Welcome Sam,
From what people have told me on my post. If you want a tough and reliable robot, the best way to go would be to design the robot before you make a shopping list.
I'd agree with Gary, check out other posts. They are really useful and are what I am currently looking at for my first featherweight Trident.
As for components, as you won't have any weapons, your main focus should be on armour that can take abuse from other robots as well as a good shape to push other robots.
Finally, look at other examples, there are a bunch of pushing robots to look at, the first that pops into my head is Tiny Toon. But, as Mrsam replied on my post, specify what kind of event you plan to go to, do you want to be fight spinners and drums and many more in Robo Challenge or, do you want to go for the safe route and face flippers, axes and other Wedges at Robot Wars, either way, you will need tough components and armour ment and a decent shape. Can't wait to see how it turns out, as we are in the same boat, I can't wait to see you at an event.
Enjoy the life of a roboteer
Doodle
Bookmarks