[spank]

Hi Tom,
I just picked up a larger CNC router from a local engineering company that was fitted with DC servos. I'm fairly certain that they will work fine with a snapamp, but I just wanted to run them by you first to see if this is indeed the case. Here is a series brochure for the motors, which were made by Reliance Electric (E690 to be exact):

http://www.reliance.com/pdf/drives/d...eets/D2897.pdf


Any thoughts are appreciated,

Thanks

Spank

[TomKerekes]

Hi Spank,

There isn't much info on the motors in the brochure, and I don't understand which model you have. Some seem to say 1750RPM at 120VDC and some 1750 at 240VDC. SnapAmp has a max supply limit of 80V so you would most likely get a proportionally lower speed. But otherwise I would expect them to work.

You don't want to use the existing amplifiers?

Regards

[spank]

Hi Tom,
Thanks for getting back to me. I have the 1/2 horsepower motor listed, which as you state seems to want 120VDC. Hmm. The machine didn't come with any control at all, hence me thinking of snap amps, but I suppose I could find a suitable amplifier and then just connect that to a Kflop. I could also swap out the motors completely and put something in that runs at 80V. I'm having a hard time sourcing much information on those motors beyond the brochure I posted above. Baldor now owns reliance, and I'm pretty sure they stopped making and supporting that series quite a while ago. I'm tempted to go with a brushless motor now... we'll see.

[spank]

I've taken a look around, and I've found some drive solutions that would work. Right now I'm thinking of going with a Granite Devices VSD drive to control both the X+Y axis. Here is the link to the drive page4: Versatile Servo Drive VSD-E & VSD-XE | Granite Devices. I can run two axes independently with one drive, and it allows for a wide range of drives to be used should I want or need to swap out the motors that are on the machine. One thing I am trying to get my head around is the issue of Encoder feedback. Looking through the Dynomotion documentation and reading threads here and on the Yahoo forum it seems as if you can connect the encoders either to the drives or to the Kflop or both? If I connect my encoders back to kflop/kanalog, then I can bypass the drive correct?

[TomKerekes]

Hi Spank,

If you operate the drive in analog torque mode and have KFLOP+Kanalog close the position loop then I don't think the drive should need the encoder position. Unless it needs it for brushless commutation. But to operate the drive in Velocity or Step/Dir modes then the drive would obviously need to see the encoder feedback.

HTH
Regards

[spank]

Ok Thanks Tom. What about tuning the motors? Granite Devices has a nice tool for doing this, does it matter if I do it with their tool or with Kmotion?

[TomKerekes]

Hi Spank, Which ever way you prefer. Our tools are better
Regards