Horse drawn Galion road grader circa. 1913?

[crueby]

That is stunning. 

Only problem now, is my shop elves want you to build them a gerbil-drawn coach!

[mike mott]

George those wheels are beautiful did you soft solder the spokes?

Mike

[kvom]

Where's the penny?    

[Craig DeShong]

gorgeous work George.   

[gbritnell]

I'm making the trunnions (axles) for the grader. They consist of the axle (.25 dia.) on the end of which is a boss. Vertically from the boss is a shape which has a round center with 4 radial ribs. At the top is another round boss (.23 dia.)
How to make it? The original piece is a casting but this will have to be fabricated.
I turned the axle from a piece of .50 round stock leaving material at the end to create the boss. The part was put in the dividing head and the pivot hole was drilled and the outer radius was stepped off.
Another small hole was drilled at 90 degrees to the pivot hole.
The ribbed section was created on a piece of .25 round brass bar. I made a cutter from drill rod. I cut 2-45 degree angles leaving a sharp corner. I then went in with a tool having a .115 radius on the end. .
This would form the central round shape. The cutter was fluted and hardened. I drilled a .062 hole in the end for a locating pin and turned a .062 diameter pin on the other end before cutting off.
The upper boss was turned, drilled and cut to length.
The next order of business was to make a fixture for fitting the parts and the eventual soldering. I turned two studs with the appropriate diameters on the ends. These were bolted to the base with 8-32 screws.
The ribbed section needed a radius filed on the end so it would match the .23 dia. boss. Once everything was fitted using the fixture a .062 dia. pin was inserted between the upper boss and ribbed section.
The first pictures show the cutter and the ribbed section with upper boss.

[gbritnell]

The next pictures show the fixture and the parts assembled on it.
When I made the axle pieces and stepped of the radial shape on the end I left a small central rib which will match up with the central ribbed section. After soldering I will file the rib shape flush with the proper angle.

[gbritnell]

The final pictures show the parts assembled awaiting soldering.
With the fixture, cutter, machining time and fitting and assembly I have 6 hours in these 4 small pieces.

[cnr6400]

Beautiful work! Thanks for sharing the pics!   

[crueby]

Super detail! I went back to the first post to see where these parts go, and there sure are a lot more bits to go on this project!
 

[gbritnell]

Hi Chris,
You're not kidding. By the time I get through with this it will have as many or more parts than some of my engines.
gbritnell

[crueby]

Hi Chris,
You're not kidding. By the time I get through with this it will have as many or more parts than some of my engines.
gbritnell

And thats not counting the parts in the mechanical horse to pull it!

[scc]

That is stunning. 

Only problem now, is my shop elves want you to build them a gerbil-drawn coach!

     Do the gerbils use CAD I wonder

[Don1966]

The final pictures show the parts assembled awaiting soldering.
With the fixture, cutter, machining time and fitting and assembly I have 6 hours in these 4 small pieces.

I can relate to that George been there too. Small parts are time consumers!

[Dreeves]

Always amazed at the work you do. Sure would like to see you at the Cabin Fever shoe in January.

[gbritnell]

There's so many parts to make for this machine that some of them have no particular order but need to be made. Yesterday I felt like cutting some gears.
 The axles are composed of two pairs of angle iron rails, top and bottom. At the ends are the trunnion pieces I showed in the last post. One pair of angle irons are mounted to the frame and the other pair have the gear segment shown. There's a gear box between the angle iron frames in which is a worm gear set that drives a spur gear that moves the circular gear segment. I had to do a development when I was drawing it, meaning as the lower set of angle irons move laterally to tilt the trunnions they naturally get closer to the upper angle irons so this change the engagement of the spur gear with the gear segment so the gear segment had to be created from the widest point of the angle irons to the narrowest point when they were laid over. I came up with a radius for the gear segment then had to calculate a diametral pitch for that gear to somewhat replicate the tooth count of the original. The pitch came out to 36. They don't make 36 D.P. cutters so I had to make one.
 To make the cutter I have a 14.5 degree high speed tool ground. The diameter of the cutter isn't critical and in this case I used a piece of .50 diameter W-1 drill rod. I chucked the stock then cut a 14.5 degree chamfer on the end. I use this to set my tool properly. I set my compound at 14 degrees so that the cutter only cuts on one side when going into the rod. Much like when cutting threads. I do a layout in CAD to see what diameter rods to use for checking the depth of cut. I have a set of thread wires and try to use one of those for measuring the depth. After cutting the rings the stock is transferred to the dividing head and the flutes are cut into it. After fluting I file as much clearance behind the cutting edge as possible. The cutter is then hardened and using a flex shaft tool and a small cut-off wheel I hit the face of the flutes to clean up and burrs that might remain from the milling process. The cutter does rub a little but for brass it's not noticeable.
 I turned to discs .132 thick and mounted them on a mandrel. The mandrel was clamped in the mill vise between V-blocks, the center picked up and the mounting holes were drilled for 1-72 screws. I was able to get 2 pieces per disc. While set up for drilling I also milled the blanks to the proper width.
 The mandrel was then transferred to the dividing head to have the teeth cut. The disc would have had 60 teeth cut into it but I only needed to cut the segmented areas.
After the teeth were cut I rough sawed the discs then mounted them on yet another fixture to finish putting the radial cut-out and the radii around the bosses. The parts were then filed and polished.