New robot with chain drive

[Laser]

I looked at the sprockets from Technobots and the description said they were quite(very) heavy!I am going to use a 8:1 gear ratio and run the speed 900 at 30v.
how many toothed sprocket did you attatch to the shaft of the motor?
Are the bigger sprockets heavy?

[RogueTwoRobots]

What sprockets are you looking at? Technobots list the weight of their products underneath the part number so you should be able to look there, see the weight and roughly work out how heavy your drive system would be.

For featherweights, you'll want to be looking at the 6mm or 8mm sprocket sizes. I'm not sure what size 4 4 Toon uses, but as an example, I think DB5 uses the 6mm size and they have been very reliable. And for an average guide, a 40-tooth sprocket from the 6mm range weighs 144g, which isn't too heavy.

[Laser]

http://www.technobotsonline.com/tbot-st ... tooth.html
this is what im looking at.
ive gone off the idea of chain, I'm going to buy 4 speed 900 and have spur gears and make a gearbox

[typhoon_driver]

that's the half inch pitch sprockets. Only ever used it in heavyweights as it's industrial type chain. You want to look here at the 6mm pitch stuff

http://www.technobotsonline.com/sprocke ... ckets.html

btw the pitch describes the distance from one tooth to another on the sprocket.

[Laser]

i've gone off the chain drive and i'm going to have 4 speed 900 with gearboxes (using spur gears) directly onto the wheels

[Laser]

Hey clive what is the ratio in 44 toon and how many teeth do your sprockets have?

[geoff]

Team Torque have done a bit of R&D for a drive system based on Speed 900 motors for the new Pillow Torque. We have finally setteled on 2 stage 0.8mod (HD) spur gear set-up with an overall reduction ratio of 20:1

The Speed 900 has a KV of 680 rpm/v
So at 24v no load motor speed is +/- 16,000 rpm
20:1 ratio gives a wheel speed of +/- 800 rpm
Using a 4 wheel gives a ground speed of around 9mph (allowing for transmission losses) with exellent control and plenty of torque.

I have driven a machine with Speed 900's @ 19.2v with a ratio of 6:1 0n a 5 wheel and it was truly scary undertaking (WAY too twitchy for me!)

[Laser]

Geoff, how many teeth did the gear on the wheel have?
And did you get the gears from Technobots?

[rob]

Geoff, how many teeth did the gear on the wheel have?
And did you get the gears from Technobots?

Check out these wheels and gears, Pm him or email if you want them
viewtopic.php?f=166&t=3461

[Laser]

Thanks Rob, but i'm going to make my own gearboxes