I started with the offset upright that supports one side of the brake wheel housing. This is a 4”x4” L shaped angle that runs from the bottom chord and stops within a few inches of the top of the car.
The offset portion of the angle complicates things. If I had correctly sized angle stock I could bend it to the required shape. This would be simpler but the flange thickness of commercial stock is heavy to my eyes. A primary objective with this build is duplicating scale cross sections wherever possible, so I scratch built the post from 0.005” sheet.
It starts with a stripwood jig with a shallow rabbit on the bottom side that allows the the brass sheet to slip underneath it. The profile on the edge shapes and holds the right angle flange for soldering. In this photo, the brass sheet sticks out on the bottom to demonstrate how it fits under the jig.
I’m more thorough in prepping parts for soldering now. I lightly sanded the brass for a bit of tooth and cleaned the pieces completely to get rid of skin oils and other contaminants. This prep makes all the difference in getting a solid clean joint. My standard practice now is to place small bits of solder along the joint rather than feed it from the roll. This gives better control and avoids excess solder going everywhere.
In the photo above, the pieces are cleaned and positioned. Small bits of solder are placed and will flow nicely when heat is applied. A pair of clamping tweezers hold the flange in place while soldering. If needed I can adjust the alignment at this stage to ensure everything is straight.
With the flange soldered, you can see how the jig forms the bulk of the L angle, leaving a bit of excess material at the offset to remove by hand filing. Here I’ve marked out the profile of the offset using 0.080″ sq. styrene for a gage. A coating from a black marker makes the scribe line easier to see. The extra material on the left serves as a clamping surface for holding the part in the vice (photo below).
I carefully used a cutoff disk in my rotary tool to remove the excess material staying well away from the scribe line. I can’t emphasize enough how easy it is to ruin the piece at this stage from an impatient heavy hand. For example, it’s easy to melt the solder in the joint if you take an aggressive cut. The rotary tool likely isn’t the best choice for this task but it can be done. Once the bulk material was out of the way, I brought the edge to shape with careful hand filing, until I was satisfied with the profile (photo below).
In earlier test pieces, I learned that the sequence of making this part matters. You need a way to hold the blank for filing the inner flange to the offset profile. That’s why I make the pieces oversized and shape the interior-facing flange first (photo above). If you do the outside corner first, then there’s no way to safely hold the piece. Once the inside flange is done, it serves as the clamping surface to do the outside corner.
We often consider time away from actual work as wasted. Nothing is farther from the truth. Reflecting on a procedure is time spent practicing in the future. I spent a lot of time thinking about this part and different ways I could make it. When I sat down at the bench I had a game plan that I modified as needed. This helped a great deal in building confidence as I saw the fruits develop before my eyes.
Pacing is Critical
This small piece took several days to make. What you see in the photos is the third or fourth one made. The earlier tests helped me understand what this process wants to be. I not only made multiple pieces but also rebuilt the soldering jig to refine the shape and dimensions. The quality of the jig determines the quality of the finished pieces, so time spent getting the jig right is invaluable.
There is no doubt that this is delicate work. I quickly discovered I have to pace myself in order to adjust to the demands it makes. When shaping the offset on the one flange, I was amazed at how tempted I was to use the power tool to remove just a little bit more rough stock. Even as those thoughts were going through my mind, I realized what a recipe for disaster that would have been and almost walked away from the bench before making a stupid choice. Instead, I found a sense of freedom in knowing where my limits are. Being aware of my thinking, all it took was a moment to settle my mind and keep filing by hand. I refocused on how the file felt while working the material. I learned to sense the amount of resistence and how it changed as the filing angle changed. The job was done a few minutes later and I felt a great satisfaction from the process.
A Piece at a Time
Delicate assemblies like this need a change in mindset. I’ve learned to ignore the volume of work ahead of me, and focus solely on the piece at hand, treating it like a model in its own right.
I often state that model building is a journey. Stretching your skills and concepts of what possible, developing your confidence and problem solving abilities are part of what that journey looks like in my view. A few short years ago, I wouldn’t have attempted work like this. A year from now, I may look back and moan at how crude this work appears. Step-by-step is how a model gets built and how we grow as a result.