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Unread 22-09-2013, 13:20
ErvinI ErvinI is offline
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Re: Modifying Vexpro Ball Shifter transmissions

This thread will answer a few questions:

http://www.chiefdelphi.com/forums/sh...t=window+motor

Specifically, regarding 67's shifting this year:
Quote:
Originally Posted by Adam Freeman
We were unable to package our typical window motor shifter with the smaller chassis size. We then designed a VEX-393 motor shiter setup that ended up stalling out and frying a digital side car (or two...). After that, we tried to design a typical servo shifting system. We ran out of time before the season started to install the servo shifter, but after looking at it more closely I don't think it would have worked very well. We were trying to emulate the AM-Super-shifter servo setup, but had a hard time getting the rotation of the shift arm transferred into axial movement of the shaft that shifts the gear box. There seemed to be a lot of play in that shaft. Probably just needed some additional constraints that we didn't have time to design in.

I also looked into trying to find a suitable electric solenoid to shift with, but was unable to find one that seemed like it met all the rules and had enough power to shift.

In the end, we just zip tied the ball shifters in high gear and attempted to avoid pushing matches.

Maybe the guys at VEXpro can design one for us teams that can't seem to make room for a pneumatic system.
Regarding electronic solenoids (Adam touched upon it in the above quote, also):

Quote:
Originally Posted by AllenGregoryIV
We also looked at the possibility of electronic solenoids to shift or be brakes and couldn't find any that had enough power or worked in a way that we though would be reliable or adaptable for that application.
In conclusion, window motor shifters are very large, VEX motor shifters fry up a lot, VEXpro doesn't make servo shifters (and 67 had issues making a replacement), and electronic solenoids aren't strong enough.

Last edited by ErvinI : 22-09-2013 at 13:24.