EX Rotary Crash Course

Hey all, we’re still working on some official documentation on using the rotary on our new EX controllers.

For now I have created a “rotary crash course” for you to check out:

This will show you start to finish how to setup and calibrate your rotary on an EX control

Thanks for doing this Eric. This is very helpful.

Glad I “winged” it and did it right :wink: Thanks for the video. Was pretty straight forward after we got it working.

@Eric probably should put this in another thread, but with the servo what is the max RPM configured to for the rotary axis?

Don’t hold me to this, but at max speed on the rack drive (so your X or Y axis) it spins at 600 RPM to go 1000 IPM, so on a 10:1 gear reduction for the rotary you’re looking at 60 RPM.

Again, don’t hold me to that!

Also, think about surface speed too, that changes depending on how far away you are from the centerline of your stock.

Nice! That rotary calibration is our longest single macro by far. Hopefully in the future we’ll make it a little more “graphical” but I’m glad you got through it.

I thought I saw there was a straight line torque on the servos to about 2600 RPM, then it dropped off, I think on the website with the NEMA 34 motors it said it was 100RPM. I figured I should be able to push it through the constant torque line of the servo motor so at least to 260RPM, but not sure where that setting was. Just trying to chew through things as fast and safe as possible without breaking something. As they say time is money.

I’ll find out more tomorrow for you

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Nice video.

So in the rotary mode, MTC will not go over to the toolsetter, it will have you jog over to the touchplate on the tailstock so it can probe there instead, correct?

That’s correct because we have no way of knowing where that touch plate is. You have to jog there so we know.

Thats what I thought, I just wanted to verify.

I like the angle adjustment it does for any error down the rotary horizontal plane. Would be cool if it could do that on the height too, but I don’t think there is a built in feature to use for that in CNC12 like there is for rotation angle, right?

There is, but it can’t bend the laws of physics: There’s no A/B axis to tilt to compensate. We want the end mill to be as parallel as possible to the rotary, hence why it’s on you to use those jack screws to level it out.

Ya, you wouldn’t want to use it for a gross tilt, but it would be nice for that last couple of thousandths of tilt over the full length so that you can remove/replace the rotary unit with out messing with the jackscrews. I have done a lot of work shimming and pinning mine so that it goes back into the same place, but I think most people are using the stock jackscrews. Just a thought, not a big problem for sure.

Would volumetric compensation do what you’re asking @jjneeb ? Basically a way to remove taper?
It’s a beta feature right now but Centroid is working on it.

Not really. You can’t compensate for a flat end mill not being parallel with the rotary. If you could we would have done it :slight_smile:

Ah yes! I didn’t think of that. When I’ve used this (once), I was using a ball end mill to make a dowel. It turned out great, but I can see the flaw in the logic here.

Ya, that would be the one application that VC would work as long as you were just using the tip and not the cutter side.

A couple of questions:

It isn’t clear to me why recall calibrate needs to know where and touch off the the tool plate (the one attached to the movable portion of the rotary). If I have a measured tool in, wouldn’t going to rotary calibrate know everything to set the X (rotary install axis in my case), y, z, and CSR?

What is the equivalent of “unrecall calibrate”? If I am using G59 for current WCS, do a recall calibrate, how do I get back to non-rotary mode? Setting a new WCS doesn’t seem to do that.

Thanks

Great question!

Tool length =

Distance Z takes to get the tip of the tool to the spoilboard surface plus or minus the location of the fixed tool height setter. THEN a z offset is applied so:

If it takes 5 inches to move your tool to the tool height setter, and your tool height setter is 1" over your spoilboard your tool length is -6"

After you measure a tool and you jog it to Z zero (with no Z offset this would be the tool tip on the spoilboard), your machine position is +6. When you add -6 to that you get 0, this is why when the tip of your tool is on the spoilboard you see 0 in the Z DRO.

When you add in a Z offset, let’s say 1" then your Z dro would read -1 when the tip of the tool is on the spoilboard. (Z offset is effectively your material thickness)

So the important part to remember here is that your tool length is dictated by your spoilboard location

Rotary customers often go long periods of time without using their rotaries, and in that time they could have resurfaced their spoilboard.

So if the Z height of the rotary was related to the spoilboard there’s a high potential that when someone goes back to using their rotary the Z height would be off by whatever amount they surfaced off of their spoilboard.

This is why we use the touch plate on the rotary to get the Z height. It’s a fixed location in space that directly relates to where the rotary centerline is.

The rotary XYZ and angle location is transferred to whatever your active WCS is. So you can switch to another WCS, or you can go into the Set Part Zeros>WCS table and zero out XYZ and angle if you want.

Pro tip: If you “recall calibrate” to a WCS (say something like G58) you can leave those numbers in there and you can switch back to G58 whenever want to use your rotary without having to run the “recall calibrate” utility again…so long as your spoilboard is in the same spot.

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Ah, gotcha. In my case of a recessed permanent install of the rotary, the offset height of any spoil board is completely irrelevant – the centerline of the axis will always be the same fixed height above the tool setter.

I see why you can’t make that assumption for each install (and why options to switch between can add risk/assumptions).

Ah, this makes more sense now. I did the calibrate with G59 as my active WCS, and expected recall calibrate to restore to G59, not the active WCS (the dialog clearly states that).

Now this makes sense. Wonder if I could script it up so using say G59 could set boundaries for jobs to ensure that everthing is reasonably within the rotary “safe space”.

Final question: in your video, you didn’t need to use the magnet with the tool touch plate and a “prototype” spindle. Is this (please, please) going to be the case with the AV Smart spindle?

That’s correct for any rotary install.

You could use the “work envelope” feature. It’s documented in the Centroid Router manual. You’d have to code this yourself, but it wouldn’t be too bad.

It should be, and it likely can be with your current spindle. There’s a thread around here somewhere of me talking about making your own ground.

Basically what you do is split the wire for the Z sensor, you take the ground wire from it and wire it to your Z axis metal and it should work to bypass the magnet. (use at your own risk!)

We’re supposed to have adapters for this, but there’s a delay in getting them out.