G-Gauge Flat Bed Train Car



Introduction: G-Gauge Flat Bed Train Car

This comes from a typical mind set of mine. $100 for a model train car?!? That's too much for me to spend, I bet I can make one my self. It will be better and cheaper than anything I could buy. I'm too cheap to buy something that expensive especially when you need X amount of cars to make a decent train. It adds up fast. I started searching the internet and wasn't having much luck, especially with G-Gauge sized trains. Most were HO or N scale and just a few O scale models. This Instructable will hopefully put some more information out there for others to find. The only useful information I really found was from the links below. I used them as a very rough guide.



It's not a perfect build by any means, but i kinda wiped it up fast to fill my free time at night while the wife and kid are asleep. Part of my professional job is to write manuals on how to use tools and fixtures to assemble jet engines. I didn't want to bore anyone with technical writing writing so I mostly documented through pictures. On top of that I hardly measured anything so even if I wanted to document further i probably couldn't. If anyone would like clarification please feel free to ask. I'm sure i'll be making more in the future and when I have a better grasp of the assemblies i'll make some sketches with dimensions, etc..

Anyways, hope this helps someone else out there.

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Step 1: Materials

About a third of the material for this build I have been toting around and held onto. another third were for other projects and the last bit I bought.

$25 Trucks/Wheels/Couplers

$6 Assorted wood

$3 Brass strip

Pine wood

Wooden Coffee Stirrers

14 gauge wire

Brass Tube

Brad nails?

Two washers

Two Philips screws

Table Saw

Drill press


Miter box and saw

Philips Screw Driver

Flat Head Screw Driver


Blow Torch


Utility Knife

wood glue

5 min Epoxy

The Table Saw was just for ripping a few pieces of pine. if you can't find someone to help you out, scale lumber can be bought at least on ebay or hobby stores. The Drill Press can be replaced with a hand drill. you just need to be more careful not to drill to deep or too inconsistently.

In total I spent roughly $34. If I were to buy the rest of the wood and materials, it would have been maybe another $15 maybe??. Also I only used one of two strips of brass and I still have plenty of the assorted wood left for other projects. The total price will actually come down as I use the rest of the materials for other projects/cars.

Step 2: End and Side Stringers

I ripped some extra pine 2x4 that I had to about .5 x 5/16 I would have liked them a little thinner, but it was becoming challenging to cut these pieces safely on the table saw. I won't be running any trains outside for a long time (no good room, ugh) so Pine should be fine for now. I might decide to paint the car in the future, so i'll probably use either out door paint or seal it somehow. I'm not really focusing on this at the moment so i'll leave that up to the instructable masses to either figure out or leave comments.

I measured an existing car I had and came up with a few measurements. The existing car was 4" x 16" rectangle. The car I'm making will be 4" x 12" just to keep it some what simple. I stuck a piece of blue painters tape down for an epoxy mixing area. I got that ideal from another instructable. The reasoning behind it was that you can put the tape down and create an instant clean area for the glue and when your done with the glue, just rip it up and throw it away. I mixed the epoxy and put some on end of the Side Sills and stuck them to the End Sills. I could have used wood glue or CA glue, but wood glue is too slow for me and I'm out of CA glue. Epoxy it is!! Epoxy worked great for the entire build. I stuck the corners together and taped them up as make shift clamps to hold the corners while the glue dried.

*side note* After completing the build I tried to remove that tape... I guess it's porous. Some i could rip up, some I could scrape up and the rest I had to use pliers to brake it off the build mat. I'm not sure if it was the build mat or if another material would have been fine. I'm still going to try this again in the future, but i'll try it on a different surface.

Step 3: Stringers

The next step is the inside Stringers. I realized that the Bolsters that I cut were a little tall. That would just make the flat bed sit pretty high on the rails. It probably would have been fine, but I had just bought a new dovetail saw so i thought I would try it out.

