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Great Trains Superliner stretch to 85'


rbrown7713
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A drag knife is a rotating blade held by a housing attached to a die cutting machine, or in my case a cnc router.  The tip of the blade trails the center of rotation, so when guided around a corner, the blade follows behind keeping the blade aligned to the direction of movement.  The word drag refers to the off center tip, as compared to the center and is dragged in the direction of movement. The blade is held up by a magnet and set in bearings allowing it to rotate freely.   Here is a picture of a housing and a blade. Bob.

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Well, I am finally going to do some work on the cars.  I spent the last three days cleaning and organizing so that I have room to move about, boy what a mess as I have not cleaned up in a while after three or four projects, so now I can go ahead.  I have changed my approach on how I am making the sides of the Superliner and the Amfleet cars and I will post pictures when I get further along.  I am trying to make them look a little more like the prototype, if I can. Bob.

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This is what I am talking about changing the windows on the Amfleet sides to make them more realistic.  The LGB windows were not the correct size for 1:32.  I was going to reframe the windows individually, but it didn't work out, so here is what I came up with.  I am installing the whole group, easier to install. Bob.

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Thanks Joe, and you are probably wondering why I am working on the Amfleet car, well, I am waiting for some styrene sheets from Evergreen, so nothing to do, so I am continuing with the Amfleet car and I also have to make some molds for the roof, and sides. I received the trucks for the Superliner and they came out good.  Jean from the O gauge forum made some for his O gauge Superliner and he was nice enough to enlarge them to 1:32 and had his guy make them on a 3d printer, boy, they came out good, and from those, I will, of course, make some molds. Bob.

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Thanks Jerry.  I have made a decision, rather than install the window frames individually every time I build a car, whew, too much work, I have decided to mold them into the car.  Now, that poses a problem of the color of them being black, but I would rather tackle that problem of painting them than installing them individually. Trying to save myself some time consuming work, and I hope that it works out to my advantage. Bob.

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In the next few posts, I will show the steps that I use to make a two piece mold and I will try to not leave anything out.  When pouring the first mold, a seal has to exist around the part, so that when pouring the urethane rubber, the urethane doesn't leak into the cavity of the part.  The experts tell you that the best way to do that is to fill the entire underside cavity with clay to insure that there can be no leakage.  Well, clay is expensive and filling is time consuming.  The way that I do it is a little chancy, but the first thing that I do is seal the ends of the part, and in this case, it is the roof.  I sealed it with .040 plastic and it will be removed before I pour the second part of the mold.  I also seal all the way around the roof with clay to insure that the urethane does not leak into the underside cavity of the roof.   I also wax the area under the roof and not the edges of the plywood because the sides of the mold will be glued and on that area, I don't want wax, because the sides will be permanent, but the roof will have to come off of the base plywood after the pour of the first part and since I will be using CA, it will come off fairly easy where the base is waxed.  The next post will show the roof glued and sealed and the sides glued and waxed and ready to pour the first part of the mold.

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In these pictures, I have CA,ed the roof down and sealed around it with clay and hopefully, no urethane will be allowed to leak inside.  Inch by inch, I take a wooden spatula and cram the clay between the roof and the base and the proof is when I remove the roof from the base, one can see the clay that has been forced between them.  I used to cut the sides for only  the first part of the mold, but I have found it easier the cut the height of the sides for both parts of the mold and only pour half of the height for the first part and let it cure, then I turn the urethane mold over, place it back , and then pour the second part of the mold, it saves having to cut two sets of sides for the molds.  Now, I will cut the sides of the molds and glue them to the base and then wax any exposed wood, spray the roof and the wood with mold release and then pour the first part of the mold.

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Every time I see that Thilvethter cartoon, I crack up, thanks Sean, very funny, and that does represent me while working, perfectly.  OK, here I have installed the sides, tall enough for both parts of the mold.  You can see the wax in the can and I will brush all of the wood, inside and out because the urethane will stick hard without wax and the outside has to be waxed also, because the urethane pours over the sides, cleans up easily when it cures.  I am letting the glue dry after installing the sides, so tomorrow it will be poured, half the depth of the sides. Bob.

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I forgot one important thing, and that is one of the sides will not be glued, just screwed.  That will allow for the removal of the roof for making the second part of the mold. I will put caulking on the inside to seal the side, the caulking comes off easily. Bob.

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Here is the pattern for the mold, ready for pouring the urethane.  I have glued on some locating dowels for alignment, because once the roof is removed, there has to be a method for locating the two molds together. Also I have again sprayed silicone parting solution to limit the sticking of the mold to the urethane.  I will only be pouring up to half the depth of the sides. Bob.

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Here is the last step for the second part of the mold before pouring urethane.  As you can see, I have used some sticks to bridge the width of the mold to eliminate possible sagging of the urethane.  I put quite a bit of time in making the mold, so I want to insure that there is not sagging, as it would make the top of the roof thinner, and I don't want that.  It also insures that when putting weight on top of the molds when pouring the plastic the sagging does not occur.  Except for pouring the urethane, which I will do shortly, the mold is finished.  Also when pouring the part, the mold pieces will have to remain in the mold box, because the molds are flexible and would not stay straight without doing this. Bob.

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Yes, and it works.  With these molds, they are not very thick and I designed them that way because of the cost of urethane., 24lbs. cost 185.00 plus shipping, so I have to conserve somewhere.  Now, If I had made them 1 1/2 in. thicker, it might not have been a problem, don't know, but I like to take every precaution. Bob.

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