Caterpillar D6M dozer conversion

[Rich]

Several years ago, I started a project in 1:64 scale, and ended up putting it away for a while. I did not think when I started it, that it would be so involving. I have picked it back up, and have been working on it for a few days now. It is a conversion of several dozers in to a Cat D6M that Orange County Fire Authority in California uses. I photographed it at a show in Pomona a few years back. No one makes a D6M, so this one was going to be a challenge. At the time, Norscot was still around, and they had a D6 R XL and a D6 H, both in 1:64 scale. I had both, but knew I would need to do a lot of scratch building or finding other things to help with the project. I will start off with just the chassis, as I need to finish that up before I get back on the body and cab. If you notice in this photo, the D6M's U Frame for the blade, are inside of the tracks. Most other dozers in the D6 line are outside of the tracks. Here is where the first challenge was. I liked the D6 R chassis, it really matches the D6M. But I knew going in to this project, I would have to get it right the first time, or risk cutting up another donor, and by now I knew Norscot was out of business. So I decided to use the D6H chassis as my mock up. The D6 H is noticeably wider where it needs to be. I have photos of each to show you. So in order to have sufficient room for the tracks and U frame, I knew I had to modify the D6 R chassis once I had everything else in place. This photo of the actual dozer sitting next to a D6 R shows the track location difference pretty well.

[Rich]

Here you can see the differences in the D6 R and H dozers. You can also see the difference in chassis width.

[Rich]

In this first photo, the D6 H chassis has had numerous cuts made, so that the tracks and U Frame will fit the body width. Once I was certain it was how I wanted it, I started on the D6 R chassis. The second photo shows the chassis width difference pretty well. I had some milling to do around the area that is shaded in black. Not a lot, but I wanted that ridge on top gone, even though it wont show. Once I had the milling done, then it went in to the stripper to remove the old paint. Once it was stripped, I cut the track pieces off of each side. These pieces are simplified to show the location of the bogies and various works. When they were cut, I measured the inside width of the D6 H, and cut a piece of .20 styrene to that width. I glued it to the bottom of the chassis. It will work as a pattern to hold the side track pieces at the proper width.

[Rich]

Once I got the side track pieces glued to the plastic on the chassis frame, I noticed that one side was wider than the other. Even after measurements, it was off and did not look right. Rather than pull it off and start again, I cut the plastic down the center, and just replaced the side that was too wide, by moving the new plastic base inwards a bit.

[Rich]

Here you can see the top side, with the plastic sandwich of the side track pieces and the frame. Most of this wont be seen with the tracks on, but I wanted it to look good as well as function. I have to make the body and chassis as separate assemblies, so they have to fit well once they are screwed together. Notice in the background, the U Frame and blade. Every step of the way, the chassis has to be fit against the body, and the U frame against the chassis, so it all lines up when the sub-assemblies are finished. The last photo, shows the chassis, body, blade and U Frame, and cab assembly set up for fit. So far, I like it. The holes are drilled in the chassis to accept Hob Bits bolts and washers and nuts to hold the front and rear wheels to the track sides. This way, I will have eliminated the need for the big bulky axles.

[Rich]

Going to do a bit of work on the blade and U Frame now. Notice in the last photo above, where the U Frame sits on the blade mounts. The hydraulics should be at the top, with a separate mount below it for the blade, a space and then another mount. I cant do it this way, it would involve replacing all the mounts on the blade, and that would compromise strength. I want at least one of the molded in mounts, so it is strong enough to supports its own weight on the U Frame mount. The U Frame comes from an Amercom 1:64 scale D5K dozer. These things were super nice, with tons of detail. The only diecast in the entire model, was the hood and blade/U Frame assembly. The rest is plastic.

[Rich]

So the first thing I had to deal with, was that the U frame was too narrow. No problem. I cut the mount away from the front on both sides. I found the width I wanted, and glued the center piece that was left, and each side to a piece of .040 styrene. Then I made fill pieces on each side of the mount, to make it one piece. You can see in several photos, where the entire U frame is still sitting on the solid piece of plastic. For a few days, I have been taking material out of the middle of it. You can see the plastic in this shot. Once I got the U Frame to the size I wanted, I started on the blade modifications.

[Rich]

Next up is modifying the blade. The hydraulic cylinder is high up on the blade, and takes up the top mount. I will use it, and then trap the blade in this one as well. Not prototypical, but sometimes you have to adapt. I will still have to make a lower blade mount so that the blade does not move on the U Frame's mounting post. The hydraulics that control side to side movement, are mounted too high on the blade. So I have cut the top mount off, and will make another below the bottom mount to get the lower.

[Sirentoys]

This is fun to ride along on the build. I admire the little no one can see but I know bits you are doing.

[Chariots of Fire]

That's a lot of cutting but I like where you are going. I'll be following along! Cool project for /64 scale!