Super Shifter As Winch ???

[de_]

Has anyone had good or bad experience trying to us an AM Supershifter as a winch. My big concern is the #4 bolt in the dog and or the connection between the shift shaft and the shift block assembly fails. Last I had one apart, there was a tiny roll pin capturing the shifter shaft. Though it might now be some e-clip or something.
I've heard rumors that a substantially larger diameter pneumatic cylinder (or a force multipler lever) compared to stock 3/4" one is needed for the winch due to the forces. Not sure how the pin or maybe the ball bearing inside the assembly is going to stand up.

[theawesome1730]

We are doing a super shifter for our winch and we needed to do a lever with a 1.5 inch bore cylinder to disengage a custom made dog gear. You need some way to prevent back driving like a ratchet and pawl or a gear wrench you don't mind sacrificing

[TheMadCADer]

Originally Posted by theawesome1730

We are doing a super shifter for our winch and we needed to do a lever with a 1.5 inch bore cylinder to disengage a custom made dog gear. You need some way to prevent back driving like a ratchet and pawl or a gear wrench you don't mind sacrificing

Any details on your custom dog gear, for the sake of comparison to the stock AM dog?

[GarrettF2395]

We have also been attempting to get an old Gen 2 AM shifter working for a winch set up. We've got the wrench in place to prevent back driving, and that part works great, but the shifting is whats giving us problems. During our recent test run one of our largest students couldn't get it to shift out of gear even while using a large pair of pliers for leverage.
We've considered making the switch to a Ball shifter instead, but haven't jumped ship just yet.

[theawesome1730]

Originally Posted by TheMadCADer

Any details on your custom dog gear, for the sake of comparison to the stock AM dog?

Its a chunk of (IIRC) 1.5 inch diameter chromoly steel. Instead of using the tiny stock shifters, we use a much larger bore with a lever that fits into a ring cut out of the dog gear

[donkehote]

Originally Posted by de_

Has anyone had good or bad experience trying to us an AM Supershifter as a winch. My big concern is the #4 bolt in the dog and or the connection between the shift shaft and the shift block assembly fails. Last I had one apart, there was a tiny roll pin capturing the shifter shaft. Though it might now be some e-clip or something.
I've heard rumors that a substantially larger diameter pneumatic cylinder (or a force multiplier lever) compared to stock 3/4" one is needed for the winch due to the forces. Not sure how the pin or maybe the ball bearing inside the assembly is going to stand up.

The Roll pin is actually far stronger than many people estimate. Roll pins of that size properly installed are far superior to the bolt found in older generations of the Supershifter, simply because it lacks the stress risers found in the thread, and is made of a higher strength material. The Supershifter does work as a winch, but does require a much larger piston, and possibly even a lever arm to multiply the force.

This video, made by the Robot in 3 Days 1.0 group, 2 days after kickoff shows the increase in force needed to release a dog shifting gearbox. The video should be cued up to the proper time, but if not, it's at about 50 seconds. You can see the large piston just in front of the battery, behind the pressure gauge on the right side of the frame. They used Supershifter guts in a custom case, but the stock casing would work fine, except for the modification to add a non back driving device. (like a ratchet wrench)

https://www.youtube.com/watch?featur...O9OE8JZZk#t=50

A much better alternative is a Ballshifter. A Ballshifting gearbox requires limited extra force, due to the fact that there is a limited increase in friction from extra load to move the ball detent shaft. As the President of Vex, Paul Copioli said;

Originally Posted by Paul Copioli

We are testing this now to see the max loading the ball shifter can still shift into neutral. My theoretical calculation indicates in excess of 400 lbs in a 2" diameter winch.

That is with the stock pancake piston. (Paul, please correct me if I'm wrong) If you need more than 400 lbs of force; 1) I don't want to be anywhere near that ball when it leaves your shooter, and 2) the piston can be up sized just like the Supershifter.

Also remember, the Ballshifters are a lighter, less expensive, equally reliable option for creating a winch.

