Paul R. Hvidston, March 2002
Motor tested:
Pacific Scientific Sigmaline 20-4247D200F1.3 stepper motor, 635-holding, 540 oz-in @ 50 SPS running torque, 8-lead, 3.5/5 Amp, 1.3 ohm, 3.3mH/phase motor
Test bench:
Stanford Research Systems DS345 30MHZ Synthesized Function Generator Tektronix 2230 100MHz DSO 5V bench supply 60V and 72V, 15A unregulated supply
Configuration:
Motor was tested in both series (3.5 Amp) and parallel (5 Amp) winding configurations. Motor was loaded with additional mass and friction on the shaft to simulate a minimal real-world load.
Performance:
Driver was able to handle the motor in either series or parallel configuration. No additional cooling was needed for the 3.5 Amp series mode, but in parallel mode (5 Amp) the driver would overheat (and safely disable) without a cooling fan. The manual does call out the need for a fan above 4 Amps. I was concerned that I was pushing the driver by running a 635 in-oz motor, but it seems like it can handle it.
Step resolutions from 200 to 50,800 are available. It was noticed that the microstepping was not as smooth as one would like: you could still see/feel/hear the basic 200 step/rev of the motor. This is probably due to the nature of this particular stepper motor since it is designed for high torque, not linearity of microsteps. It would be nice if there was some adjustment in the driver to compensate for this, but it does not seem to impact operation, and having microstepping helps to avoid much of the motor resonance that would otherwise occur. I could ramp up and down in frequency without any hiccups or stalls.
Bottom line:
A solid, flexible, capable driver at a great price. I want some more!
Regards,
Paul R. Hvidston, N6MGN
ACKSYS Engineering
Upland, CA
Alan Trest
If first impressions count for anything they look great. Robust and high end
controllers would be my best discription.
Alan
Alan Trest
March 26th 2002
Evaluation of American Precision Industries (API) cmd-260 Microstep Drive.
Initial testbed was a Dahlgren System 500 Engraver.
(2) American Precision Rapid Sys Model 23D-6306C Steppers 2.9 Amp / 3.4 Vdc
(1) Vexta Model 5757-9212 1.7 Amp / 4.25 Vdc
24 Volt Unregulated Power supply.
Test terminated due to mechanical problem of Z axis and the 24Volt supply was inadaquate.
Second testbed is Taig CNC Mill.
(3) Sanyo Denki Step-Syn Model 232-180-DB Steppers. 2 Amp / 2.1 Vdc
Power supplied by 50Volt supply from origional Dahlgren SCU.
Several consecutive cuts thru 6061 Aluminum were made with no appreciable loss of torque.
I tested the Drives at both 400 microsteps and 1000 microstep settings. Performance in my limited opinion was smoother than my Gecko 201's. I heard no motor noise as I have with the 201's.
I have so far only done test cut's so I am anxious to cut an actual piece. I will be be cutting an actual part probably this weekend and will use these drives in place of the Gecko's. The 201 are destined for the will be used on the Dahlgren project.
Bottom line. I like them enough that I am going to order more for 4th and 5th axis conversion on my taig.
Can't beat the price and they really seem like very rugged drives.
These should be a nice option at a fair cost savings over competing drives.
I will be posting Photo's of my set-up later this week for anyone intrested.
Alan Trest
Pensacola Florida
CMD-260 Evaluation
By
John D. Guenther
Sterling, Virginia
I have tested the CMD-260 stepper driver extensively over the last few weeks
and have come away from that testing very impressed with this unit. I like
it well enough that I am going to purchase two or three more of them.
The test platform was a Pentium 266 PC with 64MB Ram, 3.3 GB hard drive,
floppy, CD-ROM, two parallel ports, video, keyboard and mouse. The CNC
machine is a Sherline 5400 with my own mounts for the X and Y-axis and a
Sherline mount for the Z-axis. The Stepper motors are Pacific Scientific,
15.4 volt .49 amp 8 wire motors wired in parallel configuration for use with
bipolar drivers. The normal driver configuration is 3 Camtronics 5AMP
Bipolar Drivers and a 35 volt 20 amp power supply. A PMDX-120 board
provides parallel port breakout from Steve Stallings. Control software used
for these tests was EMC BDI 2.12, TurboCNC 3.12, DeskNC and Kcam3.
