I am sure that this topic has been discussed before, but what do you all do to minimize derailing of the front truck on a steam engine?
I own 12 different steam engines of various wheel configurations from three different manufacturers (Bachmann, BLI and Proto) and several of them derail from time to time, from location to location on the layout. None of my two dozen or so diesels ever derail. Derailments usually occur at turnouts but also on curves. I have done as much as I can in terms of rail alignment.
I want to put weights on the front trucks, but my LHS guy says that this should only be done as a last resort. He says that a lot of guys wrap solder around the axles to add weight. I want to put weight on the truck itself.
What do you all do to minimize derailing of the front truck on a steam engine?
Rich - I had the same problems most of which were caused and cured by working on track alignment vertically and horizontally. I had several trouble spots at turnouts hard by the end of a curve and the track gage went out there as well as some kinking across the top of the rail there and where I transitioned from an incline back to flat. The latest Scale Rail advocates putting thin weights on the pilot truck to avoid having the pilot lead the rest of the rain off the rails. I really like the wrap the axel idea from your LHS as it will get the max weight n the axel and as low as possible to keep things glued down. You probably want to try both track and truck solutions. Good Luck. J.R.
Well first I would determin if the locos in question are operating on compatible track. In other words, are you trying to run a loco that requires a 22" minimun radius curve on an 18" radius curve and #4 turnouts. Since you’ve already checked your track work, the next step would be to be sure locos wheels are in gauge. Do the locos derail on both left and right curves and turnouts or say, just left. Is the truck free to swivel the necessary distance. Some locos use a “centering” spring to keep the truck centered and some use a spring to put some of the locos weight on the truck. Are these springs binding or missing? Are the wheels free to roll or are they sliding.When they roll, are they rolling true, no wobble from a bent axle? Most leading trucks on steam engines have the mounting screw some distance behind the truck and this causes the loco to be pushing the truck ahead of it. This causes a situation much like haveing truck mounted couplers on the trains cars and trying to back them around curves and turnouts. In the case of a four wheel leading truck is the tab or tunge the mounts it to the engine bent, causeing the front axle to run light or one side to run light? Also, check the wheels for nicks or burrs on the flanges. Because of the nature in which the leading truck is mounted, as mention earlier, the truck is rarily centered on the rails, even on straight track, so those flanges have to be free of flaws, a nick or burr will “grab” a rail and ride right over it. Sometimes weight must be added. For 2 wheel trucks, solder can be wrapped around the axle and for 4 wheel trucks and some 2 wheel trucks a penny can be added for extra weight. Oh, almost forgot, make sure the wheels are clean. Hope this helps some. Ken
Make sure the mounting mechanisms for the leading and trailing trucks are very free in all three directions. I have had to open up the mounting screw holes and/or the arm to truck mounting holes in a lot of locos. On only one of three BLI Class A’s, the 4 wheel trailing truck kept popping off the track. This very unique mounting arrangement had absolutely NO yaw freedom at all on this one steamer. Up and down and side to side was fine, but twist was zero. Freed that up that and no more problems.
Most brass steam engines had a sloppy fitting post screw for a front truck mount, and this was one problem they rarely had - of course if you tried too sharp a radius they either shorted out or popped off the rails. The new generation of steamers invented this issue themselves.
As long as the truck’s wheels are free to follow the track, whether it curves, twists, or goes up and down a little, you should need only the weight of the wheels to hold it on the track. Try shoving the truck by itself along the rails. If you can’t flick your finger and send that truck all by itself flying (within reason here ! ) thru any of your trackwork, something basic is wrong (wheel gauge, warped truck, untrue wheelset?).
Of course the rest of the engine may not make it thru some trackwork the truck can, once you get this taken care of, but that’s for another day.
Good luck.
On Spectrums with this problem, remove the front truck screw, lift the pivot bar off the pivot, and remove the brass leaf spring underneath.
Bend the leaf spring till it describes a 45 degree arc, reassemble the front truck and test. So far, three of four here do not require adjustment from the factory, and a 45 degree curve in the spring resolves the problem on most of the rest. One loco has close to a 90 degree bend in the leaf spring, that’s probably excessive, but it stays on track and doesn’t seem to cause any problems. If it did cause problems, I’d expect to see less pulling power to begin with, and the driver set derailing more frequently with more excessive spring curvature, if you begin to see any of this, flatten out the spring a bit.
On 4-6-0’s the pivot bar is a little hard to remove, it binds between the pivot screw housing and the gearbox. Working it around a little bit and a steady but not excessive pull gets it in and out.
Also the pilot truck needs to “float” if it doesn’t then its to stiff.Also after checking your track and lead truck then add a small piece of FLAT weight…Be sure it doesn’t bind or hinder the lead truck in any way.
I have one steam engine, a brass consolidation by Akane, whose lead truck kept derailing whatever I tried. So I took the easy way out and now operate it tender first only. No more derailings and it isn’t unprototypical.
I will take another angle… The above posts hit on theissue of track work. Usually, this is the case for the front trucks. If that isnt practical, and you decided to add more weight, maybe try this instead…
Instead of adding weight, usually they have some sort of spring device. If it is a tab, or lever spring, the fellow above had it right, take it off and some more bend to it to provide a little more presure… Remember, just alittle…
if it is a coil type spring, add maybe a small washer or two to shorten the distance and will add tension to the spring, providing more down force.
I have found that all of my lsteam ocomotive derailments, regardless of which axle comes off, is the result of improperly aligned track. Often it is at a change of direction, whether in a turnout or on a curve, and the culprit is usually a dip in the track that you can’t detect without a straightedge laid along the axis and a back-lit where the railhead meets, or should meet, the straightedge. In every case, except for one ( a BLI Niagara), my handiwork, or lack thereof, was the contributing factor. In the case of the Niagara, backing out the mounting screw for the front truck did the trick.
I agree with Crandell, the truck should not come off unless something causes it to come off, a dip, a pinch, a burr the end of a rail or a picked point…but…
Two of my Spectrum ten wheelers came with springs that had curves in them. The other two were dead flat, flopping around, not even staying lined up with the truck because the tab wasn’t engaging the slot in the top of the truck.
Now I COULD devise a straightedge and make all the curves, which all the other locos like just fine, describe Euclidian lines in 3d space, but what I actually did was put a curve in the factory flat springs.
Yet to go, a wire harness that is black on three locos and multi-colored on one, a blob of superglue that missed a handrail post, and a tender plate and cab roof that either got painted just as the reservior ran dry or was dipped in vinegar just before the paint cured. Chinese quality control, you just have to love it.
