controllers

Currents, size and weight restrictions are causing an awful bother, here.

Assuming a LEM-130, which can lift 500kg on a 5:1 gear ratio (mechanical efficiency @ 60%), then 80amps is needed. Basically, the NCC-70 is sufficient, is an attractive weight as you bolt it to the casing as a heatsink, but is an awkwardly long size that might not fit - even inside a 70cm SpiderBall. Funnily enough, the Pro-120 might be better: it's shorter but wider.

4QD's 4QD Series are beeautiful :). Only problem is, at 250 x 103 x 60 mm, they'd *definitely* be too big to fit. Oh, and quantity 12of 4QD-200 weighs in at 15.6 kg! Darn and poot.

Mmmmm :) the Axis board has two parallel ports. the CDFR (computer controlled dual forward/reverse) controllers have parallel port connectors. the CDFRs may be multiplexed together - without additional hardware - up to EIGHT controllers, on two parallel ports. mmmmm :) expensive _and_ attractive. damn. that would save me a lot of bother. Vantec's dual-controllers can simultaneously drive both motors at not-exactly-the-rated-ampage, and can drive one _definitely_ at the rated ampage. My guess is that they do this to make turning a conventional robot with two wheels real easy and fast - all the power could go into one wheel...

Same rules apply to the CDFR23 (dual controller, computer-driven). The CDFR23 would not be powerful enough to drive just one motor - despite being 80amp peak. So they would need to be doubled-up. The price / amp makes them unattractive: for the same amount of money you could get 6of RDFR33s with change to spare to adapt them to parallel ports yourself (DtoA converters from Quasar Electronics).

Might as well stick with the Original Plan: get 12of NCC-70s, which peak at 110amps. They're a bit big, relatively speaking, but lightweight. I'm happy to put DtoA converters on the parallel ports - 3118 from Quasar Electronics would do the job.

Still a way to go. We'll see if Vantec are going to do the CDFR38E some time soon, otherwise it's the NCC-70s or Pro-120s :)

Yes, oh yes! and by _far_ the winner, in size, weight, price _and_ performance, the Open Source Motor Controller. greater than 400 amps (surge) *gibber*! The home page is dmillard.com/osmc and a company called Robot-Power are supplying boards, kits, full product _and_ option boards, so you can DIY to any degree you wish. Software for the PICs is publicly available (to do ramping, braking etc). The entire project is available on-line, so you can do what you like.

If you're really pushed for space, you can take the fan off the OSMC3-2 and save an additional 25 mm on the height, but you get a reduction in the power to about 150amps.