Unused Engines

[jack6020]

I have many n gauge Bachman engines and when I Try to use them I have trouble getting them to run. What should I do to run an engine that has been stored for a year or 2? They seem to lock up at the worm gear drive gear connection.

[Ken G Price]

First thing to do is clean the track and the engines wheels.
If not clean you will get the results you have seen.
There are many things that have been written on this forum
and the other N-scale forums on how to do this.
S search should give you results.

[skipgear]

How old are they?

If they are white box locos then there probably isn't much you can do. From what you describe, they have cracked gears which is very common for locos of that era.

[James in FL]

If something is locking at the worm gear you've got problems.
You need to see what is moving/shifting to cause that, could be the motor moving, or the motor shaft, could be excessive slop in the drive could be something more.
Run them without the shell and get your eyes down on it.
Shims are easily made from blister packaging on most anything you buy. Finding the right thickness plastic to use is mostly trial and error if you have nothing to measure it with.
Calipers are a good investment.

Are you absolutely sure the problem is at the worm?


Good luck

[jack6020]

Thanks I'll try that.

[Desertdweller]

A great deal depends on what condition they were in when they were put away.  It takes very little foreign material to get into the gears to lock them up.  Try gently turning the motor armature with your fingers.  If the gears act like they are binding in one direction, try rotating the armature in the opposite direction.  You might be able to back an obstruction around to where you can pick it out with a straight pin or tweezers.

N-scale locos especially are vulnerable to fibers getting into the pickups or gears.  In a worst-case scenario, fibers (like carpet lint or hair) can get wrapped around axles or gear shafts.  If you determine that is what happened, your only option will be to disassemble the gear drives and trucks and clean them out.  If you do that, keep track of all the parts and where they go.  I would suggest doing this in a shallow cake pan to keep all the parts together.  If you have an instruction sheet with one of the units, it will be a big help as it will have an exploded drawing.

The Bachmann locos use a split frame, with spacers and insulators to keep the sides the right distance apart and to keep them electrically isolated from each other.  Pay special attention to where the clear plastic insulator goes between the motor and the frame, and where the copper contacts ride between the trucks and the frame.  It is easy to get these trapped between the frame halves on assembly.  They ride below the frame, not inside it.

The trucks are held on by the shaft that the big gear turns on (the one that engages the worm).  To get the trucks off, take a metal pin or something similar to use as a drift punch.  Push it against the end of the gear shaft just above the truck, from the side of the frame.  You should be able to push it clear out the other side, freeing the truck without having to disassemble the frame.  Try to avoid having to take the frame apart.  When you go to put the truck back on, you can use your little pin tool to line the hole in the gear up before you push the shaft back in.

If the locos have only been put away for two years, that is not long enough for the grease to have hardened.  You will only have to remove the grease and re-apply if the grease is dirty.

Check the wheel treads for black crud.  This will keep electrical power from getting to your motor.  I like to gently remove it with a narrow strip of #400 sandpaper.  Your older locos may have black traction tires.  Make sure you don't accidentally mistake them for crud and sand them off.

Another thing to check is the copper wipers that rub against the back of the wheels.  Sometimes lint can get jammed in there and prevent power getting to the motor.  You can usually clean that out with a hobby knife blade or tweezers without needing to take anything apart.

Good luck!

Les