Crazy Drive Train Ideas

[dodar]

i think it would be cool to see a crab-drive tankdrive robot

[BrendanB]

Originally Posted by dodar

i think it would be cool to see a crab-drive tankdrive robot

I believe team 2342 Team Pheonix from Nashua/Merrimack New Hampshire did a design in 2009. It was a standard crab drive robot but with added code allowing to act as a crab, tank, and ackerman steering and even some slight combined variations.

Is that sort of what you were thinking of?

[Chris is me]

Originally Posted by BrendanB

I believe team 2342 Team Pheonix from Nashua/Merrimack New Hampshire did a design in 2009. It was a standard crab drive robot but with added code allowing to act as a crab, tank, and ackerman steering and even some slight combined variations.

Tons of crab drives do that. Not to take anything away from the 5 or 6 teams each year that tell me their drivetrain is a crab drive AND a tank drive, but that's pretty standard.

I think he meant swerving tank treads or something.

[BrendanB]

Originally Posted by Chris is me

Tons of crab drives do that. Not to take anything away from the 5 or 6 teams each year that tell me their drivetrain is a crab drive AND a tank drive, but that's pretty standard.

I think he meant swerving tank treads or something.

Yah I was confused as well thinking of the same thing, "aren't all crabs tank drives?"

I think it is just one of many things that makes me crack up back on pit scouting or alliance strategy. "Our robot has a very low center of gravity!" That is great, but how does that large heavy steel arm play into that?

[mwtidd]

4 wheel crab with actuator legs (http://www.youtube.com/watch?v=IMmJtw0XYzk)

lets make the legs 3-position pneumatics.

and while we're at it, figure out some way to mount the bumper is its '10 legal.

or the beautiful rotating mecanums would be nice
i have a design that could be driven by one set of motors and still be holonomic

[Hawiian Cadder]

Hoover-craft....

i would actually like to see a robot with a bike drive train, even the most basic bicycles have at least a couple different gear ratios, and there are some bikes with upwards of 24.

[jamie_1930]

I think I have exactly what you are thinking of this was one of our programmer's, dana, idea in 2009. He called it serpentine drive and was designed to slide across the regolith, similarly to a snake. I hope I can explain this well enough for some people to get, and I'll try and follow it up with some of dana's prototyping of the drivetrain. You make multiple wheel assemblies that would include two wheels, parallel to one another and unpowered, with a center pivot in the middle of the two. Now you would have the center pivot offset from the center of a gear, then put a series of this in a line with eachother, connected with springs to the front and back of each and idler gears inbetween to maintain direction. Each of the assemblies would then be offset slightly so that when the whole thing was powered by a single motor the wheel assemblies would travel in a wave.

[Hawiian Cadder]

i just came up with another one, make a robot that is entirely encased in a hollow sphere with omni wheels on every corner facing outward, to drive the main part of the robot drives the inside of the sphere, if we ever get a water competition this would be highly helpful i think.

[jamie_1930]

Originally Posted by Hawiian Cadder

i just came up with another one, make a robot that is entirely encased in a hollow sphere with omni wheels on every corner facing outward, to drive the main part of the robot drives the inside of the sphere, if we ever get a water competition this would be highly helpful i think.

This is a drive train I've been pondering for a while and I would love to make it.

[CENTURION]

This is basically what I've been doing for the past few weeks straight

Specifically, I've been attempting to find a way of making a demo/promotional robot that our team can show off to schools, potential sponsors, and the general public (especially when we do recruiting for our summer camp).

I personally have been wanting to tackle the problem of an off-road sort of drivetrain, so I've been experimenting.

For now my favorite solution is off-road swerve/crab drive, using two wheels on each pod (ok, I'll admit, the two-wheels part is mostly to make it look cooler, but it would have it's benefits: traction, weight distribution on soft material, etc)
Each pod would be individually rotated via an FP or Window motor, and would raise and lower via a pneumatic piston and some guide bars. (the pistons could be pressurized somewhat to create a passive suspension system).

I will upload some sketches and better explanations later...

[Chris is me]

Originally Posted by CENTURION

For now my favorite solution is off-road swerve/crab drive, using two wheels on each pod (ok, I'll admit, the two-wheels part is mostly to make it look cooler, but it would have it's benefits: traction, weight distribution on soft material, etc)
Each pod would be individually rotated via an FP or Window motor, and would raise and lower via a pneumatic piston and some guide bars. (the pistons could be pressurized somewhat to create a passive suspension system).

You may be interested in this whitepaper. 1114 made a swerve drive somewhat similar to this in 2004.

[548swimmer]

Originally Posted by jamie_1930

This is a drive train I've been pondering for a while and I would love to make it.

http://xkcd.com/413/

'nuff said.

[jamie_1930]

Originally Posted by 548swimmer

http://xkcd.com/413/

'nuff said.

That is actually infuriating that is exactly how I wanted to go about it, minus the webcam although it is a nice addition.

[Chris is me]

Originally Posted by jamie_1930

That is actually infuriating that is exactly how I wanted to go about it, minus the webcam although it is a nice addition.

Why is it infuriating?

Anyway, if you want a crazy drivetrain idea... Figure out a 4wd drivetrain that is not vulnerable to pushing that goes over the bumps that can turn. I wish I figured that one out...

[JamesCH95]

Originally Posted by Chris is me

Figure out a 4wd drivetrain that is not vulnerable to pushing that goes over the bumps that can turn. I wish I figured that one out...

One that uses ackerman steering with zero mechanical trail