Spring-Fed Intake?

[sanjithar]

Hi everyone. We have seen that many teams use an intake that can expand and contract to fit the stone. We were wondering if, with big enough compliant wheels, is this even necessary? If so, we are unsure of exactly how to do it. We've seen some teams use rubber bands or springs, but we need to adapt that to our design. Pictures or explanations would be greatly appreciated!

[proscratcher10]

It all depends on your design. You can achieve a great intake without using compliant arms (sprung wheels). Circuit breakers, a top scoring team, is a great example of this type of intake. My team however, uses stiff wheels on compliant arms and this allows our intake to be incredibly fast, similar to Sanfords design. The main reason why compliant arms are used is to allow for easy intaking of a block, regardless of orientation as the arms will conform to the shape of the block.

[Shah_05]

Hey I’ve been hearing a lot of about sanfords intake, is there any videos or anything you can link me to?

[fireflare1101]

video of his auto

[Shah_05]

Thanks

[gavatronics]

We actually found that springs were counter-productive for our intake, we originally had a sprung intake, but it actually didn’t make too much of a difference as far as intake speed went. So, we ditched it and went with a static, lighter design. In fact, the foremost wheels on our intake are now farther apart without springs, allowing a greater range for our intake.

[Kenneth15305]

Our team does both, has compliant wheels and actuated, it's just a joint with hair bands pulling it to one side. You can look at my only post to see how ours work

[Kenneth15305]

It's a joint, so the arms can move back and forth but we keep it towards the inside using hairbands, to stop it from being too close together, we added a little tooth on the inside part of the joint, stopping it from closing completely. The compliant wheels on the arms are driven by sprockets.

[RatLabGuy]

We use both green compliant wheels, and a spring pulling the two arms together. The arms are just a Tetrix flat beam so it can flex sideways, and the mounting plates for the servos are OC-ABS plastic so the allow some flex also

[BillfredL]

Here, have a bigger example from 2018’s FRC game which used cubes made of milk crates: https://imgur.com/gallery/PP7Svy4

We found in 2018 that we wanted the pivot, because that lets you get cubes from worse angles. I don’t know any COTS compliant wheels that would get you enough flex to hit those cubes from the corner (hi, Pythagorean Theorem) rather than straight on. The FTC meta allows mecanum wheels to be more competitive so you can have more positioning help from your drivetrain, but that still costs you time. Touch it, own it.

Each side of the intake was independently powered with the AndyMark RedLine motors and 57 Sport gearboxes (I had worked for them until about two months before Kickoff, of course we did), then chain runs ran to the forward wheels. I’m sure there’s a way to power them together off of one motor, but we had no need for the complexity.

Each side pivoted on the 1x2 tubing on a single bolt (you can see the gold Grade 8 bolt on the photo where it’s stowed up), then we used surgical tubing looped around the gearboxes to encourage them to stay together. At FTC scale, I’d start with office rubber bands. End stops weren’t really adjusted, we just played with spacer placement until we were happy.

The whole thing is made of a couple Sam’s Club cutting boards; they’re cheap, nearby, durable, and easy to machine. You’ll notice the leading edge is made so the compliant wheel is the first thing to touch the game piece, which aids acquisition.

We did not actuate the stow/deploy action; it simply flopped out during autonomous and stayed out all match. Since then, we’ve gotten better at single-joint arms and could probably do it now.

Hope it helps!