an old 1500 WA phase > > linear audio amp power transformer for a motor psu, it could turn > > the spindle in a much bigger lathe than my toy 7x. I can still get > > to 1500 rpms, not fast enough for real CSS at small diameters, but > > usable for above 0.75" OD stuff. > > I'm thinking of a much less expensive way to put a gearbox on an old > Montgomery Ward manual lathe. One box of 9 ratios isn't as good as the > 5 and 8 position dual lever (and hard to find+expensive) Logan > original. A New-All or one of the other 1 or 2 old brands of > aftermarket boxes are even harder to find. > > I need to be finding some good ACME rod for the 9x20 CNC, motors etc. > I found that the Chinese rolled ballnut screws in 16mmx5mm thread size for the z drive were:
A) already equipt with snug felt debris wipers so I didn't have to enclose them for the amount of use I'd give them. B) Not that much more than some Nook 1/2x10 screw and a pair of their Bronze nuts so the backlash could be adjusted down to a thou or so. It would have been north of $130 since the nuts were $50 ea. So in comparison, Nook priced themselves out of my consideration. In comparison to x drive with its very limited nut space under the crossfeed, one of our list members rescued me with some 8mm salvaged takouts whose nuts had no seals and no flange so they were nominally 9/16 in diameter and about 5/8" long. I made a container cage that effectively made them about 5/8 square & 7/8" long, used the mill to make room for that in the H saddle. Unfortunatly I have destroyed the cover to keep the swarf out by moving into -0.00 territory on several occasions, so now I can hear a dirty ball clicking once per rev but the motion seems fine yet. That screw in the lathes x has the original balls in the nut and if I get froggy this summer I'll take it apart, clean it up & put oversized balls in that one also. I bought 500 on fleabay for a tenner. I might even redesign the cage for the felt wipers while I am at it. My motor is on the back, and in that direction the carrier could grow enough to make room for the felt wipers & maybe even a bit of wead eater gas line to get some oil into it occasionally like I did on the mill. And maybe rig a limit switch to keep from destroying the dust cover over the rear of the cross-slide to motor mount. I have not been able to find Chinese screws & nuts that size on the web, they generally are 10mm diameter minimum and all have nuts with huge flanges there isn't room for in this smaller stuff unless you can figure out how to grow an extra 1/2" between the table/base and table/table. So I may have the last of those in captivity. Steve Stallings sold them to me at a give them away to get them out of his way price when I was looking for screws for my mill, which is also way too crowded to even consider the use of a flanged nut in either table drive. I had to make nut containers for those too, but made these so they are packed with felt wipers cut from an old western hat I'd gotten terminally greasy from 20 years use as a hat. Seems to have worked fairly well. I made the nut pockets cap by making a disk with spanner drive holes, and threading the disk and the nut carrier at 50 tpi so I could take it up as the felt was crushed by the pressure. But to tighten/adjust, I still have to take the tables off & apart. I also put a thou bigger balls in the nuts, so its just under a thou for backlash when freshly snugged up. Precise enough now that I can detect thermal growth as it warms up since the z drive is relatively long, I didn't intend to but I can take the top rollers of the head sled completely off the top of the post as the gear housing come up and hits the z drive mount above it. Extra "wheelbase" on the z sled in the form of 4 skate bearings riding the machined area of the post either side of the gibs solved some really huge motion problems in that sows ear mill, a very early Harbor Freight. Cheers, Gene Heskett -- "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> ------------------------------------------------------------------------------ Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
