building a drum spinner

[Max]

Re: building a drum spinner

My drum design is pretty similar to drumroll's but I defiantly can't afford to use 3mm steel for the drum, it's either 1.5mm or a push 2mm thick steel or 3 or 4mm aluminium ( not 100% sure on the thickness for aluminium as I havn't done the math. Which material do you think would be best?

[typhoon_driver]

Re: building a drum spinner

Then make it 2mm thick. Not only will you have a hard time welding to 1.5mm without blowing through it, but a vertical hit to it will make a decent dent if not go through. I'd also advise stainless steel if possible. You can pick some stainless tubing up pretty cheap on ebay (it's used for those stupid boy racer exhausts).

I wouldn't use aluminium. You can't weld steel teeth to it.

[Max]

Re: building a drum spinner

Could I use hardened steel?

[Max]

Re: building a drum spinner

Hi, sorry to re-post this but I want to get the drum made soon, can/should I make the drum out of hardened steel?
Also do people use some kind of glue as well as screws to fix hdpe together?

[typhoon_driver]

Re: building a drum spinner

what do you mean by hardened steel? Mild steel that's been tempered or some other material?

Glue's don't work well with HDPE. The best way to join it is to heat it up and melt the edges of the panels together.

[Max]

Re: building a drum spinner

I mean heating then cooling the steel drum once it's made to strengthen/harden it

[typhoon_driver]

Re: building a drum spinner

Yeah sure, should be fine. Just make sure you temper it to the correct hardness. You don't want it to be brittle.

[Max]

Re: building a drum spinner

Hi again,
The drum is being made and i don't want to start putting together the rest of the robot until it comes in case it is not done to my exact specification meaning I will have to change to design slightly to fit it in.
One quick question, i have (and only have the weight to have) two 12v batteries. Before I thought I would use on for the drive and one for the weapon, now however I want the weapon to run off 24v but still want the drive to only be 12v because otherwise I fear the batteries will run low in the battle and I get no gain as it is not a pusher from the extra drive power.
Is there any way of getting these two voltagesfrom my two batteries?
Thanks

[Max]

Re: building a drum spinner

How much ground clearance do you think I'll need because at the moment I will only have a few millimetres and am worried that the bot may get beached on the ground!

[typhoon_driver]

Re: building a drum spinner

What capacity are the batteries?

A few mm will be fine in the robochallenge arena as it is flat. I can't vouch for other arenas though.

[Max]

Re: building a drum spinner

They are 2400CR each if that's the capacity?
Because it's a drum spinner it can only compete in robochalenge area anyway so I hope ground clearance will be ok.
I know there are only two robochallenge events a year but when are they?

[typhoon_driver]

Re: building a drum spinner

2400mAh. Those cells should be fine to run both the weapon and drive from at 24v for a 3 minute fight. If you attempt to use one of the packs to power the drive and both for the weapon then you will be discharging one pack more than the other. A potentially dangerous situation.

[Max]

Re: building a drum spinner

Would my sabertooth 2x25 be able to handle two drill motors at 24v without blowing up?

[Laser]

Re: building a drum spinner

24v is a bit of an overkill for the sabertooth, you'll need somethink like a victor 883 or a sidewinder

[Max]

Re: building a drum spinner

On dimension engineering's website it says it can take 6-24v nominal 30v absolute maximum, but I have heard that when put to it's limits it may explode, what do people think?