I’ve not been able to find the answer to this question and presume its been asked well before myself - so my apologies.
You have a choice in FTC of one of four kits:
Studica
Rev Robotics
Pitsco Tetrix
GoBilda
-Which would you choose and why? I’m in Canada and see benefits of each kit, but if you could only pick one? Why that kit? What would you be missing without this kit that buying parts afterwards would be more costly? I’d love to know what championship teams in multiple regions have gone with, and like swerve dominating teams ability to control robots, does a similar statistical result exist with the base kits chosen?
-we do not have CNC abilities if it matters but do have access to 3D printers…
I coached a rookie team this year, and I went with the Rev Robotics kit. At the time it was a choice between Rev Robotics and Tetrix, and our regional advisors strongly recommended Rev - they said Tetrix kits were outdated and barely used anymore.
Before our team was disbanded*, we were planning to switch to GoBilda for next year and had even bought and assembled a GoBilda drivebase. GoBilda is overwhelmingly the drivetrain of choice around here (PNW); there were only one or two other teams at our events who weren’t using GoBilda. The mechanum drive is vastly more maneuverable than the Rev tank drive, even the Rev tank with omnis. The GoBilda mechanum kit was also much easier to assemble. Maybe partially because the kids were a little more experienced with tools, but I think mostly because it actually is more user-friendly, and doesn’t require any fiddling with chains (among other things).
*I work for a nonprofit that ran and funded the team, and our partnership with the district has ended unexpectedly
Gobilda is by far the market leader in terms of the comprehensiveness of their ecosystem.
REV is fairly solid, although mostly used by teams on either end of the extremes of no tools/lots of custom.
I would not touch Studica or Tetrix personally. Tetrix is extremely low quality and has inane standards. Studica engages in some particularly shady business practices of stocking competitor parts until they make clones of them, and then selling that.
Personally if I was buying in today with money but no tools, I would go with Gobilda.
If I was buying today with limited money and no tools, I would probably go REV.
If I had lots of tools, I would be mixing and matching GoBilda and REV.
As for additional parts, I would recommend buying into or developing a solution for a mecanum drivetrain and linear slides based on the ecosystem(s) you choose. There are kits or you can part out/design one given your choice.
Given 3D printers of reasonable quality, you can do a lot in FTC— even with relatively standard PLA you can print structural parts for an FTC robot that will survive for a reasonable amount of time.
Outside of 3D printing, there are a variety of laser sheet services that have popped up (SCS, Fabworks, etc) that make custom sheet very approachable to teams, though perhaps more expensive for you given Canada.
We had a preview at champs but AndyMark will be releasing our new FTC build system this Fall for purchase. The primary focus of Robits is to promote accessibility, allow for iteration, and foster progression.
Mechanum wheels on frc ive found really want 2d fields and when you add things like barriers or ramps to drive up on done work well…at least imho…
Related have ftc teams gone into swerve drive and if so which way? Build, buy, was this part of reason for the choice of four kits chosen…
Ive done frc a few years, and ftc is more financially viable for us….but how many are using swerve drive at championships? Are most tank, mechanum, or omni wheels? Like swerve for interest and future goal, but if buy build then thats a large funding expense….any ideas related to above…initially both are related…which kit and drivetrains are most important to figure out initially….again imho…
Swerve drive is not very common in FTC, and largely does not present the same competitive benefits present in FRC. This is in large part due to motor restrictions— you are allowed 8 DC motors and 12 servos. This can make it difficult to fit modules into the motor budget, as servos for your azimuth motor has significant disadvantages.
That being said, teams have run custom differential swerve modules in FTC and this is what I would consider the “state of the art” for swerve.
Rest assured that you are not at a competitive disadvantage in FTC whatsoever, at least in terms of gameplay, running mecanum. Most of the disadvantages of mecanum in FRC simply aren’t relevant in FTC, and many of the benefits are significantly stronger on the smaller field.
For a variety of reasons, including the relatively arbitrary COTS rules of FTC, I would not expect swerve to make significant inroads in the competition until something significant changes with the competition rules.