The CMD-260 was installed in place of the X axis driver since most of what I
am currently working on uses the X-axis more heavily than the others. After
initial installation and configuration of the CMD-260 I began by determining
which of the micro step settings would work the best with the control
software at hand and the motors I am using. I settled on 2000 steps per
revolution, which seemed to work well with EMC and the other control
programs I was going to test with. Setup of these drivers is easy, just
remove power, set the appropriate dip switch(es) and apply power again. All
settings are conveniently labeled on the top of the drive case.
Once every thing was configured, I cut some air using G-code files that I
had previously used to make Quick Change tools holders for my minilathe.
This all seemed to work as it should have so I decided it was time to make
some chips. I mounted a piece of 1018 steel in the vice, loaded up the
first program for another tool holder in EMC and hit run. Everything
performed well and I think I got a better finish due to the micro stepping
feature of the CMD-260 drive. I then switched to TurboCNC to cut the
dovetails and again everything worked very well. I then went back to EMC to
machine the slot for the tool bit on the opposite side of the 1018 blank.
The final cuts were made with DeskNC to finish the ends of the tool holder.
The initial tests proved to me that the CMD-260 is a versatile driver which
should satisfy the needs of most home shop systems, including the ability to
handle larger motors if a person moves up to bigger machines as most of us
would like to do.
The second set of tests was performed using mostly TurboCNC since EMC has a
problem with certain combinations of parameters of the G02 and G03 commands.
The second test was to machine a new front panel for my driver box to
provide openings for fans and make a neater job of the entire panel. This
job requires cutting 4 56mm diameter holes in the .125 aluminum panel. I
had tried this before using my normal drivers in ½ step mode but I was not
happy with the results. This time I also added a borrowed Gecko 210 to
drive the Y-axis so that I would have micro step capability on both axes.
FlashCUT 1.41 converted the drawing of these four holes to G-code; the blank
was mounted in the mill. Since the blank is about 5 inches by 16 inches it
is necessary to machine part of the panel, flip it over and machine the
remainder because of the Sherline 5400's work envelope. I started up
TurboCNC, loaded the g-code file and hit run. I must say that the micro
stepping really smoothed out these 56-mm diameter openings. The micro
stepping also eliminated the resonance problems I had been encountering as
each axis reached its maximum travel as the circle was machined. And as
before I got much better cuts using my combination of machine and motors
with the CMD-260 in place.
With a current handling capability of 8 amps at a maximum of 80 volts these
drivers can serve you well with almost any type of CNC machine you would
want to run with stepper motors. These are obviously very expensive higher
end drivers that Tim has gotten us a great deal on.
Would I recommend these to someone, Yes by all means! These are really
nice drivers with a lot of features that make setup and use a real pleasure.
Will I buy some more, absolutely, there is no question about that.
John Guenther
'Ye Olde Pen Maker'
Sterling, Virginia
Review of 8 amp API CMD-260 Microstep Drives
by
Todd Hanson
Sacramento, CA
I just completed testing one of the API CMD-260 Microstep Drives on my CNC-converted Shoptask 3 in 1 Lathe/Mill machines. I originally used a surplus 48V power supply running a kit-built driver for 3 150oz stepper motors on my 3 in 1 Lathe/Mill machine.
I changed out the mill axis to use the API-CMD-260 drive. I found the documentation usefull and accurate. There is a label on the drive that clearly indicates the connections and settings. I especially like the compact design that will enabled me to mount this unit in the same metal housing that I mounted my power supply in. Now everything (for this drive) is in one fan equipped box.
The CMD-260 worked smoothly with my Eastern Air Devices 150oz 3.8V 5.2amp stepper motor. I run my system with an older PC - AMD 200Mhz with 32MB running Windows98. I use DeskNC for Dos as the CNC application. The clean, compact design is much better that my kit built setup. This is a professional package that is a steal at the price. It has the range to drive much larger steppers than I have currently - so I won't have to buy a new driver when I buy a larger lathe or mill and convert it to CNC.
I like the CMD-260 feature of being able to set the output current to the stepper motor in .25 amp increments using dip switches. This allows you to quickly make the appropriate setting. On my old setup I had to adjust of pot. while checking with a meter until I reached the required amperage.
Tim Goldstein is a wonderful guy to work with. He is courteous, prompt, honest, and very knowledgeable. He has helped me in the past when I first started getting into the machining and CNC hobby. You will have no regrets in buying this API CMD-260 driver from Tim.
I plan to buy additional units to finish the other 2 axis for this lathe/mill and additional units for a wood engraving project that I want to build in the future.
Todd Hanson
Sacramento, CA
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