Team MedBots

[joey_picus]

I think a few people are off at Robot Wars, hence the forum being dead I don't think any fleas use 1S motors - at that weight and size, generally you can still work with 'full size' components, so to speak - but a lot of nanoweight spinners do use them. They're normally used in very small models though and consequently are fiddly and fragile, and I suspect a nano is the only application where they offer any advantage. You can pick up very lightweight 2S motors from Micron or Hobbyking that do a more than adequate job, so...

[Max]

We are planning a small competition amount ourselves at uni and my thinking was if we limit robots to use 1s lipos they can be charged by much cheaper chargers (like £2) so we could have one each and can have a spare battery or two all for not much money. Also means everyone is on a level playing field and avoids issues of voltage regulators as we will be using the SG90 boards to drive gearmotors.

Also, do people recon the SG90 boards could run the 3v gearmotors on 1s?

[Rapidrory]

SG90 boards will run the standard gearmotors from china fine... only ever used the 6v variant, but I should imagine the 3v would be much the same...

[peterwaller]

The data sheet for the SG90 says the supply voltage range is 4.8 - 6 volts so you may have problems on one cell which is 3.7 - 4.2 volts.
http://abc-rc.pl/templates/images/files ... -tower.pdf

[Max]

Hmm interesting thought Peter, so far it has been working fine on 1s but I've been using this one: http://www.hobbyking.co.uk/hobbyking/st ... ec_9g.html

I might just order a small brushless and see how it performs on 1s and if it proves not powerful enough for a spinning weapon will just have to use 2s and a Bec/voltage regulator.

[Max]

Just tried running it off a 2s lipo connected to a brushless esc with a 5v 2A Bec running 1 6v gearmotor. It seemed to work well but then I noticed when I put the wheel under load or went quickly from full forwards to full backwards the lemon rx would cut out for a bit before reconnecting to the transmitter.
Looks like if we go 2s we'll need a better Bec

[Shakey]

The LemonRX doesn't need a BEC it can be run straight off of a 2S.

[Max]

But as I'm running the SG90 boards I can't have the rx running at 7.2V or it will likely blow the boards
I guess I could power rx directly off battery then run a Bec in parallel with the battery and use that to power the sg90 boards but by that point all the wiring is getting relatively complicated and I would still be over stressing the Bec