Re: [CAD_CAM_EDM_DRO] Defiance Spindle specs

Marcus & Eva wrote:

> Hi All:
> Here's what I have on the guts of my Defiance so far.
> I will add to it as I get more info.
> The spindle bearings are Fafnir. They are ABEC class 7, and they look to be
> about 30mm ID. (I will get numbers to you as soon as I get them from
> Defiance.
> There is a single upper and a single lower bearing spaced about 5" apart.
> They are pressed into a cast aluminum head, and I can't find evidence of a
> preload spring on the service manual drawings.
> The lube specifed in the service manual is Kluber Isoflex NBU 15 high speed
> grease.
> The spindle motor is 1hp brushless DC. There is no nameplate anywhere on it.
> Max speed is 5000 RPM, and it drives the spindle at 2:1 for a top end of
> 10,000 RPM.
> Speed is controlled by the controller board in the PC; how it does this I
> don't know!
> The servos that control the 3 axes are 100 oz in direct drive DC servos with
> 2500 line encoders.
> They deliver 250 lb of thrust.
> The ballscrews look to be about 1" dia x0.250 pitch.
> Table travels are 12x8x9 in X, Y, and Z respectively.
> Max rapid with this control is 400 ipm.
> To give you a practical comparison of this machine's capabilities, if I
> circlemill a 2" dia pocket at 30 ipm it will indicate round within 0.0005".
> My Sherline with Flashcut on it will cut the same bore at 10 ipm and
> indicate out of round 0.002.

Well, that tells you the axes are truly orthogonal, the ballscrews' preload
is correctly set, the servos are tuned up just right, etc. Very good!

>
> The super fancy Okuma at the toolroom where I used to work will mill the
> same circle at 30 ipm so accurately that you can't detect out of round
> condition with a tenths indicator.
> The Sherline setup cost about $2000.00 USD. The old model Defiance cost
> about $30,000.00 USD (I got it used for a LOT less)
> The Okuma is $225,000.00 USD
> The high speed spindle option on the Okuma cost more than the whole
> Defiance!

I guess this proves that you get what you pay for, at least on these 3 machines!

Jon