Best Of Scratchbuild Project - CC&F Twin Trailer Flat Car

[jpf94]

Thank you for taking the time to document your amazing work.  Inspiration to us all.  Can not wait to see them behind your power running in a test video...…(wink wink)

Wonderful work!

[craigolio1]

Tim please continue working today so we can see it on trucks!

[peteski]

This should be a BEST OF thread.

+1

[BCR 570]

Bolster Hubs and Trucks
The bolster holes are now ready for installation of the bolster hubs.  These are short lengths of 1/8" styrene tube, whose outside diameter fits nicely through the bolster hole in the Micro-Trains trucks and whose inside diameter can be threaded for #2-56 screws.  It is imperative that the bolster hubs are installed as straight as possible or the trucks will not track well.  Here is a close-up of the bolster hub after installation:




After installation, it is time for a test fit of the trucks on the bolster hubs:




For the bolster screws I will be using #2-56 x 1/8" which are available from Kadee (part #1703).  To tap the bolster hubs for the screws I will use a #2-56 Tap.  This is available in a Tap & Drill Set from Kadee (part #246).  here are the cars with bolster hubs installed, and screws and tap ready to go:




To tap the bolster hubs, the cars go back up on the angle blocks:




The #2-56 goes into a pin vise and the inside of the bolster hub is slowly tapped for the truck mounting screws.  During this process it is important to go slowly, and frequently stop to back out the tap and clear the threads of styrene debris.  Back in for a few more gentle turns, back out to clear the thread, etc. etc.:




The bolster screws are installed for a test fit to ensure that the tap has gone far enough through the bolster hub:




The trucks are then installed with mounting screws for a test fit.  They need to sit level on the bearing plate and rotate freely on the bolster hub:




Here are the cars with both trucks screw-mounted:




Up until now most of the work on these models has been upside down on the workbench.  Now, for the first time, it is possible to set them on their trucks and see what we have so far:




The cars are brought against the Micro-Trains coupler gauge to see how the coupler mounting height has turned out - not bad!




Two views of the cars from slightly different angles sitting on their trucks and on the tracks:






The cars seem to roll well and track well through curves and turnouts with the push from a finger.  A more thorough test will have to wait until couplers are installed and they can be hauled in a test train.  For now, so far so good.

The next step will be to manufacture the side sills.


Tim

[craigolio1]

Excellent work Tim, quite a mile stone!

Craig

[BCR 570]

Side Sills (Part 1)
The next step in building these cars is to fabricate and install the side sills, which will go a long way towards achieving the final appearance of the models.  As we can see in the prototype photograph of two cars at the end of their lives, the side sills are essentially a simple C channel down the entire length of the car:




There are numerous details along the side sills, including gusset plates, chain bins, and tack boards. There are also some cut-outs and smaller gusset plates at each end of the side sills, and in the 'BL' corner for the handbrake stand, as seen in this second reference photograph:




I considered making my own C channel from strips of .010" styrene, but I didn't think I could do better than the #263 .100" channel from Evergreen.  This channel was just about the right dimensions for the web and flanges, and when cut to length could be added as straight and solid pieces.  The strips of channel were cut to a length of 84'-0" scale feet to match the runways:




I thought that it would be easier to fabricate and install the various detail parts onto the side sills prior to installation.  (We'll see if I am right.)  With all of these parts I began by making a few and then test-fitting them in a scrap piece of channel.

There were two sets of four gusset plates located under the tie-down racks; I am guessing that they provided reinforcement for them when the trailers were chained down.  These were tiny parts to make.  I cut them to lengths of 12" from .010" x .040" strip styrene and tapered them over half their length:




Here is the same piece glued into a scrap piece of channel for a test fit:




To locate the sets of four gussets on each side sill, I lined them up against the set square and marked the locations simultaneously with a pencil:




There were some bins attached to the side sills below the tie-down racks.  They angled out toward the top.  I am thinking that they may have been for spare chain or hooks.  Like the gusset plates, these were left in place when the tie-down racks were eventually removed.  I couldn't see assembling these from individual pieces of styrene due to the small size so I manufactured these from #262 .080 channel.  These small pieces of channel will sit vertically on their edges on the larger channel for the side sills.  The bins were cut to a height of 12" and then tapered on their edges to get the desired angled out effect.  This worked quite well and I was pleased with the results.  Here are some parts, with one sitting in a scrap piece of channel for a test fit:




There appears to have been two tack boards per side.  I assembled these from 12" lengths of .010" x .040" strip styrene with vertical edges cut from .010" x .010" strip styrene.  This particular size of styrene is not available from Evergreen, but is available from Plastruct (#90709).  Here are the assembled tack boards, with one sitting in the channel for a test fit:




Installation of these parts was fairly straight forward but was time-consuming.  The photograph below shows a pair of side sills with the gusset plates, chain bins and tack boards installed:




That is all for this instalment.  Next are the cut outs at the ends and for the handbrake assembly, and associated gusset plates.


Tim

[cv_acr]

Those side sills are looking really great with that gusset detail. And in N scale! That's impressive making details that small.

[BCR 570]

Side Sills (Part 2)
A little more progress on the side sills.  As can be seen from the prototype photographs above, there are some short cut-outs in the top flanges at each end of the side sills, and a longer one in the 'BL' corner for the hand brake assemblies.  Removing these portions of the top flange requires slicing down through the flange with a #17 blade, and then using a #11 blade to carve and scrape away what has to go.  The goal is to get it flush with the web of the side sill.

