Scratch Build a 1:20.3 scale 29’-6” Flatcar

Chapter 1 – Building the frame and decking

By Wayne Spence Brisbane, Australia

Please take the time to refer to the following link, in which Dwight Ennis describes his approach to scratchbuilding his Backwater Water Tank. This fine water tank construction article takes you through all the steps required to build a 1:20.3 structure that would complement any narrow gauge inspired garden railroad. It also highlights the safety requirements associated with use of power tools required to produce strip wood needed to build this flatcar.

Dwight explains the need to select the right lumber required for this project. The choice of lumber will determine whether your flatcar is suitable for 'all weather' running or must be only used during fine conditions. As most of my scratchbuilt rolling stock is made from white (clear) pine and glued togeather with white carpenters glue, this

makes them unsuitable for all weather, all year round exposure. If your flatcar were to be exposed to the weather, your choice of construction materials would have to take this into consideration.

Large-scale lumber will have to be resistant to the weather by either using proven timber such as redwood or cedar and applying a preservative or painting the model. Here in Australia we have several species of timber suitable for model making, including hardwoods, but I prefer to use white pine, the reason being that in my case, its free. This pine is leftover off cuts from a furniture manufacture. It is similar to basswood, same color and easy to work, but doesn't seem to have that "fuzz" that basswood produces. Don't forget to use a waterproof glue to assemble your rollingstock.

http://www.mylargescale.com/resources/articles/WaterTank/Watertank02.asp

This flatcar project will be constructed in four parts.

• Chapter 1 - Building the frame and decking.

• Chapter 2 - Adding the details to the frame.

• Chapter 3 - Trucks, couplers and brakes.

• Chapter 4 - Painting and decals.

The Model

It is proposed to build a 29'-6" 3' narrow gauge flatcar, primarily from lumber, as used by the prototype. The car's construction loosely follows the designs used by the D&RGW, RGS, C&S, and several other NG roads, but is not of any particular prototype, rather a design suitable for 'first time' modellers.

This car can be built from any suitably available lumber - you chose the type of trucks and couplers. The photo at the head of this chapter has had three additional longitudinal planks added to both sides of the deck. This flatcar was built as a heavyduty flat, suitable for transporting large pieces of machinery, like tracked logging dozers. This additional decking will be optional in this project. Note the rusty chain tie down eyes mounted on the deck.

Downloading the Drawings

Each chapter in this series will have links to 1:20 scale full sized drawings listed below. I made sure these would fit on a standard 8-1/2 x 11 piece of paper, and I've converted each to an Adobe Acrobat PDF file. To open/view these files will require that you have Adobe Acrobat Reader installed on your system, a free program used to share documents and drawings. If you don't have the Acrobat Reader, you can download it here. Once you have the Acrobat Reader installed, download the drawings and print one or more copies of them. The PDF files are designed to print 1:1, to make sure the Shrink to Fit box is unchecked!! The following drawings are for all 3 chapters:

• Detailed Materials List

• Sheet one - 1:1 scale template drawings.

• Sheet two - 1:1 scale template drawings.

• Sheet three - 1:1 scale construction plan, left-side view.

• Sheet four - 1:1 scale construction plan, right-side view.

• Sheet five - 1:1 scale construction plan, decking.

• Sheet six - ½ scale flatcar plan.

Download All Drawings - 411K

Let's Get Started!

Use a 10” benchsaw or bandsaw to rip the side sills beams, centre beam sills and end beams. Use feather sticks to guide the stock through to cutting blade.

This is the small bench band saw I use to rip the smaller sized lumber lengths.

The digital calipers are one of the best modeling tool investments that I have made over the years. They're great for marking out repetitive measurements and checking lumber sizes.

Gentlemen Start Your Saws!

Once side sills have been cut to length, mark out area to be checked out and using the bandsaw, make a parallel cut to the line, 7mm from the end - as shown, using the preset guide fence to cut both ends of both left and right side sills.

Remove saw fence and crosscut saw remaining cuts to remove check, using the saws mitre 'T' guide for accurate square cuts. If not using a bandsaw, these two cuts can be made with a fine tooth hand saw or razor saw, making sure that the cuts are square. The flatcar end beams will be located in these side sill checks. Cut the 115.5x10x7 end beams from your stock timber.

Use a razor saw or hacksaw blade to add some 'grain texture' to the outer side edges of the side sills and to the exposed sides of the end beams.

Side sills and end beams have had 'grain texture' added, usually only one pass of the saw blade is sufficient.

