Alternatives to Ballscrews

It will work, and there are other ways.

take your threaded rod, cut 3 short sections.
turn the ends and press on bearings.

make a pair of end plates. center hole is clearance for the threaded rod.

The three holes would be on a bolt hole center so the three short
sections would spin on the threaded rod. Since it is a rolling
contact, there is no appreacable wear.

This is not a new concept, and has been done. the key is getting
bearings that are small enough and that have no axial play.

Dave

--- In CAD_CAM_EDM_DRO@yahoogroups.com, stan <stan.distortion@...> wrote:
>
> Ok, will try and be serious now.
> Would this work?:
> Get a tube of dirt cheap rollerblade bearing.
> Machine a tube to be a press fit on the bearings and with straight
groves on
> the outside at, say, 1.5mm pitch.
> Part off to fit the bearing width and press onto the bearing.
> Make 4 of them.
> Make a holder to mount 2 pairs of bearings opposite each other and
at the same
> angle as the pitch on a M10 threaded bar and the same spacing for an
M10
> threaded bar to roll between the bearings.
> Umm..run an M10 threaded bar between the bearings.
> Any reason it wouldn't work? There wouldn't be any side loads by
opposing the
> rollers, the bar wouldn't be able to go anywhere as its surrounded
and the
> pairs could be shimmed appart to get rid of any backlash in the
el-cheapo
> bearings. The load rating might not be great with just 4 but the
bearings are
> around 60c each so if it needs 20 it still leaves a lot of change
from the
> price of a ballscrew.
> cheers
>
> BTW, LOL Pete :)
>