Our team currently uses Vex versa planetaries for our intake; however, we use Rev planetary gearboxes for almost everything else. We were thinking about using the ultra planetary gearbox for our intake. If you have done this, were there any issues with strength or durability?
Our versa gearboxes have held up well through multiple competitions so I don’t want to change to something that’s going to easily fail.
Also, regardless of which gearbox we use is it worth switching the bag motors to the Rev Neo 550?
It really depends on the context but I can’t remember the last time I used a gearbox on a 550/bag class motor for an intake. A belt/spur gear reduction was all that was needed. Those motors aren’t ideal for intakes either since they have far too little power. You stall a 550 by accident for any amount of time and your intake is toast and the safety margin for stalling that motor is way too low… and an intake system is something you want a healthy safety margin
The MAXPlanetary gearbox is the REV gearbox product meant to take the abuse of FRC.
2023 was the only game I’ve used a 550 motor in an intake in the last 5 years. If I go even further back I still can’t think of many times where I would use one.
Used where it makes sense (high speed low torque), 10/10 no notes it’s a cheat code for small/light/cheap mechanisms. But consider running a pinion straight off a NEO (or whatever) as well. Even we don’t think about that one as much as we should.
The Ultra Planetaries give load ratings on the drawing, but don’t have a similar go-no-go diagram as the Max planetaries. I can imagine many relevant low-load applications where having this smaller form-factor gearbox would be useful in an FRC context.
By nearly every measure, the Max Planetary gearboxes are more robust than the Versa Planetaries.
Rev load rating table:
What is your rationale for using the ultra planetary instead of the max planetary? As for the neo 550 where do you intend to mount the motor - on the intake or off the intake?
We used a Neo Vortex for intake last year. Probably overkill but the packaging with the through bore made it work very well. We try to ensure our intake motor has a high stall torque - too many situations where the game piece could jam. Keeping the motor off the intake helps keep the weight low in the robot allowing the intake to deploy faster.
I’ll challenge this part. The UP is $48 and the cost difference between the NEO 1.1 and N550 is $20. Considering that you can run a belted connection straight off the NEO 1.1 shaft I’d say the cost difference is minimal if not slightly tilted in the belted connections favor.
The weight difference isn’t all that much either if my rough calculations are correct.
We ended up going with the maxplanetary and if need be the 550 input kit/having a few of them on hand. According to the spec sheets the neo 550 is a lot more powerful than the bag motor at believe it or not a lower RPM. That being said overall I think a single reduction off a neo is a good way to go too. Unrelated but we are going to pick up a couple vortexes and the solo adapters as they can spin the 1/2" hex shaft straight from the go/direct drive an intake.
There are very little usecases for a neo 550 IMO, once you add an ultraplanetary to make the motor useful in anysense, the weight savings are gone. IMO, stick to CIM class motors.
I challenge your challenge. You’ve got to make pulleys appear; even if you print the not-motor side, your motor-side pinion is going to be awful tiny (11/12T for HTD at TTB/WCP respectively at $11-12 each, and WCP only sells SplineXS and Falcon bores in GT2 at $14). 1/2" hex bore pulleys start around 24T, which makes for a 2:1 reduction. And with the lower free speed of the big motors, it’s worth doing the math to save the world make sure the speed is right for the application. Also, the belt stockpile that develops around teams that want to use them a lot usually ain’t free…
I’m aware there are options to get around this; we ran a belt run off a gear stage when we had counter-rotating rollers, you could use a 1/2" hex adapter, and you could switch to 3/8" hex to get the 14T HTD pulley from AndyMark.
It all works for some teams, but I don’t think the value proposition on belted systems is such a slam dunk that it negates using the N550+UltraPlanetary combo.
I challenge your challenge to my challenge. You don’t need to use a COTS motor pinion. Often times we end up using a 3D printed insert ($14.99 for a 5 pack, $2.99 each) with a 3D printed pulley. Same with the non motor side pulley, we’d use the 3D print insert (also $14.99 for a 5 pack, $2.99 each) with a 3D printed pulley. In this manner we can get a wide variety of reductions or over overdrives if the situation calls for it.
Where do these exist for 8mm key? I know VEX had a set for Falcons (seems to be discontinued), but I’ve never seen them in any other bore but 1/2" hex.
(I’m not asking this to be accusatory–if they do exist, I’d like one!)
3D printed pulleys are insanely inexpensive (even if using $180/kg Markforged Onyx). If you are using something more reasonable then your prince will drop even more. Better yet, these pulleys can be integrated into the intake hub and eliminate a bunch of components. They are also easy to design if using a proper generator like this one from MKCad.
BTW V-Belt Guys use this as the part number configuration for HTD belts
[Belt Perimeter in mm]-[Belt Pitch in mm]M-[Belt Width in mm (2 digit)]
So a 101 tooth, 5mm pitch HTD Belt that is 9mm wide will be:
505-5M-09
The 505 perimeter number is 101 teeth * 5mm pitch.
Also, UPs have a very low tolerance for shock loading. We had one survive on our '23 robot’s gripper, but replaced another set almost every match on our other DOFs on that bot. YMMV with using them, but my recommendation is to keep them relegated to FTC.
They do not unfortunately. You either need to use a 8mm to 1/2 hex adapter (~$7) or you can do the trick where you use a gear as the 3D print insert (again around $7)
Seems like a real gap in the market here for a 8mm bore to 3D print adapter.
You can make them super easily! We purchased hex stock, drilled out the center, and broached a keyway. They worked great for running printed and COTS pulleys.
3494 did this for running pulleys, chain sprockets, and custom 3D-printed parts in 2020 and 2022. We used this broach and this bushing from McMaster. We especially liked using it on churro, because that stuff is very easy to drill out to 8mm, and has sort of a spline pattern that interfaces very snugly into 3D-printed parts and also fits 1/2" hex parts. An arbor- or drill-press can easily broach the keyway in aluminum.
