Re: [CAD_CAM_EDM_DRO] Re: Need ballscrew support Bearings.

Polaraligned wrote:

> I need BOSS 4 ballscrew bearings:
>
> I just got off the phone with Hardinge and they quoted me $650/pair
> for the X-axis set, $875/pair for the Y-axis set, and for giggles
> $4135 for the X-axis ballscrew/ballnut assembly. I know where to get
> a NOS Y-axis ballscrew for $750. How bad does Hardinge screw you on
> parts?
>

I got just the bare ballscrew/nut in original factory package on
eBay last year for under $60. Made in China for Bridgeport. It
was definitely NOS, over 20 years old, but still in great shape.
Now, I just need to find an X screw like that!

>
> Can I use the lower contact angle (35 degrees) angular contact
> bearings? Or will they not be able to handle the loads.
>

These should be fine, I think. Even ordinary radial bearings
can take a lot of axial load, the A.C. should be able to handle
thousands of Lbs even in the 35 deg type.

> What if they are not a matched pair?

Unless you intend to just squeeze a pair together with no
spacers or preload clamping system, you don't need to pay for a
matched pair. You can use belleville springs or a plate that
flexes a little under load to apply the preload.

> I am not looking to have to sell my left kidney here, but I do not
> need the bearings to fail in short order.
>
> Any other input on bearings anyone?
>
> The bearings I need are:(in pairs)
> X- 80mm od, 50mm id, 16mm wide
> Y- 52mm od, 25mm id, 15mm wide

These are mighty big bearings. That 80 mm bearing is going to
cost at least $60 maybe more, as things seem to have gone up a
lot lately. Call your local bearing house, they can look up
practically anything and get you a decent price.

Jon