pic: FVC 2013 Gear shifter

[gdo]

loading photo ...

[Jeremiah Johnson]

Awesome, but how does it work?

[sanddrag]

It would appear that a servo causes the little linkage arm to rotate which in turn forces the center shaft to slide axially, engaging either a smaller or a larger gear with either a large or small gear on the motor shaft, while maintaining mesh with a triple wide gear on the final shaft.

Nice work.

[fredliu168]

wow, no wonder you guys were first pick =P

[Synergy1848]

looks alot like the one we used except that we shifted with a rack and pinion set up.

[fluffy]

solid...I like the design

[psyco_klown]

Nicely done! Hope to allience with you again. They have a great robot every year. Cant wait to see what you guys do next year.

[cire]

I am amazed, very compact and clean design. My own shifter used 1 servo on each side, and doesnt seem as solid as that one. nice work!

[gdo]

it actually uses a MOTOR, not a servo. even though this type of action is almost perfect for the servo, they don't have the torque to perform the action, we learned this early one, so used a motor with some gearing. The gears for shifting are beveled which gives a cleaner shift, I have some more rendered photos. All parts were made by my team in Maya 8. The shifter has a 3:5 and 5:3 ratio.

Update: I am posting some more pictures, and gather documentation on the shifter design. It should be posted on our site at http://eaglevex.syraweb.org in a day or two depending on how quick we gather the info.

[VEN]

I am SO trying this

[Qbranch]

VERY nice design... but I have a question...

did you guys bevel those gears on a lathe or did ifi (vexlabs) start molding beveled ones? Also, did you use a shaft encoder/limit switch to decide if you were in gear or not?

again, sweet shifter.

-q

[Donut]

Looks good, the shifting design reminds me of the shifter I tried last summer. I like the slotted shifter idea, I think I'll have to try that out in the future.

The transmission write up says your team tried a few previous versions of this shifter in the design phase. Did you always go with this design and just create improvements, or were there some other 2-speed designs (shifting mechanism or meshing system) that were tried?

[Chris1270]

You think you can seed some plans of the Gear Shifter.

[JesseK]

Thanks for posting this. I came up with a 10" wide version of this for a single side and couldn't figure out how to get it down to 9". Going length-wise just might be the key depending on the game and the robot's necessary manipulator clearance. Unfortunately with this design, it's not very plausible to add another 1-2 motors to each side without adding an entire new shifting mechanism.

If I ever get my current concept idea done I'll rebuild the old (10") design and show you what I mean -- 3 motors per side and it could push 40lbs of books across my carpet if I pushed down on the back of the bot with my finger for traction. (5:3 High and 1:6 Low)

[gdo]

This design is relatively compact. It is 1" wider than a square robot, and the same length as a square bot.