Parker 590+ 4Q 110A - problem with the table feed during processing
Parker 590+ 4Q 110A - problem with the table feed during processing
(OP)
I have a problem with the table feed while machining. Speed feedback is taken from armature voltage measure. Settings: Nom motor volts, armature current and field current are written from the engine and are set to - 220V , 46A and 3.1A . Main curr . limit at 120%. The drive has been calibrated and carried autotune . If there is no load table goes well over the entire length , but when there is resistance of the machined detail, then at some point table stops. while it stops, there is no alarm on the drive, in diagnostic- > current fbk, the value is 25A , diagnostic- > speed feedback - 6%.
Table weight 5 ton and detail is about the same.
We are working currently at 7-8% speed as it doesn't stop the table.
We have used the same drive on another machine , where the feedback is also armature voltage and there is no problem as above. The question is - should we use tachometer , or is there any parameter in the drive , which will help us to solve the problem?
Table weight 5 ton and detail is about the same.
We are working currently at 7-8% speed as it doesn't stop the table.
We have used the same drive on another machine , where the feedback is also armature voltage and there is no problem as above. The question is - should we use tachometer , or is there any parameter in the drive , which will help us to solve the problem?





RE: Parker 590+ 4Q 110A - problem with the table feed during processing
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: Parker 590+ 4Q 110A - problem with the table feed during processing
RE: Parker 590+ 4Q 110A - problem with the table feed during processing
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: Parker 590+ 4Q 110A - problem with the table feed during processing
RE: Parker 590+ 4Q 110A - problem with the table feed during processing
Wonder why the IR Compensation wasn't set by Autotuning. It should, in my opinion.
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: Parker 590+ 4Q 110A - problem with the table feed during processing
RE: Parker 590+ 4Q 110A - problem with the table feed during processing
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: Parker 590+ 4Q 110A - problem with the table feed during processing
RE: Parker 590+ 4Q 110A - problem with the table feed during processing
Glad it worked. This is not only valid for the Parker drives. It is universal and can be used regardless of drive manufacturer. Polish? Is that your native language?
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: Parker 590+ 4Q 110A - problem with the table feed during processing
We encountered today another problem with the machine, but I guess it's mechanical defect of the machine, or the thing we mount detail to the table. The feed without processing is going very smooth, but if spindle goes into the material, at about 50% table starts to stop for like few miliseconds. It stops more often over 75%. It looks like the machine choke. It's very old (late 60s) machine, and motors are powered through the amplidynes(before we replaced it with parker drive). We had similar problems with amplidyne - feed rate was floating, sometimes stoping. Everyone said it's electrical thing, so we decided to go for parker drive. Now feed rate is fixed, but machine still chokes. Have you encountered something similar? Is it really electrical thingy, or more probably mechanical?
RE: Parker 590+ 4Q 110A - problem with the table feed during processing
There are several things that can cause this. The first thing I would check is if there are any extra windings in the motor or in the circuit. You should not have any other winding than the excitation winding and the armature winding. Interpoles are OK, but remove any series winding (or make sure it is connected the right way, better remove it).
There is also your current controller. Remember that your motor is an old one that was built for pure DC (which is what the amplidyne delivered) and that usually means that armature time constant can be rather long. If you don't adjust the controller accordingly, it takes some time for the current control to "understand" that more torque is needed. That usually causes the "hesitation" that you describe.
You then need to adjust the current controller so you have a crisp and stable step response. Check the (English) manual to see how to proceed. Warning 1: make sure that the motor shaft is locked before doing it. Warning 2: do not pass high current through the commutator for more than a few seconds (it doesn't like it). Warning 3: disconnect excitation winding before doing any of the above. Warning 4: Make sure you re-apply excitation before running the motor again. If you don't, it can/will accelerate to a speed where it kills itself. Use a fast recorder or oscilloscope to observe current rise-time. Try to get close to around 40 ms. That isn't extremely fast, but fast enough. You need to be somewhat careful with the old motors. They were not built for very fast torque changes.
I am visiting the Erzgebirge/Praha region a few weeks from now. I could, perhaps, be of some assistance. Are you close to there?
Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.
RE: Parker 590+ 4Q 110A - problem with the table feed during processing
About the amplidynes - there are still 2 plano milling machines in our factory which use them! :) Actually I'm doing renovation of one of these - going to replace all telephone relays logic with the PLC as well as all 50 years old electronic inside.
As for the motor - there's just excitation and armature winding, both directly connected to Parker. In Parker drive there's autotune which sets the settings you mentioned automatically. I done it right after I mounted the device and set the basic values. That went well without errors, so I guess it's fine(not sure though). I have done the same procedure on different machine and there are no troubles with "hesitation". I'm going to attach tachogenerator on Sunday, and if that won't help I'll replace the motor. It'll be a little problematic, but might be worth trying in order to eliminate something at least.