Versaplanetary Vs 57 Sport

Technical Technical Discussion
1

Last year (our rookie year) we had nothing but problems with the Versaplanetaries. The sun gears stripped on us in our elevator, and intake at each competition. We did everything right in terms on running them in and lubricating but they still were not happy.

We switched to using AM 57 Sports at worlds, and it was night and day. The entire gearbox is built to be much stronger. They gave us no problems.

The Versaplanetary dual output gearbox also gave us problems, so we switched to an AM DeCIMate and got the same great results as the 57 Sports.

I saw many great teams using the versaplanetary system with sucess, so are we the only ones with all those problems, or do the other teams just make do with the gearboxes constantly breaking?

2

we are looking at the Sports as well. The 10% off we got from AM also made this a good time to try new things.

3

First, full disclosure: I worked at AndyMark during the run-up to the 57 Sport’s launch. (I was gone by the time it went live, though.)

The VersaPlanetary is hardly a wrong answer, with lots of options and nice things going for them. I’ve used them with success in the past on 4901, as well as BaneBots P60 (both for 5402 and my AndyMark Fight Night robot the last two years) and 57 Sport gearboxes (1293 used three last year, plus one CIM Sport on an Ri3D robot). But they do have some things that will wreck 'em, particularly exceeding the load ratings, impact damage (I notice 6911’s are pretty far out), or poor alignment during assembly. (And, of course, lack of grease…but you said you had that.)

While your mention of the DeCIMate gives a few hints, what motors were you trying to use in them? At what ratios?

4

I think Nick Lawrence could drop a cannonball on a 57 Sport and it would keep working.

That would be a video worth watching. In slo-mo. :cool:

5

First, full disclosure: I worked at AndyMark during the run-up to the 57 Sport’s launch. (I was gone by the time it went live, though.)

The VersaPlanetary is hardly a wrong answer, with lots of options and nice things going for them. I’ve used them with success in the past on 4901, as well as BaneBots P60 (both for 5402 and my AndyMark Fight Night robot the last two years) and 57 Sport gearboxes (1293 used three last year, plus one CIM Sport on an Ri3D robot). But they do have some things that will wreck 'em, particularly exceeding the load ratings, impact damage (I notice 6911’s are pretty far out), or poor alignment during assembly. (And, of course, lack of grease…but you said you had that.)

While your mention of the DeCIMate gives a few hints, what motors were you trying to use in them? At what ratios?

At our first regional, the intake gearboxes were very far out, and did in fact also take some abuse by us trying to play defense with our arm :]. We used new ones during Semifinals and the sungear stripped during the second match, and we know from the video that there were no impacts. At the second regional, the intake gearboxes were much father back, out of the way from any impacts. Sun gears still stripped. The elevator gearbox was also stripped, but still worked. We only took those apart when we got to worlds and realized it was shot and we were just lucky it never siezed. When using the versaplanetaries, we used 1 775Pro on each, and 2 775Pro’s with a versaplanetary dual output adapter.

Once we switched to the 57 Sports, we used 1 AM 775 for each side of the intake, and 2 for the elevator, mounted on a DeCIMate. At worlds we abused our robot like there was no tomorrow (even driving over a robot while playing defense) and rammed the intake into just about everything and nothing happened to them.

After all the bad experiances with them, team 6911 will not be using the versaplanetaries for some time, and will use 57 sports as well as external reductions to reach the modularity of the versaplanetary. I was opened to trying the versaplantaries during the offseason this year, but one of the advisors is not up for the frustration they gave us.

6

Out of curiosity, what gear ratios were you using?

7

Out of curiosity, what gear ratios were you using?

I dont remember what ratios we used, but I can get back on that one on Monday. What I can tell you is that we used a ratio that a team mentoring us told us to use, because I was what they were using.

