With the whole Vex situation as of late, I thought it would be a good chance to learn other options for gear ratios that don’t include gearboxes/use a different type.
In the past year our team has completely switched to using Versaplanetary gearboxes with NEOs, and after going to competition and seeing the other options that other teams were using such as just mounting the gears to the motor and controlling the ratio with the different sizes of the gears themselves I’ve decided it might be time to stop using gearboxes altogether. While we were still planning on using gearboxes for the most part, this controversy was the push needed to make a decision.
Any tips on how we can effectively transition to this new system? Currently the only experience we have is with gearboxes so any help would be greatly appreciated.
There are other suitable replacements for the versaplanetaries such as the Ultraplanetary by REV, and the 57/Falcon/CIM Sport gearboxes by Andymark. Worth noting that the Sport gearboxes are for the most part non modular, except for a 4:1 addon stage.
Sport gearboxes are great like Nelson said, and can take tons of abuse. Ultraplanetaries do have swappable stages and shouldn’t be considered as a direct replacement for a CIM class planetary like the MAXPlanetary. In FRC, they’re better suited for use with the NEO 550 In low load applications.
Max Planetaries are great, especially if you use CIM class motors (such as neos!), assuming you already use some form of rounded hex. The transition is pretty simple, and I would argue that max planetaries are a LOT easier than versaplantary gearboxes to the point where a freshman could probably assemble them with little to no instruction besides some CAD. No greasing is required, and no bothering with all the gears and stages, just stack the various stages between a base kit and bolt them together. The bolt circle on the max planetary is the 2-inch bolt circle, so make sure you design it for mounting as well.
The hex shaft is bolted in place as well, and there aren’t any funky bolts or whatever for power transmission, just 10-32. Max planetaries are really nice in that sense too. Use the pre-cut and tapped shafts if you want to be safe, but I would argue that it shouldn’t be too hard to cut your own shafts and tap them down if you need a custom size.
REV actually sells multiple shafts pre tapped up to 6" or 8" in 1" increments. The max planetary gearbox is so much nicer and easier to use than versa planetary, stronger too. Depending how many stages you use you won’t have to cut the shaft on a neo because the sun gear is designed with a hole in the center for the shaft to go through. One of the issues we ran into in the past with the versa planetary was you were stuck with a 1 1/2" shaft unless you get the adapter to convert the shaft to a female coupler and then it sticks out making you space the gearbox and motor away from your mount depending on the use. We had this issues last year on our climber in a box, we resolved it by switching to max planetary after our first event when we had a sun gear fail on the versa planetary. That sun gear was the original design that was welded and the weld broke, the newer sun gears Vex had changed the sun gear assembly to being an oblong press fit. Thats another thing that is a huge difference is when students disassemble the gear boxes to put parts away and they aren’t careful marking what size gear is in what stage, always seemed to happen, then you were down to counting teeth to figure out what ratio the gear set is and the max planetary is self contained with the ratio printed on the outside for simple identification. As far as the ultra planetary we did have a couple failures in the past with moderate loads on them. The nose assembly was held together with really tiny screws and all the load was put on those screws and they sheared pretty easily. REV has since corrected this with version 2 of that assembly by putting pins in there to take the load and the screws hold it together instead of taking the load. The other downside is the ultra planetary uses metric hardware so you have to keep some metric Allen wrenches on hand for assembling them. The only downsides to the max planetary is it is heavier and the ratio selection isn’t as broad as a versa planetary but the max planetary is a lot stronger.
Exactly! The biggest benefit to the MAX over the Sport is that you can choose/customize a wide variety of gear ratios on the MAX (whereas the sport for the most part involves buying a whole new gearbox if you want a new ratio).
But yes, 100% the sport gearboxes are a very robust option!
This has kept me away from purchasing the sport gearboxes, But mostly because I haven’t grocked how broad design envelopes are now with the brushless motors… if you’re using a NEO or Falcon, 80% of the time you don’t actually need to optimize gearbox ratios. It’s gotten safe to stock a couple fixed ratios and call it a day.
Anyone have recent experience with BaneBots (besides Sport, which I believe is BB, resold by AM)? I haven’t seen them come up in any of the recent discussions, and they seem to have several products that might fit needs teams are having of late.