My PM-940 CNC Modifications

For anyone that is upgrading their PM 940CNC from the supplied nMotion controller ( for Mach3) to the 7176e ( for use with linuxcnc ) here is the wiring schematic that my brother made for me. Its been a bit since i got it up and going, so I don't recall the details but hopefully it is of some help. Assuming the wiring on yours is the same as my PM940CNC that I got January 2017 with the Delta VFD.
Best Regards,
Jake

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Been doing a ton of research on different controllers. Stumbled across this as a good solution for no MPG for Centroid Acron:

In all my searching, I think I've come to the conclusion that Centroid Acorn is the way to go. Masso is also a good option and probably easier to setup, but Centroid builds industrial gear... they know exactly what they are doing. Also, I can upgrade my mill computer, buy the card and software for about the same price as the Masso... So the cost is kinda a wash.

PZ
 
Been doing a ton of research on different controllers. Stumbled across this as a good solution for no MPG for Centroid Acron:

In all my searching, I think I've come to the conclusion that Centroid Acorn is the way to go. Masso is also a good option and probably easier to setup, but Centroid builds industrial gear... they know exactly what they are doing. Also, I can upgrade my mill computer, buy the card and software for about the same price as the Masso... So the cost is kinda a wash.

PZ

Previously you mentioned that the Acorn wasn't realtime vs LinuxCNC. Did you resolve that it wasn't an issue since it has an onboard motion control CPU so it shouldn't incur any loss of "timing" ? I looked around for any comparisons on the subject and couldn't find any, which is why I'm asking. I do think the Acorn looks great and the company has been around the block a few times so they probably are putting out a good well thought out product and at great price point. I think Precision Mathews should consider using this as a controller, IMHO.

Thanks,

Jake
 
Hey Guys, good to hear that your onboard with the Acorn. Hopefully you see this post. If you're going to go this route, you'll want to purchase the board and upgrade to the pro software now before jan 3 2018. They are going to be raising the price of the card and software. There is a post on the Centriod Acorn forum that I read today about it. I'll be posting some info to the forum about the 940 and the setup to be sure that i'm looking to make this change from the nMotion to the Acorn without any issues. So, keep an eye out for it and you'll probably get some questions answered too. Also I found info that they are developing a driver for a wireless MPG they are testing now (might already be good to go). Something I discovered going into this is that i'm going to have to purchase a 5vDC power supply for the LeadShine drives. Looks like the 5vDC is provided by the nMotion now. Well, here we go. I'm going to craft the initial post now. Hopefully this is helpful to everyone.
 
Hey Guys, good to hear that your onboard with the Acorn. Hopefully you see this post. If you're going to go this route, you'll want to purchase the board and upgrade to the pro software now before jan 3 2018. They are going to be raising the price of the card and software. There is a post on the Centriod Acorn forum that I read today about it. I'll be posting some info to the forum about the 940 and the setup to be sure that i'm looking to make this change from the nMotion to the Acorn without any issues. So, keep an eye out for it and you'll probably get some questions answered too. Also I found info that they are developing a driver for a wireless MPG they are testing now (might already be good to go). Something I discovered going into this is that i'm going to have to purchase a 5vDC power supply for the LeadShine drives. Looks like the 5vDC is provided by the nMotion now. Well, here we go. I'm going to craft the initial post now. Hopefully this is helpful to everyone.

Thanks for the heads up Pburgh!
I'm haven't counted up the number of ins and outs to see if the Acorn has enough for the 940cnc.
Please leave a link here pointing to your post there, so we don't have to hunt for it.
Cheers,

Jake
 
Thanks Jake, that would be great. I was looking at some posts in the Acorn forum. I searched on Precision Matthews and there is a post in there of a guy who fried his VFD. I don't want to do that, so i'm a little apprehensive. They didn't give me a manual on the VFD and I have to get the info on the one that's in there. Did you get a manual with yours? I'm a little annoyed at the lack of info that came with this unit. Even though they are priced better than most of what's out there it's still a lot of money for something with such poor info. I was looking at a Grizzley unit to try to get an idea on how to connect the coolant pump and I was impressed by how well the documentation was setup. Do you know if the nMotion card provides 5vDC? I didn't see anything on the schematic or in the cabinet that generates 5v.
 
My PM940CNC came with a DVD for the Delta VFD-E however, you can get the manual here :
http://www.delta.com.tw/product/em/.../manual/DELTA_IA-MDS_VFD-E_UM_EN_20150302.pdf

Yeah, I have yet to connect the coolant pump.... but coincidently I intend to wire it up tomorrow. If you have any pointers, I'd appreciate it. It should be simple but if I remember right, its not clear cut.

I think you are right, it appears to me the 5v to the stepper drives are provided by the nMotion card itself via wire 055.
We can probably use a USB cable/charger for an iPhone as the 5v source. So its not a huge hurdle.
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Jake
 
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Thanks for the info on the VFD Jake. I didn't get much with the mill. I got the manual in a binder with the schematics and breakdown of parts, and I got a usb thumb drive for the nMotion card with the config xml file for Mach, the driver dll for Mach and a watered down version of the the nMotion manual and that's all.

As far as the coolant pump, Matt told me to connect the wires to one of the terminals with the capacitor leads and the one terminal without the capacitor leads. See the pic below. I connected mine with the hot legs on the terminals with the red arrows and the ground on an obscure threaded hole in the pump case where the green arrow is pointing. I'm embarrassed to say that I used to be a construction electrician and I've hooked up my fair share of all kinds of motors, but I've never run into a peckerhead that is setup like this one. The Chinese nomenclature for how they label their terminals threw me off. And the ground is very close to the one terminal so be careful of the clearance. I haven't tested this yet, but that's how I set mine up. Hope this helps.

pump.jpg
 
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