Let's talk about brushless drives!

[ASC]

I'm in the market for a new supplier and am wondering what everyone else is using to drive their servos.  My last few machines have exclusively used Copley Controls drives, mainly Xenus and Accelus.

http://www.copleycontrols.com/Motion/Products/Drives/Digital/index.html

These guys are nice to work with and very flexible, and the tuning software includes a function generator to get the motors tuned to hell and back.  The trade off is that they are very expensive, always over $1000 per unit, susceptible to external noise, and I have recently found their support department to be lacking.  With that in mind, I'm wondering what everyone else is using to drive their motors.

If you have a moment, please share what you are using, and the pro's and con's you've encountered with different manufacturers.

Much obliged!

[Hood]

Allen Bradley DSD or Giddings an Lewis DSA drives (same drives different name )
Pros
Excellent drives full of features, especially the indexing ones
Can be set up for Step/Dir, CW/CCW Analogue etc
Step/Dir input are differential although you can choose to use single ended if you wish
8 digital inputs ( 24v)
4 Digital Outputs (24v)
1 relay output
1 Analogue output.
I/0 can be configured for lots of different things.
Software is good and scope page for tuning amongst other things. Encoders, I/O etc can be monitored real time in software.

Cons
PRICE!!!!!!!!
Very expensive new but possible to pick up second hand at a reasonable cost, most I have paid was £180 for a 22KW drive, it was new but bought on eBay.

Hood

[kf2qd]

I have used Yaskawa/Omron branded drives and Mitsubishi Brand. Yaskawa and Omron are the same product, though Omron has a version that is Step/Direction Only.

The Omron drives were super easy to use if you used the default settings - 2000 steps per rev of the motor shaft - and had the added benefit that they have a switch dedicated to self tuning - don't have to change parameters to configure the tuning parameters. (had one setup with a large timing belt pulley that wanted to oscilate - flicked the switch and joged the axis a couple times and tuning was complete. Up to 800 watts will run on 220 Single Phase.

The Mitsubishi drives were similar, 1000 steps per rev. 

I liked the connectors on the Yaskawa/Omron drives better than I did the conections on the Mitsubishi motors. You will need to order cables as they come cut to length and terminated.

Seems like prices were in the $1200.00 and up range.


Might also look at Automation Direct though I have no experience withtheir product.

[ASC]

theres really no cheap option for this level of automation I guess, but the prices on the used allen bradleys seem quite reasonable.  $200 to $500 canadian dollars is definitely justifiable for AB drives.  The Omrons are looking pretty nice too, especially if tuning is as easy as it seems.  I spent the last 2 months tuning the copley xenus drive with a linear motor lol.

[Hood]

The Chinese drives that a few places sell seem to be reasonably priced in the USA, UK still expensive (whats new ) but afraid I have never tried them. Scott Schaefer has used the Automation Direct ones and I think he likes them.

Hood

[Hood]

Oh the AB drives also have Auto Tuning but  I prefer to tweek further.

Hood

[ASC]

The auto tune function always seems to get you in the ballpark but to get true precision further tweaking is always necessary.  That was the real shortcoming I found in the Copley systems; there are tons and tons of settings, tweaks and check boxes but very little documentation or support on what functions they perform.

How do you feel about the AB software and setup?  I still have nightmares about tuning the Copleys.

[BR549]

Don't forget "automation direct" and "Servo dynamics" also "Granite Drives"

AC servos are the cats weow and quiet as a mouse, I run SD94s with 1kw motors.  Yes they are expensive BUT you get what you pay for with any of the name brand drives as far as I have seen.

(;-) TP

[BR549]

OOPS

[Hood]

AB software is great in my opinion, if you want to have a look you can download it here http://www.software.rockwell.com/support/download/detail.cfm?ID=3655 and when you open it you cancel the first box that appears then choose new (pic 1 ) then right click and choose Ultra 3000 (pic 2)then choose a drive(pic3). You can then look through all that is available.
Hood