Armour

A plywood and steel laminate is very cheap, even compared to hardox. But not nearly as strong.

You can get the steel very cheap from a junkyard. And even 0.8mm Stailess has some good qualities.

But, as Ewan mentiones, the softer and cheaper HDPE or Polypropylene plastics are very suitable to laminate, or even to use as sacrificial armour.
Virtualy unbreakable, lighter and cheaper than Polycarbonate.And resilient.
The wheels from TAN are HDPE, and are meant to be sacrificial,because they cant be build strong enough to withstand everything in the arena.
Now you can imagine our suprise that the wheels did survive more fights than most heavies do in a complete series.

alot of feathers are turning to polypro instead of polycarb (g3 will be), due to the problems of it shattering/cracking. Polypro is abit more fibrerous and seems to be standing up to the spinners better. Blazer (middle) will be having HDPE armour as we can get it cheap :P
Polypro is also better to work with as it can be heated and bent, you can also melt two bits together.

The main advantage, according to me, for the softer plastics is that they dont absorb as much force, The disks will cut them, but wont do more damage than a cut.So less inclined to rip complete pannels of the robot in 1 go, or bend the framework.
I hope this theory is correct.

If i recall correctly, its virtually impossible to glue a thermoplast like HDPE. So a HDPE and steel armour cant be glued and im unsure if a riveted connection would stand much of a chance against disks.

Bolts it is then :proud: Theyd likely be ok, though youd be gaining some weight in the connectors I spose...

-- Kev

Tec7 or simular mastic glue holds it together good enough.
Things to remember then. Degrease the to glue parts perfectly, and give them a rough up with sandpaper, remove dust and so on. Use enough glue and be shure the edges are completely glued.
Now, if you can get the parts under a multi tonnes press let m cure for as long the glue needs.Otherwise, put the parts between 2 sturdy plates ,and pile up every heavy object you can fit on it.yes, if you can get the fridge on it.Do so, and it works even better as the fridge gets loaded with Cider or beer.In that case I come over to help doing this.Especialy the unloading of the mentioned fridge.

:-)

Going back a bit, why would you want to harden the wood? Surely its never going to be as hard as the metal, and you want it to be strong, not hard, to support the back - otherwise the first ding in the metal is going to crack it. (Wood glued onto titanium may actually make matters worse, since the titanium is likely to be able to deform and bounce back where the underlying wood would just make it more brittle. Or I could be talking nonsense.)

Ive always been keen on the idea of armour deflecting or avoiding impact energy, rather than trying to absorb it - so the softer plastics sound interesting. Its all very well having 40kJ in a disk, but that only helps if you can transfer that energy into damaging your opponent.

--
Fluppet

Mario i think you have your numbers wrong. Plywood is 0.615kg per dm^3 everything else i agree with.

I use the table here. Duglas Fir rocks.
http://homepages.which.net/~paul.hills/Materials/Materials.htmlhttp://homepages.which.net/~paul.hil...Materials.html

Regards
Ian

The mass of plywood is different for every different kind of wood and glue used in it. I just took the number I had around.

Density, weight and sizes

The density of plywood is not normally controlled as part of the product specification but is a function of the species of timber used. As such the density can have a wide range, but most construction plywoods have a density in the range of 400kg/m3 to 700kg/m3.
Thus a 2400 x 1200 x 12mm panel could typically weigh between 14kg and 24kg. Some highly compressed, specialist plywoods can have densities in excess of 1000kg/m3 and some have €œbullet resistant€ qualities.