My goal for today was to finish up the yokes and get them installed.
There were TWO things I had left to do – the first was to mill out a little clearance notch (similar to the one done on the tie plate), and the second was to make the screw holes for the running board.
To make the clearance notch, I put the yoke in the mill vice at a 35
o angle and made the cut. Easy peasy.
Making the screw holes for the running board was a little harder. I SHOULD have done this before I rounded things off yesterday. That was my plan, but clearly, I forgot. So… plan B is to mount things in the vice as vertically as I can, like so:
Then drill the mounting holes. I tapped them 3-48 too, but no pic of that. But trust me, I really did it.
Now the hard part begins; making the crossheads slide well in the crosshead guides. Kvom warned me that this was an arduous process, and he’s right. I spent the rest of the day getting this working. Luckily, I only had a few mishaps. Unfortunately, I had a few mishaps.
The first thing I learned was that you can’t install the yoke plate when it’s all screwed together. It won’t get past the rods. So, I mounted the tie plate to the chassis and went to put on the yokes one at a time. Unfortunately, you can’t access the bottom screw with the front drivers in place. So they had to come out. Luckily, I was able to disassemble the front bearings and swing the wheels out of the way without dismantling everything.
But with the yokes in place, the front wheels lost ALL their movement. They are supposed to be able to wiggle back and forth a few degrees. But there was barely any movement at all. Look at the paper-thin gap between the back edge of the wheel tread and the bottom of the yoke plate. Not good.
So, back out they came and I filed a little angle across the bottom there. If I’d known this, I might have done it in my mill set up earlier. But at this point, I decided a little file work was just fine. With that done to both sides, I’ve not got several degrees of movement back in the front wheelset. Yay!
Now, on to installing the crosshead guides between the yoke and the cylinders. The guides went in great. But once I got them installed, things moved very poorly. The crossheads were super tight and hard to move.
So I spent quite a bit of time fettling things here and there to make them move. Turns out the main culprit was that I’d left the inside of the groove in the top and bottom of the crossheads freshly machined. Once I took the edge off those groves (all around) they slid quite smoothly back and forth across the guides.
Unfortunately (yeah, another one of those) one of the things I tried early on was to widen the spacing between the guides. I did this by filing a bit off the upper mount; and thought it was helping. So I did it a little more. Tuned out not to have any effect whatsoever other than to make things sloppy and wiggle up and down. Not what I wanted. So I currently have a brass shim in place there to bring it back where it was before I went all file happy on it. I wished I'd just left that completely alone
Anyway here’s a pic of where I ended up:
And a short video to show it all working as intended!
Now back to the sad part.
Here’s the side with my bungled attempt to fix things where I now have a nice shim installed. I’m considering if I should leave it like this, or if I should silver solder a little piece in place there and make it look better. That’s probably what I’ll do. I just don’t want to mess up the parts that are already soldered in place. But I think I can do it. Any other thoughts on how to make this not look quite so stupid?
Thanks,
Kim