Sturdy Rotary Axis for CNC table

[EddyCurrent]

For the moment I'm ignoring 'on the cheap'.
I can't see how you could use it as a 4th axis and also as a 'lathe' with the same drive motor.
What about if you used it as a 4th axis with a stepper motor via Mach3, you would not need any braking in this instance and implimentation would be easy.
Then when you want to use it as a lathe you could use a cheap standard induction motor driven by a vfd, the vfd would provide variable speed and dynamic braking with ramp down.
You would just need a simple way to swap from one drive motor to the other.

[Boyan Silyavski]

For the moment I'm ignoring 'on the cheap'

I meant not too much money. And use what i have at hand.


And about the Hobbymat lathe, i meant fit a servo drive and use it mainly on the CNC as 4rth axis. may be only the head part. All via Mach3. If i need lathe, i have small stepper generating circuit.

How is that i will need no braking, of course i will. Or you think a stepper or servo can hold enough. It cant. Especially if i make pulleys there.

[EddyCurrent]

You're talking about 3 requirements.

1. cnc 4th axis
2. Indexer
3. Lathe

From the InTurn web site;

"SPINDLE LOCK:
Custom made articulated pneumatic caliper provided over 100 ft-lbs of holding torque on 90psi shop air.
Cylinder rated for 200PSI leaving a great deal of added capacity, although so far no operations have needed more than 90psi.
DOT approved hardened and ground steel vehicle disk brake rotor is mounted on a thick steel collar and balanced.
Note, the Tail Stock II has a combined spindle damper/lock provided by an internal band brake.
CNC controlled solenoid operated pneumatic valve controls the spindle lock. The valve and a CNC compatible relay are included."

So I'm thinking about a brake disc and caliper from a car scrap yard with an air over oil actuator.

[Boyan Silyavski]

Ok, so 100ft-lbs for a big mill. 135Nm. Then it seems a bicycle hydraulic brake will be sufficient. http://www.bikeradar.com/mtb/gear/ar...-brakes-24345/
That is good.

I like the look of this one + coupled with bike brake some how.http://www.ebay.com/itm/cnc-rotary-t...item232cff456c Still have not figured the dimensions of the shaft and bearings necessary.

[EddyCurrent]

electromagnetic brake or clutch