FRC 6328 Mechanical Advantage 2023 Build Thread

To be clear, I (OP) am not @TheGamingR0BOT. Both your assessments are correct. While perhaps small, the time savings in not having to worry about balancing the charging station in auto may be the difference between hitting a second or even third gamepiece in that period, pushing you closer to the Sustainability Bonus.



similar looking pfp, but different person.

edit: oops, Connor already clarified.


What size roller do you guys use and how far away are they from each other?

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Very cool design! Are you thinking of picking up cubes with the “cone pinch” design as well? Or 2 “separate” Intakes?


The roller has a 1.75" diameter and 22" length. Again, this might be a bit longer than what we would ideally put on a competition robot, as these are repurposed rollers from our 2020 robot. The edge of each roller is 1" apart and the centers of the rollers are 2.5" apart.

With the “cone pinch” design we are thinking of intaking cubes with the same set of rollers. Some options we are thinking about is putting one roller on a pivot so it can open up to be wider, as with their current compression the rollers cannot intake cubes. Another idea is letting the cube run under these rollers and go over the bumper into another intake/grabber that would be mounted onto our superstructure. This second intake would be what scores the game pieces.


Prototype Progress!

Over the past few days we have been hard at work iterating on our intake prototypes. We continued developing our side roller and flange grabber prototypes, as well as explored some new ideas.

Side Rollers

We assembled our MDF prototype, which turned out to be quite large and hefty, and used a ratchet to mount it to our swerve drive base for testing. Although we were skeptical, the ratchet strap worked surprisingly well for keeping the intake in place. Initially we used a motor test rig to control all four motors, which inevitably led to quite a sketchy setup.

We eventually switched to running the motors straight off of the robot. With the adjustable design, we spent a good bit of time modifying the position of both sets of wheels and the back stop, as well as trying out different types of compliant wheels and playing around with the intake angle. The intake seemed to work well for the cone, but we couldn’t get the wheels to hold on to the cube after intaking it. To fix this we made the outer wheels constantly spin at a slow speed, which we found not only keeps the cube in place, but also helps guide the cone into the back wheels. We also swapped the outer set of wheels to smaller, more compliant wheels, which worked better with the cube. We were eventually able to run cycles with the robot, and the intake seemed to work fairly consistently.

With this design showing promise, we have started designing a next iteration made out of polycarb, which will be smaller and lighter than our current version. We are planning on putting the polycarb intake on the end of an arm that would attach to the swerve drivebase, and would be able to score both the hybrid and mid nodes.

Flange Grabber

We improved this design quite a bit over the past few days by finding ways to vector the cones into the middle of the intake. First, we added 3d printed mecanum wheels on the front roller and covered the back roller with duct tape because the rubber was too grippy and didn’t allow the cone to vector. We found that this worked pretty well.

For the next iteration we fully replaced the back roller with an ABS 3d printed corkscrew to help vector while gripping the feet of the cone better. We also slightly offset the rollers to the front one is higher than the back. The main problems we found with this roller was that the edges of the corkscrew were too sharp and the pitch was too low. Also, mounting it on the robot cart made it a little higher than we wanted. Overall, it was decent.

Attempting to solve these problems, we improved the corkscrew by increasing the pitch, blunting the edges, and increasing the diameter. We then CADded side plates and cut them out of MDF so we could keep the intake at an ideal height and wouldn’t need to use the robot cart anymore. This design unfortunately did not work very well as the compression of the flange was too high to work reliably. It only ended up working about 20% of the time, and was shredding up the cone a little.

To solve the problems of the previous iteration, we CADded and cut new plates that reduce the compression, slightly lower the rollers, and add space for another roller of 4” compliant wheels to go below the corkscrew. This additional roller is intended to help kick up the cone into the top two rollers. It is not built yet, but we have our plates cut and ready for Monday.

Other Prototypes

We played around with something similar to 4481’s “weed wacker” prototype to try to orient the cone in the same direction no matter its position. As expected, this worked best when approaching the cone straight on, and the effectiveness tapered off as the angle of the cone increased. This could potentially be something that is placed in front of an intake, to orient the cone in a position that the intake can pick up.

We also started working on a claw-style intake with 2 positions, one for a cone and one for a cube, using parts taken from the 2018 intake design. We started only using one set of wheels to prove the concept and had temporarily placed some surgical as a backplate so that the game piece doesn’t fall out. We played around with different piston sizes in order to find one that is the correct length and stronger than the tension of the surgical tubing. We found that this intake did a good job at holding on to the game pieces, although we may need to test out different compressions so that we can intake a game piece earlier. Next time, we want to add a second set of wheels and also mount this to the robot and test out different heights.

As always, if you have any questions or comments feel free to post here, or shoot me a PM.

-Aryan, @Advaith , @manthan , @Matthew3


First, WOW

And second, that one cube in the gigaintake video looks like a mummy with all the tape on it.


How much compression on the base of the cones was necessary to pull them in? Also is there enough grip to flip the cones to an upright position with that?

