TOPIC:

Hi all

New to the site so hello everyone 👋

I have a original grasshopper 2 and I have been rebuilding and hopping up some parts.

Now I have a problem, for a few years (I know, part timer 😂) the car runs okay for a few minutes then either shuts of or the steering and throttle become very erratic. Also the servos crackle/pop.

So in the last few days I have got a new nimh battery, tried a new old stock msc, and got a new esc but the problem still persists.

The Msc was a original Tamiya with new resistor, and the new esc is a mtroniks auto sort 20.

The motor is a hpi Saturn 27t brushed.

Radio acoms techniplus with ar-17 servo/s and at-2/27 bec receiver.

Help please!

Thank you

Could be lots of things, but most likely a bad servo. If it has an internal short it could be overloading the BEC causing the whole thing to shut down.

Hi Blakbird!

All the acoms gear came together as a set, is it likely this could happen?

To further detail, the car will resume operation again after a few seconds but for the most won’t be under my control.

If I have the car up off it’s wheels the throttle is mostly fine with maybe a few quick blips, however the steering servo can crackle. (This with new esc) however I can have full control most of the time.

I thought replacing the msc might help but not quite.

I was leaning towards the receiver, and have spoke to a hobby shop who suspect this also.

Unfortunately my local shop closed a few years ago and none very near now.

Thanks

Is the problem from a distance? Near 3 4 meters? The matter can be from receiver or a servo. If your antenna has been cut or a dry weld

Hi stingray

Yeah probably 3-4 metres after a few minutes use.

Tx still original acoms screw in type antenna no damage to it at all.

Have two as-17 servos, if using esc steering goes mad, and if using both with msc both go mad.

It’s driving me mad! 🤪

In my mind, 3 4 meters, it should be the rx antenna wire too short or simply a crystal mater. Try another crystal pair. And measure the antenna length. For the 27mhz it should be 25 or 50 cm lenght ( longer is better)

And don't roll the rx antenna wire. And insukate it from motor and other wires.

All the above are good suggestions - but another thing is that 27mhz radio gear has always been prone to interference. Road vehicle spark ignitions, Cb, power lines, radio/tv masts etc etc all caused issues back in the day, but in comparision the air now is super saturated with RF signals both in & outside the home.

One test you could try is seeing how it behaves in the most remote place you can find (difficult under present circumstances). There's a reason why people paid a premium for 40mhz sets BITD, and everyone uses 2.4ghz sets for any "serious" use now.

Hi stingray

I have measured the tx antenna and it’s nearly 50cm and no damage or kinks that I can see.

I have another set of crystals so will try them, but with electronics all on bench I still get servo jitter with both sets of crystals I have.

Thanks for the advice thus far!!

Hi Jonny Retro

I did wonder about wether to update my radio gear to a 2.4ghz set. I have been offered a Carson reflex stick pro 3.1 2ch plus receiver for £30 so that might be the way to go!

After that all I’d have left to change is the servo if it persists! 😩