Mitsubishi MR-J2S-40A and Servos!!!

[Jugster]

We are doing a retool on a machine at work and are going with the next latest greatest Mitsubishi Amps and Servos.  That being said I will be able to acquire enough of these to build another machine.  My first machine was built with stepper motors and even though I haven't had any issues, I would like to build a larger one with these servos.  The drives are Mr-J2s and I believe that the motors and gear heads are HCkfs43.  I was curious what type of Bob to incorporate  with this build.  My other  machine uses a C10 bob, and I haven't done enough research yet to see if it is feasible for this one.(Voltages, ETC.)  I typically do the mechanical design at work and the build and leave the electrical to the programmers.  I had a blast building my last machine from start to finish but did pull my hair out a few times due to ordering some components that was exactly the best for my application.  I was hoping to get a little bit better plan together for this and avoid some frustration.  Any input would be greatly appreciated.

[Hood]

It is likely the drives will be 12v I/O and theres not really any breakout board that supports that at the moment. There is the Centipede which is an external controller that I think can quite easily be set to use 24v I/O and then of course the Galil and I imagine the DSPMC as well but all of these are not just simple breakout boards and not simple price

I use 24v I/O on all my machines and mostly I use a PLC for that but  E-Stop and Limit switches go back to my breakout boards, for the E-Stop its ok as I use a two pole E-Stop with the 24v for the contactors on one pole and the 5v for the Bob on the other. For the limits I have them going to relays with 5v across the contacts so that the BOB gets the 5v. I actually have the limits to my PLC as well but thats to disable servo drives enables etc and wont go into that.

Hood

[Jugster]

Hood,

Thanks for the input.  We have got several mistushbishi Q racks, processors and I/O Cards chocked full in a cabinet at work and I am sure I can get one.  The only problem is I am not very familiar with that type of programming.  I do have an Allen Bradley Micro logix out in my shop right now off an old machine but it was pretty simple not for sure about the I/O count on it.  I just thought that since these units had gear heads as well thought I might be utilize them.  I do help the programmers calculate all the ratios on these units but as far as interfacing them with a plc it might be over my head.  I have never let it stop me before but I will have to ponder this one.  Just thought this may make a pretty slick machine if I could pull it off, but I don't want to put a boat load into  it just to salvage some servos.  If you don't mine me asking, what type of plc's are you using.  I am more familiar with the allen bradley but I don't have any of the software.  Any input would be appreciated.

Thanks!!!

[macona]

I used Mitsubishi's MR-J2s on my Hercus lathe. You can drive them with current limited 5v straight from the bob. You dont need to use 24v logic. Now I did have to on my mill which I used MR-H drives.

[djc]

As Macona says, the Mitsu servos work fine on 5v level step and direction signals for position control. Obviously, if you wish to use one in 'speed' mode, you need a 0-10v signal, so any board that works with a VFD will work (eg. Digispeed).

What it might pay you to do is make breakout boards for the cables that plug into the servo using the 20 pin 3M connectors. There are 20 wires in each of these and there are two connectors per servo axis. The majority of these 20 wires will not need to go to the PC/Mach BOB.

Similarly, it might pay to set up suitable RS422 boards etc so you can use the MR-J config software in a painless manner (using RS232 means you can only look at one axis at a time and have to physically change cables to look at a different one).

If you need any detailed help setting them up, please ask.

[Hood]

I was meaning the drives I/O such as enables etc rather than Step/Dir, however regarding the Step/Dir it is probable they will really prefer differential signals although likely will accept single ended. I always use differential and its fairly easy to make up a line driver to do that, it just makes it so much more noise resistant On my current project (Bridgeport refit) I  designed a pcb and got it professionally done then populated myself but as the other pic show its fairly easy to either rout one yourself or you could  even use some vero board to do it.

Regarding the PLC, any that can talk via Modbus should be fine, I use the Automation Direct DL06 PLCs

Hood

[djc]

I was meaning the drives I/O such as enables etc

FWIW (i.e. apropos nothing), the Mitsu. drives can be self-contained, so enables etc. just need a switch (or relay). Their internal supply is 15v but I believe you can externally supply 24v as you said.

As an aside, any experience or thoughts on the Cubloc pseudo-PLCs? They speak MODBUS, and can be programmed in ladder or a VB dialect very similar to CB in Mach.

Do you have any online pointers or have you posted on your single to differential boards?

Thanks.

[Hood]

Yes the drives I use (Allen Bradleys) can also be set up that way, in fact they can be set up so that as they are powered they are automatically enabled but to me thats not a great idea, I like to have enables coming from Mach and also the  limits and E-Stop button  to take away the enables to the drives and also inform Mach of an E-Stop situation. I also like have such things as drive reset going back to Mach so I can reset from the screen.

I have never had any dealings with the cublocs personally, I know a few that have used them and they like them but from what I gather they do have a bit of a learning curve to set them up, then again what doesnt

The line drivers are very easy to make, all that is needed really is a line driver, I use this one http://uk.rs-online.com/web/p/products/630-875/ its a quad so is enough for two axis Step/Dir

Hood