Dean, Zee, Gail, Bernd, Chuck, Arnold & putputman...Thank you for your kind comments.
Thayer...I'm going to you for future Photoshop work.
Jim,
A "stop valve plumbed over to faux governor" crossed my mind, but this is a representational model AND I'd like to finish it in my lifetime!
Post 49
Steering
I made the front axle much earlier in this build, but hadnt provided for a way to attach the steering chains.
The first step is to cut two 1/4 long pieces of 3/8 tubing (5/16 ID) to use as attaching collars. These slip over the axle. Next bend two small rings to serve as chain attachment points and silver solder the rings to the collars.
It took two Third Hand devices to hold things in place.
Then position the collars on the axle and Locktite them in place.
The drill bit helps get the orientation right. As you probably know, any Loctite not in the joint wipes off cleanly after the joint cures.
Finding steering chain I was happy with was a real ordeal. I dont know how many samples I bought from various craft, beading and jewelry supply stores. They were all either; too shiny, too small, too large or too weak. About the time I was ready to compromise, I noticed that Gary Hart (ghart) had what looked like exactly the right chain on his tractor. I PMed him and he said he used clock weight chain. Bingo! Dont know why I didnt think of that.
So, off to the nearest clock repair store. I told the guy what I was looking for and he brought out his junk drawer and let me dig through it. I found exactly what I needed. He said if I wanted more to ask for No. 1 Cuckoo Clock Chain. Link dimensions are 0.145 wide, 0.290 long and its made from 0.033 wire. Six feet for $3 bucks, plus he let me take whatever I wanted from the junk drawer. He was an older gentleman and said mechanical clock repair is a dying business and he would never use up the pieces. Depressing.
In Garys email he also pointed out that he had added a guide spring to the steering chain roller to keep the chain from tangling. Its a nifty enhancement. Thanks, Gary.
I made my guide out of a piece of 12AWG copper wire. Probably should have been brass, but I didnt have any.
(Note: The spring shown is a right hand one. To steer properly it needs to be left hand. All of the following photos except the last one show right hand springs. Sorry, but by the time I figured this out and how to wind a left hand one, I was too frustrated to retake the photos.)
The spring is wound around a 3/16 mandrel. I turned the lathe by hand
no power (although it could be powered if you know what youre doing).
The tool Im using is a Hojarth Perfection Spring Winder patented in 1907. Ive had this for years (I collect old tools) and never had occasion to use it before. It seems to work very well.
The tool consists of a handle, a tension adjusting nut, clamp (brass) and a spacing guide (brass). The spacing guide has various thickness lands and it controls the spacing between turns. I picked a land that matched the link width on my chain.
In use, the wire is threaded through guide holes in the handle and between the two brass plates. Feed enough wire through to hook on the chuck and turn the chuck to wind the spring. The amount of tension you put on the star nut determines how tight the spring gets.
Heres an overall shot of the winder.
This one is about 9 long. They came in several sizes. If youd like to know more, Google patent 861,283.
To wind a spring without a Hojarth, check out Deanofids excellent thread, Springs and Things"
here
But I digress
It took me numerous tries to figure out that I needed a left hand spring and that turning the lathe backwards doesnt get you one. To get a left hand one, you have to wind from the tailstock chuck toward the headstock. If theres another way, please tell me. At this point, I get a headache just thinking about it.
Anyway, after winding the spring/guide, grind the ends perpendicular to the axis.
and install it on the steering chain roller and wind on the chain.
This is the first photo with a correctly wound guide. Also note that the chains cross. The guide and the crossed chains are similar to the real Case tractor.
Regards,
Dennis