Chariots of Fire

The last part of the build is nearly done. Some of the air brake components have been added and the last thing done was to make the two ramps that allow access to the trailer deck. It took me a couple of tries to get them right but the time involved was worth it. The ramps are made of plastic sheet stock using 0.010, 0.020 and o.030 thicknesses. A drew out a series of templates for the sides (there's a third one inside) and taped them to the sheet stock. Then they were cut out and smoothed up. The 0.030 sheet stock was used for the center one and the 0.020 stock for the outside. I had to check to be sure that they were all the same so a bit of sanding and adjusting was done along the way. At first I tried filling in the curved parts with strips of small stock but that did not work well as noted in the unpainted ramp. It was also the wrong shape. I ended up using the thin 0.010 sheet stock for the surfaces and the scale thickness really made a difference. It bent around the curves easily. CA glue really does wonders in cases like this! Not all of the individual air lines and tubing have been added but much of the mechanical part that is visible was put together with plastic tubing, plastic rod stock and some 1/16 diameter aluminum tubing. Common pins were also used. A look at the underside with all of the various lever arrangements to get to the final results. Nothing wrong with the tires. They float in two different directions but sit flat on the ground due to the trunnion design with no problems. This is where the ramps go. Now I have to make the attachments that will fold and allow them to sit on the deck. Here's a look at the M-20 and M-9 when put together. They take up a lot of space! Last to be done will be the lift cables for the dozer.

Hi, Peter. I had two to choose from and decided to give away the better one. But honestly, for what I do? The older one works just fine.

I also have the Chopper by NWSL. Had the version that Peteski shows but gave it to a fellow modeler who had none. I kept the original one that has a masonite base and uses a single edge razor blade. I use it all the time for cutting small stock. When needing repetitive pieces the same length it is indispensable.

Here's a look at the prime mover and the trailer together. It's going to take up a lot of shelf space so I will have to add one to the display case just for it! The D-7 bulldozer is not finished yet. The blade and hoisting cables need to be added. It will be the load for the trailer.

You've got good eyes!!??

The double sheaves are painted and installed. The long lifting handles were made from common pins and set in holes drilled in the face of the upper plate. Some CA underneath holds them in place. Some Tamiya gun metal highlighting has made the sheaves stand out a bit. The brackets that hold them in place are Evergreen strip stock shaped and glued down. Almost ready to tackle some of the underneath stuff. That should be fun!?

I started with a pattern which I taped to some brass sheet. Then cut each piece using a dremel and cutting disc. Before cutting, holes were drilled in the center, at the base and top in the first one so that it could be used as a pattern for aligning the holes in the other pieces. When pins were inserted in the center hole and one of the other holes, it served to secure both pieces so the remaining holes could be drilled with some precision. When this was done three pieces of brass were held together by the pins and then clamped in a vice grip and the edges of the pieces smoothed up to be the same. It was a bit tedious, but the results speak for themselves.

Work continues on the front of the trailer. Two air lines have been added and the front portion has now been painted. Latest project was to make to double sheaves that will rest behind the air filters on the bed. They have turned aluminum pulleys and brass work for the rest. The brackets need to be added to the trailer bed to secure them in place, although they were intended to be removed for recovery operations. Still needed are two lifting handles for each one. The real ones are heavy!!

Got a little bit more done on the front end. The underside of the trailer is now painted but the top won't be done until I've figured out all of the stuff that needs to be included. Brake lines and levers, the spare tire rack, all need to be put in place. Anyway here is what the front end is beginning to look like. Some things are just set in place until final painting of the trailer itself.