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Do you guys think you could test the vectored intake wheels on the bottom roller similar to how Spectrum is intaking tipped over cones?

Thanks! - Ethan


What was the back roller made from? Is it duct-taped pool noodle?


I assume you’re asking about the flange grabber design, but please let us know if you meant something else. In our first three iterations (two rubber rollers, one vectored + one duct tape, and one vectored + one small corkscrew) we had a 1" space between the edge of each roller. This worked pretty well, but we figured we could use some more compression, so for the next one we tried 0.45". Unfortunately this was too much compression and it didn’t work well, so for the next iteration we are trying 0.7" (not yet tested).

Flipping the intake up with the cone wasn’t tested before, but now that you asked we probably will. The 1" compression was pretty tight on the flange, so any compression of 1" or less we think could definitely hold the cone upright if the intake was pivoted 90° up.

This is definitely something we thought about. The main reason we are using the vectored intake wheels on the top roller is because this design is more suited for when the flange of the cone is toward the intake, not the tip. This matters to us because the corkscrew deals with the bumpy feet of the cone well and the vectored wheels work with the flat face of the flange well. If our next iteration of the corkscrew doesn’t work as well as we hope, using two sets of vectored wheels is definitely something we might test.

It is the same rubber roller from this post but just covered in duct tape. It is much heavier and less compliant than a pool noodle. Because of the weight and size of the rubber, we wouldn’t want to use one of these on our competition robot this season, but they are great for testing.


- YouTube 6328 Mechanical Advantage showcases their latest intake prototypes and overviews their successes and failures so far during the 2023 Charged Up season on The Open Alliance Show



Any chance we could get a link to that last side roller prototype? Our team would love to use that as a point of reference for our own intake :DD

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I am assuming you are referring to claw-style intake (the last two videos in the post). We will grab the critical dimensions of the prototype tomorrow, but that design does not have any CAD.


Quick Updates!

Side Roller + Arm

To further test our side roller prototype we designed a single-jointed arm that attaches to our swerve drivebase on which we can mount our intake. This will allow us to test scoring on the hybrid and mid nodes, start with software automation, and begin driver practice. The arm is currently being built, so we will be sure to showcase it along with a longer writeup soon.

Flange Grabber/Auger

With a few changes, here are some videos of the current state of the flange grabber intake. There is a longer writeup on the changes made coming soon.

Claw Style Intake

Not much new with this one. Here are some videos of the prototype intaking off of the floor from a robot cart.

Robot Superstructure

We had a full-team discussion to decide on the superstructure we would like to design this year. The main designs we evaluated were a double-jointed arm, a tilted elevator with a virtual 4-bar, and an elevator on a pivot, among some other miscellaneous options. 3467 made some great mockups to illustrate all of these mechanisms.

We eventually decided on the double jointed arm for many reasons. It meets all of our needs, as it can comfortably reach the mid and high nodes, and pick up both game pieces from the double substation and off of the floor. This design also allows us to be flush with the wall when getting game pieces, and flush with the grid when scoring them at both the mid and high nodes. This is advantageous as we can run our bumpers into these areas without fear of damaging the arm. We are also considering the possibility of having the arm swing through itself to score on both sides of the robot. Additionally, this design leaves open the possibility of adding a ground intake with a hopper, and a handoff to the end effector, which is an idea that we are actively exploring.

If you have any questions feel free to ask here or shoot me a PM.

-Aryan, @Advaith , @Matthew3


Actually I was referring to this. Our team loved the design!





Here is the CAD for that. It is currently built, but not tested, so we should have videos of it soon.


Awesome, thanks!


Updated Auger Write-Up

As seen in the videos from the previous post, we made some significant updates to the flange grabber/auger prototype. After countless iterations of finding the optimal compression and exploring roller options, the prototype has gained some very effective improvements. After the unsuccessful 0.4” compression version, we had low hopes for this intake going forward. But, after trying the 0.7” compression and new auger design, we were very pleased to see it work quite well. We also added a 3rd roller of 3” compliant wheels as a safety net to kick up cones that could have missed the top 2 rollers. We are also exploring the idea of using this 3rd roller to actuate up and intake cubes.

Please note the two plywood plates sticking out on the sides were a quick idea to adjust cones at odd angles, but after further thought we will likely not use this on the robot. It inhibits our ability to quickly ram into walls and collect game pieces at the Loading Zone, and being able to do this was a major reason for wanting a ground intake to begin with. Another solution we are considering for this problem is spinning the bottom 2 rollers in opposite directions to intake the tip of the cones.

Overall, the design is looking quite promising as it is intaking and vectoring cones very quickly, so we are likely going to use this as a ground intake on the robot.

Auger CAD
*The assembly is not very robust; we only needed some parts to make the essential side plate dimensions.

Charge Station Testing

We began playing around with balancing on the Charge Station. This gave us a reference point for what frame dimensions we might want to use.

What’s next?

Starting from today the team will be transitioning away from initial intake prototypes and beginning our robot CAD. We haven’t set a hard deadline yet, but we expect to have most of the CAD done by the end of next week.