Saturday 23 December 2017

RPO Part 3

These CN RPO's feature an Arch Style roof with rounded ends.  An Athearn 70' Round Roof Coach was sacrificed to provide the roof.

First the roof was separated just below the upper rivet strip using a large razor Saw.

Next I scraped and sanded the roof even with the rivet strip.

It was determined that this point the roof was too wide to mate with the RPO body.  I calculated the point at which the roof narrows along the arch profile where it would be the correct width.  I used my height gage and scribed a line around the roof at this point.

Then I used a small modelling plane and my plexiglass mounted sandpaper to remove this material.

I now had an Arch roof of the correct profile and width to match the car.

The forth step was to shorten the roof to the correct length.  A razor saw and miter box were used to cut out a section from the middle of the roof.  I then used my milling machine to end mill the roof sections to the correct length to match the RPO body.   These were glued together using Testor's model cement, as it has a slow cure time compared to MEK.  I used my machined gluing jig to keep things lined up.

The final step was to reinforce the joint from the inside with some sheet styrene.

Next steps will be to detail the roof correct for the 7810-7812 series RPOs.

Monday 11 December 2017

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.

Friday 8 December 2017

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...

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.