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

Your wire numbers are very different than mine. I cant't really tell what is going on in the pics, however the diagram makes perfect sense. If it's actually wired like that it "should" work.

Have you removed the limit switches from the equation to see if you can get it to fire up.

PZ
 
Hey PZ,
it does work now. It goes into a fault when I try home the machine at the start. And then I can't move any axis. I have to turn everything off and move the axis manually. I'm checking to make sure that I have the machine setup to home properly. I also have to go over the limits again and make sure they are engaging correctly for this configuration to work. One of the switches is set with the conductors in reverse of the other 2. if the make/break is equal on both contacts, then it shouldn't matter. But if contact hinges, then there might be a problem. I don't want to take too much apart to determine that. I'll get it figured out, but it's frustrating that this thing wasn't put together more consistently. BTW, if you are having any intermittent issues with something not working 100% of the time, you might have a loose crimp on one of the crimp sleves they use. I found 2 when I was rewiring the VFD for conductors 97 and 99. They both literally fell off. So I had to redo the crimps with new sleeves

Doug.
 
I was thinking if you disconnect the limit switches, and leave the home switches, then try to home you might be able to narrow the problem down. If you have the same problem with the limits disconnected than your problem is probably with the home switches. Just a trouble shooting technique.

I had the same issues with loose connections from the start (x axis would drop out right out of the box). I got tired of it and did a pull test on every wire, and probably 90% of them were loose, as in with a light tug the would come out of there terminal.

PZ
 
phazertwo said:
I was thinking if you disconnect the limit switches, and leave the home switches, then try to home you might be able to narrow the problem down. If you have the same problem with the limits disconnected than your problem is probably with the home switches. Just a trouble shooting technique.

I had the same issues with loose connections from the start (x axis would drop out right out of the box). I got tired of it and did a pull test on every wire, and probably 90% of them were loose, as in with a light tug the would come out of there terminal.

PZ
Click to expand...

Sigh.... It’s probsbly why they wired it NO. So it wouldn’t fault before it left the factory test. It’s sad but it’s been said before, you basically have to tear these mills down to the bare bones or you’ll have surprises like this, mostly lacking in hidden workmanship.

It’s good iron and mostly good components. A good base to work from but it needs to treated as though it wasn’t put together with tons of care, imho.
 
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cut2cut said:
Sigh.... It’s probsbly why they wired it NO. So it wouldn’t fault before it left the factory test. It’s sad but it’s been said before, you basically have to tear these mills down to the bare bones or you’ll have surprises like this, mostly lacking in hidden workmanship.

It’s good iron and mostly good components. A good base to work from but it needs to treated as though it wasn’t put together with tons of care, imho.
Click to expand...

I think you're probably right about the NO. I also agree about the good iron and components. Machine it's self is quite nice IMO, and the only gripe I have with the controls (besides the nMotion :bs:, but we don't need to talk about that) is that they are 24vac not vdc, other than that it's just been workmanship issues. Honestly for the price... I can tinker with it. No buyers remorse at all, if I wanted a perfect machine I would have saved longer and bought a PCNC1100, but than I wouldn't know nearly as much as I do now about CNC!

PZ
 
Guys, you are both right on. I was telling my wife that if I had CNC'd this thing myself, I'd know it worked right and I'd have learned the ins and outs as I went. This is a little more frustrating because you have to back into it. And without documentation and it being Chinese, it makes it more difficult. I want to thank both of you for your help and support in this. I got very little info with this mill. On another note, I was reconnecting a couple of the limits and one of the forked ends came off of one of the wires. So that may have contributed to part of the issue. I almost hate to dig in too far because i'll eventually have the whole thing reconstructed which is what I was trying to avoid. But i'll continue to troubleshoot tonight and hopefully get somewhere. A couple of other questions. Where are the dogs set for your home limits? As your facing the limits, mine is on the right top on the X, the left top for the Y and the top front for the Z. Then the hard limits are set at either end on the bottom for each axis.
My other question is, did you get a manual with the oiler? or is there a way to cut back on the amount of oil that it disperses? I have to keep cleaning up the puddles that collect in the chip tray. Sorry to be so long winded...

Thanks,
Doug
 
My home switches dogs sound like they are in the same location as yours. My dogs we also loose, so check on that, the could be sliding back. I also had wires break in the horse shoe terminals... They're consistent if nothing else!

I don't remember if I have a manual for the oilier, but I defiantly had to turn it down. I just pulled the wires out of the terminal block while I was tuning, it was just a waste of oil. I'd be interested to see how the Acorn controls the oilier, maybe based off of inches traveled instead of time?