The trailer is now up on wheels. Was able to complete the basics of the rear trunnion and axle assembly for the 16 tires and wheels. The information was a bit sparse but when the trailer is finished most of the work won't even be seen unless the trailer is turned upside down. Still plenty to do but a but part of the build is now behind me. Now on to some of the other details! The two brake wheels and assemblies need to be made for the front. Also the sheaves and rollers for the cable are needed. Spare tire racks to underneath in the center opening of the frame. Brake rods and air cans are installed on the back of the front axle bracket. The rear tires float in both directions so that there is always pressure on each tire, even on uneven ground. The trunnion allows movement from front to back and the swivel axles allow rotation of the four sets of tires from side to side. Rotation is obvious here with the front set out of apparent alignment. The tires are not on the wheels yet and won't be until after they are painted. I can still separate all of the parts for painting the under side of the trailer and all of the axle parts. The tow bar was made of brass. Each one of the small lifting handles was soldered in place. The prime mover and trailer. The trailer is wider than the truck and is longer. Makes for a long display shelf when all is said and done!?

Thanks, Randy. Rest of the build is on hold for now as I am trying to finish up the trailer that will carry the D-7.

The only thing you are going to need when you are done is some scale salt and scale sand. The rest of this is one magnificent build!! ?

Those hinges are on the right track but need to be a smidge smaller and thinner where they attach to the box and the door. Sanding them down might do it so you don't have to make them all over again.

Fine work! Love the restoration of old tools and a new life for modeling!

These rigs were not very fast, Bob. 23 mph was top speed for the prime mover. They probably did wear out a lot of tires though. Tire pressure was noted on one photo I saw as 115 lb!!

Got a bit more done on the trailer. The front axles and frame have been quite a bit of work. The more I studied the photos the more I saw. There is still more to go but this is where we are as of today. I made a master for the front axle supports from strip stock. First was to make a template for the web which was made solid. The flanges were then glued to the top and bottom edges. Then the interior braces were cut from strip stock and glued to the web. Once that was done holes were drilled in the web to create the open spaces. Tubing was added to each end and at the center bottom. It was enough to make just one but to make a second one that looked the same and had the same dimensions would have been a challenge. So back to the mold again to make two copies. Once cured, the thin flash was easy to remove from the openings. Here are the two axle frames mounted on strip stock and sheet stock platform that will form the pivot for the front set of tires. Details were built up with strip stock, some small springs and additional sheet stock. This is what the bottom side looks like. The tires and wheels go on each side of the axle frame. The hard part is going to be getting the inside tires in place and secured. I first tried holding them on to the axles with screws but it is impossible to get the inside screws in place due to the close spacing of the inner tires. Got to get the thinking cap on and the little gray cells working. The front tires and assembly in place on the trailer. The platform of the trailer is supposed to be about 38 scale inches above the ground. It came out about right. The brackets for the tow bar will be attached to the box that is just above the tires. There will be two brake wheels; one in the front center of the box and one sitting upright on the small platform on the front left. There are sixteen tires and wheels left to make axles for in the rear. There are two tandem axles to construct and get mounted. That's it for now. Back to the study session to see what's next. Sooner than I thought, the axle problem is solved! Since I can't get the inside wheels in place and tighten a screw on the hub to hold the wheel in place I substituted a different solution. The axle consists of the bushing or sleeve that is in the wheel, the axle itself in two pieces and an inner rod that with be epoxied to both ends of the two part axle. I'm using telescoping tubing so I can slide these pieces inside the wheel easily with a good fit. The axle on the inside wheel has an outside soldered hub that will secure the wheel in place. The rod will be epoxied to it. If I use a small amount of two part epoxy on the rod and slide it back and forth inside the axle, I can bond the two pieces of the axle together. The outer axle half has a similar hub on it to hold it in place with a dab of epoxy. All of the wheel sets will still be able to turn.

How old is the paint? I'd try Tamiya clear orange instead. Water based acrylic.

Nice building on a 1/32 scale kit! I see you changed the differentials a bit. Any reason for that? Perhaps I missed it.

When Ibuilt the IH Loadstar master I made door handles from brass and put them in place. When Dave Natale cast the cab he was able to cast it with the door handles and with the center open. Great casting work by him. The first casting that Dave sent me as I received it is below.

Hey, Paul. Can I make a suggestion? Instead of thickly printed hinges try some small plastic tubing such as made by Contrail Model Aircraft. English made but they come in 5 sizes from 0.020 to 0.080. You could add a tab of thin strip stock to the edge as support. Obviously each one would have to be cut to the proper length but it would reduce the look if your hinges are going to be outside like you show. I used the smallest one on the tailgate of the M-20 above. Brass rod fits nicely inside with no slop. And since it is plastic it glues up nicely.

