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Just curious, why four?
Also, I've had a think about the Wotty, and I don't know if I could afford it, without some serious saving, and the team chipping in, and there's no Sunday jobs to help around here, sadly. Being 15 (Almost, 16 days), it's tough to get anything done.
Ah, most bigger motors have 4 brushes. These work together as 2 pairs of contacts , each pair doing half of the windings.
This is very obvious in the magmotors, who have 4 wires coming out.
I believe you can drive a Magmotor S28-150 with a pair of TZ85's, @ 5S
In the Bosch it's done by connecting the pairs on the brush-holder. And that is what Marto suggests, decouple the pairs, and control each pair with a TZ85.
For non-overvolted wheelchairs, a TZ85 will do fine, especialy when you add a fan to the speedo's. Don't expect any world shattering speed or acceleration, but it will move, and if done well, you can build yourself a cheap bot that can take serious punishment. Just use thick enough steel and shock mounting. A nice bodyshell with a cool paintjob, and you'll have a great starter heavy.
Don't buy anything for a heavy yet. Build something small n get used to it all first :) The main problem with the smaller controllers is that they get hot. Even though there are small controllers with the amps rating, a small plastic box cannot dissipate the heat a big meaty dual controller can. Buying four small controllers divided between two big motors will be a nightmare to cable and set up.
I may get moaned at for costing someone a sale but £180 would nearly buy you a good quality dual controller. I am by no means an experienced robot builder, but I am an experienced electronics technician by trade. Please message me if you need any help and ask questions before you spend money.
@Maddox - That does seem a hassle, and might not work as well, despite being lower cost. I may invest into a Vyper, or a Wotty, depending on what happens.
@Daveimi - I see your point, but the thing is I've done that, bought a couple feathers, and built, smashed and rebuilt more. McCheapo, Shazam, and the original version of McCheapo, what was to be called something else, never worked out, sadly. I could never get them to work, and hated them, to be honest. I'll try to get one feather actually working, although I was close to one, I just never got it going. I'll post updates on McCheapo, the Wonky Wheeled, Weaponless Wonder. As in, "I wonder how that even got into the arena?" I'll be wiring it up soonish, I have all the components.
Yeah I mean it's hard not to sound condescending and I have no idea of your building experience, you're probably a better fabricator than me! I just couldn't stand by whilst you put nearly £200 down for something your not sure about wiring and so on.
Try an pick up a pair of 2nd hand 4QDs, will handle whelchair motors easily, not the nest control in the world but fine if your only running wheelchair motors. Pair normally go for around £100.
Josh,
I've got a pair of 4QD's nc70 or something like that I can't quite remember. Will have a look for you tomorrow if you're interested.
Harry
brand new un boxed including rc interface form 4qd would be round £230 ish, looks like they have stopped doing the ncc version and are making one called vtx instead.... seems pretty similar
http://www.4qd.co.uk/prod/vtx.html
http://www.4qd.co.uk/accs/dmr3.html
What are the stats on your wheelchairmotors? The ones I handled in the past were rated up to 400W, on 24V that means less than 20 amps. (mobility scooters are another matter, and can go as high as 1kw on the single motor that drives the dif)
Even if we stick to the rule of the tumb that a brushed motor does 4 times nominal current in stall it won't blow the TZ85's.
But if you want to be sure, go for the Wotty. Then you support a roboteer. Buy British manufacture and have super fast and accurate repair work if needed. And it's made for our purpose...
Well, I may have to see what happens. I may be buying Eric from antazz, if it's still available, and making my own modifications (Both cosmetic and internal) to it. I just don't have the skill and confidence to build a heavy from scratch, but to have one that I can run and repair, builds confidence. I may end up going into building one from the start, it all depends on what I can deal with. I tend to learn by having a finished one in front of me, to maintain, so I can understand what I'm dealing with.
Harry, I'll probably be interested in those 4QDs if you can find them. I'll PM you.
Thanks for the support everyone, it's really helped me understand what I'm dealing with, again.