rabler
Cast Iron
- Joined
- May 25, 2020
- Location
- Rural S.W. Indiana
I've gone the long way around to saving the DC motor on my 10EE rebuild. As I've posted earlier, it came with a Danfuss controller that wasn't delivering full RPM range. I completely gutted those electronics and started over. Ebay for a Parker 514c-32 and 507. Decided I wanted lots of features like the original factory setup, anti-plugging, full field braking, etc, so I built a digital controller to manage the two Parker units. That interface is all working (on a test bench) to control the motor. I'll need to tune the Parker's to get good performance, and I haven't wired up all the current/voltage/rpm/interlock monitoring circuits yet but those are relatively easy compared to getting the control algorithm right.
At this point it looks like the DC motor needs some attention before spending more time on the controllers.
Debating the merit of pulling the motor apart and replacing the bearings. Not totally obvious that is necessary but it seems prudent.
Also, this motor looks to have 2 brushes, reading back through lots of threads it seems like the 3HP typically had 4. Am I totally missing something?
1) New brushes (order from Monarch)
2) Stone commutator
3) replace bearings (?)
4) time brushes
If I pull the motor apart to replace the bearings, should I consider slightly grooving the mica on the commutator?
Right now the motor arcs quite a bit in reverse and sometimes in forward. It will sometimes hang on startup if the brushes are in a bad spot. And it is rough at low RPM. I'd rather get all of that cleaned up and running nicely. Doesn't make sense to me to try to get the drive controller tuned to a motor in poor shape.
I suspect I have close to $2k into the electronics at this point. The Parker units weren't cheap even used, plus I had a couple of small circuit boards printed for the digital interface. Going with a VFD and a 7.5 or 10HP motor would have been more straightforward and probably less confusing if I ever tried to resell this thing (very unlikely), but I'm far enough along to keep pursuing this path.
I currently have the apron apart on the bench, so I'm swapping between these. I'll probably want to finish the apron before digging into the motor, especially if I pull it apart for new bearings. Too many loose parts on one project machine otherwise. Not to mention the other project machines.
At this point it looks like the DC motor needs some attention before spending more time on the controllers.
Debating the merit of pulling the motor apart and replacing the bearings. Not totally obvious that is necessary but it seems prudent.
Also, this motor looks to have 2 brushes, reading back through lots of threads it seems like the 3HP typically had 4. Am I totally missing something?
1) New brushes (order from Monarch)
2) Stone commutator
3) replace bearings (?)
4) time brushes
If I pull the motor apart to replace the bearings, should I consider slightly grooving the mica on the commutator?
Right now the motor arcs quite a bit in reverse and sometimes in forward. It will sometimes hang on startup if the brushes are in a bad spot. And it is rough at low RPM. I'd rather get all of that cleaned up and running nicely. Doesn't make sense to me to try to get the drive controller tuned to a motor in poor shape.
I suspect I have close to $2k into the electronics at this point. The Parker units weren't cheap even used, plus I had a couple of small circuit boards printed for the digital interface. Going with a VFD and a 7.5 or 10HP motor would have been more straightforward and probably less confusing if I ever tried to resell this thing (very unlikely), but I'm far enough along to keep pursuing this path.
I currently have the apron apart on the bench, so I'm swapping between these. I'll probably want to finish the apron before digging into the motor, especially if I pull it apart for new bearings. Too many loose parts on one project machine otherwise. Not to mention the other project machines.