Just in general, I would recommend leaving any preconceptions of competitive robotics you might have at the door when you run FTC. It’s not the same competition as FRC in terms of scale, rules, culture, or gameplay.
Mecanum is king in FTC. Teams have used mecanum wheels without much issue in games with obstacles (Freight Frenzy, Relic Recovery) as well as flat field games (Skystone, Ultimate Goal). Generally speaking you won’t have issues getting over things as most of the COTS mecanum wheels are about 4" and any obstacle we’ve had over the past like 7 years has been 2" or less.
Swerve is still pretty new in FTC with some teams using a differential swerve and others using newer brushless servo technology for coaxial designs. These are not common and I wouldn’t expect this to be something you could buy anyway. If you’re looking for a fun engineering challenge, this could be a route to go but there are so many other facets of a robot that could use innovation vs the drivetrain.
If mechanum is used then are teams leaning heavily on the imu of the control hub for telemetry?
Slippage is i thought quite common in this drivetrain so wheel encoders might not be as reliable to predict positioning?
Something ive seen others do is have omniwheels for this purpose but inexperienced so seeking others thoughts on this?
If mechanum is the choice of then im assuming gobilda is better than revrobotics version is preferred…
This then adds to my challenges as a canadian team playing the importation game of brokerage fees…surprise…should i use somewhere like a cbi usa….vs ups, and finding how to pay the least taxes for an educational organization…that is suppose to be tax free??? Yet pitsco charges, basic shipping, taxes, then vat on ups shipping??? The game of getting the best resources for my team at the least cost…thoughts???
Our teams operate at a mid level and we use the built in gyro from the control hub. Higher perfoming teams use dead wheel odometry for localization.
I’m a bit biased but I like the BB mecanum from AndyMark. The size is essentially the same size as the GoBilda wheels but it has nuts and bolts instead of eclipped rollers.
Even internationally, I think gobilda might end up the best value for your dollar. Slipping is common with mecanum drivetrains under acceleration which is why the deadwheel odometry pods are used, I’d honestly suggest manufacturing an open source design or buying them from a vendor (I believe there is one coming out this year? Rumors are floating around).
As for the mecanum wheels themselves… there honestly isn’t an appreciable difference between the gobilda, rev, and andymark BB wheels. Each ecosystem’s wheels are easiest to use with that vendor’s ecosystem obviously, which is why the gobilda mecanum wheels are so popular
It’s used by a lot of top teams (more than any other kit by far) and you can do a lot with just gobuilda kits (Roboplayers 2023)
We’ve used it for years and It does everything we want it to, our 2023 robot was mostly made up of goBuilda and 3d print. Also as small as it seems having motors fit inside the gobuilda u-channel is very nice to have.
REV is fine i don’t have a lot of experience with it but from what I know it seems like you can build a simple robot with it quickly but not quite as versatile.
i’d agree with cadandcookies on studica or tetrix, low quality however from some quick looking it does seem like studica is much cheaper than gobuilda or REV.
When looking at drivetrains I’d say that mecanum in ftc will always be a good option and it’s currently the most popular (and in my opinion the best) option. Mecanum usually comes with 2 differant auto approaches: Time based, or dead wheels. Time based will run the mtoor for a certin length of time and is very susceptible to slippage but they can still work (I.C.E robotics 2021) you can use the gyro to try to help with rotation and correct some of the slippage but it will still be a problem. Dead wheels are the best option [Open Odometery] (https://openodometry.weebly.com/) and Road Runner are simple ways to get dead wheels working well so while they are more complex than time based i wouldn’t say that they are inaccessible to any teams.
Swerve is very rare and very technically complex with little benefits. It can be faster and more defense resilient but I personally don’t think it’s really worth the effort given the types of games ftc has had.
Teams use dead-wheel odometry to avoid the use of drive encoders or the IMU (which is slow due to how the apk handles I2C)
But either way, I would suggest the gobilda ecosystem because it is made to a much higher quality than all the other build systems by a long margin. Tolerances are tight, motion is based off of ball bearings and hex shafts, parts are built stronger than other builds systems, and many gobilda parts are still relevant even when building a primarily-custom robot.