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

[phazertwo]

Guys,
Are you using the ENA terminals? Do you think that the drives have to be reconfigured for the motors? I wonder if some of the dip switches have to be changed. Did you get a manual for the drives for your mills? I didn't.
Regards,
Doug

Sorry I just realized I missed this. Yes I WAS using the ENA terminals, however if there is an e-stop condition than the Acorn will shut the drive down and the motors de-energize so they are very easy to move and lose position. So I just unplugged the ENA terminal strip from the drives. I did have to do some funky stuff in the advanced axis configuration in the wizard but I cannot remember what it was. Let me know if you need it and I will try to get it for you tomorrow.

Hopefully you can get her choochin' with the relays! Once you get it up and running it's going to feel like a whole new mill, at least mine does. I ran that plastic part at 0.004" ipt which was 52 ipm, and she was fast and smooth. With a 70% step over at that speed the motor wasn't super happy, but it did it! Might be upgrading to the AC bearings and belt drive like Jake has sooner than I anticipated!

PZ

 

[pburgh]

Well Guys,
I got it to run with the relays back in place. Still haven't been able to check the spindle. Now I have an issue with an e-stop. I think it's one of the limits. To tired to run that down tonight. Hopefully i'll see that tomorrow.
Regards,
Doug

 

[cut2cut]

Well Guys,
I got it to run with the relays back in place. Still haven't been able to check the spindle. Now I have an issue with an e-stop. I think it's one of the limits. To tired to run that down tonight. Hopefully i'll see that tomorrow.
Regards,
Doug

Did you remember to bring 24v into the IN circuit ?

If your estop is mostly NOT working but works a little bit on restart of the program its most likely because you haven't supplied 24v to that part of the card.

 

[pburgh]

Yes, I have the 24v feed above input 4. This is weird, I was jogging all of the axes this afternoon waiting for an answer about the VFD and they all worked as I expected, except where I had to move or adjust the dog for the home limits. The x,y and z limits all worked and jogged as they should, but when I started the program after I reintroduced the relays, and went to home everything it went into a estop fault. Weird... I was too tired by that time to dig into it. I'll figure it out tomorrow. This has been more painful than I imagined. Although it gets me back into thinking motor control. it's been a long time since I noodled with something like this. Over 20 years. Oh by the way, your 97 and 99 are different than mine because I think they switched them for rotation. I'll verify that tomorrow. Almost time to head to bed. I was just looking for a potential drawbar online to replace the one that comes with the machine. When I add the Bellville washers and tophat I think the original will be that much too short. Not sure where i'll get one, but I have a lot of the other things coming to start that project. I need to get the mill running so I can make the parts for it. That ought to be fun since I've never milled anything before. But you have to start somewhere....
Regards,
Doug

 

[phazertwo]

Sounds like you are hitting you're limit before hitting your home switch...

How did you wire the limits? I didn't bother with my limits because I couldn't (easily) wire them in series with the e-stop, something I hope to correct later.

PZ

 

[pburgh]

Yeah i'm going to have to adjust the dogs for the limits. What I don't understand is that before I had the VFD running, they all worked with the jog switch and were acting as I would suspect. But now I have a fault somewhere that's not as obvious. I followed the schematic that Orin on the Centroid site drew up. That follows the Centroid schematic. http://centroidcncforum.com/viewtopic.php?f=60&t=1270#p6959
I switched all of the contacts on the limits to NC and added a new NC e-stop switch and a NO Jog switch that I mounted on the side of the swing-arm control box. Then I proceeded to series the wires from the x,y and z limit switches and it all tested out fine. I'll draw up a pic on the wire colors and numbers. Although our mills will probably differ in that respect.
Question: from the mill table standpoint, where is the best place to position the home dogs? Right before the limit or further away?

Regards,
Doug

 

[pburgh]

Oh, one other thing I wanted to ask you guys about. I'm a newb on machining. For the power drawbar, what type of aluminum should I use for the base 6160 or something different? Also, i'll need to get a custom drawbar. Any suggestions?
Thanks,
Doug

 

[phazertwo]

Yeah i'm going to have to adjust the dogs for the limits. What I don't understand is that before I had the VFD running, they all worked with the jog switch and were acting as I would suspect. But now I have a fault somewhere that's not as obvious. I followed the schematic that Orin on the Centroid site drew up. That follows the Centroid schematic. http://centroidcncforum.com/viewtopic.php?f=60&t=1270#p6959
I switched all of the contacts on the limits to NC and added a new NC e-stop switch and a NO Jog switch that I mounted on the side of the swing-arm control box. Then I proceeded to series the wires from the x,y and z limit switches and it all tested out fine. I'll draw up a pic on the wire colors and numbers. Although our mills will probably differ in that respect.
Question: from the mill table standpoint, where is the best place to position the home dogs? Right before the limit or further away?

Regards,
Doug

Interesting... I'm not a fan of the jog off limits option, seems like too much of a chance to mess something up. Anyway, I would pull the wires for the VFD and see if it works as it did before. That will at least tell you if it's the VFD wiring that is causing the issue and hopefully keep you moving in the right direction.

Also, I'd agree with Marty, the VFD probably just needs to do it's own thing.

Oh, one other thing I wanted to ask you guys about. I'm a newb on machining. For the power drawbar, what type of aluminum should I use for the base 6160 or something different? Also, i'll need to get a custom drawbar. Any suggestions?
Thanks,
Doug

I'd use 6061 T-6, at ~37 ksi yield strength its right about as strong as A36 steel. Should be plenty strong, depending on the design of course, I'd be happy to take a look at a model and review it (and steal it)

As for the draw bar, your best bet is probably to design it and see if you can get someone on the board here to make it for you with a lathe.

PZ

 

[pburgh]

Hey Guys,
I'll post pics of my limits here In a bit. I wanted to get your feedback of how yours are wired. I know they are NO, but I moved mine to NC staying with the same switch location just swapping NO for NC. PZ, thanks for the info on the aluminum, and absolutely i'll share what I come up with and even take suggestions to make this thing awesome.
Doug

 

[pburgh]

Hey Guys,
Here are the pics of the limits:
On the X: Blue is OV and Yellow is 88
On the Y: Black is OV and Gray is 89
On the Z: Blue is OV and Black is 90
One thing is consistent is that things are not consistent.
Y and Z are on what i'll call the bottom switch and X is on the top switch.
OV is on the right on X and Y and on the left on Z.
I'm going to attempt to make them the same. Depending on how the switches make and break this could make a difference.
I've also attached the schematic on how I connected the wiring for the limits. Where you see the color transition are the conductors coming together on the terminal block. Again they didn't stay consistent, so there are some mismatched colors. I hope this helps. Please let me know if you have any questions or suggestions. I think this may clear up my issue.
Regards,
Doug