Not the first time I’ve seen those in robot cart threads. Would make for an excellent KoP item! 
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Any chance you would be willing to share the design of this cart?
We don’t have CAD to share sorry - it was kind of just built to sketch. The base is a 2’ x 4’ rectangle made of 2x1 aluminum tubing, joined with riveted gussets. The top of the tubing has a plywood deck. Additional plates are used to hold the casters and the handle (which is bent muffler tube). There’s an 80-20 extrusion “pedestal” on top of the plywood, which is there to elevate the robot a bit and give a place to store the bumpers, but we often tweak the pedestal to suit the robot.
Here’s a recent photo. Sorry it’s not a close-up.
My tip is to put some nonzero design effort into the cart-robot interface.
In 2022 I wrote to a friend:
This is an interesting one, we were just having a conversation recently about potentially replacing our robot cart, and I pushed back on it. I’m not super attached to the thing (some photos) but i recognize that it’s a pretty decent sized cost if we decided to replace it. A comparable aluminum platform truck would be around $500.
The rails on our cart work for West Coast Drive chassis really well, but we found that it was hard to set this year’s swerve drive chassis down on it accurately without fouling a module. We’re going to work on this and come up with a better solution.
FRC 836 has neat wooden blocks that stick up from the top surface of their cart. The blocks are reconfigurable to fully constrain their chassis.
Inspired by 836, this season I took on the side-task of rethinking the robot-cart interface to fully constrain our 2023 robot.
I came up with these plywood forks:
These are very cheap (in terms of time and money) to iterate on. They ride on t-slot rails, which can be repositioned in future seasons to support different robot geometry.
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Suprisingly enough, I don’t have any overly good shots of our robot cart on it’s own, but here’s a CAD screenshot and a half decent photo from our first event this past season.
This cart was designed and built during the 2022 pre-season. The design took inspiration from this spectrum robot cart.
Main features of this cart (in my eyes):
- Adjustable supports to keep robot wheels raised off cart (see aluminum tubing and the array of holes for adjusting from season-season)
- Light weight/easy to maneuver
- Robust 5" casters for navigating cable protectors and parking lots
- Small too chest/drawers for essential tools needed field side
- Large open space for versatile storage options
- Removable handle (helps when transporting the cart, ie shorter overall height)
- Looks good, encompasses team image and is robust enough to be used for years to come
Initially the top of the cart was about 32" off the ground for the 2022 season. For the 2023 season, we shortened the 4 legs of the cart by about 6" for a table height of about 26". In 2022 our students (and shorter mentors such as myself 
) struggled to safely lift the robot on and off of the cart. The lower height is much more ergonomic, and was still easy to work on the robot (a concern when talking about lowering the cart).
The only thing that I would add/change to this cart would be a dedicated place to store a driver station. I like the looks of the collapsible shelf brackets posted by others above, that may be a retrofit we look into for 2024…
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If I was designing an ideal robot cart, it would have these features:
- Have big wheels to get over cable protectors/bumps without being overly bulky and still maneuverable
- Be able to fit through a standard size door
- Have storage for two extra batteries, tethers, and frequently used hand tools
- Have storage for several stools or a folding bench for impromptu drive team seating
- Include a hydraulic table or other lifting mechanism for working on the robot at different heights
- Don’t need to be very careful to set the robot down on the cart in the exact correct position
To date I’ve only had carts that achieved 4 out of these 6 at a time.
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No discussion complete without 5006’s as seen here:
Chairmans 2022: One initiative at a time - YouTube
I’m an alumni from the Average Joes Team 3620 and I’ve always felt like our cart was unique so I had to share!
Storage area for technician and pit crew, driver station is the “lid” for the storage area and to top it all off a programmable LED sign of course and under glow!! (and of course we would switch out the casters to pneumatic tires for Michigan Champs, that floor is brutal)
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Coming from a team that ran one of these carts for several years, I couldn’t advise against this “feature” more. The adjustable height rarely got moved, and it adds a ton of weight to your robot cart. Personally I view this feature on a cart more gimmicky than practical/functional…
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We had one on our 225 cart, loved it and used it all the time.
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4795’s robot cart from this season folded
The whole thing was built on a 1x1 frame and held in the cart position by pins, which could be pulled out to let it 4 bar down into a much slimmer shape.
It worked pretty well, but the whole thing was kinda wobbly and creaky.
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I agree. we use our hydraulic scissor lift on our cart a lot
Haven’t really felt need to change much over the years for the main cart. Having the lift has been useful for working at different heights. Originally only had the wood platform, but a student added this polycarb & tread central feature which has been okay for robots so far.