I taped the three stringers together and marked the location of where I wanted the Bolster to be. I used the saw and cut down about .25" at my marks and then used a chisel and dug out the remaining wood. The third picture shows the fit I have.

Of course after I cut cut them I realized that I located them about .25" - .5" too far into the center of the car. Again, it's not a huge deal, but i'm just hoping that it doesn't interfere with the other cars going around the turns. It could be a slightly tighter fit, but since i'm winging this whole thing.. I think it tuned out pretty good.

Step 4: Bolsters and Queen Posts

The Bolsters transfer the load from the Stringers to the Trucks and Wheels. They basically turn the five or so contact points for each Stringer to a single point load where the Trucks contact them at the bolt. I drilled a single hole through the Bolster for mounting the Truck.

The Queen Posts and Truss Cabling are actually a really efficient, simple and cost effective way of strengthening a train car. As the car is loaded up it puts the bed of the car into compression. That leaves something to be in tension. you guessed it, the Truss Cables!!! Cables are extremely strong in tension for their size. Now the point of the Queens Posts is to move the cables away from the bed of the car in the center of it. This moves the centroid and increases the Bending Moment of Inertia and allows the car to support much more weight. I'm sure train cars today use I-Beams and other steel tubing. I would assume they are easier and cheaper to manufacture now that those shapes and ore mining is more prevalent these days... anyway I digress.

Now obviously I don't really need that strength, it's more for show. Using my poor mans miter box I cut the Bolsters and Queens Posts to length. I drilled holes for the Cable Supports in the Queen Posts. I came up with a plan and I wasn't going to drill holes in the Bolsters for the cables because they would interfere with the wheels. Then I immediately drilled holes in the Bolsters..... I don't know why. They are pretty hidden under the Trucks so i'm not worried about leaving them there.

Step 5: Main Assembly

After I test fit up everything I noticed a little rubbing of the wheels to the Bolster. The Trucks were also difficult to turn. Too much friction between the wood Bolster and the Trucks. I put a washer between the two and the problems were fixed. I also secured the Trucks to the Bolster and put the car on the tracks to see how it went around. everything seemed fine so I started to glue everything up.

I started with the Stringers by putting glue on the ends and wedging them into place between the End Stringers. I used more tape to hold them in place while they dried. Next was the Bolsters. Again putting glue on the dados that we're cut in the Stringers and on the ends of the Bolsters. Finally putting glue on each of the Stringers for the Queen Posts.

Step 6: Mmm Details, My Favorite

I made the Brake Cylinder from two different sizes of wooden dowel. I stuck those little pieces in my drill press and spun them for sanding. Finally gluing them together end onto the other end and adding a little piece of wood as the mount bracket.Once the Brake Cylinder was dry, I glued the Brake Cylinder to the inside of one of the Stringers and the Cable Mounts into their holes with epoxy.

For the cable mounts, I cut 14 gauge copper wire at approximately .75" long and bent one end over with pliers to make a little eye loop for the cable to go through. A few of the eye loops were too small for the Truss Cable to fit through so i had to... massage them. Next time i'll bend the eye loops around some slightly larger wire/rod than the Truss Cable so it easily goes through.

The Truss Cable was bent into a small loop and epoxied into a small hole in the stringers. The free end was fed through the eye loops on the Queen Posts. Once through, another loop was bent into the end and pushed into a corresponding hole. This was repeated for each Truss Cable.

The brake line was done in a similar fashion with a small loop at the end and pushed into a hole on the Brake Cylinder. The free end was fed through a small support and through the End Stringers. The Brake Wheel Mount has a small hole drilled into it to conceal the trimmed down Brake Line at the End Stringer.

The Foot Steps and Grab Bars are the same 14 gauge copper wire as before. The Foot Steps were 2" long to begin with and bent by eye until they looked about the same. The Grab Bars were 1.25" long before bending.

Has anyone bought those assortment packs of brad nails and never sure what to do with those square cross section black nails? It's apparently to add details to your train cars. The first nail started to split the wood a little so the rest were pre-drilled to prevent that from happening again.

