Ideas for Ball Shifter?

[Bryce2471]

Originally Posted by JorgeReyes

But splitting the ball shifter gears or trying to put it in front or behind the inital reduction like dog shifters would require a custom ball shifter wouldn't it? If you split them you need to have to ball shifter holes farther apart which would mean maching a custom ball shifter housing and moving it in front or behind would mean machining a longer or shorter ball shifter rod.

I might just go with a dog shifter for ease of manufacturing.

Going with a dog shifter, is not a bad choice. But with a little design work, you should be able to use the cots ball shifter shaft. You would definitely have to make custom plates though.
If I were you, I would consider hanging the CIMs over the drive rail, and putting the cluster gear above your chain drive. (Or belts, if you prefer)

[asid61]

You can make a 1 stage shifter f you use 4 inch wheels and can machine a couple gears down to length.
Basically, have an 11t pinion and a 14t pinion on each CIM shaft and have them gear to two gears- a high speed and low speed gear. Then shift between the two gears.
That's a single stage version, but you can only get a spread of around 1.4x due to the maximum size of the gear being limited to the size of the wheel. Adding a second stage would allow you to have massive spreads.

[magnets]

Originally Posted by asid61

You can make a 1 stage shifter f you use 4 inch wheels and can machine a couple gears down to length.
Basically, have an 11t pinion and a 14t pinion on each CIM shaft and have them gear to two gears- a high speed and low speed gear. Then shift between the two gears.
That's a single stage version, but you can only get a spread of around 1.4x due to the maximum size of the gear being limited to the size of the wheel. Adding a second stage would allow you to have massive spreads.

I'm not sure that's really ideal. With an 11:76 in low gear and a 14:74 reduction in high gear, (same C-C distance with vex pinions), you get a 1.31 spread. On a 4 inch wheel (the gears have an OD of 3.9", so that's the smallest wheel you can get), you'll see free speeds of 13.4 and 17.5 fps, both of which will have you tripping breakers with 2 or 3 CIMs per gearbox.

You'd also need to find 76 and 74 tooth gears, and put in the hole for the bushing and the circular grooves for the ball shifter components.

[T^2]

I did this in the 2013 offseason. The drivetrain (WCD) worked out decently well for my team, but we ended up using a 3-stage ballshifter for the competition season.

[asid61]

Originally Posted by magnets

I'm not sure that's really ideal. With an 11:76 in low gear and a 14:74 reduction in high gear, (same C-C distance with vex pinions), you get a 1.31 spread. On a 4 inch wheel (the gears have an OD of 3.9", so that's the smallest wheel you can get), you'll see free speeds of 13.4 and 17.5 fps, both of which will have you tripping breakers with 2 or 3 CIMs per gearbox.

You'd also need to find 76 and 74 tooth gears, and put in the hole for the bushing and the circular grooves for the ball shifter components.

Whoops, I forgot about C-C distance.
Actually, you can put one shaft at an offset to the side for the low gear and put the high gear on the main shaft. You still shift between the two gears on the main shaft, but when you shift into low gear it could go through an extra reduction.
I will need to make a picture. Bascially, you have two pinions on the CIM shaft, but the 11t (low gear) pinion is mated with a gear on the side. That gear is on a shaft which connects to a small gear on the 2x1 side of the gearbox, which is mated with the main shaft. That makes a 2-stage reduction for the low gear, and a 1-stage reduction for the high gear.