by a reknowned Moron of few Talents and a frankly poor Grasp of the English Language, with Apologies
The price of antweight speed controllers has gone down a bit over the years. First they were available only from the colonies, and as such the price fluctuated depending on what mood the world economy and US dollar were in. Then, like a beacon in the darkness, Peter Waller came forth with his tiny speed controllers for reasonable prices, halving the average price from about £60 to £30. This price point has remained about the standard even since Rory arrived, took the beacon from Pete, and rigged several dodgy looking headlights to it to blow the darkness away entirely. (There's also the Sabertooth, which about half of the forum had as their first controller despite them weighing about as much as a baby elephant and costing about £80, but we'll gloss over that)
But, short of resistors and servo boards, what if you could go even lower, and have a fully functional dual-channel speed controller for around 12* British pounds? From the combined forces of Chinese capitalism and comedy names come Banggood *snigger* and the DasMikro 2S6A**, which were initially spotted by Micah Leibowitz on the Facebook, and which I decided to order a couple of last month while watching the closing stages of the Olympic marathon.
They arrived today, three weeks later, which is fairly reasonable by China*** standards. So, what exactly does 12* British pounds plus free shipping get you? It gets you this:
Das Mikro. Sehr gut? Ja, ja, mein Luftkissenfahrzeug ist voller Aale. Achtung, Englanders!
Next to a few other common antweight parts for comparison. Weight fully wired up is about 5g, the board is really quite light.
Talking to Rory he mentioned it looked quite similar to the NanoTwo, using a similar PIC and four SH8M14 chips to drive the motors as half-bridges rather than the full-bridge chips he uses. The regulator used is a fairly beefy 1A one so you can probably run a decently sized servo off it, although I think most people just run them on full battery voltage these days. It comes as just a bare board with slightly odd connections, so reasonably precise soldering is required, although they do provide all the cables needed:
The power and motor wires are really nice silicone ones, although this is compensated by the signal ones being horrible PVC ones that almost certainly harbour some kind of disease.
I hacked up a quick test chassis using the base from a joke entry long since passed, the Pololu 50:1 HPs out of The Hurting, an OrangeRX, and some wheels I had lying around. In the spirit of science, I christened it "The Sacred Chariot Of Swakopmund", which I trust is a suitably impartial and fitting name.
Swakopmund is a coastal city in Namibia (population ~30,000 people) whose name literally translates to 'bum mouth'. Someday I shall move there as it is clearly my spiritual home.
And so to testing it all worked! (via the medium of an absolutely terrible video)
Well, for something that costs £12*, it works far better than it has any real right to (in that it works at all!). It handles the motors no problem, the mixing is surprisingly good, and out of the box it's actually not too bad - most of the erraticness in the video was from me having the controls backwards and so not really knowing what I was doing (so no change there). Compared to a Roryboard or one of the Peter Waller controllers, the deadband is really large, and outside the deadband acceleration is very quick, but it's fairly usable in all honesty with smooth control. There doesn't seem to be much braking, though, and while this isn't too much of a problem going from forwards to reverse quickly, it does mean the motors run on a little bit if you let go of a stick. This is annoying, but workable, and feels a little bit like driving in a slippey slidey ice world. I only ran the Chariot on 2S, but I ran it for a good long time (about fifteen minutes) without noticing any discernible warming of the driver chips or regulator.
Rory thinks it should run alright on 3S, and I'll leave that judgment to him as he's ordered one to destr-test. A man of science I may be, but I'm a man of science on minimum wage and I'm loath to detonate something that works!
In conclusion: Honestly, I think this has some potential - being PIC-based, it might be possible to tweak the software a little so it functions a lot better - again, I'll defer to Rory on that - and the stock software isn't all that bad, I'll probably assemble something more competitive to give it a proper run-out at the next World Series and see how it copes in combat. It's not without its flaws, but yeah, a working dual channel controller for less than £12*. It might be possible to have a complete antweight built for less than £50 before too long...
*more or less. £12.22 at time of writing. Subject to market fluctuations and inexplicable referendum results.
**you'll want option A for the mixing, or option B to use in-transmitter mixing.
***or, if the shipping label is to be believed, Vanuatu. Sadly you don't get stamps...
