Machsupport Forum
General CNC Chat => Show"N"Tell ( Your Machines) => Topic started by: James70818 on July 06, 2024, 10:41:12 PM
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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
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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.
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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.
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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.
(https://1drv.ms/i/s!AnOS60y9MK8XjfZvGIRpsJPzxVsirw?e=eO2pqc)
Electronics right now, still need to mount the VFD and finish up the wiring like proximity sensors and e stop.
(https://1drv.ms/i/s!AnOS60y9MK8XjfZudmtK3aeMz7LofA?e=PsfigV)
The Z axis has 36" of horizontal stroke. Direct drive 2005 series Ball Screw.
(https://1drv.ms/i/s!AnOS60y9MK8XjfZwalMrD7-IfH77WA?e=9iz7fP)
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.
(https://1drv.ms/i/s!AnOS60y9MK8XjfZtf2unCwOXdi65OQ?e=HhlLPa)
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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
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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
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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.
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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
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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.
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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.
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So it looks like the general consensus is to move the rotary axis to the A axis and that way in Mach it can be setup as an angular axis. That with using a wrapped axis post processor, it should work. We will see really soon. My final parts arrive Friday and we should be able to fire it up this weekend.
Thanks,
James
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The machine is alive! I need to program the VFD for the spindle later today. Still have all the proximity switches to setup and then I'm sure there will be a few things to tweak in Mach. Getting the motors tuned now. I need to tension the Ball Screws, I'm getting more whip than I expected but with 2800mm screws you are going to have some whip. I have an idea for dampers that float and raise/lower with the gantry. Really happy with the stiffness of the Z axis when fully extended. Upgraded the lifting steppers to 1900oz x4 and now I don't need counter weights. The design with just two wasn't working. Hope to start making snow later tonight.
James
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Is anyone familiar with the Wrapping Gadget in Aspire? I can get it to make the continuous cut that wraps around the A axis. But it starts from the bottom and works it's way up. In my situation I would like it to work from the top down. I cant seem to find a setting that would do that other than flipping the axis in my Mach configuration. That's a crappy way to do it but technically would work. Just seems like there has to be a way.
Thanks,
James
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You could draw/move the profile to the opposite side of the datum point in Aspire e.g. if you are drawing on X- side move it to X plus side. Don't mirror it unless the profile is the wrong way round.
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No, that doesn't move either.
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Stepper motors just swap 2 wires on A+ A-
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Stepper motors just swap 2 wires on A+ A-
I still need y0 to be Y0. But the wrapping gadget in Aspire seems to only start at 0 when I need it to start at the top and work its way down. Reversing the machine will not help and would actually make it worse since the current bases are typically large.
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What do you have in the job setup tab?
Job Type : Rotary
Job Size : ????
Z Zero Position : Surface
XY Datum Position : Top Right : Use Offset X???? Y????
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See the screen shots. The Datum is set to the the lower left. If I move it to the top left, nothing changes. In the 3D view, you can see it at the base of the material and will work its way up. I want it at the top to work down.
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Okay, what do you have in the Home / Start Position in the toolpath tab?
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0,0 for x and y
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It is on the right hand side Toolpath Material Setup tab on my version.
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So I can now do move the start point. Here are the lesson I learned.
First, the Wrapping vector has to be ungrouped. I guess when the wrapping gadget creates the vector and you then create the toolpath it groups the vector and the object it is projected on.
Secondly, You have to be in 2D View. While you can select the vector in 3D View with the node editor, it will not let you move the start point. Once you are in the 2D View it will allow you to relocate the start point.
Thanks for all the feed back. Stay tuned for some neat stuff I hope to post this weekend.