Don't try this at home...

posted Sep 17, 2011, 8:04 PM by Randall Hammill   [ updated Sep 18, 2011, 5:00 AM ]
I have quite a bit of progress to report. It has been a busy week, so although I've been able to squeeze in some modeling here or there, I haven't had time to update the blog.
 
But the most interesting news is the saga of the K-1-d. I can't possibly do justice to the great amount of fun and laughs we had with four of us trying to get this locomotive to work. But I can at least explain what we did. Pieter took a few pictures and I'll post them when I've got them.
 
I picked up this locomotive on eBay, and it didn't have the box, etc. The seller said he had used it for years, but I couldn't get it to run. I gave it to Chris to operate on it on his test track. Even when applying power directly to the motor it wouldn't work. So Chris started to disassemble it, but it's a somewhat complex process on this model, so he decided to wait until I came over to continue. He had also chatted with John Grosner, who thought he might have an extra motor for it.
 
So most of the crew was there on Thursday, and John started to take a look at it with me. It was clear the motor was dead, so we decided to see if we could get the worm gear off of the shaft and put it on the new motor. No big deal, but it's press fit and we didn't have the proper tools (a Puller and a press would have been good...)
 
Did that discourage us? Of course not. How hard could it be?
 
John locked a pair of pliers on the shaft below the bearing and worm gear and rested the end of the pliers on the edge of the table. He put as much downward pressure as he could to minimize bounce.
 
Dick then held a mill file end flat on top of the shaft, also with as much downward pressure as possible.
 
I hammered the mill file, driving the shaft down. It actually worked. Once the shaft reached the edge of the worm gear we used a nail set, a tiny screwdriver, and finally a nail that would fit inside of the gear. Dick held whatever implements were needed along with the mill file on top while I hammered. Chris and I went to find a suitable nail, and the first one was slightly too large and we widened one end of the gear, which also introduced a small crack. But we got it off with a smaller nail without any other issues.
 
Of course, now that we had it off, we decided that we ought to be able to put it on the new motor. Obviously, the 17 minute drive to Dick's for his press was out of the question, so we made do. In this case we needed to find a way to push the gear onto the shaft. This requires pressing on only the shaft at the other end of the motor, as pushing on the motor itself would destroy it. Our solution? Turn the motor upside down, on top of the worm gear, use the nail set on the back of the shaft, and hammer from there. Dick liked the cutting mat on Chris' workbench, and we couldn't be bothered to move the piece of glass out from underneath it.
 
Believe it or not, it worked. And we didn't break the glass either. We put the shaft in the gearbox, and tried it out. It hummed. We wiggled it around a bit, and got it to run. But the problem was that the shaft was shorter than the old motor. As a result, only the bearing closest to the motor was actually on the shaft. Without the other bearing, the motor and shaft could wander too far and it would bind up.
 
But, what if we reversed the gearbox? The bottom of the gearbox was wider on the side closest to the motor. If we reversed it the motor could be placed closer and we might be able to get the second bearing on the shaft.
 
That's right, more hammering, test fitting, them more hammering. We were able get the motor close enough to use both bearings. And it works when reassembled.
 
So the next test is to put it back in the locomotive. So we attached the gearbox to the chassis, turned it on and...
It hummed. John isn't so sure we can reverse the gearbox. We loosened the gearbox, and when it's loose enough it works, but as soon as it's tightened enough to mesh with the driver gear it binds. Until I wiggle the motor into a slightly different position. It works! And it's smooth, too.
 
Now we have to try to assemble it in that position. However, you have to take off the gearbox cover, because the motor and gearbox have to be slid into the boiler before attaching the boiler to the chassis. Chris and I managed it with four hands. It worked, but the placement of the motor needs some adjusting, and that requires us to take it apart several more times. The screw that holds the motor into place is at a very awkward angle and lining everthing up is difficult because the hole on the bracket doesn't actually line up with the hole in the chassis. Of course, we're too lazy to drill and tap a new hole, because if we tilit the motor up we can get it. We need to do that in order to get the backhead to fit anyway, plus it's the best position to get the gears to all mesh properly in the new configuration. To complicate matters, the screw is too long and hits the bottom of the motor. We were going to cut it, but then half of the head broke off making it useles. Then we figured out it was really the screw to hold the chassis to the boiler through the cylinders. I should also mention that there are six additional screws that were missing when I aquired the locomotive.
 
So, the motor is now attached with double-sided foam tape. Works great, except we'll have to disassemble the whole thing again to attach the wire for track power (John didn't like the wire that the guy had put in it because it was huge). I actually want to use smaller gauge wire myself, and it needed to be longer anyway.
 
It's still at Chris', partially assembled, waiting for the wires to be installed and we'll need to retap some holes and reassemble it. But I can say at this point that it's working, and has decent low speed performance as well. The paint job is pretty good, although I'll have to reletter the tender (the 'New Haven' is huge). I probably won't have it operating for DC because I'll run all of the wires I need for DCC now so I won't have to take it apart again.
 
Of course, I'll need to take apart the K-1-b to install DCC in that one, and Pieter and, if all goes well, Chris each have a 'd' that will need decoders too.