surging steam locomotive problem solved.

[mark.hinds]

Loren, do yourself a *BIG* favor - stop listening to 3rd party-hosting folks and upload the photos directly from your Mac to the Railwire.  It is really much easier and it works.  I posted rudimentary instructions earlier in this thread.

Pete, I just now attempted to post a test photo using the RailWire photo posting system. I did exactly as you said, step by step, but when I tried to finish up by clicking on the "Add Picture" button, I got no response at all. Any suggestions?

Loren;

When I tried using the Railwire image hosting system, I recall 2 situations where nothing seemed to happen.  They were (1) where I didn't complete the popup window fields to Railwire's satisfaction, requiring me to scroll in the resulting error screen to the point requiring correction, and (2) where Railwire actually did insert a line referencing my image in the editing box, but it was down at the bottom and out of sight.  This latter situation required a cut-and-paste by me to put the image where I wanted it. 

Also, scroll up in the thread to my post where I illustrate an example Railwire popup window (Reply #7).

MH

[nkalanaga]

"OR, you can simply type img at the start of your photos address, encasing it with square parentheses...these ----> [ , and type /img at the end, likewise encasing it with square parentheses...these ----> ["

That's how I've been posting photos since I started on the Atlas forum.  Just type, or paste, the photo's URL between the bracketed codes.  It also works for actual URLs, using the same format, but with "url" instead of "img". 

If the photo is uploaded to TRW I'll use the "insert photo" buttons, but that hasn't been an option for very long.

[Loren Perry]

Here's a new photo (now that I'm learning how to post them) of my 4-8-4 showing the position of the traction tire that was the source of the problem. The geared driver axle is the one ahead of it.

[Loren Perry]

One more tidbit of useful information for steam aficionados - this same 4-8-4 once again started derailing as it entered my curving tunnel; I thought I had fixed it with the traction tire but there was another problem.

Inspecting the track work inside the tunnel opening with a flashlight, I spotted a short section where the rails' curvature isn't as uniform as I had thought. There was a short section where the curve radius increased a bit and then reverted back to a smooth contour. This increase was just enough to cause the big rigid wheelbase engine to climb over the outside rail when under a load. The problem's inconvenient location would require massive amounts of work to correct, so I decided to turn my attention to the engine instead.

My ultimate solution was to take a page out of the real locomotive manufacturers' rulebook and make the pilot truck functional, i.e. have it exert a slight amount of lateral push to guide the drivers around the curve.

I did this by making a small flat spring from .003" phosphor bronze stock I had lying around. The spring is a single T-shaped piece with a small hole in the center of the broad middle leg of the "T". The hole is sized to fit closely over the threaded portion of the pilot truck's mounting screw allowing the shoulder of the screw (the slightly larger diameter section immediately below the screw head) to press down hard against it thereby locking it against the driver axle cover plate. The two "wings" of the "T" are located just aft of the screw and are bent up (or actually down in this case) 90 degrees to entrap a small projection that is conveniently part of the articulated "tiller" that joins the pilot truck to the frame. This arrangement causes the phosphor bronze spring to apply gentle pressure to the tiller when it's displaced left or right, guiding the engine frame into the curve.

After several tests under load with 12 passenger cars in tow, the engine now sails through this curve without a problem, and at virtually any normal speed. It also operated flawlessly around the rest of the layout including through turnouts of several types.

It's a very simple fix involving one small and very simple part with absolutely no surgery on any of the engine's components. It's even reversible in that it can be removed easily if desired.

[mmagliaro]

Loren,

Any chance you can post a close-up photo of the little "tiller" spring part you made?  I would be very interested to see it.  An effective way of guiding the front of steam locos, especially long wheelbased ones, would be a very handy thing to have in one's bag of tricks.

I understand what you mean about the radius.  It's a common problem, even on carefully placed track, to inadvertently have a small section of it go "sharp".   Radius guides help (like Sweep Sticks), but even then, the rails can shift over time.

[robert3985]

Here's a new photo (now that I'm learning how to post them) of my 4-8-4 showing the position of the traction tire that was the source of the problem. The geared driver axle is the one ahead of it.

Loren, I really hate to tell you this, but all I'm getting is the gray circle with the minus sign in it....

Cheerio!
Bob Gilmore

[mmagliaro]

If it helps diagnose this, that image DID appear okay earlier today, and now I get the gray panel with the minus sign in it.

[nkalanaga]

On my Firefox I don't even get a gray panel.  There's no evidence that a picture should be there, just the text.

If you've found a way to make a functioning pilot truck, that works better than the (almost useless) springs manufacturers have been using, PLEASE send it to the manufacturers!  That would be the greatest advance in N scale steam since decent tender pickup.

[Loren Perry]

Loren, I really hate to tell you this, but all I'm getting is the gray circle with the minus sign in it....

Cheerio!
Bob Gilmore

Hi, Bob -

Lord knows I wish I could figure out what causes that, but the photo opened up perfectly for me just now. And it's opened up for me every single time I previewed it and posted it in the time since I first attached it to my message. I've seen that circle with the minus sign on other peoples' posts, too. But a day or even an hour later, there's a photo in its place. The internet is truly a wretched hive of scum and villainy.

[Loren Perry]

Hi, Max -

I'll see if I can shoot a photo of the device later today. It's so tiny and my camera's macro feature is so limited that I may have to get imaginative. And my imagination isn't what it once was, sad to say.

Loren,

Any chance you can post a close-up photo of the little "tiller" spring part you made?  I would be very interested to see it.  An effective way of guiding the front of steam locos, especially long wheelbased ones, would be a very handy thing to have in one's bag of tricks.

I understand what you mean about the radius.  It's a common problem, even on carefully placed track, to inadvertently have a small section of it go "sharp".   Radius guides help (like Sweep Sticks), but even then, the rails can shift over time.

[Loren Perry]

Here are some photos of my pilot truck centering device. The first photo shows the fully assembled unit in place. I'm trying to figure out how to post several photos in one post but am running into roadblocks.

[Loren Perry]

Here's a photo showing the parts for my pilot truck centering device. The "wings" on the T-shaped spring are bent up vertically and are hard to see in this shot. There's just enough space between them for the rear projection on the tiller to fit between them. Also, the hole in the spring is just large enough for the threaded portion of the shoulder screw to pass through, but not so big to allow the shoulder to do so.

[Loren Perry]

This photo shows the spring positioned over the screw hole with the tiller in place, ready to be secured with the shoulder screw.

[Loren Perry]

And finally, here's the fully assembled device with the screw in place. When sufficiently tightened, the screw's shoulder engages the sheet metal spring and holds it from rotating. Notice how I've squeezed the "wings" of the T-shaped spring so they tightly enclose the tiller's rear projection for minimum freeplay. It only takes a very slight amount of nudge for the device to be effective. Even though the pilot truck frame has an elongated hole for the mounting screw at the front end, the tiller still manages to engage the truck when it's most needed, ie. on tight curves. You may need to tweak and adjust by trial and error to get the right amount of force for your engine's application. If your engine has a tiller with no rear projection, it's still possible to make your spring fit the main arm of the tiller forward of the screw.

[mmagliaro]

All minus signs, I'm afraid.   Sigh.

Loren, I'll send you a PM with an email address.  Send me the photos directly, and I'll rehost them.