Centroid Community CNC Support Forum

I have a ridged head knee mill with no way to manually run the quill.
Is it possible to add a hand wheel to run the servo while the e-stop is active?
What I want to do is keep Z active to run manually and not power x and y so I may use the machine manually for quick cuts.
I need some method other than running the knee up and down.
I toyed with adding a bevel gear under the servo with a shaft and a hand wheel but it will not stop someone from over running the limit switches and possibly damaging the ball screw.


Chris

Are you running Mach3 or CNC11? You wouldn't be able to use Estop because that takes all motor power away (at least on a properly wired Estop). We can provide some pointers (or a custom program) to use an aux key to free up the X and Y axes in Brains or a custom PLC but need some more info.

I want to use CNC 11.
If Mach is the only way I might have to consider it in order to keep the DRO in manual mode.
My last ditch idea is to use the limit switches to activate a break on the back of the servo to keep from damaging anything but this will require double pole limit switches and a costly electric break, not to mention buying the materials and effort to make the gearbox for the z hand wheel.

3 electronic wheels to do x/y and z might work, Jog mode works on the MPG but how responsive is it?
Could I do this with cheap encoders and some PLC code with CNC 11?
Any pointers ideas are welcome.

Chris

What I want to do is keep Z active to run manually and not power x and y so I may use the machine manually for quick cuts.

I think you can already do this.

Use the F1/Setup -> F4/Feed -> F3/Free option to release power on X and Y. Alternately, just press E-stop, then release it again. The X and Y axes will be free to turn by hand.

Use jog buttons or the MPG handwheel to move Z. The control will enable the Z servo if needed, but X and Y will remain free as long as you don't try to move them with the jog buttons or handwheel.

OK this is good.
Can I add a single hand wheel to run Z?
If so can I hack the design to make a handle similar to what you would see on the side of a Bridgeport head.
Also is there a way to get the % load of the z-axis servo out to the outside world?

I am a mechanical design engineer by day and have some electronics buddies willing to help me.
Call me crazy but if possible I wan to use current limited source to run a small DC motor to provide force feed back.
Chris

Can I add a single hand wheel to run Z?

Yes. See the MPG connector pin-out on your wiring diagrams or MPU11 or All-in-one hardware manual. You can probably make your MPG on/off switch close directly to the 3rd-axis select signal, so it is either off or controlling Z. You can hardwire the increment select too, if you don't want to provide a switch for that.

If so can I hack the design to make a handle similar to what you would see on the side of a Bridgeport head.

You can if you want. You just need a suitable encoder: 5V differential driver output, suitable line count (usually 100). You can add mechanical detents yourself.

Also is there a way to get the % load of the z-axis servo out to the outside world?

As far as I know, no. You would have to hang some sort of DC current sensor on the cable.