New PM-940V

[ptrotter]

I pulled the trigger on a new PM-940V to convert into a CNC machine. I drove down to PM to pick it up.

At the PM warehouse.

My machine in the warehouse

Loaded into my truck

Part way uncrated

Out of the crate.

So far everything looks ok. Fit and finish is as expected for a Chinese product. I'll decide when I have it apart if I want to repaint it. I plan on doing the CNC conversion soon so I will not be placing it on the stand until that is done. I will be taking it completely apart to do so and will try to document the process at least to some extent. At this point, I plan to go with an ArizonaCNC kit for the CNC with Clearpath servos.

The people at PM were very friendly, I got a tour of the warehouse from John and then spent a half an hour with Matt. A long day, a 6 hour drive each way, but I avoided dealing with common carriers. I guess now the adventure starts.

 

[7milesup]

Congrats! Looking forward to your build thread documentation.

 

[Kiwi Canuck]

Paul, that's great that you got to go pickup your machine.

I would do the same if they were that close to me just for the experience, but I also love long road trips.

Did you pick up anything else while you were there? accessories or tooling?

David.

 

[ptrotter]

I didn’t pick up anything else. I thought about it but decided I wasn’t sure about what I want yet. It will be awhile before I have it up and running so I have some time to figure out what I need.

 

[davidpbest]

Hey Paul, good for you. I’d love to hear your thinking on how you plan to control the beast (I’m planning on Acorn) and what if anything you’re thinking about on spindle improvements. Looking forward to your follow on posts about this project.

 

[Skowinski]

Congrats on the new machine!

 

[Janderso]

Good for you. I hope all goes well with your new PM

 

[ptrotter]

David, I've been playing around with Acorn on my little Sherline mill. It seems to work fine but like anything, there is a learning curve. There seems to be pretty good community support for it in their forums.

 

[ptrotter]

I'm starting to move along slowly. I have ordered the CNC conversion kit from ArizonaCNC, the Clearpath servos, a power supply for the servos, as well as the connectors to make up the servo power and control cables. I have most of the rest of the components. I need to figure out where I will put the power supply and the Acorn components.

My first step is to determine how much CNC control I want. If I go full CNC, I can remove all the manual controls and their associated relays and control everything via the computer, including spindle on/off, direction and speed. This simplifies the wiring considerably as all control is done via signals from the Acorn board to the VFD. This frees up a lot of space in the control box for the power supply and Acorn board. The downside of this is that it makes it much more complex to do simple things as I would have to do everything via the computer. The current manual controls uses a number of relays and a few things I'm not sure what are so I'd kind of like to simplify it. The wiring diagram in the manual is very cryptic, I may post a picture of it for amusement. Since I will need to use the computer to move the axis, I guess there is no reason not to go full CNC. I am curious as to what others have done in their conversions.

I am starting to break down the machine in preparation for the ball screw installation. So far I have just taken off the motor and will probably remove the head tomorrow. The picture below shows the motor and you can see the belt drive. I'm not sure what the 2nd connection to the motor is for, maybe a temperature sensor as it is up in the fan housing. I'll have to trace it out. I'm going to see if I can figure out how to put an encoder on the spindle so I can send rpm info to the Acorn.

 

[mksj]

The motor is most likely a TEBC, they have an electric fan that often runs continuously on 240VAC (mine is connected to two power legs before the VFD). I have a TEBC motor on my mill, I ended up putting a timer on my fan so it runs only when the motor is operating and for about 2 minutes after stopping and then turns off. Might be interesting to see the motor plate and at some point dig into the VFD parameters.