pros and cons of metal (steel mainly) and hdpe for robots?

what are the various pros and cons for using STEEL and HDPE for a featherweight are? i am able to work with both but i want too hear the pros and cons and see which would be better?

hdpe is good for taking impacts and is easy to work with

true, if i were to make a whole robot out of 3-4mm steel, would it be too heavy?

also, what is it like for absording shocks from spinners etc?

Steel can take the abuse but its usually advised to put it at angles so things glance off. Satanix is made entirely from 4mm steel, and its had a few bends and a large whelt in the back, but generally its stood up quite well. Its not the easiest to work with, but if its contrusted well I think it takes the knocks better than HDPE, less likely to split wide open.

In terms of weight, you'd be advised to keep the robot small, Satanix is 13.6kg and its comparitivly small for a feather (but then again I have an 8mm steel lid and a 10mm spacing bar at the back :P)

this one would be made probably from 3-4mm steel and have a steel box tube frame for re-enforcment.

so if i amgled it properly, did the sides 4mm and the top and base plate 3mm with a box tube frame, do ya think i would come under 13.6kg?

Could you not then make your reinforcement out of hdpe and your shell out of steel? Take the best of both world. :rofl:

The truth with regards to material is, that it depends on what you require from it.

I have found with Seraph that HDPE is the best material the wheels are made from 8mm and has taken a direct hit from NST that ejected NST out of the arena and Seraph went on working, But this is because the design allows for the robot to be made that way the thinnest armour on Seraph is only 3mm HDPE!

Tron on the other hand is a classic steel box design, and has 5mm steel sides this has been bent by NST or LS1 I can't
remember, but the damage was small and didn't cause a problem I would say as a general rule, round the edge is best
steel and the top can be HDPE.

But you know your design, and the weapons of the other robots you will be fighting and try to design a robot to
circumnavigate the opponents attack. try to think smart and come up with different designs (to everyone else) that way
you can have the edge on the other robots.

i guess i could go for steel sides then make some bracket of them and have hdpe lid and base?

i would go for the other way round thick hdpe sides and a steel front, top and bottom

im thinking more the steel for spinners so primarally sides then hdpe top for axes

my reasoning is that if your steel sides get bent inwards after an impact it may cripple your drive, it would more likly take a chunk of hdpe and throw the robot a little. having the thicker sides would also help to keep the front plate on.

ah, i do see your thinking, there are pros and cons to both set-ups and both are about the same, its just which i decide to choose :)

10mm hdpe + 2mm steel bolted onto that :)

If you were to slope the sides and have them made of steel would it not just deflect the blow? then your top could be hdpe for as you said for axe blows?

i was thinking 8mm hdpe to keep weight down and that would still protect against most axes and 4mm angled steel. or would i get away with 10mm hdpe?

it depends entirely on your design

well, very compact and kinda like the new Carcinus re-build shape :)

I think what Johnny means is you need to know the surface area you're going to need to cover, and then the weight of a certain amount of 10mm and 8mm hdpe so that you can times it up by whatever the ratio is. Then calculate the difference between the two weights, and whether or not it's worth sacrificing, pretty much based on your own opinion.

yep, it also depends on the weight of your components. if you've got the weight for 10mm go for it

HDPE robots shells like our team uses on the Hannibalitos stand up to discs reasonably well. They look a mess after a tournament with lots of spinners, but nothing a hot air gun or old soldering iron cant fix. The key is thickness and flexibility. Our armour is mounted in such a way that it can absorb impacts rather than deflect them. It is best however to have HDPE made out of one solid piece. You can weld HDPE together with hot air and HDPE welding nozzle and material, but those welds are the weakest at all times.

Hardox is heavy, and very durable. It is not as easy to work with as HDPE but when working with Hardox you can get a more accurate sleaker design, as HDPE tends to warp a bit. If you going to weld or angle grind Hardox, try to keep the Hardox as cool as you can, as heat destroys the positive properties of Hardox.

i have got some checkered mild steel, everything from 2mm to 6mm (minus some 4mm) for the sides and i will probably have 8mm hdpe for the lid :)