Maybe Team 6911 is just cursed to use versaplanetaries

8

with some versa planetary stages the sun gears are so small that they break very easily, usually anything above a 7 will break under much load so that could have resulted in them breaking

I dont know other than that we have almost never had problems with them even in some pretty extreme conditions going as far as dragging some across the ground and having them run over after our intake fell apart in a match last year and they still worked

maybe if you bought these at some point in 2017 there was some ring gear tolerance issues at least in the middle parts of the 2017 season

9

1712 has had at least one VersaPlanetary on each of our robots since 2013, and we have never had an issue.

10

We love our versa’s, being able to change the gear ratio is awesome.

11

Can you provide a source here? I’ve lifted robots using 10:1 stages in the mix, so I’m doubtful.

12

We have had a few 10:1 stages break… Though we were pushing it…

I found when making higher ratios like 70:1 for example.

It was far more robust when 10:1 stage was NOT on the output shaft.

YMMV

13

vex has a load rating chart on their website its a pretty good reference, some of the time you can get away with 10s as the first stage and having 5s or lower on output stage or even an external gearing after that but not always usually anything above 70 is pushing it unless you had another stage of external gearing

I was mainly referring to versas with a single 10 or multiple high reduction sets without external reductions which is usually fine for intakes but for lifts it would be sketchy

14

That wasn’t clear in your original post, so I think the distinction is important when trying to give advice that the OP (and potentially many others) will read.

Relevant document is here.

Versaplanetaries should be perfectly fine for usage on intakes, and failures are likely due to some issues with the setup.

15

We used VPs on our intake with no issues. I don’t know how you managed to strip gears on something that low-load, perhaps a mismatched sun/planet combination did it? Especially if you mix up 9:1 and 10:1 gears, that’s easy to do.
I’ve only had issues with VPs at high reduction. The split collar isn’t great and can come loose though, so you have to make sure that’s tight. I’ve had a bad failure once when a robot hit the VP on our climber in 2017 from the side.
The 57 Sport looks good for 100:1 reduction and exposed situations, but you should not have broken a VP in the first place.

16

Any chance we can see pictures of your setup and the ratios you used? That may help answer why you had some problems.

I’ve used the versaplanetary line since they came out and can’t ever remember having a complete gear stage failure. Last year we lifted 2 robots with two of the gearboxes with no issues. That’s 300+ pounds of weight with a robot hanging off our ramps and those gearboxes survived all season. Consult the load rating guides on VEX’s website as a starting point, they’re very easy to read and are useful.

Keep in mind with the 57 sport you lose some flexibility to change ratios. There’s no doubt they’re more robust but we changed ratios on just about everything last year at some point to dial things in. To me that’s an extremely valuable feature that we probably can’t live without.

17

The only times we have damaged VersaPlanetaries have been when we were using them improperly. You should really share details of how you were using them so that we can identify what the root cause was.

Things like: ratios used, what order those ratios were in, what motors used, details about the mechanism it was operating.

We keep using them mostly because of the versatility in being able to swap ratios in a matter of minutes without buying a full new gearbox.

18

One comment I’ll make about Versa planetary and P60’s. In a positioning application they wear over a course of a season and the backlash increase for us has been a problem. For 2018 we tried some thing different. We used NEMA 17 planetary gearboxes that are commonly used with NEMA 17 steppers. For the steering on our swerve 100:1. They have held up amazingly well. Almost no measurable increase in backlash. For other non-positioning applications we use the versa planetaries for their versatility. We have a sport but have not used it because we are invested in Vex.

19

We used a VersaPlanetary 100:1 reduction with 2 775pro motors for our lift. It worked for the regional and for a couple of matches in worlds. One of the gears stripped then (I do not remember which one), and the build team replaced it. It seemed to have worked later. We thought the gear stripping was the result of not using ramp up/down in the software. Did any other team experience a similar problem and could trace the cause to a software issue? Does it make sense to use motion profiling for the lift operation?

20

100:1 with 700 watts of power your lucky you didn’t twist off the output shaft.