Swerve Drive complications

[explodingcan]

Our robot is rectangular shaped and using a swerve drive. As we ran a few tests, we realized that the robot wasn't able to turn.

We did not know that the robot needed to be a perfect square in order for the robot to turn.

We need ideas as to how to fix this problem ASAP.

Anything is appreciated. Thank you

[Bjenks548]

What pods are slaved together for driving the wheels?

[explodingcan]

What pods are slaved together for driving the wheels?

all four are on the same steering motor

[MrForbes]

If you provide several pictures of the robot, including some with just the chassis, we might be able to see what you're up against, and offer helpful suggestions.

[WileyB-J]

all four are on the same steering motor

wouldn't you need two separate steering motors to be able to pivot?

[Vikesrock]

wouldn't you need two separate steering motors to be able to pivot?

You can pivot if the pods are all steered together if they are not all powered together.

As Squirrel suggested a picture or two and some descriptions of the driving setup (driven in pairs or independently?) would allow us to give you some suggestions.

[explodingcan]

You can pivot if the pods are all steered together if they are not all powered together.

As Squirrel suggested a picture or two and some descriptions of the driving setup (driven in pairs or independently?) would allow us to give you some suggestions.

They are ALL powered differently. Photo coming up as soon as possible.

It is currently on Arcade drive with an open four motors jaguar

[explodingcan]

Here are photos: http://hilovikingrobotics.com/first/swerve/

[Vikesrock]

Yes, when the wheels are pointed forward that drive will act like a 4WD in the long configuration which many teams have discovered over the years has difficulty turning if all 4 wheels are high traction.

The robot likely will be able to rotate if the wheels are pointed sideways. Not exactly an ideal solution, but any solution is better than no solution.

[thefro526]

Your turning issues have nothing to do with the fact that you're using a swerve drive.

Long base, four wheel drive robots will have issues turning with 4 high traction wheels even if they aren't a swerve drive. A quick fix to this problem would be to swap the front or rear wheels out to omni-directional wheels so you have less lateral resistance to turning.

Another solution would be to add a second steering motor and steer the front and rear wheels independently in turning.

You could also reposition your swerve modules so that the contact points of the wheels create a perfect square, or close to it...

[big1boom]

Assuming that your wheel pods are able to rotate while on the ground...
Looks like you have discovered why it is recommended to use a 6WD instead of a 4WD long tank.

At max weight, your motors will not have enough force to overcome the scrub caused by driving the wheels in opposite directions.

3 Possible solutions exist.
1) Turn in the wide configuration, rather than long.
2) Add another turning motor so that the front/back are separate.
3) Swap in omni wheels for one of your sets. However this kinda defeats the purpose of swerve.

[Hawiian Cadder]

if you redo the chains that are turning to form an X rather than II configuration, then you will be able to turn, the disadvantage is it requires some recoding. the x means that two wheels on either corner are always parallel, which makes the robot turn around the point where the chains cross.

[KrazyCarl92]

Solution: whenever you usethe turn command on the controller, first turn the wheels so that they are in a wide wheel base configuration rather than narrow. Then power the proper wheels in the proper direction and watch the robot turn very easily. There is almost no four wheel crab drive configuration allowed by the dimensions in the rules that would not allow a robot to turn unless your wheels just have a ridiculous amount of traction that causes ridiculous amounts of scrubbing.

[explodingcan]

THANK YOU FOR ALL YOUR SUGGESTIONS! WE HAVE SOLVES OUR PROBLEM BY ROTATING OUR WHEELS HORIZONTALLY!!!

this was certainly a perfect display of gracious professionalism