squarewave
11-02-2004, 04:16 PM
Here is an easy one for you guys. My spindle is running opposite the way it should. Is there a way to reverse it in the setup? I tried using a negative 1 on the GEAR paramter for that axis, but it didn't change. :confused:
I know I can swap the SPINFORWARD and SPINREVERSE in the M code file, but I don't think that is a great idea (in case there is other logic existing or I write some in the future and I forget it is reversed).
I have a DC spindle motor and drive, so if I have to rewire it, I assume I swap the Tach leads and the main leads (that go to the brushes). What about the field winding?
jjmachine
11-02-2004, 04:43 PM
the field winding does not matter i think.How did it get this way?
jjmachine
11-02-2004, 04:46 PM
and what servounit some have setting on the board and some in parameter
bunalmis
11-02-2004, 05:18 PM
This schema say why motor direction don't change.
http://www.cnczone.com/gallery/data/500/1242direction-thumb.jpg
Al_The_Man
11-02-2004, 07:00 PM
It all depends on the type of DC motor you have and how the drive is controlled, if it is a wound field motor shunt connected (field in parallel with the armature) the armature has to be reversed conected with respect to the field.
More information is required.
Some controllers have +-10vdc control, some +10 and a reversing input.
Al
squarewave
11-03-2004, 07:52 AM
Thanks for all of the quick replies!
jjmachine:
During the retrofit, I removed a D to A converter and hooked the speed command directly to the Galil card. I assume that somehow the D-A converter had an inverted output. That is my only guess as to how it got this way.
The drive is a Contraves Compact Series 200 ADB/F. I have an operating manual for it, but it doesn't refer to any method of reversing the direction sense.
bunalmis:
Thanks, but I am afraid I don't understand what you are trying to show in the graphic you posted.
Al:
From the drive, I have two connections going to the field, two going to the armature, and two for the tachometer. I guess that swapping the field pair would serve to reverse the field relative to the armature?
The drive has a +/- 10V analog input. There is not a separate reversing input.
I assume this means there is no software setup in Camsoft to reverse the spindle?
Al_The_Man
11-03-2004, 08:28 AM
The Galil card has +- analogue output so it can be reversed from the control M3 and M4 are the M codes for sp fwd & rev, M5 is spindle stop.
First method is to reverse the spindle directions in the M3 & M4.
2nd method if the spindle fwd & rev commands runs the spindle in the wrong directions you could just reverse the analogue input into the drive.
Otherwise you would have to reverse the field and tach connections.
First method is preferable.
Al
squarewave
11-03-2004, 08:52 AM
Thanks Al.
I would prefer not to do it in the M3 and M4, because I still want SPINFORWARD to actually spin forward.
I am not positive that the speed input on the drive is isolated (my documentation is not that good) and I don't believe that the Galil is either - they seem to use a common ground for everthing. I think I'd better play it safe here as well.
So it doesn't matter if I reverse the Field or the Armature, as long as I reverse the Tach as well. Is that correct?
HuFlungDung
11-03-2004, 09:00 AM
Just make sure you have your Estop handy to cut power to the motor when doing the switchover. The thought of runaway motors scares the **** out of me!
squarewave
11-03-2004, 09:15 AM
Exactly, Hu. That is why am taking such caution and making sure that I am understanding what I should be doing. The first time I enable the spindle, it will be with a manual switch and it will be for less than a second - or at least as fast as I can flip the switch on then off!
Al_The_Man
11-03-2004, 10:17 AM
Yes, if you want to go that route, changing either the field & tach OR Armature & tach should do it, you can check for run away without a command, if it is stationary when you switch on, you only have to give the motor shaft a small spin manually in a safe manner and it should not run away.
Al
HillBilly
11-03-2004, 11:07 AM
You can reverse either field or armature along with the tach as long as your DC motor does not have a S1 S2 field in addition to the F1 F2 field. If you do have the S1 S2 connection you must reverse the armature.
Darek