Electric motor advice

[Coyote]

I'd like to know more information about electric motors. One of my many project ideas is to power an office chair with 3 electric motors. 2 on it's base so it'll be controlled much like a tank, and a third spinning the seat for an added degree of difficulty. I was wondering what motors should I be using for such a system? Would old vacuum cleaner engines have enough power? What could run off 12 or 24 volts. Am I barking up the wrong tree by asking an over zealous biker forum waiting to rip into and crush an obviously silly idea?

If I get one going, I hope to make a second and strap paintball guns to both.

[Dargor]

Thats a brilliant idea! do it.

As for vacuum's being strong enough, maybe if you have some lying around try.

[Coyote]

Thats a brilliant idea! do it.

As for vacuum's being strong enough, maybe if you have some lying around try.
Chur

My parents have an enviromower. Might see if I can have a look inside it and see what motor it has. Don't think it'd have much oomph though.

If all else fails, the minimoto motor will be stolen. Don't know how I'd make the base steer in that case. Having 2 motors move in different speeds or direction to make it turn would be easier and it'd turn on a dime. If I wait a while maybe I could buy another minimoto engine, they're pretty damn cheap: http://www.trademe.co.nz/Trade-Me-Motors/Motorbikes/Parts-accessories/Engine-drive-train/auction-172169827.htm
Wouldn't be able to reverse though. But it would be ridiculously awesome having 2 of them underneath an office chair.

[SlashWylde]

A vacuum cleaner motor isn't the right type for your application. They are meant to run at relatively high rpm and produce low torque. They need the air drawn from the cleaner hose to flow over them to keep them cool.

You need lower shaft speed and high torque to move a person sitting on an office chair.

I would suggest a 12v or 24v DC gear motor for moving forwards and reverse controlled by a motor controller using wig-wag control. See www.dynamiccontrols.com (http://www.dynamiccontrols.com/)

Their R50 unit is a good little controller which you can use to control the speed and direction using a throttle like a motor cycle, but one which twists backwards (palm down) as well as forwards. This is wig-wag control. Download the data sheet on this (http://www.dynamiccontrols.com/index.cfm/1,79,html) page for circuit details.

For the seat rotation, I would use a stepper motor. Go to www.jaycar.co.nz for motors and project kits which feature stepper motor drive circuits.

These motors and controls will cost you probably several hundred dollars. Alternatively you might need to search the net for home brewed motor controllers to save a bit of money, but you will still need a DC gear motor and a stepper motor. There are probably other ways of doing it but these would be the easiest for someone new to electronics.

[Ixion]

Gentle Annie washing machine motor.

[SlashWylde]

Gentle Annie washing machine motor.

You'd need an inverter drive to run one of those. I don't think that would be suitable given the need for an ELV battery supply.

[bungbung]

Go to pick apart, look at big windscreeen wiper motors or little starter motors. Cheap too

[Coyote]

As much as I'd like to have the nicer, expensive stuff, I can't afford it. When I start making that money I'll be saving up for a new bike instead. I'll tag along with some mates when they're off to Pick a Part and ask how much their motors cost and have a general look around.

[1 Free Man]

Have a look at motors out of mobility scooters. They may not be fast enough for what you want but they are DC.

[Ixion]

DC truck generator, running as a motor?

[Coyote]

Several R/C car motors?

Could nick the one off my car that's got no radio gear and give it a shot. Could get one that's set up for torque (though it still won't be that torque-ee o'corse).

[Hoon]

How much are you willing to spend?? Something like this will easily cost over $1K

You'll need:

Car battery
2 x DC motors
1 x wiper motor
wheel/track assembly
Electronics
Controls

The biggest challenge will be sourcing/building the tank track assembly. I'd go modular and build the drive unit first - go with 2 car starter motors + solenoids, a car battery and switches, mount it all in a box with the keyed output shafts sticking out each side to fit the tank track drive sprockets eventually. Prob find you'll need to use pulleys/sprockets to get the desired gearing.

[cheese]

How fast do you want it to go?

