BACHMANN Alco 2-6-0Wow, this one was an adventure! I came into this fight woefully unprepared for the battle that I would face. In the end, I succeeded. However, this was probably above my experience level (although I
think I can say that the experience has made me stronger!)
Bottom Line Up Front: I used
short shank scalebox (modified) for both front and rear coupler.
Let's start with the reason I was unprepared. Looking over the model, it appeared to be a straightforward conversion using a Universal Conversion for both front and rear. The reason is that the front and rear both had coupler pockets with screwed on lids. Below are photos of both (I removed the lid to the rear coupler prior to taking the photo.)
Should be easy, right? Drop in the spring splitter, drop in the universal coupler, screw the lid back on, and we're on our way, ready to pull freight!!
Well, NOT SO FAST!Unfortunately, the Bachmann coupler, despite being massively oversized, has a very thin shank. Because of this, when you screw down the lid, the tolerances are such that they essentially clamp down on the N-Possible coupler. So, instead of having a nice, quick, easy conversion, I had a good-looking but useless coupler at each end of the locomotive. I had to re-think this.
I started with the pilot, because I thought this would be easier to work on, since removal of the pilot is straightforward. Disassembling the coupler assembly that I had just installed, along with the metal spring splitter, it appeared that the cause of the tightness was in fact flashing where the coupler rests. So, I grabbed a file and filed it as smooth as practical:
That worked a little better. Still not optimal. I played around with it as best as I could, and got it to kinda-sorta work. A little better, but still tight. Operation was not smooth; on top of this, it was measuring a bit low.
There HAD to be a better way.
I set this aside for a bit to work on the other (tender) coupler. THAT one should be easy, right?
NOPE. Same problem. Using the universal conversion, the coupler is too tight. Looking it over, the box lid that was included could never work; the height of the center post and sides of the coupler box (which the lid rests on) are too short. There HAD to be another option.
Looking over my parts bin, I thought - "What if I took a Scalebox floor and filed down the post ALMOST flat? This might give me a bit more room in the box, and I would then also no longer need the splitter." So, out comes the file, and I started filing down:
This solution was successful! I went back and forth to ensure that I filed enough without taking off too much. In the end, I had a nub of a center post on the Scalebox. But it worked AND it worked very well! (I did need to apply some PVA glue strategically to keep the box in place. But once I figured this out, I was completely satisfied with the result, both on height and performance:
With this in mind, I decided to use this same approach on the pilot.
(
ASIDE: The pilot is a bit unique in that the center post is also used to house the entirety of the screw threads. Meaning, if you remove the center post, you'll have to drill a hole THROUGH the pilot and leave an unsightly hole in your pilot. So removing the center post wasn't something that I really wanted to do.)
The only issue I had with following this same approach with the pilot is that the hole for the coupler is fairly tall. I needed to install the Scalebox bottom such that it slid into this hole as well. However, the scalebox plus coupler shank is smaller than the thickness of the original coupler with coupler lid. I needed to add a very thin shim to ensure that the coupler wouldn't "droop." I used a small rectangle of construction paper; that did the trick. Once again, some strategically applied PVA helps hold everything in place.
Here's the final result: (And - not sure why the scalebox appears crooked in the photo. It really isn't crooked at all. I think some of the shadows and glue give it an appearance of being crooked.)
This was a complex installation, but manageable by modelers of at least intermediate skill.
The biggest lesson I learned is that things aren't always as straightforward as they initially appear. But, I am glad I had a chance to learn from this and hope that this helps other modelers with similar installations going forward.
And - in my opinion, the Scalebox (and the N-Possible couplers overall) are both magnificently engineered! I appreciate the time that
@turbowhiz put in to ensuring that these would be the best they could be before release!
Regards,
Jim
