Dynomotion

Group: DynoMotion Message: 14187 From: tmday7 Date: 12/1/2016
Subject: DMM Tech servos
Hello all,
 Anyone used DMM Tech AC servos and drives? With Dynomotion or with something else? Looking at retrofitting my old Hurco BMC 20 with there 1.3 or 1.8KW servos...and of course Dynomotion boards. :)
Thanks for any info,
Troy
Group: DynoMotion Message: 14191 From: mmurray70@hotmail.com Date: 12/1/2016
Subject: Re: DMM Tech servos
I cant offer much help with how well they work with Dynomotion products, but DMM servos look impressive, are priced reasonable and the support seems good too. Easy to get them on the phone and they email fast if you have questions. I almost bought a set of 1.0kw motors to retrofit a lathe a while ago, but lathe project got moved to back burner after buying a mill. 

Just curious, how would you tune a system like this? Would it be done with Kmotion or with the DMM software in the drives or could it be done either way? Could the DMM autotune software be used or is this only if in step/dir mode? 
Group: DynoMotion Message: 14192 From: Colin Fera Date: 12/1/2016
Subject: Re: DMM Tech servos
I have them, I used the 750 watt servos in closed loop step direction mode with the drives providing the quadrature feedback. These are installed on a Bridgeport boss 4 series 1.

 This works great, one caveat though I have used some real big motors and drives in the past but never for anything like this so my basis for comparison is narrow.


Sent from my iPhone

On Dec 1, 2016, at 5:28 PM, tmday88@... [DynoMotion] <DynoMotion@yahoogroups.com> wrote:

 

Hello all,
 Anyone used DMM Tech AC servos and drives? With Dynomotion or with something else? Looking at retrofitting my old Hurco BMC 20 with there 1.3 or 1.8KW servos...and of course Dynomotion boards. :)
Thanks for any info,
Troy
Group: DynoMotion Message: 14197 From: tmday7 Date: 12/2/2016
Subject: Re: DMM Tech servos
Performance is as advertised with your 750W? And how does the quality of motor,drives and cabling appear?
Thanks for the info,
Troy
Group: DynoMotion Message: 14198 From: tmday7 Date: 12/2/2016
Subject: Re: DMM Tech servos
I would believe you would use the DMM software for tuning the drive.
Group: DynoMotion Message: 14199 From: Dan W Date: 12/2/2016
Subject: Re: DMM Tech servos
That would depend on t be e setup.  If you used step and direction input then you will have to rely on the tuning in the drive. 

If the DMM drives are put into torque mode and an analog input is used I think all the tuning is then done in the Kflop. I think this would be the most reliable method of controlling the servos. 

-Dan



Sent via the Samsung Galaxy S®6 active, an AT&T 4G LTE smartphone


Group: DynoMotion Message: 14202 From: Colin Fera Date: 12/2/2016
Subject: Re: DMM Tech servos
I would say performance is as advertised and the quality of components is excellent.

I would prefer it if the drives could more easily route cabling through flexible conduit in my application that would be neater. And I plan to make some conduit attachment boxes to use smurftube to clean up the wiring.

I experimented with analog control. Either way you will have to do some tuning in the dmm drive software. I much prefer step direction as it was allot easier to set up. I am using kflop to close the loop around the drive with an integrator only control. 

Long term I plan to integrate some 1um glass scales and close the loop using the scales as the feedback mechanism. 

My setup runs about 65k steps per inch and my best indicator is .0001" the system is total repeatable to around .0003" for the simple movements I am able to measure. This with about .0006" backlash from the belt drives using kflop backlash compensation.



Sent from my iPhone

On Dec 2, 2016, at 12:21 PM, Dan W engnerdan@... [DynoMotion] <DynoMotion@yahoogroups.com> wrote:

 

That would depend on t be e setup.  If you used step and direction input then you will have to rely on the tuning in the drive. 

If the DMM drives are put into torque mode and an analog input is used I think all the tuning is then done in the Kflop. I think this would be the most reliable method of controlling the servos. 

-Dan



Sent via the Samsung Galaxy S®6 active, an AT&T 4G LTE smartphone


Group: DynoMotion Message: 14203 From: tmday7 Date: 12/2/2016
Subject: Re: DMM Tech servos
Thats what iam planning also. Doing a dual closed loop with glass scales. I would slo like to do a direct drive to ballscrew, if i can figure out a way of mounting motors on all 3 axis. Might have to rework guarding. Anyone recommend some good 0 backlash couplings for attaching servo motor shaft to ballscrew?
Group: DynoMotion Message: 14205 From: Dan W Date: 12/2/2016
Subject: Re: DMM Tech servos
I have bought all my couplers from McMaster Carr. Do a search for "shaft coupling"  there are three types I have used. 

Helical flexible shaft couplings 
Servomotor flexible shaft couplings
Zero-backlash replaceable-center flexible shaft couplings 

The Servomotor ones were Zeromax brand, The helical coupler was Helical brand (I think) and the Zero-backlash was Ruland brand (I think). 

-Dan

Sent via the Samsung Galaxy S®6 active, an AT&T 4G LTE smartphone


Group: DynoMotion Message: 14210 From: mmurray70@hotmail.com Date: 12/3/2016
Subject: Re: DMM Tech servos
My machine uses helical couplers between servo and encoder and i replaced a broken one (previous owner installed encoder off center) with a mcmaster helical brand coupler and it was WAY more flexible in torsion and the servo was not stable and would vibrate. These allow for alot of flex and may not be the best choice. And in my case this was just connecting the encoder, if it have been the connection to ballscrew it probably would have been even worse. 

Next time I might try the others you mentioned thanks.

mark