PM-940m CNC - VS Motion Controller Conversion to Centroid Acorn

Hey Jake,
Yes, that's right. I haven't tried connecting the forward/reverse/common without the An_GND and AN_Out yet. I've been looking thru the manual and online to see if I can find something that will help me understand the VFD a little better.
 
pburgh said:
Hey Jake,
Yes, that's right. I haven't tried connecting the forward/reverse/common without the An_GND and AN_Out yet. I've been looking thru the manual and online to see if I can find something that will help me understand the VFD a little better.
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I thought Phazer also wired it without the relays ?
 
I'm not sure if he used the configuration. it should work. I'm wondering if there is something programmed for the nmotion board that the Acorn doesn't like.
 
pburgh said:
I'm not sure if he used the configuration. it should work. I'm wondering if there is something programmed for the nmotion board that the Acorn doesn't like.
Click to expand...
Perhaps a post to the Acorn forum about the issue ?
 
cut2cut said:
I thought Phazer also wired it without the relays ?
Click to expand...

I did not... I was thinking I would leave them until I need a set of relays for something else.

The VFD seams to be programmed for MI1 = fwd, MI2 = Rev, and 0-10v for speed, so it "shouldn't" be any different. If you think about it, all the relay is doing is tying DCM on the VFD to either MI1 or MI2 depending on which relay is engaged. Shouldn't be any different than going to an output on the Acorn as long as the COM on the Acorn and the DCM on the VFD are tied together.

Pburgh, my next step would be to put a meter on continuity check between DCM on the VFD and any COM on the Acorn (I would actually check it to a few COM terminals on the Acorn) to make sure you have continuity between the digital COM on the Acorn and VFD. Sounds to me that you have a strange ground loop that is causing this issue...

I just checked on my machine and the DCM on the VFD does not ring out the earth ground, however the Acorn ties earth ground to COM on the board (pretty standard for industrial stuff). I wonder if the VFD needs the two separated... You could try tying the second DCM on the VFD to ground and see if that helps out, but if the VFD needs them separate, we're stuck with relays.

PZ
 
Hey Guys,
I just posted to the Acorn forum, so we'll see what they say. PZ, i'll look into what you suggested, but i'm afraid that you may be right. We may be stuck with the relays. The generic schematic that is in the Acorn Schematic group shows using the Drive OK and reset features too. I wonder if all of those settings need to be in place. Also, looking at the manual, there are 2 switches one is set to PNP and the other is set to ACI, but we're connecting to AVI. Not sure if that has anything to do with it. Let's see what the forum comes back with.
Thanks Guys
 
I thought I was actually going to make chips tonight... but it doesn't seem to be the case. I programmed a simple-ish part to be made out of UHMW as a test. I set the machine up and tried to run the program above the part in mid air, to make sure everything is rockin' before I start a real cut...

Well the thing just totally farts and gives up when I run the G-code. It actually makes it thought the initial rapids, and tool change (not an actual change, but it says insert tool 1 and press cycle start), but as soon as it starts an actual "cut" X and Y start missing steps like crazy... like they barly even move.

I'm running 125 IPM and 0.2s acceleration on both the X and Y axis, I can jog all over all day with no issues. I'm only running 80 IPM in the G-Code. I tried running it at 50% feed rate, but no dice. It seems like it's not applying the correct acceleration while running the G-code...

I'm going to dink with it for another half hour and then make a post on the Centroid boards about it...

PZ
 
phazertwo said:
I thought I was actually going to make chips tonight... but it doesn't seem to be the case. I programmed a simple-ish part to be made out of UHMW as a test. I set the machine up and tried to run the program above the part in mid air, to make sure everything is rockin' before I start a real cut...

Well the thing just totally farts and gives up when I run the G-code. It actually makes it thought the initial rapids, and tool change (not an actual change, but it says insert tool 1 and press cycle start), but as soon as it starts an actual "cut" X and Y start missing steps like crazy... like they barly even move.

I'm running 125 IPM and 0.2s acceleration on both the X and Y axis, I can jog all over all day with no issues. I'm only running 80 IPM in the G-Code. I tried running it at 50% feed rate, but no dice. It seems like it's not applying the correct acceleration while running the G-code...

I'm going to dink with it for another half hour and then make a post on the Centroid boards about it...

PZ
Click to expand...
I am going to post a video soon of what I milled today But the max Speed I have tried is in the 10 ipm range. No issues that I can tell, with multiple tool changes too. Look for a link to the video fairly soon

Btw, with Linux CNC I could only get my x and y to run 70 IPS and about 50 IPS on the Z before I lost steps. If memory serves correct... foggy memory however. It didn’t bother me as i’m not pushing anything hard because I don’t have many carbide bits... yet :)
 
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Very cool Jake, so that's what it looks like when it runs. I like your chip guard. how did you attach it to the table?
 
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