(If this is the wrong forum, please move it to the right one. Thanks!)
I have four of BLI's original Powerhouse Series heavy Mikes (the QSI ones). These were purchased w-a-a-a-y back in the early 2000's, when they first came out.
They have been generally trouble free, reliable and well-running locos. Unfortunately, one of them has developed a tendency for the valve gear to jam the mechanism when running in reverse.
Specifically, the expansion link has excessive lateral wobble, and the bottom of it sometimes moves far enough inboard to jam either the side rod or the main rod.
The valve stem bounces up and down excessively, rather than moving smoothly in and out of the valve housing. This causes the radius bar to bounce up and down wildly as well, which probably contributes to the expansion link lateral motion.
Anybody have any ideas for approaches to fixing this? BLI no longer support locos this old.
For reference, I used this web page for the valve gear parts names: https://en.wikipedia.org/wiki/Walschaerts_valve_gear.
If I can get a clear video of the goofy motion of this thing, I'll post it on my YouTube channel (tomorrow) and link it below.
Mark P.
Website: http://www.thecbandqinwyoming.comVideos: https://www.youtube.com/user/mabrunton
Depending on the hour total on the mechanism, it is probably quite worn, Mark. Apart from the wobbling expansion link, the wobbling/jumping valve rod might also be severely tired. This sounds like quite a project. You may have to manufacture parts, or acquire a donor loco on eBay.
But, I don't see how this will go away unless you remove the linkages, maybe drill and add new, slightly larger wire pins, or widen the expansion link somehow (doubling it up by sistering it to another..I'm just wingin' it here....).
I can't imagine why BLI wouldn' just sell you a pair of valve gear and rod sets from another version of their Mikes, even the USRA ones. You'd think they'd keep the scale correct, or close, and that the items could be made to fit.
Look for a loose rivet, a bent part or a loose screw. Since you have many of these, put 2 side by side and compare both mechanisms. A loose rivet can be gently tightened with pliers. A bent piece can be re-bent. I've replaced pieces with some from an entirely different engine from my junk box. No one can tell because you can only see one side at a time...
Simon
selector I can't imagine why BLI wouldn' just sell you a pair of valve gear and rod sets from another version of their Mikes, even the USRA ones. You'd think they'd keep the scale correct, or close, and that the items could be made to fit.
Mark, have you actually called BLI to discuss the problem?
Way back in 2005, I bought a new BLI Powerhouse Classics 2-8-2 Heavy Mountain Mikado. Within a year or two, the loco came to a sudden stop and literally fell off the track. When I examined it, I quickly observed that one of the connecting rods had bent and jammed.
I had done nothing to cause this damage, but thinking that it somehow was my fault, I did not contact BLI and I tried to fix it myself by bending the connecting rod back into position.
Occasionally, the problem would recur. So, I finally contacted BLI, and I was told that they no longer had exact replacement parts but they could sell me similar parts which should work. I never acted on it, and I finally sold the loco on eBay a few years ago, honestly describing the problem.
Here is a photo of the damaged part after my attempt to straighten the connecting rod. You can see the bump in the center of the connecting rod. When the derailment first occurred, that connecting rod was bent considerably outward.
Rich
Alton Junction
Mark, here is a link to a thread that I started some years back. Maybe there is something in this thread that may be helpful to you.
https://cs.trains.com/mrr/f/88/p/242669/2701981.aspx#2701981
Rich, I read through the thread you mentioned last night. Unfortunately, it wasn't helpful in this instance. Thanks though...
Here's a link to the video showing the vallve gear issues.
As I thought, BLI doesn't support these older locos anymore.
Any ideas?
I watched the first runpast showing the lifting valve rod. I also watched until you showed the inverted engine where your pencil poked the expansion link. I don't see anything wrong there. Instead, I think the problem is with the pin on the combination lever, partway down, below the pin at the radius rod's upper end. The valve rod gets lifted somehow at the end where it is pinned to the combination lever. Why is it lifted? Because the union link below it is binding somehow and forcing the combination lever to rise. If I'm wrong, and who knows, then it's a wear problem in the orifice of the valve rod that permits it to lift like that.
Or, I'm stumped...
There is a very serious PRR Modeler who has many BLI I-1 AND M-1 engines. He recently posted on a PRR board that once a year he always lubed the rods with a drop of neolube and has never had wear problems on any of the engines. Won't help in this case but maybe for others.
Thanks for all the feedback. Update:
I fixed it!
(sort of)
When I bought the three CB&Q-liveried Mikados (around 2004), my best friend bought me another one for my birthday, lettered for the Central Railroad of New Jersey. I'd always planned on relettering it as a fourth Burlington loco, but never got around to it. Except for initial testing when I first got it, it has stayed stored in an Axian Technology storage box for over 15 years.
I dug it out about an hour ago and tested it. It still worked, so I simply removed the Burlington superstructure from the ailing mechanism and swapped it out with the CRR of NJ superstructure. I lubed the new chassis and attached the old tender. While I was doing that I installed the QSI upgrade chip in the decoder (yesh, I got that sometime around 2007. I'm just really s-l-o-w). Works like a charm!
Maybe someday I'll try to work on the old mechanism and see if I can correct the problem. But meanwhile I'm back to three functional Mikes on the layout again!
Mark, that is totally unfair. You cannot keep spare locomotives laying around just in case you need parts. How dare you.
That said, congratulations. Glad you fixed it! (sort of).
LOL! Rich, you are absolutely right! It is unfair!
I'd forgotten about the fourth loco until just a few hours ago.
But I can't let this thing get the best of me too easily, so at some point (unless I forget about it again) I'll dig the old one out of the box and tear into it. I'll either fix it or destroy it trying - someday.
Mark, you lead a charmed life.
Hi there. I had a brass loco that had a weird problem: when put on its back, the valve stems (got that from the Wiki you posted - what a great source!) would fall out. I never really understood what was off in the mechanism that would cause that. Anyway, the fix was simple: I glued two little U-shape covers at end of the piston valves to prevent the valve stems from falling out. Painted black, it is totally unnoticeable. A bit unorthodox, but that and other little fixes saved that loco that I really enjoy now.
20210613_200059 on Flickr