I think they are great modules. The original wheels are terrible but rev stepped up with the best customer service I’ve seen in a hot minute in that regard.
The only issue we ran into with the modules besides the wheels is having a bolt loosening off enough to decapitate the encoder as the module swung around.
Balance a wrist against gravity, make sure a mechanism retracts passively into the bot if something breaks, create a pivot point that is sprung one direction to help control systems and can collapse on contact (I e. Everybody arm running into feeder station this year), pull backlash out at a mechanism (intake) pivot point vs fighting so much with chain/belt tension.
I would love to see that too! Such a product would be great packaging for counterbalance applications, and would (theoretically) be a lot easier for teams to implement than CF springs or gas springs.
I’d also like to see some form of a brake added for shafts, preferably independent of a gearbox (so it can be added after a chain reduction, for example). We’ve got a system set up this year for a bicycle disc brake that’s working well, but having something a bit more off the shelf would be awesome - especially since all the disk brakes we can find have metric hole spacing, which makes them annoying to try to use with standard FRCFIRST Robotics Competition hubs.
A friction clutch for shafts would be nice to have too. You can get them from McMaster fairly easily, but then need to go through a process to integrate them with hex or MAX Spline shaft - something off the shelf there would be an awesome way to power arms/intakes (final chain reduction through the friction clutch) that can easily retract on impact without having to back drive or stall the motor.
Absolutely, maxspline is the perfect platform for a COTSCommercial, off-the-shelf disk brake or drum brake solution. Clutches too.
Team 6081 also had a similar failure mode on the 2x1 MAXtube. Once on our elevator base, and we have also seen it fail on a neighboring team’s robot. The scribe line makes the tubing very weak on that particular face.
We used 3D printed jigs with drill bushings to (mostly accurately) pattern our own tube by hand last year. This stuff is a lifesaver.
We’ve experienced 2 failure modes, though both could be contributed to misuse.
Crushing thin-wall tube (from both short and long sides). We’re one of the reasons TTB created those crushblocks lol.
we used a tube plug to mount 2 thin-wall tubes in a T-joint for our intake. When said joint took an unintended hit, the tube plug ripped cleanly through the 1" face. We swapped to thick wall and it hasn’t been an issue since.
Overall, super happy and intend to keep buying!
We have had similar cracking failures. I’m not an engineer but .04in feels way too thin on the 1in face for these applications.
A disclaimer since 2220 is a REV sponsored team.
We have made extensive use of all REV’s MAXTube extrusions in the course of building and running several robots since last fall, including our competition robot which competed at Heartland last weekend. We have also been using MaxPlanetary gearboxes on all our mechanisms, a Max 90 gearbox on our wrist, their #10 tube nuts, a variety of gears and wheels… you get the picture, we’ve use a ton of REV ION this year.
Going bit by bit
MAXTube: We now have a standing rule that maxtube gets a printed spacer insert if it’s getting a bolt through a thin side. The wall is uncomfortably thin and easy for a student to crush otherwise. We’ll also sometimes use fender washers or custom plates to distribute load when an internal spacer is impractical. That being said, as of yet we haven’t had a failure of it on our competition robot after running 11 practice matches and 14 official matches at Heartland. Even with mitigation steps, it has been a huge step up in both time and reliability for us.
MAXPlanetaries: I was a bit concerned about these after we saw some failures on our climber last year, but am happy to report that when you don’t cantilever the shaft, forget loctite, and climb on them, they are extremely robust. We’ve been running one on our shoulder and one on our wrist all season, as well as one on our intake.
Max 90: We uh… somehow managed to assemble this wrong and kill some bearings in it. Oops. That being said, after we sorted that out it held up pretty well.
#10 tube nuts: I love these as a product. We have torqued some of them out of their stars, which is a pain to remove. It seems pretty inconsistent, because we’ve also had some of them take some huge abuse
Tube Plugs: These are fantastic-- they’re very nice quality and work well. Not sure what else to say about them, we haven’t had any issues and they have all the same benefits as the WCP ones we used last year, just compatible with REV tubing.
Gears: We used the hex and maxspline 40t gears on our wrist, and they’ve taken a lot of abuse there. Big fan of them so far. Love that they’re indexed and marked, and are about as light as it gets for a steel gear.
Wheels: We pretty much have only used the medium durometer 2" wheels on this robot, but they’ve held up really well.
We weren’t able to do literally everything with REV ION this year, but we got pretty close, and I think it was the easiest experience we’ve had so far building an FRC robot.
I suppose we’ll see if I’m still of all the above opinions after Houston, but as of right now I’ve been very satisfied for most of the REV ION stuff we used.
The assortment of ION Hardware we’ve used thus far has all been pretty great.
One thing we did notice, and perhaps this is already on the way for Phase 4 - but the MaxSpline ecosystem seems to be missing certain components - would be nice to have 2" Flex Wheels that slide over a Max Spline, along with 2" Wheels that are in some other Hardness option other than the “Hard Option”.
I want to say there was also some sort of “MaxSpline Roller” Extrusion Floating Around at one point, basically a sleeve that slipped over a max spline turning it into a round roller - this would be useful if it made it to market.
This all probably falls under the “It would be nice if Max Spline played well with smaller wheels” which may be a weird ask, considering that there’s not much difference between a 2" OD wheel and the 1.375" Spline OD, but may as well ask.
Also, MaxSwerve is generally great. Only real comments relate to the molded wheels, which I won’t go into here. Otherwise, it works well - sounds weird - but that just seems to be the nature of things.
