Bitza Mk2

[mattsdragons]

Maybe there is too much friction on the bottom and top plates which makes it hard too drive?

small bit of hdpe under that should make it easier

[Max]

I would guess the problem may be lack of weight over the back wheels and lots o weight at the front where it scrapes along the ground making a lot of resistance.
It may help to put some ball castors at the front to reduce the resistance and if you make it so the robot is slanted backwards then more weight may shift to the back? You could also possible move the fan motor further back or the wheels further forward.
Did you just use normal bike chain for power to the drum? Did you use 1 or 2 chains?

[leorcc]

Move the wheels more to the sides and the middle with the drive motors behind the wheels. It will improve the handling immensely. We had the same issue as you with Blackdevil Warzone, and it is simply due to not enough weight leaning on the wheels and the wheels being too close together. It works great for a straight line but specially cornering is horrific like that.

[PJ-27]

Thanks for the input guys, pretty much confirmed what I thought.

The drum is 3.5kgs, the fan motor 1.5kgs, plus the box section uprights, chain (just the one) one way bearing are all in the front of the wheels, which is just scrapping on the floor.

Hoping to move the drum closer to the wheels, move some components behind the wheels (to balance it out) and put some BTUs in the front.