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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.
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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;
Quote:
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.
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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.
