HO Projects 2026

MDC Part 1     MDC Part 2     MDC Part 3     MDC Part 4

3.  Drill Out the Holes
Use the .055 drill bit to clean out the queenpost beam holes. I laid the underframe on a piece of wood and held it down with my fingers to prevent it from lifting when the drill bit is lifted.

For the trussrod holes, I cut down an aluminum pin vise and put the .040 drill bit in it and then put these into the drill. This was done because the drill would not hold the small drill bit. I hand held the underframe during drilling as it was easier and faster than laying it flat. It is shown laying on the board so I could take the photo.

4.  Underframe Cleanup

a.  Top
Sand the top of the underframe on 320 sandpaper. The ends may need to be done individually. When completed the top should be smooth.

b.  Sides

Use the flat file and smooth off the sides and the edges in the area between the bolsters.

c.  Bottom
File across the area where the queenpost beams attach. Note that one centersill is higher than the others. Keep filing until the area is smooth. The queenpost beams have to set level or else the car will have the appearance of sloppy assembly.

d.  Stirrups
Some of the underframes have a large amount of flash at a couple of the stirrups while the other end is not bad. Use the square file to clean them up.
The flash was so thick I had to use an odd bit in my Dremel to clean it up.
Test fitting the cleaned up underframe in a body.

5.  Attaching the Plastic Parts
TOP LEFT: the brake cylinder placed in the hole. It does not sit level.

TOP RIGHT: I removed the stub and smoothed the bottom.

LEFT: the brake cylinder CA glued to the underframe over the hole.
TOP LEFT: The queenpost beams need to have smooth bottoms so they will sit level on the underframe. Notice the amount of flash on the molding seam. Scrape with knife blade to smooth.

TOP RIGHT: Remove any flash noticeable.

LEFT: Clean off flash from the top between the queenposts.
LEFT: file down the nub from the sprue attachment.    RIGHT: this piece is molded poorly as the halves of the mold apparently didn't line up.
A generous amount of CA glue was applied to the underframe and a 1/4" square dowel was used to insure the queenposts were perpendicular to the frame.

6.  Installing Trussrods
I have substituted the monofilament line for the thread included in the kit because when the thread is painted it looks like a cable instead of a rod. The monofilament line is the correct diameter and is smooth.
Above is the kit's instructions for installing the trussrods.
To manage the line, I put it in a plastic bag and feed the end out as needed.
Tie a knot in one end of the line. I made three knots so the final knot was larger than the hole in the underframe.






Thread the line per the kit instructions but leave it loose.
CA glue and accelerator. I made a holder for the accelaterator as I tipped my last bottle over several times. I used a spray paint lid lined with clay.

This CA bottle has a fine tip. The accelerator is not sprayed as it wastes too much. The spray tube is dipped into the liquid and dabbed onto the glue area.
Pull the knot tight against the underframe and CA glue it followed with a dab of accelerator.


Start with the trussrod at the knot. Pull the line over the queenposts and pull it from underneath with a small pair of pliers. It doesn't have to be tight, just take out the slack. Then put CA in the trussrod holes where the line enters and on top of the queenposts. Then follow with accelerator. This glues the line in and keeps it taught.



Continue this procedure until all lines are glued in.
CA glue the lines on the top of the underframe. Give the CA a few minutes to harden and trim off the excess line. The last line should glue to the underframe to help hold it.
This is an earlier underframe on which I glued in four separate trussrods. I used a piece of styrene to hold the end of the line against the underframe while the CA set.

7.  Painting the Underframe and Trucks


LEFT: Remove the wheelsets and check the truck sideframes for flash. Trim as needed.

ABOVE: underframe and trucks painted in spray booth.


The underframes for the two Colorado Midlands cars were first spray painted flat black and then dusted with the red primer. This was to give them a dark red color closer to the body color.
HO Projects 2026

MDC Part 1     MDC Part 2     MDC Part 3     MDC Part 4
Copyright © Jack Hess 2025