Steam Experts - Help with my HO Spectrum 4-6-2

[Anonymous]

OK, so I finally got bit by the steam bug. I purchased a used Spectrum 4-6-2 that has a dead motor in it. I had some problems disassembling it, but finally I got it apart. And now the questions:

1. How can I pull the gear off of the shaft? It is an older Spectrum with a single shaft motor with one gear on the end of it. I don't care about the motor, but I don't want to damage the gear. Is there a tool out there?

2. During the disassembly process, I forgot to take notes on the placement of the side drive rods where they connect to the drive wheels. They fell off during this process and I'm not sure of the correct placement. I assume they should be placed back into the correct orientation. Is there some sort of diagram, or rule on how these should be placed.

I'm counting on you steam buffs to help this newbie out.

Dave

[Anonymous]

I've picked up a few British steamers in the same situation - mine had mangled valve gear that I replaced with parts from one with a dead motor. The tool you refer to in your first question is called a puller - it fits around the gear and pulls it gently off the motor shaft when you tighten a screw. I think North West Shortline have them, but others may also.

Secondly, the important part to get right when reassembling the loco is the quartering - the right-hand cranks should be a quarter turn ahead of the left. It's possible to buy a gauge to set this accurately which might be a worthy investment. This adjustment is imperative to ensuring smooth running - my loco needed a few days of tweaking and adjusting before it would run smoothly, now it runs better than a brand new loco of the same type I bought later!

As far as reassembling the valve gear is concerned, Bachmann UK have downloadable exploded diagrams of locos on their web site which proved of great help - they might well do the same with their US locos.

Hope this is of help, and best of luck in fixing this - I find repairing supposed "non-runners" a very satisfying task, the secret is to put the loco down and do something else for a while if it's refusing to co-operate rather than damaging parts by getting frustrated. The loco I rebuilt took the best part of two weeks to get running how I wanted, but it was worth it.

[cacole]

A gear puller is what you need to get that worm gear off of the motor shaft. Depending on how tight it has been pressed on, you might be able to get by without having to purchase a special tool. I have been able to remove worm gears without a special puller, using needle nose pliers.

Try pulling on the gear by inserting needle-nose pliers between the gear and motor and seeing if you can get the gear to move by prying on it or pulling against the pliers. If it doesn't move, then you may need to invest in a gear puller.

As far as the valve gear is concerned, the drive wheels should remain properly quartered, even if you have taken them out of the frame -- you must, however, keep them in the proper order front-to-rear. Most Bachmann valve gear is held in place on the wheels by very small bolts or screws, and there may also be washers that have to go between the wheel and side rods, or side rods and valve gear. Provided the valve gear hasn't fallen completely apart, it should not be too difficult to figure out how it fits, because it will only fit properly on one side.

The exploded drawing that came with the engine should show the valve gear placement, as well as the location of the necessary washers and screws.

[Anonymous]

Thanks for the help! As far as the drawing goes, it only shows the drive wheels completely assembled, and the resolution is not that great. There is not enough detail to show how they should be put back together.

I see what you mean about the nut on the main drive wheel. I can place the outer rod in one of several position, that is what concerns me. The quartering is fine, its just the side rod placement I'm worried about.

[nfmisso]

QUOTE: Originally posted by cacole

.... I have been able to remove worm gears without a special puller, using needle nose pliers.

Try pulling on the gear by inserting needle-nose pliers between the gear and motor and seeing if you can get the gear to move by prying on it or pulling against the pliers.

The above is highly likely to damage to the bearings in the motor, so do not use it on motors that you plan to re-use.

[ndbprr]

I have also removed worms from motors in a crude but effective manner. Cut a slot in a bar of wood or metal that won't flex as wide or lsightly wider than the motor shaft that will fit between the motor and gear. Place this accross the jaws of a vise and using a nail or nailset tap the shaft out of the gear. You should be able to repress it on a new motor the same way the railroads put tires on engine wheels. heat the gear and it will expand to where you can tap it on or press it on easily. the only things to be careful of are:
1. Don't get the motor so hot you fry it
2. pressing on a gear is not reccomended when the other end of the armature shaft is not exposed