RPO Part 5

Well here it is CN RPO #7810.

I used ScaleCoat CN Olive Green Paint for the body. Tamiya Flat Black for the roof and under frame bits.  The decals are from Microscale, the CNSIG set in particular.

The rivets are a combination of MicroMark and Archer.  There's at least 2500 of them on it!

It sounds like a lot, but it was only three evenings work to put them all on. One evening for the ends and then one for each of the sides, spending about two hours or so per.

The Mail room windows are Tichy Work Car frames, with the sill removed.  Using 0.010" x 0.030" styrene, a frame was added to the top of the outer portion to make these into single hung windows.  The Tichy muttons were not used. Clear styrene representing glass, was slid between the new upper framing and the rabbet in the Tichy window frame.  It would normally receive the muttons.

The Bars are brass wire held in some styrene blocks that I milled grooves into. The grooves space them correctly. The assemblies are then simply glued to the inside of the car.  The mail room windows, got a coat Testors Dullcoat to frost them.

The roof is held on with magnets, a method I will be using again.

I am very happy with how this car came out. It's the first passenger car I have modelled and I can't wait to get started on some more.  It really pushed my modelling skills up a notch. Here is my lessons learned.

Being a more complex build, it forced me to slow down and put more into the planning before each step was taken. 

At a minimum I have new found skills in working with styrene and decal rivets.  I also have a better understanding of passenger car details, and figured out a method to reproduce roof panel lines.  

All of these new skills will make tackling other projects easier while resetting the bar for what I can achieve.  

I even spent some time figuring out the white balance settings on my camera, so I can take better pictures.  Hopefully this has removed a road block, in me submitting a magazine article in the future.

RPO Part 4

Trucks

The Branchline under frame is designed to work with the kit supplied 3 axle trucks.  ACF built these RPO cars with short wheel base, 2 axle trucks.  The Walters 8'6" passenger car truck was selected as the closest to the prototype.  In order to mount these trucks, the under frame was modified in the following manner.

1. Mill off the bolster even with the surounding material.

2. Install a block of styrene for the truck to rest on, that provides for the correct coupler height.

3. Drill the truck mounting screw on center and the correct distance from the car end.  To ensure the screw is centered, I coloured the block with some pencil graphite and then used my dividers to scribe two arcs using the moulded holes near the end of the car, on either side of the coupler.

4. The smaller piece of styrene helps to keep the Branchline swinging coupler box wiskers,  flat against the under frame, improving the coupler mounting box angle.

5. The openings were filled with sheet styrene from the inside.

The trucks were modified by adding a small washer to fill in the large hole to size it for a 2-56 screw.  These were glued using ACC.

 
The underframe was detailed the best I could figure from my reference photos and a photo supplied by one of the blogs readers, of his Bethlehem Car Works kit of this car.

 
The Sill steps were formed from Details Associates flat stock in a simple wood jig and soldered together.

 
The roof was sanded of all detail including the panel lines, as they were in the wrong location for this car.  The panel lines were recreated, by first priming the roof, then masking off the half of the panels, followed by adding 4 more coats of primer.  The masking tape was removed shortly after the last coat, while the paint was still soft, so that it would not chip.

The roof was detailed with Custom Finishing Vents, brass bar stock for the drip rails above the doors and a brass wire with mounts for the Gas Lighting Pipe.

In the next installment I will show the final car so Stay tuned.....

RPO Part 2

Over the weekend I made substantial progress on the RPO.

I scratch built new sides from Evergreen styrene sheet and strip.  Commercial sized strip was used to keep things simple.

In the first photo you will see some finger clamps I constructed to assist in the process of making the sides. I saw these over on Joe Smith's Blog and thought they were just great.  Mine are made of mild steel with a piece of Tig welding wire pressed into a drilled hole.  They are basically a mini finger to hold things while your gluing etc.  What great idea and now that I have them, I can't live without them!!  Construction is done on plate glass set against a metal scale.

The first layer is made of a piece of 0.010" thick material with 0.060" quarter round on either end. The second layer is all made from 0.010" strip of varying widths.  A piece of 0.100" and 0.080" strip is attached along the top and bottom of the sides respectively.  The top and bottom of the three doors are made with 0.080" strip centered on the pencil lines.  These are made longer than actually needed.

Here is a close up of the side as described above.  The strips are set 0.010" off of the top and bottom strips to leave room for upper and lower door sills.  The top of the side is against the scale in this photo.

Next I applied the mutton's to the upper half of the door to frame door window openings.  The mutton's are 0.040" styrene and the outer edge is 0.080" which will be covered with a 0.040" quarter round door jamb that will leave a 0.040" door boarder to match the mutton size.

Here is both sides with the doors and windows all framed up.

Next the remaining areas were filled with 0.010" sheet to complete this layer.

The third layer starts by adding 0.040" sheet on top of the second layer using individual pieces followed up with 0.010" x 0.040" strip set vertically at the top and bottom of the door openings.
Unfortunately I didn't take a close up photo. Finally I added the 0.040" quarter round on either side of the door to form the door jamb.

Next up is to cut out the window and door window openings, followed by adding the belt rail and letter board using 0.010" strip.  I will fill any seams with putty and sand if needed before mounting on the car floor.

