Sonic or Ball Shifter?

[Ajennings8896]

Hi, my team has been looking at using some two speed shifters for our gearboxes this year and I've been wondering what type we should use. We're looking mostly at the VexPro Ball shifter and AndyMark Sonic Shifter. I know that the sonic shifter can shift while moving and I know that theyre supposed to be pretty sturdy. But I dont know if its worth the price tag that it comes with, and my question to you guys is what are some pros and cons of both and is the Sonic Shifter worth the extra money of the Ball shifter.
Thanks,
Andrew Jennings

[JVN]

Originally Posted by Ajennings8896

We're looking mostly at the VexPro Ball shifter and AndyMark Sonic Shifter. I know that the sonic shifter can shift while moving

The VEXpro Ball Shifter can also shift while moving (on the fly).

[Chris is me]

The Sonic Shifter just came out this summer, so not a lot of teams have had the chance to test it yet. Just be aware of that while soliciting replies. It is a further iteration of the shifting concept that AndyMark has used in AM Shifters and SuperShifters.

[BrendanB]

A Ball Shifter is lighter and smaller compared to the Sonic Shifter. The Sonic Shifter does have more options compared to a Ball Shifter.

FRC is starting to hit a point where with so many suppliers while some products may be better you really need to decide what you want in a gearbox (weight, size, specific speed, #of motors, #of speeds, mounting, etc) and there are plenty of options out there find what you want.

[magnets]

Personally, I love the Ball Shifter. Looking at the specs, it's $100 cheaper, 1.25 lbs lighter, and smaller. It shifts on the go, and teams have already used it for one year and the reviews are all positive.

I really can't find a single reason to purchase the sonic shifter over the ball shifter.

[T^2]

Originally Posted by magnets

the reviews are all positive.

This is untrue. In many previous threads, there have been complaints (mine included) about several of the ballshifter's shortcomings.

[Peyton Yeung]

I've heard negative reviews over the ball shifters output shaft falling out.

[z_beeblebrox]

I'd hold off buying for now. IFI is likely to release an updated product line before build season.

[BBray_T1296]

Originally Posted by Peyton Yeung

I've heard negative reviews over the ball shifters output shaft falling out.

This is more of a consumer abuse problem than a defect in the ball shifter. On the end of the output shaft, there is a #10-32 hole to secure whatever gear/sprocket/spacer/etc assembly from falling off the end of the shaft. You put a washer larger than the output and screw it down, covering the end.

What teams who experienced this "falling out" problem were doing, was putting too much "tube length" onto the shaft. I don't know the exact specs of the output shaft, but let's say it is 4". People would put their sprockets on wedged between spacers to keep it in place. Problem was, they put maybe 4.1" worth of stuff onto the shaft. When someone went to screw down the end, they really cranked down on it (like you would expect-who wants their drive sprocket flying off?). This created a reverse gear-puller like device (a gear-pusher I suppose), putting compressive pressure on the spacer/sprocket combo into the gearbox wall, and a tension force on the drive shaft, as the screw was driven deeper. As the screw reached it's last rotation, 0.1" had to come from somewhere as the washer hit the 4" mark. That somewhere was the pressed-in output shaft, causing the complaints you saw.

Lesson is, make your spacers the right length!

[Pault]

Originally Posted by BBray_T1296

This is more of a consumer abuse problem than a defect in the ball shifter. On the end of the output shaft, there is a #10-32 hole to secure whatever gear/sprocket/spacer/etc assembly from falling off the end of the shaft. You put a washer larger than the output and screw it down, covering the end.

What teams who experienced this "falling out" problem were doing, was putting too much "tube length" onto the shaft. I don't know the exact specs of the output shaft, but let's say it is 4". People would put their sprockets on wedged between spacers to keep it in place. Problem was, they put maybe 4.1" worth of stuff onto the shaft. When someone went to screw down the end, they really cranked down on it (like you would expect-who wants their drive sprocket flying off?). This created a reverse gear-puller like device (a gear-pusher I suppose), putting compressive pressure on the spacer/sprocket combo into the gearbox wall, and a tension force on the drive shaft, as the screw was driven deeper. As the screw reached it's last rotation, 0.1" had to come from somewhere as the washer hit the 4" mark. That somewhere was the pressed-in output shaft, causing the complaints you saw.