I like having the space under the cart for split bumpers. And usually easy to find a battery spot. We do have some pouches for storage and it would be nice sometimes to be more organized.
Having a bigger cart is handy for competition and at the shop, but sometimes for outreach or going places it is too much and in that case, a dolly is useful to have. The HF one above is what we use.
And we did build an Apophis-styled cart, but using it competition didn’t work out in 2019 or 2020 and really haven’t tried since last year. It does get driven around the shop some.
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So, the team took the old cart apart and forgot to build a new one. Through this together over the weekend before competition.
Hold 2 batteries, spare bumpers, mix of fixed and caster (no air tires), rasy height. Removable handle for improved access, and “tunnel” for tools/quick fix stuffs.
Footprint was intentionally kept as small as we thought would be reasonable.
Upper robot support boards are easily removeable/modified for other robot footprints/needs.
We later added tiedowns for the robot for transit, and of course, a pink accessory bag for the coach. Later, we added on the handle side some water bottle holders for the comp team.
It may look like Wile E Coyote ordered it from Acme, but it was actually a pretty nice cart for the season. Nothing crazy fancy, but lots of lessons learned applied in its architecture and formation.
Start to finish was just myself with a handful of handtools and about 6 hours of labor.
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+1 on making a narrow pedestal for your robot so you can fit bumpers around it. Bumpers are big and awkward, and it’s nice not to have to store them somewhere in the pit. I’ve even seen teams use an upturned KOP tote for the purpose.
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This is so clean
Team 696 (and one other team I saw at Champs 2022) has a Moto Cart Jr. ELT and it’s pretty great. We just VHB’d two 2x4 aluminum box tubes across the table to support a robot by the frame rails and keep the wheels off the table.
Pros
- Hydraulic table that lifts about 6 feet high. I’m 6’2" and I’ve changed swerve treads at eye level. It’s pretty good for working on any part of your robot comfortably.
- With the lifting table, it also works as a makeshift driver station on practice fields at comps. Drivers can stand with the driver station on it just like at the field.
- Motorized wheels so it can just pull itself along, such as for the mile (ish) walk across the venue at Champs. Also great for venues like at Chezy Champs, where there’s a ramp up a small flight of stairs. I’ve seen teams need running starts with 3 people to make it up the ramp, and some occasional crashes. A small person can handle the bot by itself with this.
- Reverse beeper can be handy for getting people out of the way in the pits (re Stop Yelling Robot)
- 1000 pound capacity makes it pretty useful around the shop. We’ve used it for moving big air compressors around campus, dragging carpet rolls around, and as a makeshift scissor lift (don’t tell OSHA)
Cons
- It’s a bit of a beast. Weighing in at over 500 lbs, it takes a bit of practice to get a hang of how it drives and how to maneuver it well.
- You have to charge it. The battery lasts quite a while though, so I can probably count on one hand the number of times its needed to be charged in the last 4 years. When we’ve forgotten to bring the charger on trips, it’s always lasted just fine and the battery indicator (which may have questionable accuracy) never budges.
- It can act up sometimes and seem to stop working. At Champs this year it did stop driving the wheels, and the manual override switch leaves you pushing a 650-pound (with robot) cart back and forth, which seriously sucks.
Conclusion
It’s got some nice features, but can also be seen as more trouble than it’s worth. We used one of these from Harbor Freight for many years and it was great too. Light, decent lifting height, not bulky at all. The Moto Cart Jr. ELT is not for the faint of heart.
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A previous team achieved the same functionality by putting a stack of grey totes on the deck of the cart. The totes were used to bring parts, batteries and tools to the competition and were just taking up space in the pit otherwise.
After FiT Championship, we emulated 118 by adding a space for an extra battery and an invert with a 120V output for keeping the driver station laptop alive.
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Team was severely restricted in resources so we created this for less than $80 and built it in under 2 hours with hand tools. We used a Harbor Freight Hand Truck ( FRANKLIN24 in. x 36 in. Folding Platform Truck - $60 now but was cheaper when it bought it 4+ years ago), $12 in 2"x4"s, wood screws, and some long bolts ($10).
- 5" bolts (x4 - they might have been longer) are for going through the 2"x4" and the cart. These can be easily removed if needed for fitment into a trailer.
- You can zip tie or use metal hanger strap to secure the handles to the upright 2x4s, but we didn’t find this necessary.
- Total height of the robot platform was ~25". I like the robot higher up (assuming it still fits through doors) because it’s much easier to work on.
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