Need Help!- Anyone running Dugong drives and Keling servos?

[derek]

Hi
I have a Dugong drive and a Keling KL34-180-90 servo with a US digital 250 line encoder. I've tuned a few servo systems before but I can't seem to get it tuned at all. Not even on the bench! I can't seem to get any kind of smooth motion out of it. By the time I get enough AP so that there is power and enough AD to stop oscillations the moment is really jerky. I spent 4 hours yesterday trying different tunes and changing out encoders trying to get this figured.

The Dugong drives are currently running my router and I was just going to upgrade the X axis so it had more oomph so it's not a defective drive. I also have 2 of the servos and they both perform the same.

Does anyone have some starting tune numbers they can share?

Thanks
Derek

[Jackal66]

derek,

Do you have all of the tuning stuff for the Dugongs?

The have a sheet and the software. When I was looking into those drives, they have the software that you can put on a separate computer to tune with, while your main controller computer tells the machine when & how fast to move.

If you can't find this let me know and I'll put the links up for them.

JAckal

[Jackal66]

derek,


Here are the links. You may already have all of this. I would rather give you the info and you already have it, than for you to need it and not have it.

This being a holiday, you might have the time to fix it.

Dugong manual:

http://cncdrive.com/datasheets/Dugong_manual.pdf

Configurator 3 software:

http://cncdrive.com/Software/Servoconfig3_R17.zip

PID tuning guide:

http://cnc4pc.com/Tech_Docs/PID_tuning_eng.pdf

Arturo at CNC4PC is the US dealer for these. He is very knowledgeable on the Dugongs & Mach3.

He can give you quick answers. I think he calls Balasz directly.

(Balasz is the inventor/owner of Dugong drives)

Hope this helps,

JAckal

[derek]

Hi JAckal
Thanks for the info. I had everything but the doc from CNC4pc.
I had emailed Balazs directly and made this post at the same time as a hedge, Although in hind sight Balazs has never failed to answer an email request for help.
He emailed me 8 different setups to try and I've taken screen shots of the results of each and emailed them back. At this point I picked the best out of the bunch and it already runs better than what I was coming up with!

I've had Geckos, Rutex and these Dugongs and for me the Dugongs are the best drives I've ever had. Plus the support from Balazs has always been spot on.

I'll post my results when I (Balazs) get it dialed in and maybe the settings will be a good starting point for someone with a similar setup
Thanks again

Derek

[LUCKY13]

How did you ever get along with this? I have the same servo's and was thinking of buying the Dogone's so I could feed these motors what they need for a big mill.


How much voltage you running to this servo and drive?

Also how many amps will your power supply feed?


Did you add some resistance to the servo feed? I believe they say you have to have over 1.0ohm resistance through the servo and the Keling servo you listed I believe only has .85ohms resistance.



I was going to get a power supply that gives 88v at 30amps to run on mine. BUt if this drive doesnt want to play right with this motor maybe I should think about a different drive. There is not many high power drives out there and the Granit Devices was a nother drive I was thinking about but they cost more. When I seen these drives ( Dugone) I thought they might be what I need. Everyone says they run great.


Jess

[derek]

Well I got it to a point where it ran well and then I started in on a long term pattern project so I haven't done the final tune yet. I've got about 300 hours on it so far with zero problems. Most runs last 8 to 10 hours. some as long as 30 hours straight.
This is the power supply I'm using for the X and Y

Antek - PS-15N105

I'm using a braking resistor. I can't remember the value right now but it one that Balazs recommended.

At this point I can't think of a scenario where I wouldn't buy these drives. They have just been flawless.

Derek

[Tig]

Hi Derek,

" I'll post my results when I (Balazs) get it dialed in and maybe the settings will be a good starting point for someone with a similar setup
Thanks again "

Any further progress with the tuning?
It would be very helpful if you, or anyone else running this same KL34 motor / Dugong drive combination, would share their Servoconfig3 screen shots of the "works best for them" configuration.
Some time back I corresponded with Steve Simpson as he had had the same combination of the Keling servo and Dugong drives.
Unfortunately, by that time he had sold the setup, and no longer had the tuning inputs, but remembered a very different PID Critically damped curve than the one recommended in the guide.
I look forward to your input.
Thanks,
Tig

[LUCKY13]

Derek you running the 105 volt PS? What amps is this PS?


