Sonic Shifter - recent feedback?

[James3245]

If this year's game warrants a 2-cim shifter we will be considering AndyMark's "Sonic Shifter"

I read some earlier posts (2014). It would be helpful to have recent thoughts from users on how this product has been for:

-ease of assembly/installation
-operation
-reliability over time
-use of encoder (which I understand comes pre-installed)

Thanks!

[TylerS]

Are you locked into the idea of using the sonic shifter? Vex and West Coast products have options which are better than the sonic shifter in almost every way.

[cbale2000]

Originally Posted by James3245

-use of encoder (which I understand comes pre-installed)

I do not believe this is accurate. There is an output shaft for an encoder, but I don't think one comes included with the kit.

Beyond that, my 2cents when it comes to 2-speed gearboxes is to give VexPro a look. Their 2 CIM Ball Shifter (or even the 3 CIM Ball Shifter) is lighter than a Sonic Shifter, has a fully enclosed housing to prevent debris from getting into it, shifts more smoothly (in my opinion at least) than a dog gear due to the ball shifting mechanism, and will hold up through a whole season and beyond without any issues (if properly lubricated), and it's fairly easy to use an encoder with. Oh, and VexPro gearboxes are also quite a bit cheaper than AM gearboxes.

I don't have any particular problem with AM gearboxes, but when it comes to comparing two similarly functional and reliable products, lower weight and price always wins for me.

[Peyton Yeung]

Originally Posted by TylerS

Are you locked into the idea of using the sonic shifter? Vex and West Coast products have options which are better than the sonic shifter in almost every way.

Would you mind listing what the differences between them are?

[BoilerMentor]

Originally Posted by TylerS

Are you locked into the idea of using the sonic shifter? Vex and West Coast products have options which are better than the sonic shifter in almost every way.

Let me remind you that the very team you're mentoring this year had three, successive failures of the aluminum gears in the final reduction stage on three cim ball shifters. Including a pair of back to back failures that took us out of a one day offseason event we traveled 8 hours round trip for. I can assure you, based on that experience from 2014 we will NOT be using vexpro gear boxes in the drivetrain.

[pilleya]

Originally Posted by Peyton Yeung

Would you mind listing what the differences between them are?

Both the WCP DS and the AM sonic shifter are dog-shifting style gearboxes.

An encoder can be fitted to the Sonic shifter out of the box, while a WCP DS does not, but a grayhill or CTRE mag encoder on an outer axle or a CIMcoder

In terms of weight the WCP DS, 2.92 Spread Kit with pinions weighs 1.93 lbs. The AM sonic shifter weighs 3.41 lbs with pinions.

The WCP DS is more compact than the Supershifter especially in terms of height.

There are 18 ratio options for the WCP DS. The Super shifter has 8 ratios options, but is capable of much lower gearing because of the inbuilt third stage. The WCP DS comes in a 3CIM version and the 3CIM is compatible with a PTO.

The WCP DS has 7075-T6 gears with teflon infused ceramic coating which is meant to improve efficiency.

Uses lithium grease for lubrication, not the fun red tacky grease as in the Sonic Shifter(because of lack of steel gears)

The Sonic Shifter can use a servo for shifting if required

The 2CIM WCP DS is $227.96 and the Super shifter is $279

[Tom Line]

We've used the sonic shifters quite a bit - we used two in our drivetrain and one powering our winch. We had a comp bot and a practice bot, so we had 6 in all.

We abused the one powering our winch to the extreme: we knew we were pushing it FAR beyond the design envelope with the forces were were shifting it under. We upsized the shifting cylinder and removed a stage so we could shift it into neutral. We routinely loaded with with 200-300 pounds and were releasing it.

We expected it to break, and it did. The shifting pin sheared and the dog gear rounded off the ears and the pocketed slots twice during the season.

The drivetrain shifters were installed and used as they were meant to be. The did not fail at all. In the off season we went in and had to change out the dog gears because the ears had rounded off.

We used encoders on them and had no issues.

Used as expected, we would recommend the gearbox to anyone.

[PurpleInk]

Originally Posted by BoilerMentor

Let me remind you that the very team you're mentoring this year had three, successive failures of the aluminum gears in the final reduction stage on three cim ball shifters. Including a pair of back to back failures that took us out of a one day offseason event we traveled 8 hours round trip for. I can assure you, based on that experience from 2014 we will NOT be using vexpro gear boxes in the drivetrain.

Our history with the 3 cim ball shifter:

[jeremylee]

Originally Posted by BoilerMentor

Let me remind you that the very team you're mentoring this year had three, successive failures of the aluminum gears in the final reduction stage on three cim ball shifters. Including a pair of back to back failures that took us out of a one day offseason event we traveled 8 hours round trip for. I can assure you, based on that experience from 2014 we will NOT be using vexpro gear boxes in the drivetrain.

Hmm, we haven't had any problems at all after 2 regionals and 2 offseasons with our 2014 bot and our 3 cims ball shifters.

[Joe Ross]

Originally Posted by cbale2000

I do not believe this is accurate. There is an output shaft for an encoder, but I don't think one comes included with the kit.

That's not what the Product Page says: Will be shipped with an am-3132 encoder pre-installed.

