Re: [CAD_CAM_EDM_DRO] Re: Max feedrate of ball screws?

JanRwl@... wrote:

> Complex engineering project? Expensive to machine? What do you expect, a
> "free lunch" (paid for by HEW) ? ? ?
>
> If precision is not a factor, you might consider sprocket-chain or even
> "timing belt" and toothed sheaves, etc. UGH! Makes me thing of earth-moving
> machinery, not "precision gear"!
>
> But yes, I agree! BSA should be reading this thread and publish drawings in
> their catalog which SHOW how one might rotate the dual, preloaded nut, rather
> than the screw. Hmmm . . .

I've mentioned this in the past, and I think for some applications it might apply quite well for a home brew "Driven Nut" on the right sized machine.

Use a Front wheel, or all wheel drive hub from a Car... Crazy ?

If you think about some of these hubs, You know, the part with the wheel bolt pattern and a bearing kindof wrapped around the outside ? They have a heafty Sealed bearing slid over a good size chunk of
steel that contains a large diameter opening so that the axle shaft can stick thru.

You'd have to first find the Right one to use. Then machine a housing/holder/motor mount to accomplish the following:
Capture the O.D. of the bearing, while, creating a motor mount that allows the motor to mount parallel to the lead screw. This component also has to form a flat location to mount the whole mechanism to
the moving part of the machine.

Then Machine down the Hub area to accept a toothed pulley, which obviously will have a large I.D.

Machine Out the old spline that used to keep the axle connected during burnouts.

Mount the nut Inside !

Now I know a lot might be thinking that a wheel bearing is not accurate enough for this. I might beg to differ, Reminding you that I said "depending on your application". Many hubs/bearings that I have
seen for the Front wheel/Four wheel setups are very tight bearings. I have not put a dial on one, but I do not think they at all resemble the bearings where "we snugged 'em up, then backed 'em off".
Because these bearings are so wide, And they have to take loads from all directions, I wonder what the real "category" of them are ? Maybe they are double row angular contact bearings !?

It's just a "potshot" and I'm sure that there is a dinky Jap car that has the perfectly sized hubs to do this with. Don't forget to look under the back of Subaru "all wheel" puddle jumpers. Hey, What's
in those fancy Four Wheel ATV's ??

You know, with the high cost of "linear" hardware, We just have to find some alternatives in places we never thought to look.

As a friendly warning though, you might want to avoid taking parts off your homebuilt Router and sticking them on the steering portions of your car. :-)

Chris L