Re: My ballscrew / bearing block design.

--- In CAD_CAM_EDM_DRO@yahoogroups.com, fj62@s... wrote:

>
> A couple more questions...
>
> I picked medium preload because light went from 0 to X lbs of

preload. I

> wasn't sure that would guarantee no backlash. Will a light preload
> generate a no backlash setup?
>
> I'm sure I learned about shrink fits at some point in my machine

design

> class but that was 15 year ago...If I shrink fit a piece on the

ballscrew

> and then machine it will it "loose its grip and slip" (obscure

reference

> to 'you ain't got a hold on me' - AC/DC)?
>
> Is there a technique for getting the required surface finish for the
> seals? I was also wondering about the hardness required for them.

I was

> contemplating just putting speedi-sleeves on these portions of the

shaft.

>
> Thanks,
> M

machine it size to size than heat it up to red and put it in place
very quick, don't press it or it will deform and expand taking the
shape of the shaft and do the AC/DC thing.
I've sent a ballscrew to a machine shop to do the same thing,asked
to machine it size to size, they sad no...it must need to have
interference or it will slip later on.
Well, they made it smaller heat it up than press it in, guess what?
it expanded took the shaft shape(diameter) and came out losse on the
first try. Asked to do it again, size to size this time they agree
with me and it still working.
Eaving If you don't have backlash you still have elastic
deformation on the nut and bearings.If it is for a large load than
you should go for a bigger bearing.

Fogassa.