Originally Posted by cbale2000

I don't have any particular problem with AM gearboxes, but when it comes to comparing two similarly functional and reliable products, lower weight and price always wins for me.

If you consider the included encoder, and the fact that the sonic shifter does ratios that require the 3rd stage on the ballshifter, the price difference is much smaller. $215 for the ball shifter + 40 for an encoder vs 279 for the Sonic Shifter. Weight does favor the ball shifter.

[pilleya]

Originally Posted by PurpleInk

Our history with the 3 cim ball shifter

That looks really nasty, did you contact VEXpro.

I can see why your reluctant to use a ball shifter again

[BoilerMentor]

Originally Posted by jeremylee

Hmm, we haven't had any problems at all after 2 regionals and 2 offseasons with our 2014 bot and our 3 cims ball shifters.

Three failures on different drive train sides isn't a coincidence. We ran that drive train hard as you well know (Central Illinois 2014). It was geared aggressively and we used (honestly, inadvertently) down shift motor braking constantly because of our automatic shifting routine in our programming.

It is my belief, the reason for the failure is primarily related to the fact that the shafts that carry the final stage reduction are cantilevered. In looking at the damaged gears it was apparent the failure propagated across the gear teeth, which indicates angular misalignment. That angular misalignment also would have occurred during the periods where the gears were under the highest load.

I do believe that had that stage been steel gears they might have tolerated the abuse, but to me, the ability for the shaft to deflect and allow that angular misalignment is a design flaw. I believe there are a number of features that don't promote a rigid configuration, but the cantilever is the largest problem.

We still use the drive train as a demo robot. We chose to modify the gearbox configuration to eliminate the cantilever and we haven't see another incidence of the failure to date.

[James3245]

Originally Posted by Tom Line

We've used the sonic shifters quite a bit - we used two in our drivetrain and one powering our winch. We had a comp bot and a practice bot, so we had 6 in all.

We abused the one powering our winch to the extreme: we knew we were pushing it FAR beyond the design envelope with the forces were were shifting it under. We upsized the shifting cylinder and removed a stage so we could shift it into neutral. We routinely loaded with with 200-300 pounds and were releasing it.

We expected it to break, and it did. The shifting pin sheared and the dog gear rounded off the ears and the pocketed slots twice during the season.

The drivetrain shifters were installed and used as they were meant to be. The did not fail at all. In the off season we went in and had to change out the dog gears because the ears had rounded off.

We used encoders on them and had no issues.

Used as expected, we would recommend the gearbox to anyone.

This is helpful, thank you. Any other comments from teams with field experience with Sonic Shifter would be helpful. (We are already familiar through direct experience with several options from other vendors) I appreciate the input.

[cbale2000]

Originally Posted by PurpleInk

Our history with the 3 cim ball shifter:

What lubricant were you using and what was the overall reductions in your drive system (including wheel size)?

IMO our 2014 robot put it's 3 CIM Ball shifters through far more abuse than the average team and the gears still look as good as new. For that matter, I've yet to see so much as a chipped tooth on any of the over 75 various Vex Pro gears we've used on competition robots in the past two years.

Originally Posted by Joe Ross

That's not what the Product Page says: Will be shipped with an am-3132 encoder pre-installed.

Good catch, not sure how I missed that, I did look at the page. Still getting used to the new AM site layout I guess.

Originally Posted by Joe Ross

If you consider the included encoder, and the fact that the sonic shifter does ratios that require the 3rd stage on the ballshifter, the price difference is much smaller. $215 for the ball shifter + 40 for an encoder vs 279 for the Sonic Shifter. Weight does favor the ball shifter.

True the difference is smaller in certain configurations, but still less regardless, and Sonic Shifters doesn't really offer anything the Ball Shifters don't also (save a few gear ratios perhaps), so if you can still save some money and weight, why not?

[BoilerMentor]

Originally Posted by cbale2000

What lubricant were you using and what was the overall reductions in your drive system (including wheel size)?

IMO our 2014 robot put it's 3 CIM Ball shifters through far more abuse than the average team and the gears still look as good as new. For that matter, I've yet to see so much as a chipped tooth on any of the over 75 various Vex Pro gears we've used on competition robots in the past two years.

Gear ratios were 18.75:1 and 7.08:1. Gearboxes were lubricated with moly grease containing Teflon. The gearbox direct drove a 6" x 2" wheel at the center of the robot which was chained to the other two wheel in the drive train side, also 6" x 2" wheels. All wheels were treaded with blue nitrile. Center direct drive shaft was supported with a bearing in the outer plate. Two other axles were dead shafts with bearings in the wheel.

The high load situation I believe created the problem was encountered when the driver returned the control stick to a neutral position with the robot at a high speed. The auto shifting code would have immediately tried to shift the robot to low gear with all three cim motors braking.

I've spent a fair amount of time "behind the glass" as it were. I'd challenge you to find a driver who pushed their robot harder and drove more aggressively.

I truly believe that we saw this failure because we pushed the design to its performance limit and shaft deflection leading to angular gear misalignment and ultimately gear tooth failure was the manifestion of that failure. If it had been on only one drive train side or it only happened one time I would write it off as bad luck, but that was not the case.