New procedure making flush number boards for E-8

[rbrown7713]

Some of you have seen the procedure that I used before on how to make flush number boards.  That method was hit or miss and had some inherent problems that made the procedure difficult, so I am trying something new to make this method a little more user friendly.  Instead of attaching the outside lens with rubber cement, that made is stick too much and therefore, when demolding the board, part of the seal of the board would stick to the mold and then render it useless.  This new method fixes the outside lens, the paper number and the inside plastic, with winding some thread around the assembly to hold it in position while the epoxy sets up.  The board is drying as we speak and I will demold in a couple of days to make sure that it has set up, so I don't know at this point if it will work, I have my fingers crossed.  Here are some pictures of the project so far.  I might be posting this procedure in vain because, really, how may people are making scratch E-8's?  However, this procedure can be use for a number of different type number boards.  The clay that is laid on top of the top plastic is to form an opening for the light to come through for a bulb to light up the numbers.  When I demold the board, it will be ground down to the clay with a dremel and then the clay will be removed allowing a void for the light.  I would like to know, if possible, if anyone is using this procedure, or if not what procedure they are using to make number boards, it would be nice to share.  So, here are some pictures of the project, so far.  I mixed black pigment into the epoxy to represent the rubber seal around the lens. The first picture, I forgot to mix the pigment into the mix, so It will have to be painted black. Bob.

Edited September 20, 2016 by rbrown7713
spelling

[rbrown7713]

Well, my new procedure was success.  However, I must have dislexia because I installed one of the numbers upside down, but that is ok, because I think that I will use these number boards to make another mold so that I can install the clear plastic and the numbers after the board is made.  The problem with doing the procedure by including the clear plastic and the paper number is that the resin leaks between the clear plastic and the paper number discoloring the white numbers.  The mixing of the pigment with the resin, I thought at first was a mistake.  I thought that I had put too much black pigment in the mix, and I might have.  The mixture took a long time to cure and never really cured to a hard condition, more like a hard rubber.  That part is good, since the seal is made of rubber.  So, today, I will try to figure out how to make a part without the plastic lens and the number so that I might add them later which would eliminate the problem of a discolored number. Here is a picture of the boards. Bob.

[enginear joe]

Do these numbers light up well? I need to make some for my F40PH build. I was wondering how to do it. I feared it was harder than it looks.

[rbrown7713]

Yes Joe, they light up well.  What I use for the numbers is premium glossy photo paper and print in a black background and white letters using Turbocad cad program.  When choosing a white letter, it tells the program not to print in the letter area.  When choosing the background, the rest of the area is black.  The difficulty when making these for the E-8 is the compound curve and the fact that it is flush, only having a little seal to hold the lens in.  I don't know what the F 40PH looks like, so please post a picture.  I am in the process of making a mold for the board so that it makes it easier to install the lens and the numbers.  This is the most difficult piece that I have conquered and I am still fighting it. I will try to find the video that I put on YouTube as to the method that I used to make the first set. Bob. 

[rbrown7713]

I hope I do this right, here is the link on YouTube for the procedure that I first used.  

 

[rbrown7713]

Joe, I looked at a picture of the number boards for the F40PH and they will be easier to produce because they are flat and not a compound curve, also you only have to make one mold.  The E8 boards are both different, right and left, so these are a little more difficult.  Depending on the shape of the seal, a ball cutter can be used in a router and cut out of Bondo for one side of the mold and then construct out of wood the other side of the mold and cast in Urethane.  It would be easier if you had a mill. Bob.

[rbrown7713]

OK, here is the pattern setup for the pouring of the first part of the mold of the new number boards. Bob.

[rbrown7713]

Here is the first part of the mold poured and the part in the mold ready to pour the second part of the mold tomorrow, letting the mold to cure some more. Bob.

[todsmods]

Bob you are  the  casting  master

[rbrown7713]

Thanks for the cheers, but every move that I make regarding molds is new to me and a new learning exercise, like a never before seen puzzle,  and that is what I like about it, the challenge. I can't quit making molds.  I just bought the shell and a bunch of parts of an LGB P42 Genesis as a 3D model to make a 1:32 model.  That ought to be interesting. Bob. 

[todsmods]

Hi  there  Bob  your cabs are great  ive now glued  the  locomotive  sides  together  and she really  looks the  part now .

Time to work on the  fuel tanks and will fit a speaker  for sound later on.

[rbrown7713]

Beautiful work Tod.  I like your laser work.  That laser comes in handy. Bob.

[enginear joe]

On ‎9‎/‎22‎/‎2016 at 7:44 PM, rbrown7713 said:

Thanks for the cheers, but every move that I make regarding molds is new to me and a new learning exercise, like a never before seen puzzle,  and that is what I like about it, the challenge. I can't quit making molds.  I just bought the shell and a bunch of parts of an LGB P42 Genesis as a 3D model to make a 1:32 model.  That ought to be interesting. Bob. 

There was a post of a brass 1/32 scratch built Genesis model. I thought that was an interesting build. It has a brass frame structure that I never considered modeling. I look forward to see what you do too.

[rbrown7713]

Yes, somewhere in my heavyweight truck post, I posted some pictures of that project.  What a project.  That guy is a master builder, way out of my league.  He took the 1:32 drawings and had some company cut the parts out of brass and then soldered them together. What a beautiful model.   I have no idea yet how I will build mine, but probably the same way I modeled the E-8 with patterns and molds. Bob.

[rbrown7713]

Here are the number boards installed on a cab.  The nice thing about doing it this way is now I can install the clear plastic and the paper numbers with having to apply any contact cement on them allowing for a clearer presentation of the numbers, it worked, finally something that worked.  I also molded into the cab when pouring the whole thing, the windshield frames, and that makes it easier also. Bob.

[enginear joe]

Yeap right on the first page! I should have known it would have been posted by you! I remember contacting him. I don't remember any answers.

"

Don's 1/32 scale #1 gauge genesis, AKA "The Big Uggly" is built from photo etched steel and brass sheet. Don is building 2 units.

[rbrown7713]

Yes, I tried to contact him and also no answer. I guess the big boys like him don't have time for a peeon like me.  His work is beautiful though, and I will probably reference some of these pictures for the building of mine. Bob.

[rbrown7713]

OK, I have finally figured out the final procedure.  I used urethane 50/50 poured plastic and added the black pigment.  The pigment doesn't seem to effect the hardness of the plastic, as I put quite a good dose into it.  Unlike the epoxy, when adding the pigment, it came out spongy.  The second part of the urethane mold didn't work out so good, so I used the hard epoxy pattern for the second part of the mold and that did the trick, well defined edges, looks like a real rubber seal as it should.  So after it is installed in the E-8, I will have to take care with the painting to make it look proper.  Here are some pictures. Bob.

[rbrown7713]

Now that the number boards and molds are done, I thought I would show you what I am doing now.  I am spreading dirt with my tractor.  I have already spread 36 yards and now I am spreading the last 18 yards to bring it up to grade.  Here is a pic. Here is a rough representation of the layout, all will be viaduct sections, If I live long enough. Bob.

[enginear joe]

2 hours ago, rbrown7713 said:

 I am spreading dirt with my tractor.

What's that? You don't like shoveling?

Snow or dirt, it's gotta be done.

[rbrown7713]

OH, I am sure before it is all done, I will have shoveled my share of dirt. Bob.