[lgalla]

Post your experience or questions on DMM servos.
Larry

[lgalla]

Web site
Motion Control Products - DMM Technology

[lgalla]

What is the max voltage rating on the Dyndrives and 900W servos?I have a 60V supply.
Larry

[mactec54]

lgalla

It's best not to go over 48v for the Dyna Drive 2 50v max, There is a 100v drive in progress, but are not sure when it will be made available for sale, That will double the performance of that same motor

[lgalla]

Here is possibly the stupidest question ever on the zone.If the servos are A/C,why is the power supply D/C.Are the A/C servos brushless?Sorry for the stupid questions as there is little information on A/C servos on the zone.
Larry:withstupi

[Al_The_Man]

Larry, Simply that a DC supply is needed in order to electronically create the variable frequency output as in AC sinusoidal or the switching pulses for BLDC.
VFD's also have use the same principal for 3 phase induction motors, i.e. create 3 phases from a DC supply.
Here is the BLDC commutation.
http://users.tinyworld.co.uk/flecc/4...otor031102.swf
AC and BLDC motors are built practically identical.
Al.

[mactec54]

lgalla

The motors are AC servo's & brushless, It's like when you have a VFD you put AC into the drive, but you don't get AC out of the drive,you get DC for the supply to the AC induction motor, These & other AC servo motors run the same way

[skray775]

I am considering using the 3 axis system on a RF31 clone. I would love to hear more from anyone using the system.

[mactec54]

kregan

There are a lot of Zone members that have the Dmm system, They have there system running, but have not completed there machines

You can see the Dmm system working [nomedia="http://www.youtube.com/watch?v=YZb7nJMx_68"]YouTube - cncvids 028.AVI[/nomedia]

The build is here http://www.cnczone.com/forums/diy-cn...kes_first.html

This is another Build http://www.cnczone.com/forums/cnc_wo...5_cnc_cut.html

[rodjava]

Hi,
I might be one of the initial users of the DMM system. I bought my DMM system in July 2010 and will be coming up to 1 year using my cnc router on a weekly basis. I'm only a home shop machinist and not into production.

I have a build log and started talking about servo choices and DMM here: http://www.cnczone.com/forums/diy-cn...s_first-5.html

My initial questions about the DMM system were:

Aren't AC servos only used in very high end machines?
How can DMM price their AC servos the same as DC servos.
The DMM encoders have some very high encoder counts compared to other servo encoders.
Aren'e servo motors hard to tune?
What kind of service will I get from a new company like DMM?

I was pleasantly surprised to learn that, Yes, AC servos are typically used on big expensive machines and the DMM AC servos are a scaled down version of the same.

I still don't know how DMM set the prices competitively with other servo motors. I'm guessing a close association with the manufacture as well as a large wholesale order. All I know, is that I took advantage of the prices.

I'm not into production and encoder counts was not a big concern for me. I just knew that more is better. It was a bonus for me that the encoders were pre-installed on the AC servos and pre- wired too.

I found out that tuning these servos was not as complicated as I have read in many cnc zoners post. DMM supply's some simple software that tunes the servo's perfectly. You just need to follow the documentation carefully.

The biggest advantage with going with DMM was working with their tech support. I asked some pretty dumb questions, not just once, but two or three times. Each time my question was answered in a timely manner and thoughtfully in a way only a novice electrician would understand. In other words, they didn't make me feel as if I was wasting their time.

Knock on wood, but I have not had any problems with by servos or other components from DMM. I'm planning on a building a 4th axis using the same AC servos.

Sorry I cant quote any technical specification with the AC servos. That's not my thing, but making chips is!

Rod
San Francisco

[skray775]

Can you repost those build thread links... they both say page not found?
Nice video!

kregan

There are a lot of Zone members that have the Dmm system, They have there system running, but have not completed there machines

You can see the Dmm system working YouTube - cncvids 028.AVI

The build is here http://www.cnczone.com/forums/servo_...nc_router.html

This is another Build http://www.cnczone.com/forums/servo_...r_project.html

[mactec54]

kregan

Try the links now, I don't no what happened to them, They looked ok when I posted them, they are working now, Plus Rod just posted, one of the links is his build

[giz]

As someone who is planning on purchasing four of the 900W motors, I'd be very interested in the 100V driver they are working on. Do they plan to release a power supply to pair with it?

I don't plan on purchaing until 2-3 months from now. Think it might be available by then? I would hate to buy the 50V version and then have the 100V come out shortly after. Also how much of a price increase are we looking at (ballpark)?

[mactec54]

giz

At this time The 100v Drive Has changed track, it now will/is 120/240V AC input, there will be no need for a power supply, but this drive is just in the build stage, the front end is all done,

The Dyna-2 has also changed, & is now a max of 75V DC it would be good to run around 65V DC to the motors, These are being made right now, This will improve the performance of the 7.2Nm motor as well to around 1350RPM

[giz]

Wow, very interesting! I guess we'll see what is around 2-3 months from now.

[heavycnc]

Hi Mactec

I have a new build started and will be using DMM Technology package

"Peak 7.2Nm(1015 OZ-In) high torque AC servo motor, 3 Axis CNC kit for MACH"

With the new drives being made, you said the rpm will be around 1350, but what about the torque?

I included a picture of the system case I'm putting together.

Heavy

[heavycnc]

Mactec,

I was looking at torchmates machines and they give you two motor options for the same machine. You can order it with either a 380 oz. inch. stepper motors or 152 oz. inch. servo motors. I'm curious, do you know if a AC Servo torque 1015 oz = 1015 oz Stepper motor? Based on what torchmate offers it seems as though a servo motor is more than twice as strong as a stepper motor.

Heavycnc

[skray775]

I have the price quote for the 3 axis 300 watt setup and will order as soon as I can get payment details.

[mactec54]

heavycnc

Servo motors are rated in watts & N-m or in-lb, Only very small servo's will have a N-m oz-in rating listed, although you do see people using oz-in they have converted the in-lb to oz-in,to try & get a comparision, But this does not compare the two,in terms of performance

The one you posted at 152 oz-in would be around a 250watt motor, If the 152 oz-in is the rated output, but most likely is a DC servo with brushes, These are not the same performance as AC servo's

A Servos that is say 400W (.53hp) Rated output 181 oz-in, Peak output 542 oz-in

[lgalla]

Will a pair of DMM 900Watt servos move my 500lbs gantry at decent speeds and have enough torque?I understand it is a vague question.I would be using 12DP R&P with 2"
pinion
Larry