Lesson is, make your spacers the right length!

I am fairly certain that the super shifter had a similar method of mounting sprockets to the output shaft, yet you didn't hear super shifter teams complain about this malfunction. Therefore, it is a disadvantage. It may not seem like a big deal to you and me, but what about that student- built team that doesn't have mentors ensuring that every spacer is exactly the right length?

[AllenGregoryIV]

I wouldn't be surprised to see a some new things out of VEXpro before this season starts. The idea that the you can only get one spread from a ball shifter may be a thing of the past.

[BrendanB]

Originally Posted by BBray_T1296

This is more of a consumer abuse problem than a defect in the ball shifter. On the end of the output shaft, there is a #10-32 hole to secure whatever gear/sprocket/spacer/etc assembly from falling off the end of the shaft. You put a washer larger than the output and screw it down, covering the end.

What teams who experienced this "falling out" problem were doing, was putting too much "tube length" onto the shaft. I don't know the exact specs of the output shaft, but let's say it is 4". People would put their sprockets on wedged between spacers to keep it in place. Problem was, they put maybe 4.1" worth of stuff onto the shaft. When someone went to screw down the end, they really cranked down on it (like you would expect-who wants their drive sprocket flying off?). This created a reverse gear-puller like device (a gear-pusher I suppose), putting compressive pressure on the spacer/sprocket combo into the gearbox wall, and a tension force on the drive shaft, as the screw was driven deeper. As the screw reached it's last rotation, 0.1" had to come from somewhere as the washer hit the 4" mark. That somewhere was the pressed-in output shaft, causing the complaints you saw.

Lesson is, make your spacers the right length!

I can attest this was not a user error. Our first set of Ball Shifters it wasn't confirmed as before we could check how long our spacers were our drivebase team had already ripped the system apart.

For the next set we ran through our two regionals we purposely made sure the shaft was not under compression and they still feel out during Champs where we eventually decided to pin them in.

Considering the cost and weight of a ball shifter, pinning the shafts isn't the end of the world because they were more reliable internally compared to the 2011 Super Shifters we had. The encoder mount is pretty flimsy, we took ours off when they started getting sketchy.

[JamesCH95]

Full disclosure: I haven't used either in a robot (yet) but recently made the same decision (and went with the ball shifter).

Strictly from an analytic standpoint I like the gear ratio spread on the Ball Shifter better than the Sonic Shifter. The ratios aren't too different, but I like the closer ratio of the Ball Shifter.

The Ball Shifter includes the shifting air cylinder, whereas the Sonic Shifter does not. You will have to add $20-$30 onto the price tag of the Sonic Shifter if you plan on shifting penumatically. On the other hand, if you do not plan on having any pneumatic components on your robot otherwise, the servo shifting of the Sonic Shifter becomes very appealing.

The Ball Shifter has options for Greyhill and US Digital encoders, whereas the Sonic Shifter appears to only have provisions for US Digital encoders (though it's not explicitly specified). If you plan on using Greyhill encoders, this is certainly something to consider.

[Paul Copioli]

All,

Just so this thread doesn't turn into a "if your ball shifter shaft fell out, then you did something wrong" back and forth thread, VEX did have an initial manufacturing issue on one lot of VEXpro output shafts where the parts were not properly cleaned prior to the application of the Loctite 680 permanent shaft retaining compound.

We have been 100% inspecting these shafts for retention ever since the customer reports of shafts falling out started. A fully cured part needs approximately 5,000 lbs to pull out.

The bottom line is that, yes, there have been ball shifter output shafts that have come out during operation that was 100% due to a manufacturing error.

Pinning fixes the problem, but you could just as easily use Loctite 680 on a fully cleaned shaft.

[Ravage457]

We have used both the Vexpro Ball shifter and AndyMark supershifter. They both work great, we did ran into that issue with the output shaft falling out in our first regional but once we applied loctite we never had that issue again,i know vexpro will come out with something before the season, and im looking forward to using both Vexpro and AndyMark item again, overall with experince with both, depending on the years game our team can choose what gearbox to use on our robot.........Highly Recommened both