Esc Advice

[Theo]

So, building is underway now (I sanded down two edges on a shell I bought from Harry) on my new featherweight. I have motors sorted out, and a battery in mind (Ni-MH. Not LiPo just yet). The only thing left is which Esc I should pick. Due to my very limited budget, I'm going to use two speed controllers for a 4wd setup. My options consist of two of those eBay 320A dual ones. They say they can brake and there are dual motor models (still getting two though, one for each side). The question I have is as followed: do they brake or not? I can more or less work my way around the control issues, just the braking I need to know. Alternatively, I can use a pair of hobbywing dual quickruns. The dual motor option goes up to 12 cells (Ni-MH, I work with those numbers), 2 more than I need. They do cost twice as much, and I'm not sure it comes with a fan. Thanks.

[maddox10]

Forget the "cheap" options. In the short run, they will be more expensive, even if they can do the job halfassed.

Better to save up a bit, and buy a good one to start with. We're using the IBF 4.5 in our raptors and feathers.
Not the most powerfull ESC, but those 2x40 Deutsche Grundlicheids ampères outshine the 320 Chinese ampère el cheapos in any respect.

[lowndsy]

People do run Quicruns in competition so they are doable. I had a couple blow up the other weekend but to be fair I was using meaty motors and 75c 4s LIPOs and I think my signal mixer was playing up too.

[Theo]

Would they work for testing, though? To be honest, I just want a pair of speed controllers that drive the motors for now, I don't think I'll be able to make any events for another 6 months to a year (depending on if robot wars does a FW tournament). So, would the cheap eBay ones do the trick just for testing? Do they brake? (key question) ​Thanks.

[daveimi]

Buy a pre-built one "Feather2" from Rory.

[Theo]

I would, but I'm not sure they can run four 550S motors. It only says 2 in the doc. I'm going to buy 2 of those cheap eBay ones just for testing. They're £10 each so not too much of a loss. After, I might get a couple of Botbitz 30A controllers and modify them to run 2 motors each on the same channel (if that's possible), or a couple, of hobbywing dual controllers, or a Feather2 if it can do 4WD (plus I can get it repaired at a reasonable cost).

[adamclark]

Those cheap ones are probably only good for a car or truck. The 'brake' as on the one I have, basically means that you cant go directly from Rev to Fwd without having to stop in the neutral position. For a car or truck that's OK, but for a robot that is using tank steering it means you cant easily steer or drive it. There are ones without the brake function, but they seem to be import only from china.

[Maxamuslead]

well depending how "cheap" you want to go, you could get some Turnigy TZ85a ESCs re program them at £36 each , and they would do you great, however you can get them pre done but for another £28.50.

Side note, where does one buy a Feather2 and can someone link it's spec sheet?

[Roboteernat]

well depending how "cheap" you want to go, you could get some Turnigy TZ85a ESCs re program them at £36 each , and they would do you great, however you can get them pre done but for another £28.50.

Side note, where does one buy a Feather2 and can someone link it's spec sheet?

Rapid Rory makes and sells the FeatherTwo, plus Ant controllers:
http://www.fightingrobots.co.uk/members/1557-rapidrory

[Theo]

I'll be messaging Rory at some point to enquire about them. I remember a post by him ages ago saying it can run in 4WD, or that could be his beetleweight controller instead. In any case, I'll be ordering two cheap eBay speed controllers (on Amazon ironically) to test everything out. My only concern with a dual controller is if one's damaged, the whole drive is gone, with singles they can easily be replaced. Though the repair offer is good to know. Thanks. I should be opening a build diary very soon so I can get some more advice as I go along. Thanks again.

[cjsowry]

Luna-tic currently runs on hobbywing quicruns 860, the duel (double output for two motors). Worked fine for 8 fights at Manchester. I say fine and currently, the bot can turn while speeding up or slowing down, might be something to do with the greater resistance when the esc is "reversing"...?! I'm not an electrician. lol. I will be getting One of Rorys ESC's (which controls both the left and right motor) when money permits. And for the price of £55 (last checked) its the same as two quicruns anyway. I do read Rory can get quite bogged down building and repairing ESC's, so best to message him to see what his current work load is like!!

[Theo]

The Feather2 seems brilliant value, its just the risk of it being one controller for all motors. I guess mounting it in the middle around a ton of foam would be fine. How were the quicruns? did they overheat or run okay? How fragile were they? I'm sorry, just you're the only person I can find with any experience with them. Thanks

[maddox10]

If 1 ESC blows during a fight, you're out whatsoever. Most RW specific "dual" ESC's have anb advantage if it comes to set them up and get the 2 motors working together to drive a straight line.

The IBF series have the option to add a gyro. For fast, 2WD narrow wheelbase machines it's a big advantage.

[Theo]

I mean for maintenance. if I lose one ESC (let's say botbitz 30A) then I can swap it out for another (an extra £30) but if I lose a dual ESC, replacing it will cost £60. in any case, I'm still probably going to get one for convenience, value and it'll last a good while.

[maddox10]

As the Rory ESC, the IBF has a very extensive support. Reiner is very helpfull, a common trait if you ask me.
Rory and Ian have demonstrated such in the past too.