Four wheel drive question

[ajlapp]

one way to accomplish this would be to drive one set of wheels directly from the gearbox, and drive the other set with a seperate connector chain which is itself driven by those wheels already powered..

this would require adding another sprocket onto each wheel then adding the chain. you may also need to add a tensioner.....as it is a fairly long span for unsupported chain.

also, look through the gallery. teams have been building four wheel drive robots since the start, and none of them have had a ready made two motor gearbox to start with. so you should be several steps ahead!

[Mark Pettit]

We accomplished it by purchasing the ROBOT-SPROCKETS-2005 kit that is $79.95 at http://www.ifirobotics.com/kitbot.shtml
There are a couple of other threads that already discuss this.

[misterfoo]

Originally Posted by Mark Pettit

We accomplished it by purchasing the ROBOT-SPROCKETS-2005 kit that is $79.95 at http://www.ifirobotics.com/kitbot.shtml
There are a couple of other threads that already discuss this.

We used 4x drive last year and it was great, this year we are modifying the setup to have the same. I have not checked with the mech team this week, but I know the conversion is underway from 2 wheel to 4 wheel drive.

If you want to be very simple, you could order a double chain sprocket from Mcmaster. We also converted our wheels to use 5/8 shaft with a similar sprocket and a keyway.

Here is what I found.

http://www.mcmaster.com/

Search for Double-Strand (page 932)

Steel Double-Strand Plain-Bore Sprockets for ANSI #35-2 to #60-2 Roller Chain

[DDRAngelKurumi]

We are just ordering more parts, because we are doing 4-wheel drive too.

GOOD LUCK!

[Mark Pettit]

Originally Posted by misterfoo

If you want to be very simple, you could order a double chain sprocket from Mcmaster. We also converted our wheels to use 5/8 shaft with a similar sprocket and a keyway.

Please be careful of the advice you are presenting.
The sprockets that came in the kit are custom bored to fit on the kit-tranny shaft. You can't purchase stock sprockets and expect them to fit out of the box. They need to be bored out or at least pressed onto the shaft. This is the 4th time I've had to remind people of this in as many threads, such as this one.

[robolemur1236]

why cant you make the robot 4 wheel drive with just ordering two more sprockets? add those to the ends of the drive shaft, drop another chain, presto! four wheel drive

[JVN]

Refer to attached.
Here are 3 configurations of chain/wheels I sketched up in Paint that may be useful.
Two are 4WD, using different sprocket/chain combos.
One is 6WD.

Just some food for thought.
John


Edit:
Please note, these are just some ideas, there are TONS of ways to reconfigure a drivetrain, and the KOP chassis can be used for quite a few. Every team must decide what seems best.
/Edit