Stronghold Drivetrain Review

[jreneew2]

We were the first team to come up with Mecatankanum. It was four mecanum wheels with pulleys on the axles with tank treads attached. This allowed us to fly over all of the drivable obstacles easily. The reason we went with this design was because of the size of the goal compared to the ball as well as we always use mecanums because we love them. The whole robot ended up weighing in at 108 pounds! The guy who came up with the design of the rhino drive design said he loved our design and said it was the coolest drivetrain ever!

Also, we plan on making some improvements like drop down treads and maybe version 2.

[BeardyMentor]

Modified AM14U3 with the gear boxes changed to 12.71:1. We modified the chassis to accept the AM 8 inch pneumatic wheels. The wheels were tapped to take 1/4-20 screws instead of the #10-32 screws it is designed for. We theorize that this will help prevent the shearing of the bolts that secure the drive pulleys to the wheels. We also used 1/8" wall 1x2 tubing to space the frame rails and a single piece of heat formed polycarbonate belly pan that wraps around the entire bottom of the frame to help prevent getting stuck on hard edges.

[Chris is me]

We did a 10WD with all 6" Colsons. The center wheel was dropped 1/8" and the outer wheels were raised 1". The center wheel probably should not have been dropped as our wheelbase was too short and we turned too easily. This drivetrain easily handled all of the defenses, except for the moat - sometime between concept and detailed design, the drivetrain got two inches longer, and too much space was left between the drive wheels. This was my only complaint with the drive, other than weight of course.

We did not run into any issues by not using pneumatic wheels, and we enjoyed the greater traction of Colsons. We may have changed the outer wheels to pneumatic if we had to do it again though, just to be safe.

We used 25 chain with 22T sprockets, and it stretched a lot more than it normally did, but we had no issues with throwing chains or damaging sprockets.

[techtiger1]

Biggest obstacle for Stronghold drivetrains=bumpers and bumper rules. We went with a custom tank tread system with suspension although it wasn't as advantageous as we hoped the team was happy with its performance.

[jwfoss]

Our redesigned chassis held up very well, it consisted of the following:
-8WD with .160 drop centers
-6061 2x1x.125 Tubing except for over wheel rail mounts (1.5x1x.125 Tubing)
-WCP SS 6CIM Gearbox modified for #35 chain, non-direct drive, and spacers to solid aluminum/solid delrin with 1/4-20s
-WCP Bearing blocks with 1/2" Round Bearings
-4140 1/2" steel hex stock turned round through bearings, keyed for sprockets
-6" Pneumatic WCP hubs with diamond tread
-#35 Chain running on 12T sprockets
-Full Wrap Belly Pan

Built it once, only maintenance was checking tire pressure.
It's safe to say that our first time with our modified WCD was a success and the teams new baseline.

[dmorewood]

Custom designed Nanotube Modeled off of the Andymark one. 6 9.5" Harbor Freight Wheels. All the wheels were independently driven by a CIM. We never stalled out and we rarely ever got stuck on the moat. It was a rugged and reliable drivetrain and one that we may end using again in the future.

[jodge1706]

I'm almost scared to say it but.......swerve

We did swerve, because our strategy was not to focus on crossing defences, although the drive train did work well against most in practice. Our strategy was to cycle through the low bar and shoot boulders in the high goal and be quick and efficient with that.

Our drive train had 4 in diameter wheels (custom made), with a 2 speed transmission reaching very fast speeds in high gear. It worked well for our strategy, it helped deter defenders, and in eliminations at Rocket City, helped play defense like no other. We tried to prove that, in objection to popular opinion, swerve would work great for this game, which it did. I can post pictures and designs if there's interest

[Jrizo]

We used a West Coast Drive. 6 andymark Pneumatic wheels, 3 stage WCP ball shifter with 4 cims , 1/8 inch drop center with WCP bearing blocks on each end, 35 chain with 12 tooth sprockets. The only problem we ever had was getting stuck on the moat but I think that was a battery issue since it only happened twice during all of our matches.Normally we would just power out if we were hung up. I would have to go back to watch the video to make sure that that was the issue

[Ryan Dognaux]

We tried to be as COTS as possible this year and it worked great for us. We went with the AndyMark KOP chassis, ran WCP 14:60 single speed gearboxes direct driving the center wheel and used 8" pneumatic tires in a 6WD configuration. #35 chain powered the outer wheels. Our acceleration was fantastic and our top speed was controllable. The drive easily handled every static defense and could push people around as needed. We didn't throw a chain all year and didn't have any chain tensioners.

