A journal following the history, design, construction and operation of Bernard Kempinski's O Scale model railroad depicting the U. S. Military Railroad (USMRR) Aquia-Falmouth line in 1863, and other model railroad projects.
©Bernard Kempinski All text and images, except as noted, on this blog are copyrighted by the author and may not be used without permission.

January 8, 2021

Update on the Locomotive Build

 I have received several questions on the status of the locomotive build.  I decided to take a break from the locomotive project to work on some other things that I have been thinking about for a while.  But here is where I left off on the locomotive.

A few weeks ago I painted and assembled the parts of the locomotive that I had completed. I used some new metallic paints from AK Interactive in Spain. They are very good. They look like metal but are easy to apply.

As I was examining the model, I realized  I needed to make a lot of changes. In particular, I did not like how I did the crosshead guides. I also need to make changes to the firebox and the interior of the boiler.  The frame needed  modifications to the rear saddle and the back deck. On the inside of the stack, I need to add a lip so the screen will sit securely and not fall into the stack. I needed to correct the rivet pattern on the smokebox. I want to name a name plate holder on the side of the boiler. Most importantly, I need to adjust the location of the hole for the subframe. Somehow it ended up too far forward by about 1/8 inch.

All those changes required that I modify my drawing. But, because of the way I drew it using imported dxf's and joined bodies, making changes was very difficult. This is was because I am not that familiar with Fusion and didn't know about the proper way to set up a file so changes would be easier later.  Fusion uses a top down approach, so each new part references existing parts. If you make changes to a part, the changes bubble through the whole drawing. I was getting a lot of errors as Fusion was unable to implement some of the changes I was making mostly because I did not set up the file correctly. 

So I started the a new drawing from scratch using the proper file layout.  A big change in the design is how the cylinders and cross head will attach to the frame. It will be easier to show later than to explain now. 

 I did about 8 hours of screen time on the new drawing.  It was getting tedious,  and the way Fusion works with my mouse, my fingers were getting sore. To pan you have to push down on the mouse wheel and to orbit you push on the mouse wheel and hold shift. The pressure on my finger from pushing on the mouse wheel was making my index finger sore, so I took a break.  It is possible to reconfigure the mouse buttons and that is something I should look into doing. I am using a nice Logitech MX Master 3 mouse, but the mouse wheel is big and take a lot of pressure to push. I have thought about getting a Wacom tablet. My former Wacom tablet, which was about 10 years old,  would not work with the new computer and OS. 

Anyway, here is a screen cap of where I left off on the new drawing. Note the file structure on the upper left. Hopefully this will make changes easier. I still haven't quite figured out how the timeline in Fusion works. I have learned that doing multiple un-do's using control Z doesn't work in Fusion like it does in other programs. Also, all the parts share an origin, which makes things a lot simpler. My previous drawing did not, and parts were referenced from different origins which made alignment tough. I have to chalk this up to learning pains from teaching myself Fusion360. I am sure an experienced user would have no trouble with this. 

I ordered some brass detail parts made by  Precision Scale for the loco from my favorite shop, Mainline Hobbies. They came in and I did some work assembling them. The light bracket, bell and whistle will work just fine on the loco. I'm not sure about the cow catcher yet. It won't be hard to draw and print a proper cowcatcher if the brass one doesn't fit.  Also, note how the brass parts compare to the painted 3-D printed domes. The painted parts look just fine.  I was able to put a nice shine on the brass bell.  I can always make brass domes on my lathe if I find I want them really polished. 


  1. Bernie, have you considered a 3D mouse? I don't use one, but I know people who swear by them. Rene

  2. No, but I will look into it.

  3. You are right, there has to be a better way. Aren’t there any keyboard shortcuts that can make things more efficient?