The driver quartering and bent side rods are all definitely worth looking into. I had the same symptoms on one of my N scale Bachmann locomotives. The problem with my engine was the eccentric crank on one side of the engine. The screw had loosened allowing the crank to rotate to a position where it would jam the valve gear at one point in the rotation. I readjusted the eccentric crank and tightened the screw and the problem was gone. It might be worth a look....
Another possible reason for jamming not mentioned yet is that one or more of the siderods may have had their holes worn to a larger size. On steam engines that have a lot of heavy use on them, this is a real possibility. Check to see how much slop there is on every siderod. It shouldn't have much at all. If there's too much slop, it can cause the wheels to be out of alignment. If that's the problem, the only real solution is new rods. Bachmann should have replacements for most types.
Paul A. Cutler III
To the OP:
snjroyYup, I tried CA on one of mine and it did not hold.
That's why I suggested knurling the axle a bit. Note the "a bit" part. Otherwise the wheels may be difficult to get back on or they won't be square on the axles.
There is nothing wrong with using a bit of CA too. It can't hurt unless you get it in the wrong places.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
Yup, I tried CA on one of mine and it did not hold.
Southgate As already noted, out of quarter is your most likely problem. Older Bachmanns are notorious for this.
As already noted, out of quarter is your most likely problem. Older Bachmanns are notorious for this.
If you take it apart, take a look at the motor. If it is square and flat, that would qualify as an "older" bachmann. All of mine are now part of the "parts" box...
Hi DCHO:
Bent connecting rods can definitely cause the problems you are experiencing. They don't have to be bent by much either. Out of quarter wheels will also mess things up severely.
My suggestion would be to take the locomotives apart so you can push the drive wheel assembly by hand. The motor has to be removed. You should be able to push the drive wheel assembly back and forth on the track using very little force. It should roll freely in fact.
If it binds keep the wheels in that position and carefully examine the connecting rods to see if anything is touching. Like I said, the bends may not be very obvious. It could also be a rivet or pin that has come loose. If you find several bent rods then you need to question how the locomotives are being handled or stored. Bumping or squeezing the rods will cause problems.
If nothing shows up there then you have to check that the drivers are properly quartered. In other words, the points where the rods attach to the wheels have to be offset by the exact amount. This can be done by trial and error but the NWSL quartering tool would be a good investment if you have a lot of steamers. It will identify any problems immediately.
If you discover that the wheels are out of quarter test the wheels to see if one or both are loose on the axle. They won't be sloppy (hopefully) but if you can rotate one of the wheels while the other stays still without extreme force then you need to tighten the joint between the wheel and the axle. This can be done by removing the wheel and slightly roughing up the surface of the axle (emphasis on 'slightly'). One method is to use a pair of ribbed jaw needle nose pliers to form slight ridges on the axle where the wheel sits. When you put the wheel back on the axle try to have it as close to quartered as possible so you don't destroy the ridges when making adjustments. A little thin CA can help but make sure you have cleaned all the oil/grease off the mating surfaces first. Quarter the wheels and then add the CA, not the other way around!
Good luck. Others' advise may differ.
It's always possible that one set of drivers is "out of quarter" for one reason or another. Northwest Short Line makes a nice tool that automatically quarters drivers. They run about $40 or so and the tool can also be used to compare the quartering of different driver sets to see which one is causing the problem.
Wayne
Modeling HO Freelance Logging Railroad.
Is there any write up or other information on how to set up or adjust the linkage on the sides of a steam locomotive. I have several Bachmann Steam Locomotives that appear to freeze up because the linkage has jamed. Is it because some part has worn, linkage has bent slightly or other reasons. How can it be corrected? I would appreciate any ideas.