Control Levers
Real engines had three motion control levers: reverse, throttle and clutch. This model only has a throttle. However, Im adding dummy levers to represent reverse and clutch.
They mount on a 1/8 shaft that runs between the horn plates. The levers are made from 1/16 brass.
The upper hole is for a 1/16D control rod. At this stage I drilled both holes 1/16 so I could use them as locating points when milling the lever sides.
When one side is finished, its a simple matter to flip the part over and mill the other side using the same depth setting.
There are two lever types.
The top of the lower lever will be cut off. I left it long so Id have more widely spaced holes to use as locators in the mill.
The next step is to round the lower end.
and drill it out to 5/32.
The upper end of the lever is rounded with a file to accept a handle.
The handle is a piece of 1/8 rod with the end drilled 1/16 and tapered with a file.
The top of the handle is rounded by inserting a slightly knurled piece of 1/16 rod into the handle and mounting it on a Dremel. The spinning part is then held against a 3-M deburring wheel to round it.
The handle slips onto the lever and is soldered in place.
The movement of two of the levers is limited by what on a real tractor is a latching mechanism. I dont know what their correct name is. I simulated them from a piece of .016 brass.
The levers and latches were soldered to a piece of 5/32 tube (1/8 ID) so they could be mounted on the shaft between the horn plates and have some stability.
One additional piece was necessitated by poor planning on my part. The reverse lever needs to be held in position on the 1/8 shaft. If Id have thought this through earlier in my build I would have drilled some holes in the horn plate to do that. As it is, the only way I could come up with to hold the left (reverse) lever upright was the odd piece shown below.
It and the simulated latch are soldered to the tube. The odd shaped piece then locks on one of the bearing blocks.
Here are the lever parts the way theyll be mounted.
The reverse (left) lever moves freely but doesnt do anything. Its movement is restrained by the latch mechanism which is anchored to the bearing block. The throttle (center) lever actually controls the throttle and is restrained by the latching mechanism which is soldered to the clutch (right) lever which will be restrained by a rod attached to the lower end. Whew!!
Here they are in place.
Thanks for following along.
Dennis