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Author Topic: Advice needed on interface to Kollmorgan drive or new drive recomendation  (Read 842 times)

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I am new to CNC machining and purchased a platform for a laser cutter that was half build from a company that went under.  It has one axis complete with a Kollmorgen PSR4 power supply and BDS5A servo drive along with one B-104 Servo motor and an additional power supply not sure what for, all of these items are believed to have zero time.  I found some Kollmorgen motionlink software which I think is for motor setup and was able to fire up the unit and get motion out of the motor through the controllers serial; port, but I am a long way from doing any machining with this.

I am trying to figure out where to go from here, my research led me to the popular Mach3 software, which has a large following, I was getting ready to pull all the guts out of this unit and replace them with stepper motors when I thought I better slow down and figure out if that was what I wanted to do.  When I looked at the cost of the servo motor I have vs the cost of stepper motors I figured there must be a reason, and it looks to me that for CNC servo motors are probably more powerful and may or may not be better.
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So looking for advice, should I keep the one setup I have and add 2 more servo motors, replace all or add 2 stepper motors.  If I keep what I have, what do I need as an interface between Mach3 software and the servo driver (if anything) and/or the servo motor.  I appreciate any advice.

I have attempted to post some images hope they work.

Thanks
Bill



« Last Edit: April 17, 2018, 02:32:06 PM by cocoabill »
Hi,
if you can use those servos do so, they are good.

You say you have a BDS5A drive but the pic you attached is for another. Which is it?
The one pictured is an analogue servodrive, old school but useful if you have an analogue controller.

Mach is a step/direction controller but there are controllers that will produce analogue output from Mach3. Galill, Kflop and CSMIO, none of them are cheap.

Can you post the manual of the drive you have?

Craig
My wife left with my best friend...
     and I miss him!
Thanks for the reply.

The unit is a BDS5 the line drawing was not correct  sorry I did not look closer at driver that came out of the goldline motor catalog. According to what I can find the BDS5 is a PWM driver, the cut sheet on this unit appears to be unavailable.
« Last Edit: April 17, 2018, 04:46:11 PM by cocoabill »
Hi,
quick scan through the manual, don't quote me on this, this drive expects realtime RS485 communication
which is not Machs forte. You could probably achieve realtime RS485 with a Gallil motion controller, very
nice buit thousands of dollars.

I note you can fit an analogue board which converts the drive to analogue. Would still require an analogue capable
board to interface with Mach and you would still require RS485 to program the drive, albeit not realtime.

Mach3 and the motion controllers that work with it are step/direction. You could work around that to drive these
servos but it would be an expensive and time consuming proposition.

Good steppers and stepper drivers would be much cheaper or if you want/need high speed operation then step/direction
capable AC servos are a good way to go.

Craig
My wife left with my best friend...
     and I miss him!
Thanks you are making up my mind to sell these on eBay and use the proceeds to get something else.  I think the Kollmorgen stuff is valuable if you can find someone that has an an existing system that needs them.  That being said what do you recommend for driving a mill with the least amount of hassle with Mach3, steppers or servos?

Thanks
Bill
Hi,
good steppers with PROPER drivers and power supply are extremely good value. Provided you work WITHIN their
limitations they are really really good. Where most people come unstuck is they will try to achieve good results but
buy substandard equipment and/or demand that their machine exceed the limitation of the steppers.

Don't be hoodwinked into buying closed loop steppers, the manufacturers are playing on your fears about losing steps.
The premium you pay does not gain you enough to make it worth it.

AC servos are the way to go if you want high speed, power and resolution. Delta and Teco are two Chinese/Taiwanese
brands which are economical and yet very good. There are cheaper Chinese ones but with increasing question
marks over quality.

As a ballpark:
34 size stepper (700 oz.in) plus 80V driver plus 72V supply approx $250
400W Delta servo/drive (230V input) approx $400

No matter which way you cut it steppers are cheaper but the 400W servo will 'eat it for lunch' .

Craig
My wife left with my best friend...
     and I miss him!