Railway Post Office Service on the Grand Trunk NEL

The Grand Trunk (NEL) rostered  three Railway Post office Cars #'s 7810-7812.  They were built by ACF in 1929, possibly for subsidiary GTW and transferred at a later date.

The Canadian National Historical Society magazine CN lines Volume 9 Issue 1 has a article pertaining to these cars and similar RPO's used on the Central Vermont and Grand Trunk Western.  Here is a picture found in Morning's Sun Colour Guide to Northern New England Cars.

I am going to kitbash one of these cars using a Branchline Coach as the base model.

I recently discovered Joe Smith's Blog "Signal Station 199" regarding his efforts in building a New Haven themed layout. He has a set of blog entries showing his techniques to kitbash a similar RPO for the New Haven.  Go take a look, but I warn you Joe's modelling and blog are top notch so your  going to be there for a while.  Here's the link...

https://signalstation199.blogspot.ca/search/label/RPO

Now that your back, here's where I'm at with this project. Follow along as I put what I learned from Joe to good use.

First off I enlarged a drawing provided in the CN lines issue and copied the dimensions over from the soft copy, that were blurry when enlarged.

Next I cut the floor and spliced it back together to give an length over the couplers of 66' - 61/2".

The floor is braced with a sheet of styrene and some square stock.

The second photo shows the floor sections I removed.  I also removed the side vestibule doors and walls on either side of the end doors.

Canadian Style Youngstown Doors

  A couple of months ago I started on five Postwar 40'  boxcars.  3 CN, 1 CP and 1 TH&B.  The base model I used was Intermountain Railway's 10'6" AAR Cars with 6' door openings.  These kits come with 5/5 Dreadnought ends or 4/4 Improved Dreadnaught ends and Murphy Raised Panels Roofs.

  The cars I wanted to model either had PS-1 style or diagonal panel roofs and NSC 3 style ends, save for the TH&B car which required the 4/4 IDE end.  I ordered some PS-1 car kits from Intermountain and stole the roofs from them for the CN cars.  The other three needed diagonal panel roofs so I ordered Branchline parts from Atlas.

  As for the NSC3 ends - I could have used Sylvan Scale models NSC3 ends, but I have never been happy with the pattern work, as its missing the rivets and weld lines between the panels and the shape of the ribs don't seam right.  To my eye they look like a compromise based on the available styrene shapes used to make the patterns. 
  
  So I designed my own 3D models and had the ends printed on a 3D printer.  I took measurements and pictures from an actual NSC built 40' boxcar,  at the West Coast Railway Museum in BC, a few years ago.  One of the models has Sylvan ends on it.  I had a set, so I decided to use them up.

  I added Archer weld beads to define the separate stamped panels that the prototype ends are built up from.  Archer rivets needed to be added on the sides of the part because, the 3D printer puts  support material on the side of the part to print rivets sticking out - this messes up the face when the support material is removed.   I elected not to put them in the 3D model.  The support material leaves a different texture on the part that would show up after painting.  The rest of the rivets are in the print, but do to the colour of the plastic they don't show up in pictures.

The project stopped when I got to the point where I needed to add the doors.  The kits come with Youngstown doors with early roller fixtures. Youngstown doors with late style fixtures are available, but they do not have the correct rib pattern and the panels are not riveted in the valleys between the ribs - as on the Canadian version of the Youngstown door.

 These are available form Sylvan Scale Models but the moulds are old and need to be redone, so the parts don't come out very good anymore.

 The solution was to cut and spice two of the American version of the door into a Canadian version. Add Archer rivets, then make a Silicone RTV mould.  Something I have never tried.

  I made a trip out to Sculpture Supply Canada in Etobicoke with Doug Currie and the nice folks there helped us select the products I needed to make the mould and cast some parts.  Here's what they recommended.  The mould release is an extra thin version, which works better for highly detailed parts, The Smooth Cast 320 is an off white colour that they said would tint easier. 

I glued the new door into a Styrene box and followed the instructions to make the Silicone Mould.  Doug came over to help out with the poor etc, and having an extra set of hands was very helpful.

  The silicone I used is a platinum cure type that mixes 1 to 1, and doesn't require degassing.  The mould turned out great. It has a few air bubbles on the back side but nothing on the part face.  It cures quick also, 30 minutes per the instructions.  I left it a bit longer just to be safe. 

   Casting took some practice.  I managed to make 8 good doors in about 14 attempts.  I poked the air bubbles out using a toothpick and slid a backer plate onto the back of the mould, but on top of a sheet of thin slippery plastic - rather than dropping it face on.   Using these tricks I had good parts coming out of the mould.  I ended up not using the tint. It was much easier to find air bubbles in the clear resin.  The resin turns off white as it cures.  I only needed 8 parts as the TH&B car will use the earlier style door included in the kit.

Here's what everything looks like.

I actually glued on the kit doors and let this project sit, while I came to the eventual realisation, that I would not be happy with the wrong doors on these cars.  I managed to get them off with little damage.

  In the end this project was pretty easy to do and a lot of fun, I should have just got on with it from the beginning.

At this point I have no interest in laying out a whack of Cash for Vacuum pots/pumps or pressure vessels to make full car bodies etc. 

Now I can get back to finishing these cars.  More to come....