Flipping Tank Drive

[kingc95]

New Bright Test Lab: 1:3 RC 710 Kobra

I’m wondering how this mechanism works and if anyone in FRC has done similar. With the theory of “Going up stairs to a stage” as a possible challenge in this year’s game, I think learning about this might be valuable. Any thoughts?

I also just picked up one of these off mercari for $32. If no one knows I’m gonna tear it apart and figure it out the old fashioned way.

Edit: I’ve seen this style of adjustable tank outside of FRC but I can’t recall seeing it IRL at an FRC event. Other examples

Robots To The Rescue

How do you move the movable flippers while still being able to control the tread movement?

[BrendanManning]

This thread said coaxial shafts which would also be my first instinct.

Rotating track flipper design

Edit: Adding this Vex link.
https://www.vexforum.com/t/packbot-flipper-design/20452

[kingc95]

So one hollow shaft connected to the tread pulley for both sets on one side. Then another shaft inside of that which controls the rotation of the flipper through that side plate?

[BrendanManning]

I think so. Basically what I’m envisioning is a swerve module but with a spur gear driving tread instead of a bevel gear driving a wheel.

[AdamF]

I think the main issue using this with FRC is bumpers.

[kingc95]

The bumper zone is definitely a limiting factor, but in endgame that rule usually is waived. Like 2019 hab. Maybe if it only swings under the robot perimeter and not outside of the extension limit?

[Peter_Matteson]

The shaft for the outer pivoting drive section is also a live axle that everything rotates on.
We did something similar to this on our 2010 robot see the pictures below. We used a live hex axle to drive everything. The full system was contained below the bumpers

pic: 177's articulation test

[f5fd6fd4c6a2005f0b5b099c0c4cd313_l.jpg] This was taken during the the first articulation test 177 performed on this year’s robot. We had our active suspension driving over the bump a few hours later, but at this point we just rolled it across to make sure all the articulation and clearances worked properly.

[AdamF]

That could work if you used it more like stilts. Other ideas I thought of is a frame cutout and inset that extending section of track.

[s3529]

I wonder what ever happened with this partnership between Transcend and AndyMark? https://files.andymark.com/Transcend%20Press%20Release%206-17.pdf
It looks like they have lots of experience with these types of things.

[JonathanL]

Still going strong! That’s the project I spend a majority of my time working on. We actually just created a new ~1/2 weight and waterproof version for MARSOC.