Torque required for hammer to self right?

[daveimi]

Hi, quick question. To build an electric axe capable of self righting what sort of size of motor would I need to look at to power it?

[Coolspeedbot]

Would a normal cordless drill motor do the job as a axe motor if it is geared correctly?

[maddox10]

There is only so much power in a batterydrill motor. Gearing won't amplify it at all, just make it a tad more efficient.

[RogueTwoRobots]

I used a cordless drill motor as an axe motor on a 5:1 ratio. In short, no. There are small steel pins inside the drill gearbox that keep the small pinion gears in place, and the forces from a weapon like that just cause the pins to fail (basically falling out of the holes in which they're mounted).

If you want to go for an electric axe, have a look at electric scooter motors on eBay, specifically around 300-350W power rating. I changed my drill motor on the axe to one of these and they are vastly superior. On the same ratio the axe hits a lot harder and faster, and the motor can definitely take it. Sam also uses one for his robot Hatchet and has it working well for him.

[Coolspeedbot]

I see, what exactly does the 5:1 ratio mean? I would guess small gear to big gear type of set up.

[Coolspeedbot]

I used a cordless drill motor as an axe motor on a 5:1 ratio. In short, no. There are small steel pins inside the drill gearbox that keep the small pinion gears in place, and the forces from a weapon like that just cause the pins to fail (basically falling out of the holes in which they're mounted).

If you want to go for an electric axe, have a look at electric scooter motors on eBay, specifically around 300-350W power rating. I changed my drill motor on the axe to one of these and they are vastly superior. On the same ratio the axe hits a lot harder and faster, and the motor can definitely take it. Sam also uses one for his robot Hatchet and has it working well for him.

something like this?

http://www.ebay.co.uk/itm/24-VOLT-30...AAAOSwBLlVcco6

[Graw]

something like this?

http://www.ebay.co.uk/itm/24-VOLT-30...AAAOSwBLlVcco6

Just out of interest, what sort of difference in power could you get from one of these (http://www.robotmarketplace.com/products/0-A28-150.html) in comparison to a scooter motor for an axe? Just looking at all my options.

[mrsam]

Sam also uses one for his robot Hatchet and has it working well for him.

As Jamie said, my robot Hatchet uses a 350w scooter motor on a 5:1 ratio running from a 6s (22.2v) lipo.

This video shows best how effective a weapon and a selfrighter those motors can make, and they're damn cheap too.

[Coolspeedbot]

Can I ask what voltage is your drive motors and the scooter motor?

cause the scooter motors I've seen on eBay use 24volts and I didn't know if they could handle a lower voltage input

[RogueTwoRobots]

Yep, the drill motor had a sprocket on it with 8 teeth, and the axe had a sprocket with 40 teeth on it, connected to each other by a chain. So for every five rotations of the drill motor shaft/sprocket, the axe arm only rotated once, thus the 5:1 ratio. It reduces the speed but increases the torque (or turning force) so that it isn't as much of a struggle for the motor to turn the heavy arm.