Generally looking at the current cad model is a good way to see if there is "an e clip or something" in any part you are unfamiliar with. There are multiple free cad software packages offered to first teams. If you need any help, I am quite familiar with those gearboxes, and I live quite close by. I wouldn't mind visiting and giving some help.

Hope this was helpful.

[Rstrzelecki]

My team built a winch using the dog gear from a super shifter we had trouble getting it to disengage and had to result to using a lever

[Dan.Tyler]

You could also momentarily pulse the drive motor forward and then off while disengaging to reduce loading momentarily. Even if you are ratcheting/anti backdrive, it will still unload the dog gear momentarily

[Crance]

We milled our custom dog gear out of a piece of 1.5 inch chrome-alloy steel. It is almost twice as thick and only has the "teeth" on one side. We then hex broached it to fit on our shaft. If you want more info on it don't be afraid to PM me.

[de_]

Note I was the original poster.
Thanks for some of the good ideas.

I'm really looking for someone who has used a stock supershifter with the stock shift block and shaft assembly and hopefully has significant experience with it (launched 50 balls would be nice).

Anyone thinking of using a past year supershifter should read the following.
A previous generation shift block assembly used a tiny roll pin which we have broken more than once in past years (as a transmission) with a standard 3/4 pneumatic cylinder (ie 24 lbs force). So for example we can't see how that pin could possibly survive the 102 lbs force of a 1.5" cylinder in a winch application.

Our new Super Shifters arrived today (basically free with the use of our PDV) and close inspection of the current shift block shows it is using a captured E Clip which should have many times the shear force strength of the tiny roll pin used before. The "captured" feature should mean the E clip cannot "back off" accidently, it can only shear off under normal operations.

[donkehote]

Originally Posted by de_

I'm really looking for someone who has used a stock supershifter with the stock shift block and shaft assembly and hopefully has significant experience with it (launched 50 balls would be nice).

Anyone thinking of using a past year supershifter should read the following.
A previous generation shift block assembly used a tiny roll pin which we have broken more than once in past years (as a transmission) with a standard 3/4 pneumatic cylinder (ie 24 lbs force). So for example we can't see how that pin could possibly survive the 102 lbs force of a 1.5" cylinder in a winch application.

Our new Super Shifters arrived today (basically free with the use of our PDV) and close inspection of the current shift block shows it is using a captured E Clip which should have many times the shear force strength of the tiny roll pin used before. The "captured" feature should mean the E clip cannot "back off" accidently, it can only shear off under normal operations.

I cant fathom the roll pin breaking unless something was done to it. A standard 1/16 roll pin is rated for 430 lbs of shear. How a 23 lb piston broke that is beyond me. Possibly poor quality roll pins, or damage before/during install? Here is data to back up the numbers.
http://www.engineersedge.com/roll_pin.htm

E clips are rated for more, 600 lb shear strength, and should survive with no issues.

https://www.huyett.com/getmedia/3f09...Clips.pdf.aspx

If you want to find someone who has shot a lot of balls, contact either the RI3D guys (they are on this forum) or Andymark, as Andymark is selling the Supershifter winch that the RI3D guys made with Supershifter internals. This uses the stock shift block and shaft assembly.
http://www.andymark.com/product-p/am-2774.htm

Hope this helps

[de_]

Originally Posted by donkehote

I cant fathom the roll pin breaking unless something was done to it. A standard 1/16 roll pin is rated for 430 lbs of shear. How a 23 lb piston broke that is beyond me. Possibly poor quality roll pins, or damage before/during install? Here is data to back up the numbers.
http://www.engineersedge.com/roll_pin.htm

The Andymark usage of the roll pin is not remotely similar to the SAE fully supported static load test. The AM installation has unsupported ends and is subject to repeating dynamic shock loads. We and other teams have broken these pins and AM is not longer using the pins in the current design. A good comparative example is concrete that can stand 5000lbs static load can easily be defeated by a 5 lb 100w drill with the right dynamic load (hammer drill).