Well, I got home and I had a package waiting for me from Narrowminded.
A set of ten shoulder washers as described above.
They look wonderful.
I went and got a Kumata brass locomotive- this is a chrome plated Hallmark E3/6A. Almost all Kumata brass locomotives in N scale except about 3 or 4 use these insulating shoulder washers. So this is a common part that fails.
Here is the insulated gearbox. The frame is charged to the other truck. So there is a clear acetate insulator between the gearbox and the frame. And then-- since the gearbox screws go into the frame and are thus charged-- they have to be insulated.
Here is a pair of insulators that are in good condition. This loco does not really need new ones. But trust me-- if you have an old KMT loco, there's a good chance you know how bad these things have gotten over the 30 years the locos have been around. It is common for them to be: split, crushed, deformed, cracked, and/or melted.
In this shot, the shoulder washer on the left is stock.
The one on the right is the one Narrowminded made. It is absolutely perfect. In fact, it is better than the original.
Notice how very thick the bottom lip of the gearbox is- as compared to the next shot. This one is fat. So the longer barrel we placed on the shoulder washer worked better than the original.
I then dug out another gearbox to the Trainmaster I melted in the paint curing oven (
).
Notice the bottom edge of the gearbox is much thinner-- and the hole is a tiny bit narrower.
I had to force the screw and shoulder washer to get it into the hole. This damaged the barrel a little bit. (I did this on purpose just to see what would happen).
So.... I don't think the size of the shoulder washer should be changed at all. The size is good. The solution, if the shoulder washer does not go in easily, is to simply get a little round file and open up the hole. We're talking about 1 mil and about 8 seconds or less of work.
Now, also, the barrel length is a bit long for this loco. But that's ok. Once mounted in the gearbox, an Xacto knife would cut away any excess from the underside.
And here is a final shot comparing the two from the barrel end.
Notice that the one Narrowminded made just looks a bit tougher.
Also, this shot shows that the threads of the screw just
barely bite into the Delryn- which is good. It is just right. If it cleared it totally, then we would loose a bit of wall thickness- which was something Narrowminded was worried about.
I wouldn't change a thing.
THANKS!!!!!!!!
I just can't brag enough on how perfect these are.
(I'm just glad I didn't totally goof the measurements.
)
Oh..... And I loved the video. Thanks.
