Re: [CAD_CAM_EDM_DRO]spindle plans (was VFD Selection)

Les,

Thank you for the followup post. Yep, his drawing skills exceeded his
spindle knowledge there in the beginning<G>

As for the rear bearing preload, you didn't miss it; it's not there...

But you are correct; it needs to be...

The thread was headed towards a pretty good result, but then started
to go astray, IMO. That's when I bowed out. But it still represents a
pretty readworthy set of messages for a beginner interested in a
basic spindle design, IMO.

Ballendo

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Leslie M. Watts"
<leswatts@a...> wrote:

> Ballendo,
>
> I checked again... I did not read far enough in the thread.
> The earlier posts were unstable designs but I see that
> evolved into a proper 3 bearing unit. The only thing I saw
> missing was a light spring preload for the back deep groove
> bearing- it floats, but still needs a mimimum axial load
> to prevent ball scuffing due to internal clearance. Perhaps
> it was there and I didn't see it.
>
> And yes... I will again emphasize that this requires VERY
> precise machining. As Marcus and I have mentioned such critical
> work can be done with even small light lathes, ring laps, and
> stones. It really hinges on the ability to measure. We are
> talking tolerances here that many would find difficult to
> repeatably measure even with a 0.0001" micrometer. It can be done
> with a lot of careful hand fitting. That is almost a lost art
> but threads like this can help preserve it.
>
> Les
>
> Leslie M.Watts
> L M Watts Furniture
> Tiger Georgia USA
> (706) 212-0242
> http://www.lmwatts.com
> Engineering page:
> http://www.lmwatts.com/shop.html
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>
>
>
>
> -----Original Message-----
> From: ballendo [mailto:ballendo@y...]
> Sent: Monday, April 19, 2004 10:49 PM
> To: CAD_CAM_EDM_DRO@yahoogroups.com
> Subject: Re: [CAD_CAM_EDM_DRO]spindle plans (was VFD Selection)
>
>
> Les,
>
> You lost me. It IS a 3 bearing design. Or is the face ground AC
> bearing set considered "one" bearing?
>
> This design has been used successfully on many commercial spindles
> for years. If by three bearing you mean the ground faced set,

another

> bearing spaced from them, and then the third radial bearing for the
> pulley end; I agree. That design is MUCH stiffer. AND MUCH more
> expensive. Also requires a GREAT deal more precision in the

making...

>
> The design finally arrived at, is sold by some well known mfr's as

a

> separate spindle to "bolt-on" to industrial process machinery. I'd
> certainly trust it for use in a small mill or as a bolt-on for a
> gantry machine. I wouldn't use cat40 on it...
>
> Ballendo