Z axis motor brake

[PCM]

What is the best way to power a z axis motor brake with an all in one unit. When the brake is powered it releases and lets the whole head fall to the table. I cant seem to find a good way to wire this.

[cncsnw]

You need to use one of the nine relay outputs, and modify your PLC program to turn on that output whenever the axis is enabled.

For example, if you wire power to release the brake through the OUT9 relay, then you could add the following lines to your PLC program:

Code: Select all

ZBrakeRelease  IS OUT9
...
IF SV_PC_POWER_AXIS_3 THEN (ZBrakeRelease)

I am not 100% certain that SV_PC_POWER_AXIS_3 will be set if you just jog the Z axis, without starting MDI mode or a program cycle of some sort, but I think it will be.

[CNC-Global]

PCM you are a Mach3 or CNC11 user???

[PCM]

I am using a demo version of CNC11. Is there any more information out there about programming the plc? This is the first Ive heard of it.

[CNC-Global]

Attached is the programming manual for the CNC11

[PCM]

Thank you for posting the manual. I have not seen this posted anywhere before.

[MachineTHIS!]

I posted a question earlier today regarding the same thing. When the motors are powered at the same time as the brake, it should be holding position. Your brake is powered when your motors aren't?

[cncsnw]

As a rule, holding brakes use springs to clamp, and require power to release.

Therefore brake-control relays are programmed to close when the axis is enabled.

[MachineTHIS!]

To the previous poster: I understand how the brakes work; in my thread, which I referenced, the springs are actually suspending the axis to counter its weight. Yeah, it's silly, but it's a router table, and my Z has a lot of travel. I always intended to install a brake, but it didn't seem crucial. Until recently, when my building started experiencing momentary power hiccups. That's when reality set in. My concern is more about whether wiring the brake directly to the contactor relay for the E-stop, while using the same 24VDC power supply as the E-stop, will pose any problem. Thank you for responding, though; it's nice to get such an immediate response.

By the way, OP, sorry for the thread hijack; it wasn't intentional.

-Ron

[MachineTHIS!]

By the way, I hope I didn't misinterpret the post by cncsnw as being directed at me. I assumed(given the reference to springs) that he was responding to my reply to this thread after viewing the thread I had separately started on the same topic...

O_o