Torque required for hammer to self right?

[Daniel]

The most recent pictures I have are on this page http://www.robowars.org/forum/viewto...=asc&start=435 Videos from its fights at our Nationals are on youtube too.
1.5kg for a motor is a bit heavy, but I find the lower rpm makes up for needing extra reduction. But I've broken all my scooter motors at our last national championships and have now discovered that my local supplier has put his prices up. So I'm currently redesigning my two scooter motor powered robots to use HK brushless motors instead

[maddox10]

Funny Daniel, that is exactly the motor I have in my spares box.

[daveimi]

So something like a pair of Gimson GR02's wouldn't give enough of a kick to throw it back over?

[shakesc]

So its all in the gearing (I suspect)

So I toyed with one of thoe scooter motors and have one in my spares box

Instead I went the 2 GR01 route
Been busy at work but plan to weapon test over Christmas

[typhoon_driver]

Well why not do the sums and work out what will be able to self right?

Lets assume a 30cm long axe with worst case the majority (say 10kg) at the axe head end of the robot. Torque is simply distance x force so that would be 0.3m x 10*9.8 (to get the mass into newtons) = 29.4Nm. Call it 30 to keep the numbers simple.

Now looking at the gimson GR02 18v. That will give you 1.41Nm at peak efficiency. So in theory you would need a ratio of 21:1 to get a flip back over.

Now of course I have assumed that all the 10kg mass is on one side of the axe mechanism and is only balance by very little mass on the other side. So what I would do is roughly work out the mass distribution of your machine and then work out the imbalance that the axe mechanism has to self right. You will probably come out with a figure somewhere between 5:1 and 10:1.

I would always advise doing the sums and work out what you will need adding a little bit more for the real world rather than going down the route of yeah that should work, spending the cash and time on it then realizing it doesn't.

[PJ-27]

Certainly looks the business! Here's hoping it has the goods.

[shakesc]

Here's a quick video of it self righting
The battery is 4s with low charge but will be changing this up to a 5s
It also self rights with the axe extended



Stripped the bot down to do some welding and tidying

[daveimi]

That's really cool!

[PJ-27]

Very tidy looking machine.

[mattsdragons]

Very nice machine, what motor are you using behind the axe?