If you want to make a really easy one that won't be very fast, get a couple of cheap battery drills and use them for your motor and speed controller. you can rig it all up pretty easy. you could use one for the chairs spin bit too.

Otherwise jaycar have a range of motors with gearboxes already fitted and most couplings you should need.

As for batteries, I'd just use a few SLA's - easy cheap and not too big.

[cheese]

oh and speed controllers are generally PWM circuits.

[Coyote]

How much are you willing to spend?? Something like this will easily cost over $1K

You'll need:

Car battery
2 x DC motors
1 x wiper motor
wheel/track assembly
Electronics
Controls

The biggest challenge will be sourcing/building the tank track assembly. I'd go modular and build the drive unit first - go with 2 car starter motors + solenoids, a car battery and switches, mount it all in a box with the keyed output shafts sticking out each side to fit the tank track drive sprockets eventually. Prob find you'll need to use pulleys/sprockets to get the desired gearing.
I'm willing to spend everything I've got! Which is probably about $5 in loose change.

Will starter motors chew up too much power from the battery? They don't last long when starting a vehicle, but then there's engine resistance. Can't think they'd last much longer though.

oh and speed controllers are generally PWM circuits.
Wha chu talkin 'bout?

How fast do you want it to go?

If you want to make a really easy one that won't be very fast, get a couple of cheap battery drills and use them for your motor and speed controller. you can rig it all up pretty easy. you could use one for the chairs spin bit too.

Otherwise jaycar have a range of motors with gearboxes already fitted and most couplings you should need.

As for batteries, I'd just use a few SLA's - easy cheap and not too big.
Very.

Good idea for the seat. Would want something with more ommph for the base motors.

I'll have a look in there sometime. Wellington Motorcycles is just a block away too so I'll have to look there as well.

SLA's?

[bungbung]

SLA = sealed lead acid batteries. Wet batteries like a bike or car are cheaper, especially from pickapart

PWM = pulse width modulation, $5 won't get you a PWM controller

On your budget, wipers motors for everything, car batteries for power.
Wiper moters generally have two coils for high and low speeds, use them.

[cheese]

well $5 won't get you far.

ok, drive, if you use two motors, you steering will be hard to control and twtichy, I'd use one motor driving one read wheel adn two front for steering, teh you don't need to worry about some kind of diff or a dolly wheel (that is assuming that you want to turn). car starter motors draw shitloads of current, any speed controller or even switch would have to be pretty heavy duty.

What kind of chair you using again?

[avgas]

Use a geared DC motor (for rotation) and 2 car starter motors to propel you.
wont last long but shit it would be fun.
likewise if you go for a 12v system you can have aux solar suppy via the $30 solar panels from supercheap autos.

[Coyote]

well $5 won't get you far.

ok, drive, if you use two motors, you steering will be hard to control and twtichy, I'd use one motor driving one read wheel adn two front for steering, teh you don't need to worry about some kind of diff or a dolly wheel (that is assuming that you want to turn). car starter motors draw shitloads of current, any speed controller or even switch would have to be pretty heavy duty.

What kind of chair you using again?
I liked the idea of 2 motors so it could steer on the spot rather than having to have some forward momentum to steer. Basically like a Segway, just not gay. Plus I was thinking the wheels could just mount onto the motor shafts rather than messing around with gears. Course, this'll probably alert people to how little I know and I'll get a paragraph saying just how wrong that idea is :laugh:

If I have one wheel powering the thing it'd be more fun having the minimoto engine on board. Though that'll ruin an idea of having it inside.

Well I have the crappy $20 office chair I'm sitting on right now. Course when I have the money to do all this I could potentially get something nicer. Just brainstorming currently.

[Coyote]

Use a geared DC motor (for rotation) and 2 car starter motors to propel you.
wont last long but shit it would be fun.
likewise if you go for a 12v system you can have aux solar suppy via the $30 solar panels from supercheap autos.
That's so silly I might just have to do that.

It'll get all the ladies since it'll be 'green'.

[avgas]

mabey you should start small - how about 1 motor with wheel to do everything. like an outboard motor on a boat.
Been done before and it works quite effectively.