Re: Best simple robots based on kit chassis?
 

Team 694 won Curie this year with a kit chassis bot. It wasn't exactly a simple bot so you might not want to include it in your list, but it does technically fit the bill.

Re: Best simple robots based on kit chassis?
 

It is common in the working world to use off the shelf parts where possible to save time and effort and get to market quicker.


The lack of restriction you see as an advantage can also lead to a trap. One can spend a lot of time figuring out where to mount the components and optimizing it over and over.


There is also risk that you are not able to get all the needed parts manufactured correctly in time. A few years ago, a team in our area that had been part of a Einstein winning alliance spent the Thursday of their first Regional completing the assembly of their robot. Their sheet metal sponsor delivered their parts just a bit over 24 hours before bag and tag so they had to bag an incomplete robot along with all the uninstalled parts (it didn't even have wheels installed). The imperfect COTS parts you have in your shop will perform much better on the competition field than the perfect custom parts you only have CAD drawings for.


This robot should be included. The time they did not spend developing a custom drive train (probably giving only a small increase in performance) was probably spent on developing the scoring mechanisms and practicing, allowing them to perform well enough to become the Alliance Captain and win the Subdivision Championship.

Re: Best simple robots based on kit chassis?
 

I'd like to throw a hat tip to the VEX drive in a day chassis, 558 used it to success back in 2014 and we loved it. Its our go to for prototyping.

If you are looking to stay simple I would 100% avoid mecanum. In my time in FIRST here has only been one year that I believe it offered enough to even consider (and the game could still be dominated by a kit chassis).

Re: Best simple robots based on kit chassis?
 

While it's not a kit chassis I'd like to throw the VEX VersaChassis in as an example because it's simple to build and fairly well documented. In 5254's rookie year we were able to build a 2 speed WCD with basically a hole saw because of the VersaChassis. VEX has instructions on how to build a simple WCD along with information for multiple other simple drivetrains.

Re: Best simple robots based on kit chassis?
 

Well 2016 was the first year for my team(6060) and since we did not prepare properly or did any fundraising for parts we had to build a pretty simple robot. It got the job done and it got my team to eliminations, here's a link to view some photos of it.

http://imgur.com/a/2e9oJ

Re: Best simple robots based on kit chassis?
 

Brief message on top and the explanation below.

The best kit bots usually happen in games where the field is flat and most of the field elements are simple like 2013 and 2014. Those robots are usually not as optimized as well as many of the ones you guys have posted.

I would say if you have the capability to customize and form a proper custom chassis then that solution is preferable to using a kit chassis. It is also easier to go "custom" than people believe!

If you have a decent drill press or even better a mill then you can easily create a Vex Pro WCD by buying a step/cone bit from harbor freight or home depot. Cost is not an issue if you get the voucher instead of the kit chassis in your kit of parts because you can allocate the $400 to buy everything but the chassis such as motors and wheels. We end up saving money, weight, and time by doing this.
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Here is why I say this. I have plenty of experience using the kit chassis since they actually started to provide it in 2005. Anything prior to that for us was 100% custom. When I started my current team we used the kit chassis for 2011-2012, made a custom chassis using 221 Robotic Systems in 2013, used another kit chassis in 2014, and then switched to Vex Pro WCD for 2015 and 2016.

We loved the switch from kit to custom in 2013 and that Cadillac of a robot chassis still runs perfectly today (thank you Anthony). We purchased these components and did not make them which means it set us back a lot more on budget.

We did not have the budget in 2014 so we went with the kit again. See the pattern here? Custom is the way to go if you have the money, or capability to save on the cost do it in house. If you have neither then stick with the kit. Vex Pro products gave us the capability to do in house custom chassis because they are simple.

When we switched to vex pro it became a lot easier/cheaper for US to make the drive system because you do not need nearly as much dimensional accuracy and the frame rails can be made easily. You could even use a drill if you were careful enough. Since the bearing blocks slide on the tubing it is easy to correct mistakes and it is very forgiving for people new to manufacturing robot drive systems.

With the kits, you are often up and running very quickly on the floor and they are easy to put together....until you decide to add bumpers. Or that shooter turret. Or that arm that you made out of 80-20. Or that metric stuff you had laying around the shop and works perfectly on your prototype...how do you attach that again?

What I am getting at is that the kit bot is rarely going to fit your design without some compromise and I have seen enough teams compromise their designs because of the kit chassis they did not want to sacrifice. Some teams did sacrifice their kit chassis in a different way this year by choosing to use it with the stock polycarbonate wheels on those nice steel defenses or modifying their chassis in well... less than structural ways. On games where the floor is flat and not filled with wheel cracking shapes I am sure that would have lasted all season. Since you never know what the game is before you decide whether to get the kit bot or the voucher, we usually just get the AndyMark voucher because we can purchase the kit anyway if we change our minds.

Re: Best simple robots based on kit chassis?
 

One team I'd give a nod to has been 4909 Bionics. I believe their rookie robot in 2014 was the only year they ran a 100% stock kitbot and have made slight modifications in the following years to better fit the game. 2015 they added mecanum wheels as their strategy was to make capped six stacks by splitting the stack placing totes and then capping them after. 2016 they stuck with 6wd adding large Colson wheels and modifying the frame slighly using the older kitbot style C-Channel framing so their wheels cleared the frame allowing them to cross the defenses.

The simplicity in their drivebase has allowed them to focus more on the upper mechanisms and completing them before bag day. Its a good strategy sticking with the #1 design rule of taking inventory of what resources you have around you and using them to their maximum potential. Aside from their first event as a rookie where they finished 15th they've always been in the top 10 at their events, qualified for the District Championship all three years, and just barely missed the finals this year at UNH.