2011 FRC Robot Offseason Project

The original plan for 1086’s “2021 season” was to have an internal competition between the seniors and the rest of the team. We had chosen the 2011 game for this competition. These plans ended up falling through due to a variety of reasons. However, since the seniors on 1086 didn’t get an opportunity to build a (new) competition robot for 2021, we ended up still building out our robot for fun, cuz why not to test out new mechanisms/drivetrain for the future.

Presenting: Cheez-it (Previously named Halloumi)

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Quick overview:

Drivetrain:

  • SDS MK3 modules with fast gearing, NEOs, and billet wheels.
  • Combination of pocketed 0.125” and un-pocketed 0.0625” wall square tubing.

Elevator:

  • Two stages.
  • Continuously rigged.
  • CF spring balancing the carriage. (For lower current draw when placing on the low and middle peg, available mounting option to balance the entire elevator as well if needed. [If we were going to compete this we would balance the entire elevator to allow for consistency, hopefully making it easer to program.])
  • 0.0625” wall square tubing used for all the stages.
  • Combination of (aluminum) CNC milled and (PLA) 3D printed bearing blocks.
  • Calculated bottom-top travel time: < 0.4 seconds. (Accounting for acceleration).
  • Powered by two NEO motors.
  • Return rigging line is spring loaded to maintain tension when the length of the run changes. (Due to the change in the fleet angle as it spools/de-spools).
  • 0.125" Dyneema rope used for rigging.

Arm:

  • Pocketed 1.75”x1.75”x0.125” square tube. (Partial and full depth pocketing).
  • Gearbox is packaged in the carriage (3.75” wide).
  • 126.11:1 Reduction.
  • Four Stage gearbox. (Axles shimmed to reduced backlash).
  • Absolute encoder on the final stage of the gearbox.
  • Powered by a NEO 550.

Intake

  • Independently powered top/bottom rollers to allow for rotation of the inner-tubes.
  • Powered by NEO 550s.
  • 3D printed intake roller wheels. (Covered with neoprene rubber).
  • Pneumatic actuation giving the option to not “outtake” the inner-tubes (Counter rotating the roller wheels to spit it out). This allows for the tubes to be “placed” rather than “spit-out.”

There are a lot of features I didn’t cover so I would be happen to answer any questions. (Someone should also ask @jackoleary about the milled bearing blocks and their fixturing [check out the photos] :slightly_smiling_face:).

Photos(CAD and IRL):

Link

CAD:

Link

Something something emperor swerve x 254…

Designed by: @Casey_Gormley
Built and Fabricated by: @Clevkev, @jackoleary, @Casey_Gormley
Programmed by: James Farnsworth.

34 Likes

Awesome looking robot!

Could you provide some details on these?

follow the link to the photos and you will see both their bearing blocks before assembly. they also show a cad photo of how they are machined. From what I see the first step machining uses fixture clamps from miteebite (which can be bought on mcmastercarr) held in a custom designed fixture for a CNC machine.

The PLA bearing blocks constrain inner stages from shifting left and right as well as serving as the corner braces on the bottom of the first stage in lieu of gussets. They mount to the tube using 8x #10-32 bolts through each tube into heat inserts in the print. The 1/2" OD bearings ride on a double tapped shaft through the print so that any load is spread over a larger diameter and length (and thus area) than using a heat insert.

Pictures




The CNC aluminum bearing blocks prevent the carriage and first stage from shifting and falling apart forwards/backwards. It’s a fairly simple assembly consisting of one aluminum body, a 1/2" OD bearing, a shoulder bolt, and small spacer. The aluminum body was machined using our VMC using this fixture plate:
image
The main idea of the fixture plate was fairly simple. I needed 3 operations to finish the part, so the first one would take care of the overall shape, the second would take care of the extra “tab” around the part, and the third would drill out the side hole for the should bolt to be tapped into.
Other than some strength issues with the way I used the clamps I used (same McMaster ones as our tube vise), it worked perfectly.

Op 1:

  1. Roughed the profile of the part along the entire length of the stock (about an extra 3/16" on each end) (This make a lot of the 3d contouring turn out a little nicer)
  2. Drilled and counterbored the four mounting holes
  3. 3d profiled the surface to finish it (video attached below) (Fusion 360 Spiral toolpath for anyone who’s curious)

Op 2:

  1. Fixtured by the mounting holes, cut the part to its finished size in X and Y
  2. 3d contouring to deburr the curved surface (these surfaces needed to be clean and free of burrs since they were the z datum for op 3)

Op 3:

  1. Drilled a single .159" hole in the side to be tapped for a #10-32 shoulder bolt.
More Pictures






Profiling video: https://photos.app.goo.gl/d73uK7nsrG5Ze4o47

Carriage Bearing Blocks:
The carriage bearing blocks were built into the carriage gearbox assembly.
image
Not a ton of machining went on here. There are 8x bearing-shoulder bolt assemblies to prevent forwards/backwards movement, and 8 bearings bolted in slots through a piece of 3/8" aluminum using a perpendicular hole drilled after laser cutting.

6 Likes

Where’s your mini bot?..1610 still has their 2011 robot (and mini bot) While we updated our first robot from 2005 we’ve never updated 2011 with whats available for teams today.

Given that a minibot would probably just turn into an optimization problem we’d never actually field, it made more sense to focus on the key (and relevant in today’s FRC) aspects of the robot, of which we are very proud

1 Like

do you know the exact bearings you used? do you have any recommendations for choosing bearings for this kind of application.

The two types of bearings we used on the elevator (excluding bearings used in gearboxes and such) were 0.25" ID x 0.5" OD x 0.1875" WD and 0.25" ID x 1" OD x 0.3125" WD. (These bearings can be purchased from a variety of places including WCP/VEX/McMaster). The main factor for bearings selection in this design was size. We knew the smaller size of the two has been used before with success in similar load cases, and we knew they would be sufficiently small enough for us, so we went with that. (Mainly, we weren’t worried about the bearing strength, but rather anything smaller would likely have a smaller ID", meaning that we would have to use a smaller shoulder bolt, and we felt the smaller size would not be strong enough to withstand the loads.) The larger size was used in the carriage since we needed it to clear the material of side plates and the bearing blocks.

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