Torque required for hammer to self right?

[typhoon_driver]

Re: Torque required for hammer to self right?

As I said before, do the sums and work out which motor will work best for you. Then design the machine around 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.

[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.

[Coolspeedbot]

Oh good, I guess there will be some modding to fit the small sprocket to the motor.

[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

[maddox10]

Yep.

[typhoon_driver]

As someone who's concrete garage floor has been attacked by Jamie's axe I can say that the scooter motors are indeed well suited to this application

[Coolspeedbot]

As someone who's concrete garage floor has been attacked by Jamie's axe I can say that the scooter motors are indeed well suited to this application

oh dear . well I will get one later down the line after I make my first feather weight.

[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]

Yeah 24V is their rated voltage for the application they're designed for (electric scooters) but they will handle less. Sam's runs on 22.2V and mine runs on 18.5V, and even at that it still has a good amount of power behind it and can self-right the robot without issue.

You can overvolt motors as well to get increased speed and power out of them, though this does shorten the lifespan of the motor. As a general rule, never go more than 50% over the rated voltage, so for example, a 12V drill motor can be run on 18V without it being too detrimental, but don't be surprised if it fails somepoint down the line.

[Coolspeedbot]

Yeah 24V is their rated voltage for the application they're designed for (electric scooters) but they will handle less. Sam's runs on 22.2V and mine runs on 18.5V, and even at that it still has a good amount of power behind it and can self-right the robot without issue.

You can overvolt motors as well to get increased speed and power out of them, though this does shorten the lifespan of the motor. As a general rule, never go more than 50% over the rated voltage, so for example, a 12V drill motor can be run on 18V without it being too detrimental, but don't be surprised if it fails somepoint down the line.

Ok, good thing I didn't go with my dad's old drills, they might not even last 5 minutes.

so I take it both you and Sam use 12volt motors?