Gypsy winch for "Christine" - part 2

As told in the first part, I decided to use a blind shaft between the steam engine and the main winch shaft. This allows me to add another 2:1 gear reduction and the main drive gear can be placed on the left side. The blind shaft has 8mm diameter and runs in brass bearing blocks.
In front of this shaft, the main winch shaft will be placed. This shaft is parted into two halves. The first one carries the main drive gear and the gypsy head. The second halve will hold the winch drum and doesn't rotate on its own. This static shaft rests in a brass bearing inside the drive gear. The bearing block for the short shaft will be designed as double bearing. The last two pictures are showing a free set up of the machined parts. Next I've to finish the bearing blocks with foot plates.

On the right side of the drive gear, you can see a wooden disk, mounted with screws. This disk is a part of the winch clutch. Another disk of this kind will mounted on the drum and by pushing the drum against the gear with a lever, the drum will rotate and wind up the cable.

After adding the main bearing block for the gypsy head and drive gear, I installed the small shaft for test runs. There's a video on Youtube with comments => http://www.youtube.com/watch?v=25MX0RQaOMs

Now we need a drum for our winch. I started with two disks. The left one will be used as clutch bell and as support for the band brake. This disk was made cast iron. The right disk was laminated from some sheet metal and features a ratchet wheel for the pawl. Booth disks have brass bearings to ride on the shaft. A piece of copper pipe connects both disks to form the drum.

The left photo below shows a detail of the left drum disk, used for the clutch. You can also see the brass bearing in the center. To move the drum and let the clutch work, I needed a clutch mechanism. This was inspired by the typical donkey engines design. The end of the shaft was bored with 3.1mm to hold a 3mm brass rod. A transfer link will be placed in a slot, milled through the shaft and hold in place by a brass ring. Pushing the brass rod into the shaft, the transfer link will push the drum to the left. A spring between the main drive gear and the drum will release the clutch and move the drum back again.

At the end of the shaft, I added a piece of 20mm round steel (silver soldered). From 25mm brass, I turned a bell on the lathe that will fit the end of the shaft. I milled a slot into this bell over 90° length and 5mm pitch. A bolt screwed into the shafts end section will result in a simple clutch lever mechanism. By turning the bell in anti clockwise direction, the bell will slide up to 5mm to the left and will press the drum against the main drive gear by using the 3mm push rod inside the shaft, acting to the link. Finally I added a nice lever to the bell and some paint to the assembly.

Next I added the ratchet pawl, made from steel. Still missing was the brake. First I thought some cable logging operations will work without a brake. The first test told me the opposite :-(. So, how to attach a band brake? I placed a 4mm shaft below the drum on the front of the pilot. The brake band, cut from 0.6mm brass sheet, was mounted to the end beam and runs around the left drum disc from the back to the front. The end of the band is mounted to the shaft with a small lever and link. Finally, I placed a lever for the engineer and that's all. Maybe I'll add a small spring to hold the lever in the open position.

At last, the gypsy winch is ready to run. As usual, you'll find a video at YouTube of "The Big Logging Show" ;-)

http://www.youtube.com/watch?v=wVgPQraFoSk