Methods of shifting gears

[henryBsick]

I've designed and built a few ball shifting transmission in the past. I really dig the new Vex Pro models that are out. They've got many of the 'wanted' features I've recognized over the years, but never implemented. Kudos to them for a solid design.
Linked are two pictures.
1) Project cover page listing team members and showing completed drive base.
2) Shifting detail on the transmissions. The large exploded view is a bit crap (my apologies), but the other simple illustrations outline function showing the shifting shaft, plunger shaft, shift gears, and ball bearings.
I'm happy to share any specific details if anyone is interested in developing their own ball shifter.

[A_Reed]

CVT anyone?

http://en.wikipedia.org/wiki/Continu...e_transmission

Not entirely practical for FRC applications but it certainly would make an interesting design project to see if you can make it work.

[joelg236]

Originally Posted by A_Reed

CVT anyone?

http://en.wikipedia.org/wiki/Continu...e_transmission

Not entirely practical for FRC applications but it certainly would make an interesting design project to see if you can make it work.

Imagine having one of these on your robot. http://upload.wikimedia.org/wikipedi...xtroid_CVT.jpg

[Tristan Lall]

Originally Posted by joelg236

Imagine having one of these on your robot. http://upload.wikimedia.org/wikipedi...xtroid_CVT.jpg

190 did a toroidal CVT with power take-off in 2002. (Search the forum for more information, e.g. this thread.)

[Joe Ross]

The Thunderchickens did a planetary CVT in 2002 and published a whitepaper: http://www.chiefdelphi.com/media/papers/1361

[lukedude43]

thanks to everyone for all the information it's been incredibly helpful. Something that I didn't realize I left out is that this is a project to help me learn solidworks and because off that i'm gonna go with dog shifting just because of the easier design. Also if by some chance we actually made this instead of just buying some AM or VEX shifters, dog shifting would be easier for my team to do because they would be our first machined parts and it seems much easier to design than a ball shifter.

[Gregor]

Originally Posted by lukedude43

thanks to everyone for all the information it's been incredibly helpful. Something that I didn't realize I left out is that this is a project to help me learn solidworks and because off that i'm gonna go with dog shifting just because of the easier design. Also if by some chance we actually made this instead of just buying some AM or VEX shifters, dog shifting would be easier for my team to do because they would be our first machined parts and it seems much easier to design than a ball shifter.

Unless you have a really, really good reason, stick to COTS gearboxes.

[mman1506]

Originally Posted by lukedude43

thanks to everyone for all the information it's been incredibly helpful. Something that I didn't realize I left out is that this is a project to help me learn solidworks and because off that i'm gonna go with dog shifting just because of the easier design. Also if by some chance we actually made this instead of just buying some AM or VEX shifters, dog shifting would be easier for my team to do because they would be our first machined parts and it seems much easier to design than a ball shifter.

Make sure you do it in the off season. Before COTS 2 speed gearboxes were available are team wasted a lot of time making 2 speeds that were mediocre. I'm not sure how well the AM shifters shift but our dog shifters take quite a bit of tuning to shift in a useful fashion.

[lukedude43]

AM shifters are dog sifters

[Michael Hill]

Originally Posted by lukedude43

AM shifters are dog sifters

I don't think dogs appreciate being sifted

[lukedude43]

Haha you're probably right

[Mark Sheridan]

Pretty much the history of dog gear shifting in FIRST and the origin of Andy-Mark.

http://www.chiefdelphi.com/media/papers/1306
http://www.chiefdelphi.com/media/papers/1360
http://www.chiefdelphi.com/media/papers/1432
http://www.chiefdelphi.com/media/photos/19082


Team 45's 2003 gearbox is probably one of my favorite gearboxes. The PDF was released when I was learning to drive. So I was crazy about cars then. The 2003 gearbox is what taught me what a dog shifter was in a manual gearbox.