Cotta Transmission Cutaway Model

[Krypto]

Great job! The model does make how the transmission does it's work much easier to understand.

[Kim]

Wow, Chris! Very slick solution to keeping the unused control rod in position!  Very clever and nicely executed 

And the completed model is great. LOVE the video! It's really fascinating to watch it move through the gears.  I had to rewatch it several times focusing on different things - the output shaft speed, the different gears meshing, the shift mechanism... So much to see in this model.

Well done!

Kim

[RReid]

That's just super-cool, Chris. I can see that being a big hit at the museum - "you mean I can really actually crank it and shift it??!!"

[crueby]

Thanks  guys!


Yup, will be taking it up there for the spring event. Will have to get some pics of it with one of the trucks. One uses a four forward speed version, with reverse in another box. Thats one of the things I  love at that museum, you can actually touch things, not just look from behind a rope.

[Don1966]

Awesome work as usual Chris you never stop amazing me. 



 
Don

[derekwarner]

Well Chris, have been watching this build progress and kept on thinking not all that dis-similar to the 1949 Ford Prefect Utility that my Dad taught me to drive in 

Gearbox was 3 on the floor. just like the Cotta...but the Prefect kept jumping  out of 2nd gear....and many stalled clutch starts 

Derek

[Michael S.]

The gear transmission works very well.
And all it takes is just a drop of oil to keep it going.
My tractor has 62 liters of transmission oil in the box.

Michael

[gbritnell]

Great job Chris!

[crueby]

Thanks guys! This was a fun build, good chance to practice gear cutting.


Not sure what the next project is, got several to choose from. I took a look at the re-designed Ransome saw, and while it should work better its kind of a clunky design. It needs more work on the valve setup (based on the boiler feed pumps with a shuttle valve to control the D valve). Also have a number of plan sets from the US National Archives, some that I've already made CAD versions of, some more that I found recently, including a compact steering engine from an early torpedo boat and some pumping engines from destroyers. Top candidate so far is a pair of engines driving an anchor and rope windlass set from the battleship Kearsarge. Just found another one for a deck winch from a destroyer that is a possible too...

[tghs]

this could keep you busy for a while, I did see a daimler V-twin hot tube ignition boat engine that looks neat,,

[crueby]

this could keep you busy for a while, I did see a daimler V-twin hot tube ignition boat engine that looks neat,,

Didn't I see that in Star Wars?       Gack, that would be an enormous model!

[gbritnell]

Chris, did you ever get the Ransome log saw sorted out?

[crueby]

Chris, did you ever get the Ransome log saw sorted out?

Hi George,

A while back I changed the CAD version to use a valve setup like the feedwater pumps do, with the two slide valves, which should work, but the valve block is just too large and chunky to look good. Probably going to rework it at some point to make the valve block smaller to be better in scale with the saw - I had just copied it from the pump model as-is, it needs to be 1/3 or 1/2 the size to look right. Trick will be to keep enough flow to make the saw perform well with enough power.

In the meantime, I have gone through the other plan sets/cad models, and think I've settled on a chain/rope windlass set, based on plans I found at the National Archives a while back from the early 1900s battleship Kearsarge. It has a pair of two-cylinder steam engines, a 8x8 and a 15x14, one driving the rope drums and one driving the anchor chain drums. They sit nested in a small deckhouse on the ship, should make a fun pair to model one after the other. I've started making up the paper plans from the CAD model at 1:10 scale, which works out to a .8" bore on the smaller engine and a 1.5" bore on the larger one. Here is a screen grab of the CAD model, minus the deckhouse walls. The smaller engine would mount to the port side wall, the other rope drum projects through the starboard side wall. The chains would come through holes in the fore side wall.

[gbritnell]

Nice!

[cnr6400]