Scratch-built Logging CarbyRobin Barrows |
||
| Like many PWMRC members, Robin Barrows has a desire to build something not available off the shelf. He enjoys employing his experience working with wood and metal to create something just a little different. His most recent project is building a string of logging cars...from scratch. Using patience and a high level of skill, Robin shares his building experience. Every modeler would benefit from an evening watching Robin at the workbench. Here's the story as told by Robin: | ||
|
|
Here's a photo of the completed logging car as scratch built by
Robin. To really appreciate the details, click to enlarge the photo.
Photo by Jim Connal |
|
Click to enlarge all photos. |
||
| The car frame is a Model Die Casting 2-Bay covered hopper under-frame. U-shaped log supports are made from .093” brass square stock and attached to the frame via 00-90 screws. I used MDC arch bar trucks and Kadee metal wheels. The finished car is 34 scale feet long. | ||
| This is the starting point...a bare frame.
Photo by Jim Connal |
 |
|
| I made the log supports first – using a jig I made from hardwood. I made my first car without the jig but decided that for consistency the jig would make things go faster and make the soldering easier. The square stock can be cut with a razor saw or a Dremel cut-off wheel. I added marks to the wooden jig so I could consistently cut the brass stock to 2.5” length and notch it in the right spots to create the V shape. The vertical parts of each support are ¾” while the horizontal portion is 1” long. I cut notches with a cut-off wheel through three sides of the support that allowed a bend of near vertical. | ||
|
|
This is the jig Robin made. This makes the work
go faster and each piece is the same.
Photo by Jim Connal |
|
| Don’t worry about big gaps – they can be filled with solder. Use lots of flux and a metal clamp (or a jig) to secure the supports while soldering. I tried just using my fingers the first time – it was painful. The excess solder is easily removed with a file. Drill a hole for the 00 90 screw in the exact center of the support bottom with a #58 drill | ||
| Good soldering technique...heat the piece and let the
solder flow into the joint. The solder provides both filling and
structural strength.
Photo by Jim Connal |
 |
|
| I removed the small round hopper door supports from the bottom of each MDC frame with a hack saw and dressed the area with a cut-off wheel. The frame was drilled through both truck mounts with a # 50 drill. Both truck mounts and coupler pockets are tapped with a 2-56 tap and plenty of lightweight oil. I learned from working with the white metal that although it is relatively soft, it is brittle and very hard on drill bits and files. The small hobby bit sets numbered 60-80 are not suitable and are good for one hole before becoming hopelessly dull. I used gunsmith quality, short drill bits from a supply house known as Brownells. They are great folks to deal with, charge actual shipping and have no minimum order. | ||
|
|
One of the most used tools is the cut off
wheel...always wear eye protection.
Photo by Jim Connal |
|
|
I
drilled the bottom of the frame with a #57 bit for the brake cylinder.
If you are going to run brake lines
– drill the ends of the brake cylinder before using CA to
attach it to the frame. I
also drilled the ends of the mid frame arms with a #57 bit where I
planned to install a logging chain over the load. I’ve been saving my wife’s small, cast-off jewelry chains
for this purpose. |
||
| Here's a partially completed car. Notice the
frame has been notched to receive the cross member.
Photo by Jim Connal |
 |
|
| The notches need to be drilled in their center with a #58 drill then tapped for a 00 90 screw. I recommend drilling this hole with a drill press or be very careful to keep it vertical, otherwise your log supports will lean. I also recommend using a centering punch to tell the drill where to start. I sharpened a small punch and did not need a lot of force to create a small indentation in the metal. Drills tend to wander unless given some guidance. Use oil to prolong the life of your drills. Be sure and place a support under the area you are indenting or the frame will bend. After breaking a tap, I learned to use oil and proceed slowly, backing out often to clear metal chips from the hole. After screwing the log supports in place I cut the ends of the screws with a cut-off wheel. At this point I brushed lemon juice on the assembly and cleaned it with soap and water. The lemon juice is supposed to etch the metal and give paint some “tooth” for better adhesion. Vinegar can also be used to prepare the metal but there is no substitute for a thorough cleaning to remove all traces of oil before painting. | ||
|
|
This inverted view of the partially completed car shows
the log supports installed as well as the brake cylinder detail.
Photo by Jim Connal |
|
| I installed Kadee #5s in the coupler pockets with 2-56 screws. I zipped off the portions of the screws protruding above the frame with a cut-off wheel – but be careful – the heat generated will melt the coupler pocket cover. The safest way to install the coupler and truck screws is to measure and cut them to correct length before installation. If you make your own coupler pocket covers use .040” styrene. | ||
| Here's an unpainted, completed car. Notice the
notches in the frame for the log supports and the solder fill.
Attention paid to making everything fit properly and smooth will pay
big dividends when the car is painted.
Photo by Jim Connal |
 |
|
| I decided to paint the cars red oxide primer. The trucks and couplers were painted grimy black. The car will be weathered with more grimy black later. I used the MDC arch bar trucks because the retaining screw hole is much smaller than an Athern’s. The trucks positioned the couplers at the correct height without shims. I found it useful to slightly damage the threads of the truck screws with side cutters – to keep them from working loose while running. | ||
|
|
This close-up shows the detail of the truck, log
support and the brake cylinder and line.
Photo by Jim Connal |
|
| The logging car only weights ½ oz. with metal wheels so it will need a load of 2.5 oz. in order to bring it up to NMRA standards of 3.0 oz. Those of you with steep grades may wish to keep your cars a little lighter or plan on adding some weight to your Shays for traction. | ||
| Here's the completed car...a testament to Robin's
skills. Everything fits perfectly and everything is smooth...a
great job.
Photo by Jim Connal |
 |
|
Bill of materialsModel
Die Casting 2-Bay covered hopper under-frame, part number 90243, $2.25
each MDC
5070 Sigstrom Drive, Carson City, NV 89706 (775)-884-4388 Model
Die Casting Arch Bar trucks (frame only – no wheels), part number
29222, $1.25 for a pair or one car’s worth Brake
cylinder from a #1500 kit, which actually comes with more that just the
brake cylinder. $1.25 each
gives you several little ladders and brake wheels in two sizes plus a
pair of coupler covers in case you don’t wish to make your own. .093 inch square brass stock. .015
inch brass wire 00
90 screws: Walthers part
number 947-1002 or Hob Bits part number H 803 00
90 taps from Walthers # 947-1301 or hob Bits # H 895 drill
bits from Brownells (641-623-4000) or www.brownells.com #
50 drill, pt no. 891-450-070 ($0.78) #
56 drill, pt no. 891-456-046 ($0.80) #
57 drill, pt no. 891-457-043 ($0.91) #
58 drill, pt no. 891-458-042 ($0.91) |
||
| Return to "How Do I" page | Return to PWMRC Home | |
