HardWired II

[Flag Captured]

Thanks for all the input as always!

That worries me a little then if Demon's 6mm haha - I'm not sure how the stuff you use stacks up to Hardox, Glen, but I'm not sure I'd like to try 3.2mm knowing that! Maybe 5mm Hardox could work, maybe... My main worry is that I'm aiming for essentially a 4kg bar, at 7000rpm+ with probably quite sizeable bite - that'll put A LOT of force on the whole machine, and whilst I'm going for a static shaft, I definitely don't want the whole thing twisting after one hit! That said, I don't want to make the whole thing so shock absorbant that I end up losing a lot of the power out of the bar - I'm not entirely sure that's how it works but I'm sure I'd lose some of that energy, right?

I haven't entirely written out anything though, I did think about 20mm HDPE for bulkheads at one point and they are still on the cards if they'd work better! It all depends really. I'm starting nothing on the build until I've got the plans sorted!

Hmm, I see where you're coming from there Nick, my way of looking at it was softer foam wheels - more wheel on the ground when it gyros, but I can see that being a much better benefit! I'm hoping to stick a bearing in that outer side, so might end up with 10mm between the wheel an the outer edge, might be alright...

Thanks too Will, Inertia was one of the ones I was looking at for design ideas! The weight distribution is definitely something I'm aware of now - I learned the hard way with HardWired 2 I think haha! I'm trying to build Arch so that everything is pretty much in line with the drive so there's plenty of weight around it (will probably help control the gyro-ing too) but the bar placement is something that's being quite changeable and I'm really trying to get right - at the minute I think it might actually be a little too close into the rest of the machine...

Again, the size and weight of the bar is something that concerns me - I know it's utter overkill, but I'd rather aim high with it all, create something that'll cause carnage haha.

Something I will ask though - is there a calculation that can be use to determine say, what thickness of material you'd need to use for a set of bulkheads, or is it more just trying it out and seeing how it gets on?

Thanks again for all the help too (and apologies if any of this is horribly worded, I'm very tired haha)

[overkill]

[QUOTE=Flag Captured;453426]

I'm not sure how the stuff you use stacks up to Hardox, Glen, but I'm not sure I'd like to try 3.2mm knowing that!

After bashing away at Demon for years with hardly any dents to show for it, the steel must be the hardest known to mankind! Given the weight of the weapon, motor and batteries to drive it, I think you are stuck with 3.2mm Hardox. Its not all bad though, you can use clever design to make the frame stronger.

I don't want to make the whole thing so shock absorbent that I end up losing a lot of the power out of the bar

Its actually the other way around. If you make the frame really stiff in the vertical direction, virtually all the energy will go into the opponent. If the bot runs on skid pads at the front, place them right under the weapon support columns and the path of the impact force will look like this:



As long nothing along that path bends, the other bot will be heading into orbit .

I'm hoping to stick a bearing in that outer side, so might end up with 10mm between the wheel an the outer edge, might be alright...

That should be fine; if not, you can always increase the floor clearance a little to compensate.

Something I will ask though - is there a calculation that can be use to determine say, what thickness of material you'd need to use for a set of bulkheads, or is it more just trying it out and seeing how it gets on?

Top-end CAD programs have a feature called Finite Element Analysis (FEA) that can analyse stresses and predict how much parts will bend or break. You can then tweak the design and rerun the FEA until you are happy (or bored )