Chassis for a Pixhawk-based rover

Hello.

I was reading through the group and I was trying to figure out the best chassis for my application.

I was choosing between Wild Thumper 6WD Chassis and one of Traxxas RC cars (Slash or Stampede). After valuable feedback from TCIII (Thanks!) I figured out I should go for Traxxas cars. And here I have a few questions for you.

I want to be able to mount something on top of my car (e.g. average size WiFi access point or a camera). I think of going for 1/10 scale for that. Would that be enough? And what is the practical difference between 2WD and 4WD models in terms of how they drive? Is setting up 2WD with Pixhawk is as easy as 4WD one?

2WD: traxxas.com/products/models/electric/58024slash
4WD: traxxas.com/products/models/ele … x4platinum
4WD: traxxas.com/products/models/ele … tampede4x4

Do you have any experiences with those?

My second question is about all the other parts I need (t will be my first rover). As far as I understand, if I buy one of those RC cars, I have ESC there already, don’t need to buy separate one. Therefore, I would only need:

  • Pixhawk (with regular setup, so 3DR telemetry radio, 3DR Power module, GPS module, and maybe a second one for redundancy, buzzer and safety switch)
  • battery
  • a bunch of female to female servo cables to connect to the rover

Is that correct or am I missing some crucial elements?

What is the advantage of second GPS module? How much does it improve performance of a car? (I want to use GPS way-point mode a lot, and then test Follow Me mode).

Thanks in advance for your feedback,
Michal

Hi,
For what applications is the rover intended ? I mean how fast must it move ? On what type of terrain ?
Fom my own experiments with a 6WD rover (Wild thumper) I would say that:
-a wild thumper chassis is best for real all terrain vehicle that needs to drive on very difficult terrain with lots of obtacles (grass, forrest floor, hills). The 75:1 ratio version climbs on 60% slopes ! Check my video about it here :
diydrones.com/profiles/blogs/air … ng-level-1

A wild thumper low gear version drives relatively slow (about 5-8 km/h)/The higher 34:1 version drives twice as fast.
A big advantage of the wild thumper is its payload capacity of 6kg !!! (that means you can carry a lot of weight on it) and its chassis is ultra modular and pre drilled with holes and has transport and prtection aluminium plates.
A wild thumper is also much cheaper than a Traxxas chassis (also replacement parts are cheaper).

-A traxxas on the other hand is more of a racer vehicle that can drive very fast. But It is probably less capable to operate on all terrains. You will have to modify the chassis before you can carry anything on it.
A traxxas chassis is also more expensive (also replacement parts).
An advantage of the traxxas is that you can find lots of replacements parts and mods all over the internet.

So I would say that if you need an all terrain , rugedized vehicle, go for the wild thumper. If you need a racing vehicle, go for the Traxxas,

Just an opinion,
cheers,
Hugues

I would have to disagree on both opinions on the mentioned chassis. I have been racing and crawling rc cars for many years and a chassis like the wild thumper turns out to be a lot less durable then you might think, from the very limited articulation/suspension to the fragile direct drive. I personally see a number of failure points in that type of design, such as the plastic motor/suspension mount, not mention that it looks like low grade Chinese components and pot metal. Im really not trying to bad mouth that chassis but it has its strong points, and its weak. The one real advantage it has is the pivot steer from the six motors.
Traxxas on the other hand will be very difficult to break, and as far as negotiating rough terrain the stampede has been in use for years with millitary bomb squads to carry out missions as a cheap alternative to there $60,000 purpose built monsters. Speed wise is all about how you set it up, motor selection, esc, etc. Pay load is no issue as you can adjust the suspension for pre load and dampening. Yeah you would have to do some work to mount all the components but thats the fun part, its a great feeling to know you made your robot instead of judt a bunch of off the self stuff you just had to bolt up.
I personally would go for a 4x4 stampede over the 6x6 thumper just for the versatility, reliability, durability that a proven tough as nails chassis provides. Why be stuck with a slow, complicated, extremely specialized chassis? You could always check out MOA rock crawlers for another option.
If you have any questions about setting up a rc car for pixhawk I would be happy to help!