I have two ho scale steam engines where the front truck floats but is so light it derails easy. Any ideas on a fix?
[#welcome]
You probably noticed that your first few posts are moderated, delaying the post times a bit.
On your question, can you be a bit more specific as to what the two models are? Brand? Wheel configuration (such as 2-8-2, etc…) of each?
Does it always occur on cuves? Turnouts? A certain particular spot on the layout? Sporadically?
It’s a bit hard to answer the question as posted, as it could be any one of a number of issues causing it, and not all have the same fix.
Ted,
Two things to try…
- Loosen/tighten the front truck spring screw so that there is more downward force onto the rails
- Replace the front spring with a slightly stronger one
Tom
This is an annoying problem that I’ve faced many times… Here are a few options:
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Many locos will have a spring that forces the front truck downward. Make sure the tension is there and that nothing prevents it from functionning properly. The configuration will change from loco to loco. As mentioned above, in some cases it is held by a screw that can adjust the spring pressure (I believe this is only for four wheel configurations).
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If the truck is held by an extended arm (vs. a screw), and that there is no spring involved, you can carve a piece of weight and glue it on the truck. I’ve done this several times with success. You need a good fit that won’t create a short with the frame.
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Make sure the wheels are turning freely.
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You can also look at the track to see if the culprit is from that source. Uneven track (laterally) can “rock” the truck in curves and create a derailment. Adding shims under the track can bring it back to level. If a turnout is involved, you might have to file something off to prevent the truck from jumping.
Simon
Make sure the wheels are in gauge. Being light, they dont track well so gauge is important there. Same goes for the track at the points it is derailing. the rail could be out of gauge.
Shane
Unlike prototype model trucks carry no weight. Technically they carry the weight due to compression of any spring between the truck and the chassis but if you press upward on the sprung truck against the chassis you’ll quickly realize that’s pretty much theoretical.
So, the truck tends to bounce if a wheel hits any irregularity in the track. Even quite small irregularities can derail a pilot truck, or a trailing truck if reversing.
There’s not much room typically for weighting the truck either. I’ve tried that on a Spectrum Santa Fe without much success. Mind you that loco may have other issues I haven’t identified as yet.
Long wheelbase driver sets can pry a pilot truck out of the gauge if the pilot truck wheels aren’t perfectly engaged with the rails.
So, if the drivers don’t derail but the pilot truck does first check if this happens at the same spot on the track. Run in reverse and see if the trailing truck also derails. If it also derails then suspect your track. If the truck seems to derail “anywhere” then check the truck carefully as others have mentioned.
Trouble spots on track include frogs not quite level with the rails, guard or wing rails too high or a bit tight to the closure or stock rails, kinks at rail joints that you haven’t really noticed and, if the locomotive is new to your layout, maybe a radius too tight for that model.
Likely sources of trouble, and if it happens at certain spots, it’ll happen to more than just this one steamer if it’s that particular spot…probably…:
a. rail heights too far apart across from each other. Often it’s the outer rail on a curve that is a bit too low. The longer steamer frame with drivers under a good chunk of it, means the two trucks literally dangle at time if the entire frame is forced high on the outside just as the lead axle on the lead truck encounters a low spot two or three inches ahead of the drivers;
b. the axle on the truck, or both of them if there are two, could be just that much out of gauge to cause trouble;
c. whether spring exists or doesn’t, the part of the tongue that the screw goes through to secure the truck to the frame is bent, deformed, torsioned/twisted, has flashing that causes binding in azimuth…not sure. Even the spring, itself, might be digging in or binding and preventing the truck tongue from swinging enough, or smoothly;
d. the screw is too tight, or it could even be the wrong screw…! Happens;
e. there is meant to be a spring, but there ain’t one. [:S]
f. the lead axle of the drivers isn’t seated in the bearing boxes quite correctly. It might mean that one driver lifts and tilts the frame just enough that, with the screw and spring in place and in good order, the truck frame gets horsed at an angle just enough to make a flange lift and clear the rail head (not likely, but it’s worth determining if all else fails).
I do feel that some weight might help, but it is worth taking a cold and sober look at the loco seated on a mirror with good light all around. Does it look like all axles are in their proper places, no wheels
If you have pretty much bulletproof trackwork, get yourself a steamer and discover how much you’re wrong. I’ve done this several times. Yes, steam engines ARE more fussy and will find slight imperfections.
When you fix your trackwork to accommodate all your steam engines, then you will have accomplished something.
One thing you can do for those pilot trucks and sometimes trailing trucks is add a bit of extra weight to the trucks themselves.
Lots of good info and fixes !
Years ago I had a Spectrum 2-8-0 that was pretty sensitive. I got a piece of solder and wound it around the lead truck axle. It definitely helped, but of course if my track had been perfect, etc., etc., the problem would never have happened.
Those pilot trucks and trailing trucks on HO scale steam engines are terrible. Shame on the manufacturers who fail to design trucks that will hold to the rails. The pilot truck is typically bad, and the trailing truck is typically awful. That trailing truck typically rides the rails like a handful of Mexican jumping beans.
The problem is lack of weight to force the trucks down onto the rails. The solution is added weight or strong(er) springs. Those trucks, especially the pilot truck, hate curves and detest turnouts.
I have actually sold more than one steam engine because I could not keep the trucks on the rails without derailing here and there.
Rich
I think that many of us run our trains on very tight radius, which causes all sorts of problems. I run my steam on 22" radius curves and I’ve done a lot of tweaking to get my steamers to run on them.
Simon
8 drivers rarely cause issues whereas 10 drivers do. My worst derailers are my Spectrum Santa Fe and my Mantua 2-6-6-2 tank. On the other hand I have a Mehano Santa Fe which will run all day around the same curves and over the same turnouts. I really like those old Mehano products which came with RP 25 flanges and really good drives.
My brass locomotives have zero problems with pilot or trailing trucks derailing. The pilot truck on my Spectrum 2-8-0 never came off of the rails, nor do the “2” or “4” of my Spectrum EM-1 2-8-8-4 locomotive.
I have not run my Mantua 2-6-6-2 or IHC 2-10-2 enough to know about these yet.
This is not a problem I have had to deal with.
-Kevin
Count your blessings!
Rich
My first HO steam locomotive was a Tenshodo 0-8-0. The person that gave it to me said that the 0-8-0 wheel arrangement was the best because it had enough drivers for reliable electrical pick-up, and the pilot and trailing trucks would NEVER derail.
He was right!
-Kevin
LOL. Good one, Kevin. I was tempted, before seeing your reply, to suggest an 0-x-0 switcher of some sort, but you beat me to it.
Rich
I found exactly the opposite: they were never on the track… [(-D]
… Which probably explains why there are so many Ebay items with missing front trucks [:$].
Simon
Add as much lead weight as will fit to the pilot truck. More is better. Solder is nearly as dense as lead and can be wrapped around the pilot truck axle.