PZ
 
No problem Doug, happy to try help.... but its tough to help from afar and obviously things went sideways with the idea of removing the relays. a curve ball. Just try to put that behind you and keep at it. Things will pick up for the positive... just a little hurdle...

So, here is my homing setup just for reference :

I believe I moved my home limit stop positions from the way it shipped. This all may be something you know already, but I figure if not, its good for me to go through it again to further engrain.

My homing sequence is Z , Y , X
If I’m sitting left of the center facing the mill, the head moves up when homing Z ( towards zero in a positive direction ) . When homing Y the “saddle” moves away (toward the column/ towards zero in a negative direction ) . And when homing X the table moves away too ( towards zero in a negative direction ) . All while I’m sitting left of center facing the mill.
So Z is the only “odd” direction but its best ( in practice / use ) if the Z moves up and away to home rather than down which could quite possibly crash if you have a tool holder in the spindle. I believe the nMotion actually had Z try home going toward the table, if you can believe that ! I've tried to erase that memory, however :)

In this setup my fixed HOME stops are located up toward the top of the fixed Z column. Near me ( sitting left of center ) for the Y ( attached to the base ). And Near me ( sitting left of center ) for the X ( the home limit stop is attached to the Y “saddle” )

The best way to think about "positive and negative" in the DRO is : the cutter is the reference. So when the X axis is moving right to left the CUTTER / END MILL is “moving *relatively speaking* from left to right ( *relative* because the cutter isn’t actually moving at all ). In this scenario, the X axis DRO is moving in the positive. Same is true of the Y axis, In other words, If the table is moving back to front ( the Y “Saddle” ) , the relative movement of the cutter/end mill is moving from close to you to the back ( if you were actually sitting on the table and moving with it ).. so the end mill is (relatively speaking ) moving in the positive direction, so the DRO increments the number in the positive direction.

Z , the cutter actually moves with the head. So its sort of backwards to what the X and Y do. So when the cutter moves up, its going positive, and when it moves down…. you guessed it… negative ! lol So, every move toward your work piece in the Z axis is negative.

Hope I got all that right !

Jake
 
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Thanks Jake for the explanation. That makes total sense. I didn't understand that the cutter was the reference for +- X,Y and not the table. I was watching a video that Marty made and was confused when he was referring to the table moving in a negative direction to the right. Then i read it in the manual and had an aha moment. Pays to read the manual. That one's on me. I have to change the X home to the left. it was originally set to the right.
I'm actually catching a glad right now. I finally got this thing to work. My issues were caused by them and me. By them not making sure that everything was crimped fastened down secure and consistent, and by me for not noticing the Y home wasn't hitting the dog. The bolts holding the limit were loose. as well as the switches having inconsistent orientation. I like the limits they used and the way they are easy to adjust. I don't like that you can't easily see the orientation and don't know if mechanically they are working the same. When you are putting things in series it matters. Plus i'm partially handicapped, so I can't get down to where the y limit is located very easily. I don't want to use that as an excuse though. I should have been checking that a little closer. But, once I got it homed, I was able to fire up the spindle and check it out, so i'm moving in a positive direction. Now i'm going to switch gears a bit and see if I can get the metal I need for the power draw bar. And hopefully i'll be cutting some stuff this weekend if all goes well. I'll keep you all posted. It's been an adventure gathering all of the little parts for this thing. I wanted to try to get that going because I can't reach the top of the spindle to change out the collets very easily. Plus I invested in the Tormach quick change system so I want to start using that. I have a lot to learn, but hopefully it will be fun and interesting.

Regards,
Doug
 
Great to hear it’s starting to come together. Go make some chips !!! ;-) I’m finally starting to loosen up and not hover over the E-stop as much. This is mostly due to the Acorn, I think. But I do need to go over the connections a bit more myself and wire up the switches as NC asap. Fingers crossed but I think the person doing the crimps on mine was doing a good job!
Can’t wait to here more about the power drawbar as that is really something that will help me too. I might just go ahead and order it but it starts off a chain reaction. I’ll need a compressor, which will need to be in an sound proof box ( I hate extraneous noise ). I also worry the extra weight of the drawbar cylinder components might tax the 1200 oz Z stepper motor. The hope is to someday use a more powerful, but also servo motor, for the Z axis. I need to research how they maintain the Z at height when it’s all turned off. It must have a brake , but what if there is a power loss ? Certainly a good and rewarding project. Having fun, so it’s a good journey. Thanks for all your help too guys. Much appreciated.
Cheers,
Jake
 
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