Cotta Transmission Cutaway Model

[crueby]

Getting really close: after lunch out with friends, went back into the shop and marked out the locations for the shift gate, using the lever to move to each position and marking off the end/center points on the plates. Over to the mill to cut the slots went pretty quickly:

then back to mark which leg did what:

Next step is to head up to the engraving machine and cut in the letters/numbers. I'll fill the letters with paint to make them stand out. After that, last parts will be to make the detents (might do them with a single sping loaded rod, or two ball bearings, not decided which way yet. Also am debating whether to hang a RC truck differential off the output shaft to show the direction/speed, or might just make the front half of a drive shaft yoke fitting. Should have this wrapped up in the next couple days! 

[cnr6400]

  Lookin great Chris!

I was surprised though that the Cotta uses the I wide-serif  gate rather than the more common H gate ...    (who said font doesn't matter!)   

[crueby]

Lookin great Chris!

I was surprised though that the Cotta uses the I wide-serif  gate rather than the more common H gate ...    (who said font doesn't matter!) 

You fell over on your side again Jeff!      I'll email your elves to stand you up again!

[tghs]

looking great.. somewhere in a drawer I have a "save the manuals" T-shirt...

[crueby]

looking great.. somewhere in a drawer I have a "save the manuals" T-shirt...

No shirt here, but I do have a 17 year old Miata with a 6-speed manual in the garage!  Blast to drive, but not in this weather...

[cnr6400]

  Thanks Chris, I needed that! Only took them a minute with the jack. 

[crueby]

Thanks Chris, I needed that! Only took them a minute with the jack. 

I talked them out of the stack of firecrackers...  and the trampoline on the other side in case it was too much...   

[ShopShoe]

I like the idea of a differential or some-such driven by this transmission.

If you made a skeletonized visible one there would be even MORE GEARS to watch go round.

ShopShoe

[tghs]

looking great.. somewhere in a drawer I have a "save the manuals" T-shirt...

No shirt here, but I do have a 17 year old Miata with a 6-speed manual in the garage!  Blast to drive, but not in this weather...
[I figure my 2005 5spd ranger is a form of theft deterant /quote]

[ddmckee54]

[I figure my 2005 5spd ranger is a form of theft deterant /quote]

I don't know about a theft deterrent, but I have had more than one Jiffy-lube attendant ask me to drive it in for him.  I don't own anything that's not a Gear-Jammer.

Don

[crueby]

So, I put my crack(ed) team of engineers on the problem of how to handle keeping one control rod in position when the other is being used. They had the emergency team standing by in case of explosion or someone being sucked into the machine:


Bottom line is that the detent idea was thrown out. It would work for most cases, but if the end of the rod was bumped, it could still move out of position and jam things up. So, new plan: add a couple of arms to the lower gear shift lever bracket that would move back and forth with the lever, and engage the unused rod with a yoke around a projecting piece on the rod:

This is working quite well. It prevents the unused rod from moving at all, and only lets go when the lever is almost fully engaged on the new side. Here is a view with the lever moved towards the camera, showing how the yoke comes off the projection:

And a view from the end, showing the same yoke setup on both sides:

All working well, time for some final shots and a video!
Here is a couple shots of the finished transmissions:

All appears to be working well, once in a while it takes a double-clutch if the dogs line up with each other and wont mesh, since there are no syncros in this design.  Next step was to take a video showing how it all works:
<a href="https://www.youtube.com/watch?v=dXUPQEyDZaA" target="_blank">http://www.youtube.com/watch?v=dXUPQEyDZaA</a>

[cnr6400]

  Fantastic Chris! really nice job, works great too. 

Is the operating handle from Picken Manufacturing and Foundry, making this a Cotta-Picken gearbox?  (gotta be in the top 100 worst puns ever)

[crueby]

Fantastic Chris! really nice job, works great too. 

Is the operating handle from Picken Manufacturing and Foundry, making this a Cotta-Picken gearbox?  (gotta be in the top 100 worst puns ever)

The Royal Canadian Pun Police are on their way to hit you with a rubber chicken...   

[Brian Rupnow]

Chris, that is just wonderful.---Brian

[crueby]

Chris, that is just wonderful.---Brian

Thanks Brian!