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I am installing flush windows in the MTH passenger cars. They look more scale because the windows in the cars are almost flush to the outside. I am cutting them on a CNC mill and they fit well without glue. I am experimenting right now, but here are some pics. I might have to paint around the windows, black, to make them stand out more. I might not have them close enough to the outside, still trying the fit. Bob.
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Jens, have you decided whether or not to stretch the MTH passenger cars now that you see what I am going through? And, I am not done yet, I have to stretch the roof, that's what I will begin today. Bob.
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The fluted pattern is ready for the rest of the mold. The bottom was already made, so I didn't have to remake that. I cut the windows from the first pattern so that I wouldn't have to remake the windows, so it is ready to pour the sides. Here are some pics. Bob.
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I want to make a correction of a statement that I previously made. I said that it would take two cars to make one, that is not true. In order to fill some windows in the added 4 5/16 section, if you make a mold of several of the windows of the car and use the parts from them, the original car stays intact and the pattern can be used to restore the original car. I goofed and didn't make a mold of the windows, so I destroyed, unnecessarily, the car. I suppose, if I wanted to go to some additional work I could recover the original car, but I don't know if I want to. So, to sum up, only one car is necessary to make parts for the stretch. Bob.
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There is one final step for making stretched PS, MTH passenger cars. Now that I have made a mold for the smooth side car section, the next step is to make one for the fluted side car. One advantage of the design of the mold and mold box, is that one section of the mold is the same, the bottom, so this time, when I cut the pattern out of a fluted car, and position in the mold bottom, all I have to do, since I am using the same mold box, is to pour the sides, one less step. So there are many advantages in using the splined mold box. The next set of pictures will be the construction of the fluted car extension and the smooth side extension itself. Bob.
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For those of you that have thought about stretching an MTH passenger car, you probably have figured out that it would take two cars to do this operation, whether or not you just do it once, or you make molds as I am doing so that it can be repeated. The difference is that once molds are made, the operation can be repeated with buying just one passenger car. Like I say, you have probably figured this out, but I just thought I would mention it. The rest of the mold is setting up right now, I will be able to demold after 4 hours and I will post the final pictures of the mold before I make some parts. I am curious, is anyone doing this?, I would appreciate some response, if you are, If you have any questions, just let me know. Bob.
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The making of the mold was a success. I poured the first two sides, took the box apart, removed the two bottom fences and then reassembled and then poured the bottom part of the mold. The nice part of the design of the splined mold box, is that one side can be removed for access. In this case to pour the last part of the mold. Next post will be actually making the part. Bob. Here are some pics.
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Here are some pictures of the mold for the center section. This will be a 3 piece urethane mold and for the inside will be plastic sheets to form the inside of the walls and the floor. What is nice about the splined box is that a wall can be removed for access or pouring. The sides will be poured first and then the floor. Bob.
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Steam power forever, are there any pictures that you can think of that I might have that you would like to see?
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OK I will. The next pictures that I will post will be of the mold for the extension section for the car, when I figure it out. I think I almost have it, starting tomorrow morning.
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Thanks, even though this is quite a job, it's not as difficult as making everything from scratch as I have done before. Doing it this way saves lots of time. I am now preparing to make the mold for the section to be added to the MTH passenger car. Making this mold will be new to me, because I have always made the car in sections, not three sides at once, so this will be a challenge. Bob.
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Here is the painted stretched 41-n passenger truck. Bob.
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For those of you that wish to make your own springs, here is how I make mine. They are not functional, just for looks. They are made of aluminum 18 gauge and wound around a 1/4 inch, I believe to be a 14 threads to the inch thread. I mounted this in a tool handle with a peg for starting the wind. I then trim the spring to match the length. Here are some pictures.
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Here is the finished 41n truck minus the paint. I have stretched it 1/2 inch and tried to use most of the stock parts from the original. The sprung function also works. The only change, besides making a mold for the frame, is the stabilizer bar is also stretched a bit by using tubing to fit around the stock one, and remounting the air canister and drilling new holes and then gluing. Here are some pics, first the new one and the stock one. Also, I made new spring pads and made new springs, but I am going to try to use the stock springs. Bob.