Step 7: Decking

The decking is actually pretty simple. Knowing I would needed a lot of glue I decided to use wood glue instead of epoxy for the decking. You might say "by golly?! You cut all of those your self?!" No I must certainly did not. They are just those wooden coffee stirrers that my work so graciously donated. I suppose if you wanted larger decking, Popsicle sticks can be used. I thought they would be too large for this scale though. I started from each end and worked toward the center. the last piece stuck up a little, but I forced it down and put some weight on it until it dries. wood glue take a bit to dry, so i'm expecting to fix a few here and there.

After letting the glue dry over night, I started to cut the long ends of the decking off using the Side Stringer as a guide for the utility knife. No boards completely broke off, but few didn't fully glue down at the ends. I applied a small amount of glue to the inside of the Edge Stringers and smeared it around with a piece of wood. I put some pressure of the Queens Posts with the car top (decking) side down on the table and cut the rest of the over hung boards off.

Step 8: Trial Run

I obviously couldn't wait till the decking glue dried to see it on the tracks so i did a little trial run. I mounted the Trucks on and set up a small portion of a curve. It sits a little higher than the other car, but only by maybe .25". The only other thing was that the Bolsters are too far to ward the center of the car leaving only a little bit of the coupler exposed. Because of that it the two cars get pretty close to each other on the curves, but there is still a little clearance. Success so far.

Back to glue drying!!

Step 9: Cargo Posts

The last big thing I want to include are post pockets and posts. I made a simple jig to bend the brass in the vise to form up the pockets. It... well... didn't work. Right after I pulled it out I realized my problem. The wood gave way and allowed the brass to not bent at 90 degrees. I just need to use a different material. I also need to drill the holes with drill bits not from the '80s.

I finished up bending all of the brackets by hand, 10 total. I used a steel strip of metal .25" wide and .0625" thick (maybe .125 thick, can't remember) to bend the brass. It provided a little extra clearance during the bending process. The bending got better and easier as they went on. To make some of the bends I had to slip a flat head screw driver into one of the previous bends and tap with a hammer to make the next bend. I basically completed them all in the time it would have taken to make a proper jig. Drilling the holes through the brass was much better with a proper drill bit and cutting oil. What I should have done was used a center punch so the drill bit wouldn't track. That in tandem with the tracking and bending of the drill bit to the wood lead the brackets to be a little all over the place. The posts stick mostly strait up, but the brackets look a little messed up. Some of the posts fit very tightly with the brackets and some are loose. I didn't want the posts and brackets to be a matched set so i glued a small piece of wood to the stake to prevent the loose posts from falling though the brackets.

The last few pictures on the "Conclusion" slide show the stakes in a better state. That was after installing and removing the stakes a few times.

Step 10: Conclusion

The last bit to add, the hand brake. I drilled a hole through both walls of a a .5" copper tube. I inserted 14 gauge wire through both holes, wrapped it around the tube, and cut it as flush as I could. I bent the tang down to make a stem that would fit inside of a brass tube I had and was using as the handle shaft. I tried to solder the wire together to prevent it from snagging on anything with a soldering iron, but I don't think it was able to get hot enough... so I pulled out the blow torch!. I made quick work of that. After dipping the handle tang in flux, I flipped the handle over and gently clamped it in the vise. After sliding the tube over the tang, I drop a bit of solder that was longer than the tube into the tube and gently heated it until the solder melted joining the two. with the solder longer than the tube, I knew it started to melt when the solder disappeared into the tube. I know the torch heats small things like this up really fast so i was very careful to only apply as little heat as possible and be quick. I spun the handles in the drill press to make sure they were sort of round. I used a spare piece of wood to massage them round and flat. I didnt use too much force, just a little.

I haven't decided if i want to paint this car yet. I might just leave it plain as I think I can do better next time I build one.

All and all I think it turned out decent enough.

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