The cut-outs for the hand brake assembly are estimated to be 18" in length.  They do not extend down into the web.  Here are the two left side sills after making the necessary cuts and removing the portions of the top flanges:




The end cut-outs are estimated to be 8" in length.  They actually extend down through the web to the runways; that portion of the cut-out will be easier to do once the sills are on the model.  For now, I was content with removing the ends of the top flanges:




Once these cut-outs were made, I needed to add the gusset plates which supported the ends of the top flanges.  These are even smaller than the gussets I made earlier  .  I made a bunch from strips of .010" x .020" and used the best ones:




The side sill assemblies now feature gusset plates, chain boxes, tack boards, and cut-outs, and are almost ready for installation:




Before installing the side sills, I want to locate and drill the holes for the centre and end grab irons.  I may also install the end grab irons so I can trim them at the rear prior to installation.  So that will be next.

Tim

[philippe.whyte]

Great work Tim! You are really pushing the envelope here and everything looks so precise. Following with great interest.

Philippe

[mmagliaro]

Simply superb work, Tim!    All the separately cut and applied details, like the gussets, push a model into the "outstanding" category, which is where these models are clearly headed.  Your attention to precision, such as making more than you needed of the really small gusset pieces from .010" x .020" and then picking the best ones, makes a big difference.  The crispness and overall fit of the model is excellent.

[BCR 570]

Thank you very much for the encouraging words; much appreciated and will hopefully keep me going.

Side Sills (Part 3)
I thought that it would be easier to locate and drill the holes for the sill-mounted grab irons while they are still flat on the workbench as flat cars do not stay on their side too well.  I elected to use 18" formed wire grab irons from BLMA (now Atlas) for this project, but was a little disappointed with the parts.  Most of them were crooked across the straight portion, and the locating pins were bent at different angles to each other.  Unfortunately I noticed this after drilling the holes for them, so it was too late to switch to something else.

There is a grab iron at each end of the side sill, slightly inset from the very end.  The holes are made with a #80 drill bit in a pin vise:




There are also grab irons at the centre of the car.  These are located on top of the side sill, so the holes have to be drilled down through the top flange:




The end grab irons were glued in place with ACC with the pins protruding through the back of the side sills.  I then snipped off the pins and filed them flush with the back of the side sills.  This was necessary so that the side sills will fit flush against the runways when added to the cars.  Here are the end grab irons after installation:




The centre grab irons sit on top of the side sills.  They cannot be glued in just yet because the side sills will be added to the cars with all of the parts upside down on a flat surface.  These grab irons must be trimmed very short so that the pins do not protrude down through the top flange of the side sills.  This photograph illustrates two of the top grab irons in place for a loose test fit:




The side sill assemblies are now ready for installation on the cars, which will be a major step forward for this project:




I am currently working out exactly how to set up the parts for the installation.  I also need to trim back the centre sill top flanges to make way for the coupler boxes and that will be easier prior to adding the side sills.  So the coupler pockets are probably next.


Tim

[BCR 570]

Coupler Boxes
It is time to build the coupler pockets.  Originally I selected the #1023 coupler for its small profile and built my test end section around it.  However, road tests with the Minitrix 85'-0" cars indicated that medium shank couplers would result in better operation, particularly through reverse #5 turnouts in the yards.  I therefore decided to switch to #1016 couplers with the medium shank, and will amend my coupler pocket dimensions accordingly.

The first step is to cut the coupler pocket floor from .020" x .250" strip styrene, and add sides cut 3'-0" long from .020" x .125" strip styrene:




A thrust block cut from .125" x .250" styrene is inserted behind the coupler space to keep it at the right depth in the pocket:




Prior to adding the lid, the hole in the coupler for the mounting screw is transferred to the floor, and a lid cut from .010" x .250" strip styrene is added:




After trimming the lid and sanding all exterior surfaces smooth, the hole for the mounting screw is transferred to the lid:




The top flanges for the centre sills were cut originally to a length of 84'-0" for the purpose of measuring where everything else went.  They must now be trimmed back to the webs and bottom flanges to make room for the coupler pocket lid.  The coupler pocket will butt up against the trimmed centre sills.  When in place they will push the overall length of the cars out to our target 85'-0".  This photograph shows one car on the left prior to trimming back the centre sill top flanges, and the other car on the right with the flanges trimmed back:




And this photograph shows the same cars with a finished coupler pocket sitting in place on the car at right:




The coupler boxes are now ready for integration into the end sill assemblies, which are essentially built around them.  More importantly, the cars are now ready for addition of the side sill assemblies.  The models will look very different with those in place.  Tomorrow is a big day!


Tim

[peteski]

That looks good Tim, but why you needed to wrap the existing MTL coupler box with a larger styrene box?  It looks a bit bulky. Why not just just place the MTL coupler on a styrene spacer?  Basically your box without the sides and bottom.

[Cajonpassfan]

Tim, this is simply outstanding! The precision with which you approach this build and the way you are documenting it puts it in the “Best of”category in my book.
Can’t wait for the next installment!
Otto

[BCR 570]

why you needed to wrap the existing MTL coupler box with a larger styrene box?  It looks a bit bulky.

Agreed; I don't like the bulk, but:

1.  There is precious little for the mounting screw to bite into, so a box helps to hold the couplers in place and reduces strain on the mounting screws;
2.  There is very little for the end sills to attach to; I was planning to use the coupler box to provide additional anchor points for the end sills.

I will re-examine my design to see if there is another way.


Tim