Dagu Wild Thumper 6WD problem

Hi, I recently purchased the 6wd dagu wild thumper but I am having some problems with it, mechanically that is. Here is my setup, 9.6v battery pack, arduino mega, qik2s12v10, bluesmirf gold. The chassis moves forward and backward exactly as it should, however it does not turn. its as if the motors physically cant do it, but i know thats not the case (its only on carpet). another problem, and im not sure if its connected, when the chassis is suspended in air, none of the wheels are even, thus when on the ground, not all wheels are in contact with the ground evenly (this is on flat ground). is this a physical problem with the chassis?

Thanks for the help

Hello,

Because it uses skid steering to turn, the 6WD Wild Thumper can have difficulty turning on carpet, which is often a very high-friction surface. The chassis turns much better on surfaces like dirt (it is made for outdoor driving). Do you have all three of the motors on each side wired to one channel of the qik? What are the details of the battery you are using (chemistry and capacity)?

As for your second issue, the chassis has independent suspension springs on each pair of wheels. They can sometimes have slightly different tensions, which can cause the wheels to be uneven when the chassis is lightly loaded, but this should not affect the turning. However, it is possible to adjust the tension on the springs, so you could try that if the unevenness bothers you.

- Kevin

1)What is skid steering then? It just seems so odd that a device so rugged and powerful has trouble on carpet. Basically then this chassis would be useless indoors?

  1. I do have all three motors to the one channel and the other three to the second channel. I have no problem with powering of the motors.

  2. The problem I am having on carpet is also similar to the problem I am having in standard grass. It simply won’t turn in the grass.

4)Currently I am using a standard 9.6v airsoft battery because it’s the most powerful battery I have. But I have two 7.2v battery packs on the way, here is the link: all-battery.com/2pack72v4200 … 91087.aspx

Overall: From what I have seen of where it can and can’t turn, I’m a little disappointed in it’s performance as a 6wd platform. Especially for $350.

Hello,

“Skid steering” just refers to differential steering, meaning that the chassis turns by running the wheels on each side at different speeds, as opposed to pivoting the wheels or axles.

In our tests of this chassis, we noted that its turning on carpet was somewhat awkward and that the motors had to strain more when turning than when going straight, but it was still definitely able to turn in place. Based on what you have said so far, it sounds like you have been unable to get the chassis to turn at all; is this the case?

I am still unsure of the details of your battery pack, but it sounds like it should be sufficient if it is fully charged, and the 7.2 V pack you linked to should definitely be good enough. However, if you have a battery meter (like this one) or some other way to measure the battery’s voltage while it is running, you could do so to make sure that running the motors is not causing an excessive voltage drop. (I have seen a partially-charged 7.2 V battery provide enough power to run a 4WD Wild Thumper going straight, but not enough to turn it, because turning strains the motors more and causes them to draw more current.)

- Kevin

yes that is the case, the chassis does not turn at all on carpet. it also doesn’t turn in the grass either, which kinda implies the albeit a 6wd all terrain vehicle, there are two terrains in which it basically can’t operate. what i am kind of trying to do now until the more powerful batteries come is program some kind of different steering scheme. aka, to turn right, run left motors at 100% and right motors at 50%, im thinking that may work a little better at least right now, instead of both channels in opposite directions.

also, that battery balancer item you listed looks like it might help in troubleshooting possible problems, but i don’t have one of those quite yet, may have to wait a while.