Lay side sills (check up) on a flat surface and wood glue beams in place. Beams should 'overhang' sills by 1.5mm at each side. Use scrap wood lengths cut 96.5mm long to use as spacers to maintain sill spacing until glue dries. Check with square to make sure sills and beams are at right angles.

Beam overhanging sill 1.5mm. Set aside to dry, approximately 1 hour, if using white glue.

Set guide fence on your benchsaw or bandsaw to cut decking from stock wood. I use stock about 1200mm long to cut my decking planks from. Cut strip wood to 2.3mm widths first, then cut these 2.3mm lengths to 9.5mm stock (2.3mm x 9.5mm). The decking really has to be cut with a power saw or purchased precut timber decking. As always, use caution when cutting small size lengths like this. Use 'push sticks' to guide wood though saw blade.

I pack the 9.5mm x 2.3mm lengths of decking stock that have just been cut, into 2 rows of 10 (20 pieces) and using plastic tape, wrap tape around pack at about every 100mm. Mark decking for 112mm lengths and cut into bundles, as shown in the foreground of the above photo.

Note the stop block fixed to the righthand side of the saw deck. A benchsaw or bandsaw could also be used to cut the decking bundles to length. This multi pack cutting saves a lot of time measuring and cutting individual deck planks.

Add the decking..

OK, time to fix the decking to the frame. Turn the car frame over (side sill and end beam flush at the ends). Apply wood glue to about the first 100mm of both sides of the frame and the top of the end beam. Start laying down the deck planking, check for square every eight or so planks. Don't try and push the planks too tightly together. You want the boards to appear as individual planking after the deck is sanded. Install remaining decking.

Use scrap spacers to maintain frame width as the deck boards are glued into place.

At the other end, glue a full width plank to the end beam, if required, cut down a plank to complete the deck. Note the 1.5mm overhang, over the side sills.

Your completed decking..

After the decking planks have dried, turn car deck over and mark positions on the bottoms of the end beams for the installation of the centre sill beams. Spread glue on to one edge of the centre sill and clamp in place. Repeat with the other centre sill beams.

Beams fixed in place, note spacing pencil marks on the underside of the end beam. Set aside to dry.

Once frame and decking timbers are completely dry, sand back any high planks on the deck.

To speed up the sanding process, I use several passes of the frame over a bench sander..

After sanding, highlight the individual planks by scribing along each joint. My scribe is an old sharpened screwdriver. (Not my hands, but my wife, Carol, helping with the photos)

Lightly draw a pencil line along the full length of the both sides of the deck. Dead centre over the side sills. Notice the highlighted planks on the left-hand side.

Using your scribe punch two 'nail holes' at each end of every plank. Sand off pencil line after all the 'nails' have been punched.

As I run some of my flatcars empty, I like to add some extra weight to help the car track better. If you also wish to weight your car, cut two 400mm lengths of sheet lead to fit between outer and inner centre sills. Lead can be cut with a sharp knife, similar to cutting styrene. Lead is approx. 1.5mm thick.

Using a glue gun is a quick way to fix down the lead to the underside of the deck.

Cut-out the needle beams from the template on sheet 2. If full brake rigging is to be modelled, it is advisable to locate and drill brake rod clearance holes, prior to installing the needle beams to the frame. Glue beams to frame and clamp.

Install end sill to end beam at both ends of car frame (32x10x7), making sure that they are centred on the end beam. Clamp with rubber band till glue bonds.

Now we are ready to cut and install the bolster, to which the trucks are mounted. A bolster white metal or brass casting could be used to be more prototype in construction, but for simplicity, I will use a 96.5mmx15mmx4.5mm wood bolster. Mark the centre hole position and drill a 1/8" hole in each bolster. Insert a 4-40 blind 'T' nut in each hole and tap home with a small hammer or squeeze together in bench vice.

Glue bolster into position., make sure that the 'T' is on the bottom, ie: facing the decking.

For added strength, I drill through the bolster and insert two wood screws into two of the centre sills. Check to see that the screws are flush with the top of the bolster. If they are protruding, they may interfere with truck swing, once the trucks are installed.

Test fit trucks, if using Hartford Products trucks, place two small washers between the bolsters and truck

frames. I find that small 'fender' washers work best - 2x 12mm washer with a 1/8 hole. Use a 4-40 x ¾ socket head screw to mount the trucks.

Well folks, that concludes Chapter 1.

On completion of chapter 2 your flat will look similar to this.

Happy modelling, Wayne