ESC problem, I think - Advice Please

[JezT]

I'm a newbie - only been at this a few weeks; Me and my son, Max, run 2 Mad Rats on Nimhs/Brushed (on a Budget!).

In the last couple of sessions, mine has developed a fault and I'm trying to track down the culprit; I will suddenly lose control - the motor will go into reverse, full power, and the only way I can stop this is by applying the brake by pushing the stick full forward (not pulling back on the stick!)... then it will go into full forward so I have to release the stick.... etc,etc - I have to keep doing this while I'm trying to get the shell off to flick the switch off! I'm running this on a Spektrum DX6i TX & AR6200 RX to an Ansmann Autosport 20 ESC (the cheapest around!) - and was running fine for a while.

Where do you think the problem lies? In the TX/RX combo (hope not - I like the programmability and don't want to shell out for a new setup) or the ESC? BTW on the bench the failsafe works fine.... but when it's in the midst of it's wobbly the failsafe doesn't - ie switch the TX off and the motor still spins

Just read an advert for the AS20 - "The Auto Sport tuned 20 uses the new automatic set up software which calibrates itself to your transmitter as you are actually using it!!! - Could this be the problem?

Advice please

[sparrow.2]

Have you installed a spring to return the throttle stick to a neutral position?

If not your speedo will have a bit of a tough time if it's constantly trying to recalibrate to a changing neutral point.

Check also if you haven't got your throttle end points set to above 100%. That might cause problems as well.

[JezT]

Thanx Sparrow.

I have installed a spring in the DX6i to centre the left stick;

You have a good point with the throttle end points - I did set it to 125% a while ago (don't know if this coincides with when the problem started to occur - I'm pretty sure it was fine, on that setting, before this problem started to happen) - will set it back to 100% and see what happens.

Think I still might slightly upgrade the ESC - Max's has got an Ansmann Sirius 12 which has a little more programability in it - I would prefer to be in more control of the setup.

[sparrow.2]

If you are considering buying a new speedo wait for a decent brushless speedo to come up second hand on here. Most brushless speedos like LRP Sphere or NOSRAM Matrix run brushed motors too and then all you'd need would be a brushless motor to upgrade.

[JezT]

Excuse my ignorance - will a brushless work with Nimhs batteries? If so - good idea... if not - can't really replace all my batteries at the moment.

[sparrow.2]

Brushless will work wit NiMh no problems at all.

The only thing you need to watch out for is when you're using lipo is not to let the voltage drop too low, which is why most brushless speedos come with a lipo cutoff function these days.

[JezT]

Bit the bullit - got ourselves a couple of Exceed Race 75A w/10.5 Turn motors..... Loving them