RE: [CAD_CAM_EDM_DRO] Re: VFD Selection

Drew,

oh..gosh I think it was ER-25. Could be anything though.
It's just a standard LIGHT duty engineering design... preloaded DB
duplex angular contact on the work end and radial on the other.
Prehard stressproof or 4140 shaft... a little soft but would last
a while. I think the parts cost was a couple hundred, but machining would
be a fortune unless you do it with sweat equity.

Machining spindles requires some fairly serious precision.
Could be done on hobby machines providing you have a hobby
cylindrical and surface grinder!

One trick to make things like this easier to build is to
use lower tolerance bearing, housing, and shaft specs
and then finish machine the spindle collet internal taper
on the spindle itself. Of course then the precision is
ruined if you ever replace the bearings.

To put thinks in perspective lower tolerance might mean
+/- 0.0004 instead of 0.0001".

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
CNC surplus for sale:
http://www.lmwatts.com/forsale.html
CNC carved signs:
http://www.lmwatts.com/signwp.html




-----Original Message-----
From: Drew Rogge [mailto:drew@...]
Sent: Tuesday, April 13, 2004 5:32 PM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: Re: [CAD_CAM_EDM_DRO] Re: VFD Selection


Hi Les,

What type of collet or tool holding setup did you design the spindle
for?

Drew

Leslie M. Watts wrote:

>
> I do think I have a design for a belt driven angular contact or tapered
> roller bearing spindle that could be run from a single phase 120vac motor
> at fixed speed (least costly), a dc motor/servo amp, or a phase control
> (voltage)
> dc motor over a limited rpm. It would have torque due to the gearing down.
> I could try and find it for you if you have the capability to do precision
> (+/-0.0002") machining with your tools.
>
> Could you tell me more about what you want to cut and how fast? Sounds
> like we are getting more into Milling machine territory. A steel cutting
> gantry type machine is usually not in the hobby relm.
>
> Les
>