Armour

[bigsi]

Just thought Id chip in as we probably have more experience than most in the use of plastics in robots.

Polypropylene - good if you want something stiff but with the kind of impact energies in RWs, it tends to shatter, in a similar manor to polycarbonate.

HDPE - requires almost 10 x the energy density on polypro to shatter. It is softer, but will tend to plasticly deform and absorb impacts / spinning things better than anything Ive come across.

Our drum & outriggers are now made from HDPE.

As someone else mentioned, the way to glue it is with silicone sealant or mastic. In order for a laminate to work as armour from piercing, the layers need a certain degree of relative movement. The mastic provides this.

When our drum was made from Polypro, IronAwe knocked several big holes in it. The same spec of drum made from HDPE has yet to be pierced which kind of speaks for itself. Several things have gouged it, but nothing has got through!

Top this end, we are now building an axe robot, using HDPE for armour - in a way nobody has done before. Providing protection from spinners as well as axes. No laminates, just an intelegent use of the material properties!

Si

[spinnerboy]

I think we were pretty close to cutting through it in the spinner frenzy at series 7

[bigsi]

You are not wrong! It cut through about 8mm of the 10mm thickness. We are still running the same drum though.

The only thing to actually pierce the drum was the axe on a robot called ICU (I think), the head of which was like a pencil. Then it only made a 2mm hole!

Si

[mightymouse]

I have found that a combination of 1.6mm mild steel and 8mm macrolon is virtually impregnable. The only time the lid on Mighty Mouse has been pierced was by Matildas disc.

It has taken a full blow from Thor and sprung back into shape, and 8645t had three free shots with his axe and only cratered the surface.

The 2 materials are not bonded though, they are just bolted (csk m6 screws and nuts internally) this gives an amazing amount of flexibility. I often have to flatten dents out of the steel substructure but the polycarb is only scratched.

I have currently run out of macrolon and am using a sheet of polycarb, no idea of the make or spec, it came from a telephone box. But, although it is slightly more brittle it is no less effective.

Trev

[corsair_lightning]

I agree. Corsair uses light plastic and aluminum put together. Its not brittle, but it is rather hard to destroy.