The only problem we really ran into was maintenance on the drive gearboxes. We killed an 14T aluminum gear at Midwest and spent an hour taking off our drive side and removing the gearbox. It was definitely not designed for maintenance and we are going to take that into account for next year. Usually we wouldn't use 8" wheels in a game though so the bolts used to face mount the gearbox would normally be accessible.

[lorykzarr]

We used the AM14U3 KoP chassis with 12.7:1 2 CIM gearboxes. For wheels, we ended up getting tires from Princess Auto (Canadian Harbour Freight). We 3d printed a set of 2 piece inner wheels that the inner tube sat on. We then used aluminum plates that sandwiched the tire together after we had problems with breakages on the lamination lines of the 3d printed parts after pressurizing the tires (think of a beadlock tire/wheel). It probably would have been easier to cut down the stems on the steel rims that came with the wheels and then drill a bolt pattern to hold on the hex hubs and pulleys.

[cadandcookies]

I really want to see someone from 2220 post here-- their drive train was one of a few that I hadn't seen before this year.

As for 2667, we were terribly vanilla. We did pretty much what the OP did, but got wider wheels from Fleet Farm and used some 3D-printed parts to hold the pulleys to the wheels. Surprisingly we had zero failures at our regional and on our practice bot, even though we were using PLA at like 40% fill.

[Stephen.Yanczura]

Originally Posted by jwfoss

Our redesigned chassis held up very well, it consisted of the following:
-8WD with .160 drop centers
-6061 2x1x.125 Tubing except for over wheel rail mounts (1.5x1x.125 Tubing)
-WCP SS 6CIM Gearbox modified for #35 chain, non-direct drive, and spacers to solid aluminum/solid delrin with 1/4-20s
-WCP Bearing blocks with 1/2" Round Bearings
-4140 1/2" steel hex stock turned round through bearings, keyed for sprockets
-6" Pneumatic WCP hubs with diamond tread
-#35 Chain running on 12T sprockets
-Full Wrap Belly Pan

Built it once, only maintenance was checking tire pressure.
It's safe to say that our first time with our modified WCD was a success and the teams new baseline.

Can confirm, 558's drivetrain was good this year

[mitchyg98]

As a rookie team we went with the KOP chassis with 6wd 8" pneumatic wheel upgrade kit. A lot of teams had some crazy complex drivetrains, but I'm really proud of our simple design, which must have been one of the lighter designs. We never got stuck on any defenses, and we could cross at almost full speed with the tires absorbing most of the impact of landing. As a driver, sometimes I wished we had some kind of transmission to have more power for pushing other robots and accelerating quicker, but I can't complain. I always was surprised when I saw teams with tons of experience and complex drivetrains getting hung up on the ramparts or moat.

[jijiglobe]

Originally Posted by mitchyg98

As a rookie team we went with the KOP chassis with 6wd 8" pneumatic wheel upgrade kit. A lot of teams had some crazy complex drivetrains, but I'm really proud of our simple design, which must have been one of the lighter designs. We never got stuck on any defenses, and we could cross at almost full speed with the tires absorbing most of the impact of landing. As a driver, sometimes I wished we had some kind of transmission to have more power for pushing other robots and accelerating quicker, but I can't complain. I always was surprised when I saw teams with tons of experience and complex drivetrains getting hung up on the ramparts or moat.

100% agree. We modified our AM14U3 to have gear shifting and 8" pneumatic wheels. The gear shifting was totally pointless, but our drive train was able to go over all the terrain defenses, as well as outmanuever any defensive bots that tried to stop us. The one downside we had was that our drivetrain was very wide, making it difficult to line up with the defenses (particularly the freaking sally door).

We got to einstein with that drive train so I would say it has an amazing complexity to effectiveness ratio.

[GCarnes]

Originally Posted by jodge1706

I'm almost scared to say it but.......swerve

...I can post pictures and designs if there's interest

Yes please do. Im very interested to see how you guys designed you swerve drive to fit this year's game.