We debated a lot about what drive-train material to use because pre-patterned box tubing is great, making it much faster to build things. We eventually ended up having a sponsor pattern 1/8 box tubing because we felt that it wasn’t worth the risk to be running thin tubing, and we needed the lower CG anyway.
I wish the scribe lines didn’t exist for the grid pattern, they aren’t that necessary when you already have the holes from the hole pattern, and they look kind of ugly. Also, thickening up the 0.04 side would be nice.
Another thing is that it would be nice if REV could sell a jig or something for marking box tube to cut to length, I know teams have their own solutions, but a COTS solution you know will work is nice.
Maxplanetaries seem to be okay, we ended up having some weird shearing issues (there suddenly was a lot of metal shavings in the MP and it stopped working) in one of our MAXplanetaries (noncantilever steel shaft, arm gearbox with large chain reduction to protect) We aren’t really sure where it came from, but we replaced the gearbox stage and CIM key, and it seemed to be ok.
The CAD is kind of unoptimized though… there are so many unnecessary parts that hurt your load times for no reason, plz simplified the version.
We found the absolute encoder adapter was hard to use, so we ended up not using it and going straight to DIO.
Tube plugs work, we have some issues with cross-threading the screws, but that’s a skill issue on our part I think.
Maxspline: The bracket plates seemed to have issues with fitting with the spline shaft. Otherwise, it seemed to work well and was compatible with the stepped bushings and 3/4 tube included without not too many issues.
Overall, it improved our workflow and speed a lot, so it works.
This year we suffered from one of our design mentors prioritizing his home reno and upcoming nuptuals over build-season. This left a bit of a hole and we’ll be re-evaluating his commitment level going forward. 
But I digress.
As a result, we went with a simpler robot based substantially on Rev ION components. Our live axle is based on MaxSpline, 3/4" tube and needle bearings or bushings. I even discovered a handy hack to get a piece of hex shaft inside the 3/4" tube to drive a through-bore encoder (the hex shaft takes no load, yeah, that’s just regular 1/2" copper pipe):
We experienced no failures of the MaxTube (yet) but I also think we used it conservatively, and used lots of the inserts.
Our biggest problem this year was that most of the Rev ION stuff was not available in the Canadian warehouse forcing us to order from the US warehouse. We spent a literal fortune on shipping/dutys/taxes and waited, sometimes upwards of 3 weeks, to get our parts. This is not a slight on Rev Robotics, in any way. I can’t imagine the hassle of trying to maintain stock in multiple warehouses. Will we continue with Rev ION in the future? Unsure; but not because we don’t like it.
I will say, max planetary wise: we did run into issues with one of the planets seizing due to poor lubrication on the planet carrier pin and the planet. Considering supply chain issues this isn’t great. Lubrication out of the box seems … Well could use some improvement.
We found the the hex spacer stock from Andymark also works well to do this. The product listing says .7" OD, but it seems to be working well for us at least.
On the whole, we’ve fully bought into the REV ION ecosystem and it has made designing and building our robot much easier this season. We are replacing some parts between competitions due to the “zippering” issue, but sometimes that’s just the nature of driving hard.
One issue we did come across during build was a small batch of extrusion had some issues with the holes on the short side lining up properly. We ended up sequestering a few pieces of 2x1 light and a piece of 2x1 with max spline pattern, due to the offset being enough to cause assembly issues.
Can you elaborate on what difficulties you were experiencing? One thing I am noticing is that our docs don’t do a great job of pointing out that you need to call the CANSparkMax.getAbsoluteEncoder() method, so I’ll make a note to fix that.
Please also feel free to reach out to our great support team at [email protected] any time you’re having issues.
Maybe if we reduced the friction of the field surface, y’know, so that it would be easier for robots to bounce apart after a collision… 
The 1" face is the same thickness on the max tube, thick and thin wall are 0.04"
This is the problem with the REV 2x1 is both your thick and thin wall tubes have the thin 1" side, so if i take what your saying is to just not use REV 2x1. Don’t get me wrong i love your products and we’ve had great resaults using them and still plan on using them. The point that I was getting at along with many other is we believe that the score line along with going with such a thin 1" side is a flaw in the design. What I was stating about what the hole size was in reference to what was originally posted earlier in the thread. That does bring up a very minor effect it might be having is with that hole size along with all the holes being 1/2" on center it reduces the material between the hole. Yes that is very minor but could be a small contributing factor in the tube splitting. For the record the splitting on 1" side we had was on the thick wall. We had other thin wall tubing with the grid pattern split on the 2" side but that was due to improper application and do not fault REV for that. The pictures I had posted of that tube was to show how the grid pattern face cracked in a bunch of the surrounding holes.
We are using max tube for both our A-Frame for the arm and between our Mk4i swerve modules. We had no problem with either and we had some hard collisions. Though the resiliency of our frame may have had more to do with our steel belly pan and ballast pan. I do know a couple of teams who were involved with collisions with us ended up with bent frames.
Some of the max planetaries on our arm did get a bit crunchy but we don’t feel that was under normal load because the clamping blocks for our arm broke and that would have applied a significant cross force to the gear box instead of just rotation resistance.
I have been happy with it so far, though for frame I may steer away from it if not otherwise supported as with our belly pan.
@cadandcookies I am not sure if we had any hard impacts with you guys or not.
Well you weren’t the only ones running around the field hitting things 
