Dwell on spindle speed change (not tool change)

[rojhan]

I would like to be able to insert a dell on spindle speed change, not just on/off or triggered by a tool change.

My specific use case is do a very light, fast cut of the surface (cutting the perimeter of stencil material) prior to carving the actual text and then painting. The bit/tool stays the same, but I'd like to cut the stencil at a much higher spindle speed than the carving itself. There may be other use cases, but that's my specific example.

I have set the spindle on/off dwell time and have tried setting MOP header/footer, but the dwell needs to be after the S command.

Is there any way to accomplish this? I could probably create a dummy MOP between operations that just changes the speed and then waits, but I'd like it to be automatic without needing to remember to do something special.

Thanks!

[ger21]

Add a G04 after the S command?

[rojhan]

Add a G04 after the S command?

Yes, G04 works. But, other than header/footer is there a macro or some other way to modify the S command? Or do I need to do this on the CAD/g-code generator side?

Ideally, "here's the g-code with the different mops, tool changes, and spindle speeds. Automatically add a delay after changing spindle speed not caused by a tool change/stop"

[ger21]

Add it to your post to add a G04 after a speed change?

[rojhan]

You mean in post-processing in CAM? I'm looking into that as well (CamBam).

[ger21]

yes

[Dazp1976]

yes

Can this kind of thing also be bodged by using spin up/spin down perameters in the drive itself? (depending on your drive system used of course).

[ger21]

yes

Can this kind of thing also be bodged by using spin up/spin down perameters in the drive itself? (depending on your drive system used of course).

No, because UCCNC will not wait for the drive. This is the problem he already has.

[rojhan]

I have a brute force version of this working by adding a 3 second delay after spindle speed in each MOP as part of the MOP template. I also reduced my spindle spin-up delay by 3 seconds.

It's not perfect (there is a wasted 3 seconds between MOPs if the spindle speed doesn't change), but it gives me a place to start. It looks like I'd either need to write a plugin or a post-processor that would statefully modify any S commands; keep track of previous speed and only add the delay if it changes.

[ger21]

I also reduced my spindle spin-up delay by 3 seconds.

I think most people can greatly reduce spin up speed in their VFD settings. I had no issues setting my Huanyang accel time to 1 second.