axes in a small space (and weight)

[Danjr1]

I'll look at gears instead. I'm looking to design something really compact.

[maddox10]

After running a gear driven axe with a speed 900 , I can comment on a few things.

Mod 1 gears are to light on the last stage. They wear out in a few fights.
Speed 900 motors are expensive. And having to replace it after an event because crispy is to much of a good thing.

These mechanical issues will be adressed in the repairs/improvements in progress.

Return is done from the TX, after the stroke the motor is powerless untill commanded.

Microswitches and simular idea's are not needed, we use the same timing technology as we use in the Hannibalito's.
A command to fire the axe triggers a Ilyama custom (and expensive)build 100A+ Hbridge for a fraction of a second.

[Danjr1]

Been doing some maths on the concept of using the robowars tutorial but with the speed 900 replicas on eBay but at 22.2v. The ratio I've come to is 22.3 to 1! That can't be correct can it?!

[Ellis]

It could be correct depending on your axe length, weight, and design. If it's heavy and long, then it could be right. If it's light and short, you'd get one heck of a powerful swing, just quite slow. Plus getting a 22:1 ratio into a small space may be difficult.

[Danjr1]

i think the issue is that the speed 900 replicas deliver their power at a much higher rpm than the scooter motor does so requires the higher ratio. the only thing that was different was the motor and i increased the length of the axe to 0.4m

[Danjr1]

Had a thought though.In my calculations I used 390 watts but if I use a 30a esc/switch/relay at 22.2v, that would be dumping 666 watts into the motor? Therefore meaning the ratio could be a lot lower?

[maddox10]

Kashei used a 20.25/1 gearratio on a Speed 900 and a 300mm axehandle with 300 gram axehead.
6S 2P A123 Packs as powersource.

Result, Crispy Speed 900 after each 2 events. And that without anything going wrong.

I hope this answers the question.

[Danjr1]

Lol get the idea! No axes for me then!

[maddox10]

Now we're redoing it with a gearratio of 30/1 and sturdier gears (mod 2 for the final stages)

That should end the crispy Speed 900's.