I recently completed our company's first machine, 3GM machining and engineering. We decided to go with DMM Technology Corp. servo's and i am so glad that we did. I will break this review down into category's.
This review is for the 92GM-DHT-72, Dyn2-H, Power supplies, DMB4250-8B Breakout Board
Packaging:
The servo's and driver's arrived in a well sealed box with about 3 fragile stickers on it. I was pleased to see that the items where not crammed into one box. Instead they used 2 boxes, the static and moisture protecting plastic for the breakout board, and all drivers. Very well cushioned from the "gentle" shipping of ups.
Inspection/Quality:
Let me start out buy saying that the the enclosure for the Servo motor is all aluminum and very well machined, aligned and assembled. (Unlike some of the cheap stepper motor's i have ran into.)
The shafts turn very free, and all dimensions lined up according to the Drawing(This was crucial for our design and alignment). Also the encoder is very solid and well attached. The same go's for the Dyn2-H driver very well built. I don't feel like im going to break it by plugging and unplugging cables. The only recommendations is that the mounting holes are kind of small. i would like to see a little larger of a hole in them. Power supplies are your standard 5" switching power supply. Mach3 breakout board also has solid connections and well labeled.
Setup:
I am not all that familiar with servo's, I only know what i have read. I have only used steppers in the past. But let me start of buy saying these do not function in the same sense some may be familiar with. They are closed loop between the encoder and the motor, inside the driver. Currently on the Dyn2-H there is no support for encoder output to motion controller via A/A,B/B,Z/Z. This was a little disappointing as i did not read or see that in the literature. Non the less Dmm-Tech and there quick and excellent customer support. Apologized about the literature and website also stated that they where in the process of releasing a new website, a new servo driver, and updated literature. I can't express just how good the communication is with them(via email, i never attempted phone contact but i would imagine it's the same quality)
moving forward. I Wired all of the servo's, e-stop, and limit switches up and all functioned properly with the breakout board. I used the recommended tuning for the servo's and it works flawlessly. I only wish for the dyn2-H that since there is no encoder output from the driver, that it would display the fault either via a mini mono-chrome lcd or the machine controller. instead of just throwing the estop, in this case you must plug the RS232 into that specific driver and read the error(A tedious task when wiring and speed mistakes are made on our part). On that note the Dyn2-H software is very easy to use and works with no glitches.
As far as configuring the servo in mach3, The .Xml file given with the purchase has all of the required pin-outs, and step and direction timing already with it. All that is required is you configure your pulses per unit of measurement. On that note the setting suggested in the servo tuning for gear number is 500 for mach3, With help from There trusty tech support i now understand the gear number correctly. I was able to easily calculate what the pulse per inch was, and then adjust for ball screw error from that point. I easily obtain 200 Ipm on the second lowest kernel speed with a 5mm pitch ball screw. Everything else works flawlessly with mach3 i should also state the mach3 breakout board will work with Emc2.
Final Thoughts
The motors are virtually silent, and very powerful. Still some improvements to be made as far as adding the "extra features" like specific error reporting, and encoder out(This has been included in there new servo driver but the price has not been set and the launch date is early march. i am patiently waiting to see what this will do for our machine budget i would love to see the 6000 rpm on this servo motor and boost the rapid speeds to 1200 ipm. but i fear the price will bring the servo and driver up to what they should be selling for probably $750.00-$1000.00 per servo driver combo. but this is just a guess. and if its true im sure its worth every penny.)
I also can't express enough how helpful the tech support is, along with the sales. The tech helped with formula's for changing pitch and calculating the torque required if we were to up our lead to increase speeds. ( Above and beyond what normal tech support is required to do). We will be using the servo with every machine we sell, depending on the price of the new drive we will probably stick to the Dyn2-H, and Design and develop our own Breakout board, possibly add 3 encoders to the end of our lead screw for feedback.
I hope this is helpful to anyone contemplating buying this system. With the new redesign of the website and new product announcements Dmm is Heading in the right direction. Don't let the lack of discussion and conversation about them full you.
Gabe