Work has started on building the trailer for the M-20 Prime Mover. First thing up is to do all of the tires and wheels that are needed. 24 in all. 8 in the front steering section and 16 under the rear of the trailer. I'm using 1/32 scale metal castings for the wheel masters and a set of Goodyear rubber kit tires for the tire master. They work out to be about right for 8:25 x 15 tires that were used on the M-9. IN the background is a mold for the wheels and with the rubber tire masters set up on a pair of the cast wheels that came from the rear mold. In the foreground is the tire mold with the cured resin tire castings still to be removed. All 24 tires and 12 wheels have been cast. The wheels are sufficient to mount two tires on. The backs won't be seen at all once they are mounted on the axles. The wheel centers need to be drilled out for brass bushings. That will come a little later once I have figured out how each axle is going to be made. The frame has been started. The Tankograd photo publication has some specs with it for the overall length and width of the trailer. The towbar is an additional 6 scale feet above and beyond the full trailer length of 290 scale inches. There is an additional scale 40" in length to be added to the front of the trailer side beams. All of the work so far has been done with 0.030" Evergreen sheet plastic and 0.030" and 0.020" Evergreen strip stock. A look at the side view with the wheel placement. The front 8 tires will pivot with a separate plate that the axles are mounted on. It is a box type detail that fits under what is shown beyond the side frame. Here's the bottom side. Still incomplete but well on its way. The two open sections are where the spare tires will be stored. Additional longitudinal bracing has to be added as well. All of this work is held together with CA glue. It was very flimsy to start with but it got stronger with every added piece of plastic stock. The two driving surface plates on top really made a difference. The two raised sections on the left are the stops which keep a tank or other piece of equipment from rolling off the front of the trailer. There will be plenty more to come before this build is finished.

I like the small "H" hinges from Micro-Mark. They are only 4.5 mm x 6mm overall and the hinge part that you see is only about 3.5 mm. Pretty close for 1/25 scale. They come with the center pin and a bunch of mounting pins as well.

Here is a quick tutorial on how to make a door hinge using brass and plastic sheet stock. You may really have to search for tubing and wire to fit inside but it's out there. In case you are wondering about the bond between the brass and plastic, it holds pretty well. Just make sure the brass is clean by sanding it lightly to give it some "tooth". Lay the CA fully along the joint and then wipe off the excess. Do this to both sides. As noted below the tubing will be slightly higher than the sheet stock on one side since both the tube and sheet are laid flat together. This is good because the wire insert in the tubing needs to be slightly outside the body panel for this to work. Note: The wedges you make will be really small. I drill the hole out first in the sheet brass and then cut the wedge out using my Dremel with a cutting disc. You want them small so that when everything is done it looks like the door actually swings on the hinge and not on the wedges. I used this technique to make the hinges for the cabinet doors on the M-20 Prime Mover. Here's a look at the doors in the open position. In the first photo the wedge on the right front is visible. In this case I was able to notch the plastic below it and set the wedge in place that way. The next photo shows the doors closed. Wedges are nearly invisible. And on the left side door you can make out the brass tube that is glued to the cover. The wedges sit just outside the end of the tube so that the door is always in the right location. There is no moving of the door (or cover in this case) from side to side. Hope all this helps. Would love to hear if anyone tries it and how it works out. Check in with me if you have any questions.

Piano hinges small enough to look right are not available any more. Too bad. I have made good hinges out of small brass tubing using CA to glue them to the edge of the door panel. Clean the brass well first. Lay down the panel on a flat surface, lay the brass tubing beside it and spread a thin layer of CA along the joint. Then after that is dry turn the panel over and do the same again, wiping away the excess CA. I'll put together a how to for doing this and post it.

Interesting that the frame rails are photoetched brass. I've made them from strip brass and channel sections before but never PE. How were the cross members attached?