I'm building a special purpose machine and I need a little help on setting up the rotary between Mach3 and Aspire. The machine isn't finished yet but getting really close. In a nutshell here is the machine:

Vertical Milling machine that has a turntable.
The Y and A axis are slaved and are the lifting axis. These are driven by 2005 series ball screws. The Z axis is again driven by 2005 ball screw. I have these under control with proper steps and microsteps.

The X axis is a turntable. Typical 1.8 degree stepper 200 pulses per revolution, micro steps are set to 400. then this is into a 100/1 reducing 90 deg gearbox. So you get 200 * 400 * 100 = 8,000,000 pulses per rotation or 22,222.2222 steps per degree?

Assuming that is correct, what is the best way to handle the setup in Mach3 and Aspire? Mach3 only allows angular setup for other axis, not the X. Aspire will only allow rotary on X or Y axis.

If I keep it linear, then the setup changes for each diameter you setup.

Again just thinking, but am I over thinking this?

Thanks,
James
 

Normally a rotary axis is A,B or C most CAM systems will follow this format.

If you can I would swap the A on your machine so the rotary axis is A.

Aspire works by aligning the A axis with the X axis and the B axis with the Y axis.

It would be better if you posted some pictures of the machine to help diagnose your issue.

Hi James,

Obviously I don’t know the layout of your machine so please bear with me on this…

What you have said is just fine in theory but in practice things are not exactly what they may seem.

Standard stepper motors are unable to translate their controllers set microsteps to any degree of positional accuracy beyond say 10 microsteps per whole step. Even then the reduction in available stepper motor torque may fail to move an axis until a number of the microsteps have been commanded by Mach.

The Aspire rotary axis generated toolpaths (as far as I am aware) are intended for the rotating axis of the cutting tool to be at 90 degrees with the rotational axis of the work cylinder. That is to say that if your machine has a vertical spindle and your rotary table has a vertical axis then Aspire may not be able to produce a suitable, dimensionally accurate, toolpath.

Perhaps not very helpful but these are my thoughts.

Tweakie.

This is the machine overall. These are working progress pics but it is getting there. I have a few more aluminum plates to machine and make the rest of the cover plates that enclose the entire structure. These also add rigidity to the system. I should have the steel plate counter weights tomorrow.

It has almost 9' of vertical travel which right now is the Y and A Axis. Direct drive 2005 series Ball Screws.


Electronics right now, still need to mount the VFD and finish up the wiring like proximity sensors and e stop.


The Z axis has 36" of horizontal stroke. Direct drive 2005 series Ball Screw.


The Turntable is a mounted so it can slide to or away from main structure depending on the size of material. The Stepper is mounted to a 100:1 gear box.

Normally a rotary axis is A,B or C most CAM systems will follow this format.

If you can I would swap the A on your machine so the rotary axis is A.

Aspire works by aligning the A axis with the X axis and the B axis with the Y axis.

It would be better if you posted some pictures of the machine to help diagnose your issue.

I thought about just spliting the pulse signal from the breakout board into both the Y and Slaved Axis freeing up the actual A Axis. But Aspire looks like it is only sending out X, Y, and Z data. Are You saying that it is still producing A code that mimics the X?

I posted pics and more description of the machine.

James

The Aspire rotary axis generated toolpaths (as far as I am aware) are intended for the rotating axis of the cutting tool to be at 90 degrees with the rotational axis of the work cylinder. That is to say that if your machine has a vertical spindle and your rotary table has a vertical axis then Aspire may not be able to produce a suitable, dimensionally accurate, toolpath.

Tweakie.

That is how I have it setup or at least designed. Basically mimicking a traditional CNC with a Rotary option with the exception I want it vertical. So in Theory, it should work. I'm a little early as the machine isn't finished yet but getting really close to start moving on her own. So far, functionality is working and we are just jogging around. I'm having to make a few tweaks to the design.

James

WOW !

That’s certainly an ambitious looking machine that you are constructing, thanks for posting the pictures. Please keep us updated on your progress.

Unimportant at this stage but just a heads-up…
I think you will find that your stepper motor drivers are marked with the microsteps per revolution (not microsteps per step) so you need to remove the 200 from your initial calculation of steps per degree for your turntable.

Tweakie.

for my understanding (witch is not crucial) your machine has got a

Y, Z and C axis

in this case spindle has to be vertical.

an X-axis can IMHO never be a rotary axis.

pulsed per deg would be 400/360*100 = 111,11

I think you need to tell aspire to use a 4 axis post processor, by default it will be 3 axis only.  I think they are called Legacy (mm) etc posts.

I think you need to tell aspire to use a 4 axis post processor, by default it will be 3 axis only.  I think they are called Legacy (mm) etc posts.

I was actually thinking about that. I was looking at the AVID post processor for their Rotary and seeing if it would work. I have 2 of their machines already. They were what I started with and are still workhorses at my shop even being 11+ years old. I'll need to tweak it and possibly run this machine on Mach4.