pic: Inventor to Reality

[Hunter]

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[Max Lobovsky]

One cylinder for both gearboxes is pretty cool. What's the second plate near the output shaft for? Have any weights for the design?

[Rombus]

Can you explain how your using one cylinder to do the shifting? Also how many gears do you have?

[sanddrag]

Not to take away from the uploader of this image but I believe I can get a couple questions answered. The gearbox is a two speed. The two gearboxes are oriented such that (it's hard to see but lets just say) low gear is toward the outside of the robot and high gear is toward the inside of the robot. The gearboxes are mounted inline. The pneumatic cylinder is "floating" between them. The cylinder body is not on a fixes mount. The end of the body connects to the linkage on one gearbox while the end of the rod connects to the linkage on the other gearbox. When the cylinder extends, both gearboxes are pushed into low gear. When the cylinder retracts, bothe gearboxes are pulled into high gear. Hope this is accurate and helpful.

[Peter Matteson]

How effective is the one cyclinder shifting?

We toyed with the same idea last year but wimped out be cause we didn't want to go into gear one side before the before the other.

[Hunter]

Originally Posted by sanddrag

The gearbox is a two speed. The two gearboxes are oriented such that (it's hard to see but lets just say) low gear is toward the outside of the robot and high gear is toward the inside of the robot. The gearboxes are mounted inline. The pneumatic cylinder is "floating" between them. The cylinder body is not on a fixes mount. The end of the body connects to the linkage on one gearbox while the end of the rod connects to the linkage on the other gearbox. When the cylinder extends, both gearboxes are pushed into low gear. When the cylinder retracts, bothe gearboxes are pulled into high gear. Hope this is accurate and helpful.

Exactly. Having one cylinder works perectly, they always shift at pretty well the exact same time, and we've never had a problem with it, since it generates the exact same force as two indivdual cylinders. The main reason we have only one is because the gearboxes are too close together to put two cylinders, and we didn't want to offset them because of the drive layout.

[Hunter]

Originally Posted by Max Lobovsky

One cylinder for both gearboxes is pretty cool. What's the second plate near the output shaft for? Have any weights for the design?

The second plate near the output is there to hold the 5/8 bearing in place.

Total it weghs 8.2 lbs with both motors and all the shifting mechanism and everything (except the cylider). And since there are tracks the output chaft from this drives the back pulley, all the reduction is done inside the trannsmission so there are no chains or any other form of reduction on the drivetrain.

[Andy Baker]

Originally Posted by Dzdconfusd

How effective is the one cyclinder shifting?

We toyed with the same idea last year but wimped out be cause we didn't want to go into gear one side before the before the other.

It works well. We used a one cylinder shifting setup in 02 and 03. You just need to let the cylinder float between the two boxes.

Andy