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I am using 74-20 urethane, no bubbles, no vacuum needed, from BITY mold supplies. There are many videos from these people to help you. The 74-20 urethane is cheaper than silicon and I like working with it. I haven't had any bubble problem and it pours nicely. WWW.brickintheyard.com When you mix, try to mix slowly so you don't whip any bubbles into the mix, pour away from your part and let the urethane run into the cavities, that might help.
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Here is what I've got. The section by itself is the one that I will be making a mold of. I am making it longer than 4 5/16 so that I can match the windows on either side of the car. The window are not spaced evenly, so when the part is made, I will have to cut the sides differently so that I can preserve the shape of the windows. I also will have to fill maybe one or two windows. I cut the section to accommodate the 1/4 movement of the bolster so that the longer truck will match the skirt opening. At the other end, the bolster mount will have to be moved toward the center 1/4 inch. Well now to make a mold for the 4 5/16 inch fill piece, I will keep you updated. Bob. It kinda hurt to slice open such a nice looking model, oh well had to make it 85 ft.
Also I will have to make a mold for the roof section.
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Yes, they are supposed to be 85 ft. I'll have to stretch it 4 5/16 inches to make them correct.
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I am stretching an MTH passenger and the trucks to make it more scale. Here is the start of the trucks. Stretched 1/2 inch. Made them to hook up to the stock MTH bolster, so using all stock parts except the side frames. Made a revised mold for the side frames. More pictures later. Bob.
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Engineer Joe, I think I am going with your idea of pipes inserted length wise in the top of the structure. Using 1 1/2 pvc pipe, 4 of them I could get the weight down to about 70 lbs. I can handle that. The pipes would be secured at each end through holes in the mold and the pipes would stay in. That weight is with regular concrete. I could further reduce the weight by using the perlite mix to about 50 lbs. So, thanks for your idea. Bob. PS. Yes the little white things in the mix is Perlite.
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Vermiculite absorbs water, Perlite doesn't, so I don't think for concrete lightener you want vermiculite. Vermiculite is used for soil and planting, so is Perlite mixed with vermiculite. That is the way I understand it, also Perlite is pure white. Bob.
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Yes that would work. I have thought of making a core of wire cut foam the shape of the viaduct only smaller in size and suspend it in the center like a core, and then pour as normal. I have also thought of making the top part with smaller sections, that would make it lighter to handle also. Good thoughts. I will have to think of something, my back isn't what it used to be. Perlite is a mineral, mined and then processed, cooked, and when it expands, that is Perlite. Lighter than anything else, except ground foam. If I make a core, the problem will be to keep it from floating when pouring the concrete, I will have to investigate how they do that. Bob.
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Here are the results of the column poured with cement sand and gravel. Very few bubbles, after vibrating for 2 minutes, it weighs 16 pounds as compared to the lightweight version of 10.5 pounds. I will go with the, 16 lb. version. There was a 35 per cent weight reduction in the lightweight version, so that means on the large section, it would weigh 110 lbs., still have to use a cherry picker for large moves, so I will probably use the all concrete version rather the one with Perlite. Also the Perlite version is impossible to finish properly the top, the perlite rolls and you can't get a smooth finish. I had to add some soup after it had dried to smooth out the top. Here is a pic. Help with painting please. Bob.
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Tomorrow I will demold the one made with regular concrete and see how that one looks. I vibrated both, but still some small bubbles, can't really see them from 3 feet, so maybe I won't worry about them. I will weigh both of the columns to get an idea of the weight difference and I will post them tomorrow. The vibrator that I made worked well, lots of bubbles came out except for the small ones. Bob.
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I just demolded the column and while it is OK, I think I will use not the lightweight mix, I will use the regular mix, less porosity. There are some small bubbles, not noticeable from a distance, but close up, you can see them. It demolded easily, no problems. Bob.
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I just poured the, quote, lightweight version of the mix and I don't like it. I had to use much more water than the recipe called for just to get it in the mold. I will pull it out of the mold in 2 days. I am afraid I will have to use the regular concrete mix to get the detail and strength, we shall see. Bob.
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