Ball Shifter Vs. Dog Shifter?

[mman1506]

We ran Ball Shifters on our robot this year. We put them through a lot, 2 regionals champs and 2 off seasons full of heavy defence (We did regrease them before champs). Even after all that there was almost no wear and the shifting was only marginally less smooth. The only issue both us and 5031 had with them is they tend to sag over time but it does not seem to have a noticeable effect on robot performance.

[nathannfm]

Originally Posted by asid61

But for FRC, wear is not really a problem

MOE used the 3 CIM ball shifters this year and we experenced significant wear on the aluminium shifting shaft. I heard a few other teams experienced this on their winches but this was on our drive, enough that the most worn one was unable to shift. We also had some of the miniature ball bearings fail, possibly related to this. We never did get to the bottom of the problem (possibly user error related to the pneumatic coupler) but I have to stress that VexPro and JVN were extremely helpful and generous when we told them of the problems we were having. I also believe it was mentioned that this component would soon be replaced with a steel version which I know some teams already took it upon themselves to manufacture. If you are looking to purchase gearboxes in preparation for 2015 I would wait and see if VexPro has another product unveil in mid December like they have had the last 2 years. You don't want to be stuck with "last years model" if they come out with something better.

[Travis Schuh]

Originally Posted by nathannfm

MOE used the 3 CIM ball shifters this year and we experenced significant wear on the aluminium shifting shaft. I heard a few other teams experienced this on their winches but this was on our drive, enough that the most worn one was unable to shift. We also had some of the miniature ball bearings fail, possibly related to this. We never did get to the bottom of the problem (possibly user error related to the pneumatic coupler) but I have to stress that VexPro and JVN were extremely helpful and generous when we told them of the problems we were having. I also believe it was mentioned that this component would soon be replaced with a steel version which I know some teams already took it upon themselves to manufacture. If you are looking to purchase gearboxes in preparation for 2015 I would wait and see if VexPro has another product unveil in mid December like they have had the last 2 years. You don't want to be stuck with "last years model" if they come out with something better.

What do the gears that the balls were interfacing to look like? Is there similar wear on those from the balls engaging suddenly? We have been asking ourselves recently why we don't run ball shifters, so we are very interested to see your experience. We also get noticeable wear on our dog shifters, sounds like either isn't a slam dunk.

[nathannfm]

Originally Posted by Travis Schuh

What do the gears that the balls were interfacing to look like? Is there similar wear on those from the balls engaging suddenly? We have been asking ourselves recently why we don't run ball shifters, so we are very interested to see your experience. We also get noticeable wear on our dog shifters, sounds like either isn't a slam dunk.

No wear on either (for lack of a better term) the steel ball containment shell, or the gears. This thread has some good videos of what not to do with respect to the VexPro ones. While ours was not as obviously incorrectly assembled as is shown in those videos I suspect the travel was adjusted slightly incorrectly resulting in the accelerated wear pictured.

[Mike Marandola]

I don't have any experience with dog shifters but after 6 events and a bunch of practice, our ball shifter gears or plunger had no wear. The Teflon coating was not even worn. We usually only shifted about 1-3 times each match though.

Originally Posted by nathannfm

MOE used the 3 CIM ball shifters this year and we experenced significant wear on the aluminium shifting shaft. I heard a few other teams experienced this on their winches but this was on our drive, enough that the most worn one was unable to shift. We also had some of the miniature ball bearings fail, possibly related to this. We never did get to the bottom of the problem (possibly user error related to the pneumatic coupler) but I have to stress that VexPro and JVN were extremely helpful and generous when we told them of the problems we were having. I also believe it was mentioned that this component would soon be replaced with a steel version which I know some teams already took it upon themselves to manufacture. If you are looking to purchase gearboxes in preparation for 2015 I would wait and see if VexPro has another product unveil in mid December like they have had the last 2 years. You don't want to be stuck with "last years model" if they come out with something better.

WOW! That's bad. Out of curiosity, what were you guys geared for and about how many times did you shift in a match?

[EricH]

Originally Posted by Mike Marandola

WOW! That's bad. Out of curiosity, what were you guys geared for and about how many times did you shift in a match?

This. Something to note is that anecdotal evidence is better than no evidence, but an incomplete anecdote is worse. If all of the folks commenting on the shifters could provide this sort of information (geared speeds, average shifting/match, and any other potentially relevant details), it'd go a long way towards making a very informed decision rather than a decision based on incomplete information.

[mman1506]

We were running around 14.7 fps high and 7 fps low with 6 CIMS on a 4" Blue nitrile WCD. We shifted 5-10 times each match with hard acceleration and breaking. No damage to the teflon coating was noticed.