Horse drawn Galion road grader circa. 1913?

[gbritnell]

 First a shout-out to Chris. In going through my miniature burrs I happened to have a small container of 3/32 shank burrs that someone gave me quite some time back. I had never used them and didn't even know what the profile was. The tips were so small that I had to use my magnifier to see them and lo and behold they had probably what you called a football shape but more so an inverted tear drop. They have 6 flutes on them and go to a point. I marked my hole locations by rotating my carbide tipped scriber until a had a good witness mark then I chucked up one of the burrs in my Dremel flex shaft. Using my magnifier I carefully set the tip of the burr on the witness mark and lightly pressed down. It didn't skate and gave me a nice dimple to drill to. At that point I was thrilled and the job that I had been dreading turned into not so bad of one.
 Now to catch up with the build.
 There's a lot going on at the back of the machine, levers, wheels, handles brackets etc. In my last posting I had presented the bracket and crank mechanism which tilts the axles. Next up was to install the already made axle shift mechanism. This consists of two brackets, one on each side of the rear of the frame. The one on the left holds another set of miter gears, the one on the right just supports the end of the lead screw. The brackets are mounted to a long rectangular plate that the shuttle rides on. The shuttle is made in two pieces and is slotted to fit over the rectangular plate. Attached to it is a bar that hooks to the left side axle yoke. When the handle is turned it transmits motion through the meter gears which turn the lead screw which moves the shuttle.
First the full sized machine.

[gbritnell]

Here's the pictures of the model.

[gbritnell]

The bracket that supports the shaft for the shifting mechanism is bolted to the frame. This wasn't a particularly hard job but the corner bracket for the platform sits on top of it and the bolts go through both pieces and through the frame. I don't know if having 4 hands would have helped? Trying to hold things in place while scribing lines, what a job. In mounting the operator's platform I had made the angular brackets that go to the frame from my drawing. Well they were just a little off and with the frame tapering it didn't give me enough room to put bolts through the other 3 brackets so they had to be remade.
More M1.2x.25 square head nuts and bolts. I think when I get through I'm going to count up all the nuts and bolts I made for this project. Or maybe I don't even want to know!
Here's 2 shots of the axle assembly tilted. By turning the crank everything works like it's supposed to.

[gbritnell]

This picture was posted earlier on but it shows the rear axle tilted on the full sized machine.

[crueby]

First a shout-out to Chris. In going through my miniature burrs I happened to have a small container of 3/32 shank burrs that someone gave me quite some time back. I had never used them and didn't even know what the profile was. The tips were so small that I had to use my magnifier to see them and lo and behold they had probably what you called a football shape but more so an inverted tear drop. They have 6 flutes on them and go to a point. I marked my hole locations by rotating my carbide tipped scriber until a had a good witness mark then I chucked up one of the burrs in my Dremel flex shaft. Using my magnifier I carefully set the tip of the burr on the witness mark and lightly pressed down. It didn't skate and gave me a nice dimple to drill to. At that point I was thrilled and the job that I had been dreading turned into not so bad of one.
 Now to catch up with the build.
 There's a lot going on at the back of the machine, levers, wheels, handles brackets etc. In my last posting I had presented the bracket and crank mechanism which tilts the axles. Next up was to install the already made axle shift mechanism. This consists of two brackets, one on each side of the rear of the frame. The one on the left holds another set of miter gears, the one on the right just supports the end of the lead screw. The brackets are mounted to a long rectangular plate that the shuttle rides on. The shuttle is made in two pieces and is slotted to fit over the rectangular plate. Attached to it is a bar that hooks to the left side axle yoke. When the handle is turned it transmits motion through the meter gears which turn the lead screw which moves the shuttle.
First the full sized machine.

Great find George! Those little burs can come in handy for a lot of things, they are available in a lot of shapes, both in toothed carbide and in diamond coated.   

[crueby]

The bracket that supports the shaft for the shifting mechanism is bolted to the frame. This wasn't a particularly hard job but the corner bracket for the platform sits on top of it and the bolts go through both pieces and through the frame. I don't know if having 4 hands would have helped? Trying to hold things in place while scribing lines, what a job. In mounting the operator's platform I had made the angular brackets that go to the frame from my drawing. Well they were just a little off and with the frame tapering it didn't give me enough room to put bolts through the other 3 brackets so they had to be remade.
More M1.2x.25 square head nuts and bolts. I think when I get through I'm going to count up all the nuts and bolts I made for this project. Or maybe I don't even want to know!
Here's 2 shots of the axle assembly tilted. By turning the crank everything works like it's supposed to.

Wow. Stunning finish, AND it works!   

[gbritnell]

The next assembly to make and mount is the lead screw setup that shifts the blade. It's similar to the one that shifts the rear axle assembly. A crank handle turns a shaft that goes through a pair of miter gears. This in turn moves a shuttle along a rectangular plate. This shuttle has somewhat of a universal joint. There is a link from the shuttle and onto this link is another shaft with a yoke. The blade can be moved from side to side and up and down. This linkage allows that motion while keeping everything rigid.
The lead screw is supported much like the axle shift brackets except they're much more complex. I made the bracket for the axle shift assembly but didn't want to even try to make these two. I could have made something that worked but to try and keep the details in the model I opted to have them cast. I drew the parts up in Solidworks and sent the files to Shapeways. The cost wasn't bad at all, $15.00 each. Much, much less than the time I would have put into trying to make them. Having had parts made by Shapeways in the past I knew the shrinkage was minimal but just to be safe I added a few thousands here and there. When I got the parts an measured them they were within a couple of thousands so I was thrilled, to say the least.
The next thing I had to figure out was how to machine them. The brackets eventually bolt to the rectangular bar so I milled a piece of brass the width of the recess where the bar would eventually go and soft soldered the bracket to it. This gave me something to hold onto and rotate around so the mounting and shaft holes could be machined.

[gbritnell]

Here's a couple more picture of the model. The one shows the rectangular bar with the shuttle and linkage attached.

[gbritnell]

The upper part of the shaft has a support strap that is bolted to the rear of the worm gear housing. I had to remove the housing to drill and tap the holes for the support strap. The housing had to come off anyway to put the chain bracket onto the shat anyway. The shaft is .073 diameter and is threaded 1-72 at the top for the handle The miter gear at the bottom is cross drilled for a pin. This is so that it can be disassembled if needed.

[gbritnell]

Here's just a couple of pictures of the machine.
The last picture is the other casting I had made for the rear axle tilt mechanism.
Just a couple more pieces to complete the main machine and then I can start working on the blade assembly. That promises to be quite a job in itself.
gbritnell

[crueby]

My gast is truly flabbered. Amazing work!

[90LX_Notch]

Spectacular.

-Bob

[zeeprogrammer]

I haven't said much. Anytime I enter this thread...I'm left speechless.

What a wonderful project.

[derekwarner]

They say the simple things can be the most difficult so have gone back to post #34 to re-read the construction of the chassis I beams

Thank you for sharing....absolutely amazing ....an inspiration and a huge learning curve for members looking in

Derek

[Craig DeShong]

I’ve been working on the governor of my model and I consider the parts small; but some of your parts on this model are a magnitude of order (10 times) smaller.  I honestly don’t see how you do it.  I’m constantly awed and amazed.