I am in need of advice about my MHP mill I purchased. It uses the Hydropath III controller. When I got it home and connected the power and the air, the machine came to life fairly easy. I was worried because it had a rough ride on my trailer for 100 miles or so.
After playing with it for a few days and finally figuring out most of the buttons, and learning how to do a tool change something changed. I started to get following errors on the x axis. I have a complete set of manuals for the machine, but there is not a lot of information about the “Following Error”. If I jog the machine really easy, then I can make the x axis move, but any faster and it faults out. During the few days playing with it, I cut a 2 inch hole in ½ plate, and by using calipers it is 2 inches. There no bumps in the cut when the axis changes direction. I did not have a chance to do any more tests on run out or backlash before the problems started.
Here is what I know about the machine-- It has a 10 HP spindle, with a pneumatic hi/low changing gearbox (50 to 5000 RPM). It has a 22 tool changer that uses BT 40 collets. It has an automatic oiler. It has a Toshiba variable frequency drive, it has some way to control the location of the spindle orientation because the spindle stops at the same position every time. The servos are 94 volts DC ( I think) and use resolvers. The z axis also has a brake on the axis.
I started to do some simples troubleshooting on the x axis tonight, and here is what I found. With the servo disconnected from the ball screw, the servo is still getting errors, and is also jerky. The ball screw appears to be in good shape, and the ways are in great shape. They are boxed ways if that matters.
I am planning on swapping the x and y servo driver just to see if the following errors follow the drive.
Now for the questions---
Should I continue trying to fix the x axis, or plan on starting swapping the electronics out and re building the mill?
I have successfully built a 6 x 12 cnc flame table, and the hardest part for me was figuring out what electronics to use. After swapping parts and have problems, I ended up using granite devices servo drives, US digital encoders, the BOB from candcnc. I also tried the smoothstepper (which I still have) and the c23 BOB (still have this too) from cnc4pc. Power supplies from Jon at Antek.
So what should I buy? I have been reading up about Ajax, and the DSPMC controllers. I would like to stay with the granite devices servo drive. The only reason is that I can order 1 extra drive and use it on either machine. I would also like to use and industrial PLC. I work with AB, Mitsubishi, Fanuc, Motoman, Toyopuc (Toyoda) and a few others at my day job, so I am very familiar with PLC controllers and the Ladder Logic.
I am planning on spending between 2000-3000, to get it running.
Man am I jealous. I had an MHP 83-3000 when I had my (full time) shop and it was a tank. Congrats on a great purchase. I am not electrical, but I could provide names of two companies that still service the MHP machines.
BTW - mine had multiple offsets using E1, E2,...E6 - six work offsets(!), which i used to advantage on more than one occasion.
I would think they are dc servos on this machine.May need the carbon blowing out from the brushes and the motor and tach brushes may need replacing.Something you should check anyway.A dirty comm on the tacho will also cause jerkiness.Clean it with a pencil eraser.
sbfp... is the INDUSTRIAL DRIVES power supply, not a servo. this is a 19" card rack unit that you plug the servo drive cards into. they are part numbers like sbd2-.... they will be different for each axis so you should NOT swap motors or drive cards w/o knowing details of each. We can share this info with you as we actually have spare parts in stock for these still. We build exact duplicate replacements for these also for large aerospace companies using new drive compnents - not something you would be interested in with $$ you want to spend on it. but perhaps we can help you get this puppy back on its feet....
the motors DO have tachs; the bds2 and bds4 drives cannot run without them. what u see is probably a add on encoder mounted on the back of the motors. the motors have tachs built inside their rear motor endbells; 19.8v/krpm units. yES if you are careful you cal try to clean the comms with erasor - good plan mentioned earlier in thread. that very well could be the problem since it ran for a bit before starting to give xcess error.....
the bds drives have green and red lites on them as well as full part nos on sticker on the side of the slide out alum angle bracket. get these and motor part numbers (like TT-5301-102-B-12-C and we can tell u all about them too.
hope this helps u get it going! I can email you drive and motor data and manuals; just ask if you want. Mike@KilroyWasHere.com, Kilroy Corp, (937) 660-5313.
I used to work at MHP ( long time ago)
There are still some guys in the Buffalo area who may be able to help you. I will try to dig up #s for you.
A following error means the axis is not where it is supposed to be at any given time. Could be a lot of things. Check to make sure the ways are oiled.
so you can swap the axis cards to try if you want and not hurt motors or drives. 29360 is another name for a 2936 motor - just newer model no we went to to identify some small change in brushes or something non important to you.
actually remember if you swap the motor leads you also have to swap the tach feedback leads and control command and feedback leads too or the control will run away. be ready on the estop button when you fire it back up swapped around!