Cheap Drive ESC

**Rapidrory** · 22nd June 2014, 19:41

So I was doing some research whilst designing a beetle weight ESC when I came across these:
http://www.dx.com/p/jb-diy-10a-brush...3#.U6csjfldWSo

They're very cheap at about £5.50 each, and have free shipping to the UK. They only do 2 cell lipos, but at 10A with 20A peak they should do fine for beetle weight drive. The reviews look good as well. Has anyone else come across them previously? Seeing as I'll never beat them on price, I'm just gonna buy a pair of these instead of making my own for once :P

**harry hills** · 22nd June 2014, 20:06

I'd be worried about a forward/reverse delay. Nice price though. The voltage is a massive limit, but I would wonder if they would handle 3s fine anyway, or maybe with a heatsink or something. Still got to be botbitz for me. £17 gets you a pair, but then you get a little stung on postage and the couple week wait. Very neat find though

**mrsam** · 22nd June 2014, 20:10

I've seen those before on Ebay in 10 and 20a versions, the 20a ones state that they can handle 3s but then also have a voltage limit of 8.4v stated so who knows. They're a good price but you'll probably wait just as long for them as you would a set of Botbitz and for around £25 a set of Botbitz are cheap and you know they'll last.

Edit: Almost forgot here's the link for the 20a version in case you wanted to have a look http://www.ebay.co.uk/itm/RC-ESC-20A...item3f363a2e2a

**harry hills** · 22nd June 2014, 20:13

All that being said, when Chinese or off brand stuff is good, its good. I have £10 escs working better than electronize ever did. Might get a pair of Rory's linked ones to see what they are like and if they can handle my abuses.

**plargen** · 22nd June 2014, 20:47

ive tried the 10a esc already there naff, the ones with a brake just stop if you try to go from full forward to revers until you center the stick and put it in reverse again and if you get the version without a brake and use a mixer it tends to twitch when your not touching the controls and 1 side will drive a bit faster than the other

also if you over volt them to a 3s lipo they get warm very quickly

**Rapidrory** · 22nd June 2014, 20:48

I plan to get a pair some point soon, partly just to reverse engineer them to work out if they have any weak spots/ what their real specs are. If need be I may be able to just upgrade some components to improve the spec. Bear in mind that the featherweight ESC I made cost me ~£20 and locks up if you accelerate too fast, this is likely to be better than my thrown together homemade one would be on price, delivery time and quality.

The power wires on that 20A ones look a little on the thin side, those probably could do with upgrading a bit. The MOSFETS on it do at least look like they're up to the job. Might even be possible to up the current rating with a bit of hacking if required. Might have to get a pair of the 20A ones to replace the ESC in Richie if I can't fix the lock up issues; The difference between £13 and £25 for an ESC is substantial when the total budget for your robot is £100 :P

Edit:
Hmm, that sounds like current lockout.. what motors were you using with them?

**plargen** · 22nd June 2014, 20:52

i tried them on the usual BW motors

**plargen** · 22nd June 2014, 21:03

is it possible to remove a current lockout as i have some other esc with the same issue

**Rapidrory** · 22nd June 2014, 21:22

The overcurrent lockout is a built in safety feature of a lot of motor driver chips; if the current spikes above the maximum, the chip will shut off all outputs until the chip is returned to brake mode (center stick). It's a really unhelpful feature when used in fighting robots; I had similar problems when designing my ant weight and feather weight ESCs. There's no way to remove it as far as i know unfortunately, other than to slowly ramp the stick from forward to reverse like I have to when driving my featherweight. There must be some solution though; my featherweight uses the same driver chips as the Scorpion XL ESC, which runs drill motors fine as far as I know...

The 20A one just uses 4 MOSFETs, which means it'll have none of the fancy safety features built in. They may have added extra circuitry to include it, but that should be easy enough to remove if necessary. I might get these for a beetle then, if the 10A ones are a little suspect...