I was inspired earlier in the week to start in on a(nother) project, converting an ancient, original center drive Weaver RS-3 to Proto:48. While Comstock Road can only plausibly host one locomotive at a time, having a backup is something I want both in case of unexpected issues and so that I can still push cars around while re-detailing one to proper CNR outline. Thus, I picked up a consignment Weaver RS-3 with drive issues and ordered the drop in conversion axles from NWSL. There it sat for a couple of years.
For a change of pace from machining type model building, I took up the project again expecting to have the swap done in an hour. Here are the two axle types for comparison.
You can see the first gearbox already converted in the background. It was non-trivial only in the sense that the little nut and bolt sets holding the gearbox together were very stubborn. I foresee a purchase of precision nut drivers in my future because getting a good grip on the nuts with the end of my needle nose pliers was challenging.
Sadly, my quick project was not to be. I got the second axle of the first truck done and reassembled the truck. I quickly discovered that the new axles which are supposed to fit into the holes in the sideframes which bear the weight of the model were too short. A bit of internet searching later turned up reports of others with similar issues. It appears that a packaging/labelling error is too blame. Being way past a reasonable return date, I elected to go with another solution.
The alternate solution is to narrow the bolsters and cut new notches in the tabs on the sideframes that clip into the bolsters. Not for the faint of heart but not undoable. The upside of this approach is that the sideframes are brought in to closer to scale width. The downside is that this is a one way trip whereas the drop-in would be reversible. (Proto:48 locos have a much smaller market than O 2-rail.)
I considered making the modifications with my mill but I have no experience in machining plastic and did not want to risk melting or shattering something that is hard to replace. I settled on a combination of jewelers saw, x-acto knife and files. The initial effort before life intervened is a qualified success. I need to tweak the notch but otherwise I can believe that I can do this. We shall see.
If it all goes pear shaped, I plan to mill a replacement bolster out of brass or aluminum. Hopefully, that won’t be necessary but knowing that I have a backup plan gave me the confidence to dive in and start hacking away.
I have a request from a fellow Proto:48 modeler for some roller gauges. These handy things are just the ticket for handlaying track and, as far as I can tell, not something you can get for Proto:48. (There are commercially available gauges for most of the regular track standards) While I am not prepared to make lots of gauges on my entirely manual Myford lathe (You would want a CNC machine to do this commercially) I am not averse to knocking out a couple. Once I finished my Milling About and rearranging the shop…
Milling trials having been concluded (more on that later) and shop having been rearranged including new task lighting and a shelf over the lathe, I am ready to actually make something which leads us to objective of this post.
The relevant dimension of the target rail is the width of the rail’s head since that is the part the gauge has to fit over. The measurement reported for ME code 125 is 0.056″. The rest of the numbers needed come from the NMRA trackwork standard for Proto and Fine Scales S3.1. From the Proto:48 line we get a gauge range of 1.177-1.203, a flangeway width of .036-.039, and a minimum flange depth of .026.
From those numbers, we work down to something I can aim for on the lathe. I say aim because I can miss a dimension by a couple of thou and still get working gauge. A couple of thou is a long way in machining(famous last words).
The desired target gauge is the middle of the standard so 1.190.
We want the gauge to fit through minimum flangeways so .036 wide and .026 deep.
We want the gauge to be accurate without being difficult to fit on the rail or roll along it. This suggests a loose running fit (had to look that term up) so I will add .003 to each slot to get .059. As a check, 1.196 is well within the standard’s maximum allowable gauge of 1.203.
Here is a very low tech sketch of the planned work:
This morning I made a start on the laying the rails. Given that this is going to be all-in Proto:48 with tie plates an scale sized spikes, this is going to take a while. Good thing that I generally enjoy it.
I wanted to get a bit of track at least tacked down enough to run on to prove myself that I can still do it. I realized that I had put it off longer than I would have in the past and decided to get myself over it. All went well with no more than the usual number of lost spikes.
The raw wood ties are easier to get spikes into. I think the stain I used hardens the pine somewhat.
Raw wood spikes make it easier to see what I am doing due to the contrast.
Sanding makes it easier to get intermediate tie plates under the rail.
I need to swap the Optivisor back to the shorter focal length lens for this job.
Distressing ties is much easier if you don’t get excited and forget to do that before you lay rails…