I was thinking about ordering the same PS. I think these motors would take that voltage no problem. What kinda heat are you getting on the servo's? I even thought about going with a 120v but had not seen anyone running even 90v on them yet.


I bet they simply rip with that setup. Probably why it was a bit different to get tuned. More power than anyone has run with Mach3 and these servo's. I will either get these drives or the granit devices.


I would love to see a video of it running/cutting. I am going to be doing something soon and drives and PS are the changes I will be making. It just doesnt make any sense to buy servo's this size and not feed them what they really need. Besides I am going to save my smaller drives so they dont cook on me trying to make them work. They will work fine with a 4 amp 50 volt servo and it want be pushing them so hard.


Jess

[derek]

Hi
Sorry for the delay on getting back on this.
My tune seems to be working well. And the modifications were well worth the expense.

Here's a run down on my rig. Rolled ball screws .25" pitch. Backlash nuts that are two nuts with springs between them Keling KL34-180-90 with US digital 500 line encoder reduced 4:1 with timing belts.
Antek - PS-15N105 power supply. The best I can get for rapids is 150 ipm. I get a bit of following error but I don't cut at that speed so it's not a problem. I have 17" of travel on my Z axis so any gantry shake is really noticeable so this limits me to 100 ipm feed rates.

I've had no problems with the power supply and motor combo. It was suggested to me by Steve Simpson. Balazs did say to me though:
"In regards the problem, could you please tell me the powersupply Votlage you are using for the Keling motor?
Some customers used the same motor and I remember they had some problems with it when using with the rated 90V or above powersupply Voltage.
The problem cause was figured out finally (If I recall somebody asked John at Keling) that the 90V is a bit too much for this motor and causing the coil to saturate too fast
which causing the servo loop becoming "nervous"."
I personally haven't experienced it. I just finished a 14 hour run and the motors never got above 100 degrees F.

As I said earlier I've had Geko and rutex drives and in my opinion the Dugongs are light years ahead.

Plus since CNC4PC now stocks them they're even easier to get.

I've attached a screen shot of my current tune. Pay close attention to the encoder X mode. Switching it from 4 to 2 made a big difference in the tunability.

[LUCKY13]

Derek thanks very much for yoru info.

The 150ipm I think would be pretty good with 4 to 1 belt drive. All though if I am figuring right the motors are only reaching 2500rpm. Still though if the coils saturate to fast with higher voltage this may have something to do with the limits you hit ( I dont really know myself).



If you can cut at good speeds that is the main thing. 150 imp rapids is not what I would call slow anyway. I am glad you posted the comment on saturation it may have saved me some problems.


Servo loop being nervous? I think there may have been some have problems with the US Digital encoders acting like this. This is why many have been using the AMT102-V encoders. It may not be the same thing you was dealing with but I though I would meantion it. Jitters will the servo was holding was what others where seeing using the US Digital encoders. When they changed out to the AMT102's it all went away. Of course there could have been other things involved also so who knows.


Jess



I will have to give these drives a try. Lets see how long is it tell X-mas?

[brmachineshop]

i have dugong drives also. running a 110 v 30 amp power supply. i have the servos running somewhat smooth. however i have not been able to run it. i am using ( or trying to use ) mach3. i have my axis' calibrated to run the correct distance one axis at a time, however when i run two at the same time it overtravels way too far and im not getting any encoder error message. one guy that i talked to uses viper drives and he said he had to put his encoder info in to his tuning process. i dont see where i would tell the dugong servo tuning software what my encoder line count is or anything. not sure how the encoders are communicating with the system as a whole. he also said he believes his tuning set his velocity and accel in mach so that 10ipm programmed gets 10ipm travel. not sure mine is doing this either. any help would be greatly appreciated. thanks.