pic: Revolution Swerve Demo Robot

[Ether]

Originally Posted by KrazyCarl92

(I know they claim to be <.5 degrees, but that's what the ones we had said as well and there wound up being a difference of at least 15 degrees.)

Was this 15 degree difference consistently repeatable?

[KrazyCarl92]

Originally Posted by Ether

Was this 15 degree difference consistently repeatable?

Both sides would be off a bit pretty much all the time. When we tried debugging it in java we saw that the encoders would read equal values at angles that were visibly unequal. At times the wheels would seem fine and at other times they clearly were not our drive train would sometimes look like this (top view where "|" indicates the wheel direction):
| |
| | and other times be like this:

\ |
\ |
and when we switched them with the pots it worked fine. We were just interested in using encoders because pots are notorious for blowing out at the least convenient time possible .

So to answer the question...not repeatable.

[Ether]

Originally Posted by KrazyCarl92

So to answer the question...not repeatable.

You said in an earlier post you don't remember the model number of the encoders you tried. Is there anyone on your team who might remember?

[ajlapp]

How well do the MA3 encoders work?

We have used them for competition and on these dome bots with no issues. We were very pleased with their repeatability.

How do you connect the sensor to your mechanical component? Could you be slipping? That's what it sounds like to me.

We always use these.

Clearly that isn't an issue with all four wheels chained together in this fashion

This bot has two wheels at each end linked for steering and two wheels on opposite sides linked for drive.

We have one MA3 encoder on each steering axis.....the encoder is linked via helical beam coupling to a 1/4" shaft that is keyed to an idler sprocket.

[jethrow]

good luck with than macanum is easyer.

[JVN]

Originally Posted by jethrow

good luck with than macanum is easyer.

And we all know that because something is "easyer" it is better, right?
You've clearly put a lot of thought into the debate between a "macanum" drive and a coaxial swerve -- right?

Perhaps you'd like to show us your pro/con list for each? Of course, this list includes only quantitative engineering based arguments, right?

This is an engineering competition. Do some.

-John

[R1ffSurf3r]

I like these little systems. FIRST should take note of their flexibility and performance for the price.

Nice robot