6wd wild thumper / t rex jittery movement

Hi Guys,

Just wondering if someone can help me see if there is something obvious im missing.

I have a wild thumper 6wd with the t rex controller

I am connecting it with bluetooth and the t rex app on an android phone.

It is connecting and responding as you can see in the link (below)

but movement is sluggish and jittery, almost as though it is underpowered.

I am powering it with a 2 cell lipo.

Just wanted to know if there was anything obvious I am missing, I am quite new to robotics so am a bit of a noob

Thank for your help!

Hello @JCTNY and welcome to the RobotShop forum,

The 6WD Wild thumper has DC motors with a stall current of 5.5A, as the TREX controller has two channels, I’m going to assume you have 3 motors connected in parallel, so the approx stall current would be 16,5A but the controller is rated 18A so that shouldn’t be the problem. The other thing that could be causing issues is the battery’s discharge rate, if you’re not familiar with this I suggest checking this guide:

Discharge Rate

The continuous discharge rate of a battery is very important because if you choose a battery that cannot discharge at the required current, the robot will either not work properly or not work at all.

Example 1

You selected four 12V motors for your 4WD outdoor mobile robot. Each motor consumes 1A under normal load, and more in the case of a slope. You decide to choose a 12V, 2Ah NiMh battery pack, not caring about the continuous discharge rate. You discover that your robot stops when it encounters even the slightest obstacle or incline. Why? In this case operating all four motors consumes ~4A while an NiMh pack can only discharge at about 1.2 times the capcity (1.2 x 2Ah = 2.4A). The current draw from the motors is therefore higher than the battery can provide.

I hope that helps!