Re: Z-Axis Drive - - Tips and Suggestions

Thanks Dave, this is in line with my thoughts.

If I grab the spindle with both hands, it takes about 10 to 20 pounds
of force to pull it down.
If I calculated correctly... the Z-Axis Servo will exert about 130
lbs. of total continuous downward thrust and about 10 times that at
it's peak.
So I'm guessing this should be sufficient for most jobs and
sufficient to bust most any tool that I own.

Can someone check my math?
I have a feeling that it really sucks somehow.

Given:
Ball Screw = 5/8" Dia. (3/16" Radius) with 5 Turns per Inch.

So I first Converted oz/in to Thrust (given the Ball Screw Specs)...
(Turns per Inch * (1" divided by 3/16")) = (5 * (1/.1875)) = 26.7
(I'll call this the Thrust Factor)

Given:
Servo Continuous Torque = 40.7oz/in
Servo peak Torque = 430oz/in
Pulley Ratio 2:1

Continuous Thrust = Continuous Torque in Pounds * Pulley Ratio *
Thrust Factor = (40.7/16) * 2 * 26.7 = 138 lbs.

Peak Thrust = (430/16) * 2 * 26.7 = 1440 lbs.

(No friction factors included.)

Tom M.

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
<dave_mucha@y...> wrote:

>
> The return spring is nothing more than a counter balance. is should
> have not discernable effect in the CNC operation.
>
> Dave