Re: Ball Screw Options

OK, so lets say I've narrowed my options down to 2:

1)Basically a bolt in ballscrew kit for @ $800 buckies. Probably the
least hassle and the best overall solution. Wouldn't I still have to
deal with the ends of the screws to machine/adapt them for the motor
couplings? If possible, I plan on retaining the manual cranks for
manual operations.
2)Use molgice or poly resin to mold my own "ballscrew'esq" no
backlash setup. Reidtool has some (what looks to be) higher quality
acme screws, I could use them. My main question on this option is
will the stuff hold up? Between the molgice and poly resin, which
one is better? I guess its hard for me to imagine this stuff holding
up to the stress/pressures for an extended period of time!

Mark
www.mark.hargett.com

--- In CAD_CAM_EDM_DRO@y..., Marv Frankel <dcdziner@p...> wrote:
> Mark,
> I contacted the factory a few weeks ago, and they passed
my inquiry
> on to their local rep, here in Southern California.. It turned out
that
> their rep was someone I had done business with over 20 years ago. We
> discussed using their material to cast new nuts around acme screws,
and the
> scenario went something like this:
>
> 1. Bore out the threads of the original nut, and create several
grooves
> lengthwise inside the bored I.D.
> 2. Machine two spacer washers to fit over the acme thread, with
flanges to
> fit inside the nut, to keep it centered.
> 3. Clean the screw thoughroughly, and find the least worn area of
it. Coat
> this area with multiple layers of a release agent allowing them to
dry
> between layers, until you build up adequate thickness.
> 4. Drill two holes into one side of the nut, and clamp the spacer
washers in
> place, with the assembly around the area of the release agent.
> 5. Pump the mixed up material into one of the holes until it fills
the
> cavity, and comes out of the other hole.
> 6. Allow this to cure for about 24 hours, clamp the screw ends, and
break
> the nut loose with a wrench. They sometimes work the nut back and
forth with
> the screw held in a lathe chuck, and even apply a particular type
of lapping
> compound, to loosen it up.
>
> I haven't done this personally, but my friend tells me that the
same method
> is used to repair nuts in quite a few aircraft related
applications. I hope
> this gives you a better understanding of the process. I'm going to
try it
> myself, when I do a CNC retrofit on my Enco mill.
>
> Marv Frankel
> Los Angeles
>