Nylon 6 Vs HDPE

[Bodge Job]

I'm going for a box design with 4 blue wheels powerd by 4 cordless drilll motors. we have estmated it to weigh 9.5 Kg with a battery so we can add a weapon later. this is a basic design, all the plastic is 20mm apart for the top and botom which is 5mm HDPE. I have drawn the design full scale but it was not clear on the camera (my scaner is to small) so I vagly drew on it using Paint (the computer program). the middle space is for batterys and esc's and the recever.
thanks for your help allreddy