My Last Locomotive Project

[Woody Elmore]

Jon - PFM United engines were the Cadillac (Lexus?) of brass engines. The gearbox should be fine.

You are a brave man in wanting to disassemble the engine and you probably don't need to do that. If you do be careful with the driver springs. They are almost impossible to replace. If you take the drivers out of the frame you can disassemble the gear box and clean out all the grease and gunk. Be especially careful with the gearbox - there may be tiny thrust washers at each end of the bearings. Clean the gearbxs, regrease it and reassemble it. I've done it dozens of times and I am a complete clod.

Change the motor. Mount the can motor in silicon (not the colored stuff.) Also, you can use a piece of old bike inner tube to isolate the motor. A buddy has converted several brass engines to DCC - he uses silicon and has no problems at all.

You might consider a bigger weight once you put in the new can motor.

Headlight and other items are probably available from Cal Scale.

Good luck - you'll do just fine.

[ebtnut]

Jon:  Really, they are part of the same path.  Replace the motor and use the universals in place of the rubber tube as the first step, along with cleaning and relubing the present gearbox.  If that doesn't work as well as you would like, then you can choose to go on with the major overhaul either sooner or later. 

Note:  If you find there isn't enough room to use universals between the motor and the gearbox, you can replace the old rubber tube with a piece of model airplane fuel line tubing, which is not prone to deterioration like rubber is.

[jonathan]

Great advice, gents.  Thanks.

Got the loco off layaway today so she's officially mine.  Perhaps Santa will send me a gift card so I can start gathering parts.

For now I'll start making a parts list, and do some measuring.  Need to look for all the little details (lenses, jewels, paint colors, vinegar, etc.).

Gettin' excited.

Regards,

Jonathan

[FFJOHNL312]

Jonathan:

I'll echo what others have said about the PFM/United locos. I had DCC put into one of their PRR L-1 2-8-2's, which was smooth running to beign with, but it develops an intermittent short in spots, one of those that wouldn't have been evident on DC.

Good find and good luck with the project.

John

[jonathan]

I opened up the gearbox this morning--not too dirty, and no wear I could detect.  I see what all of you have written about the PFMs.  The tight tolerances and over all condition is excellent.  I think I'll wave off from the new gearbox.  I noticed a slight back and forth movement of the worm, so I added a couple of thin thrust washers (leftover from Athearn parts).  Now there's no slop and everything moves quite freely.  I will get it cleaned up, and take a few pics when I get a chance.

I expect a little noise from the metal worm and metal axle gear.  Perhaps the old toothpaste (or jewellers rouge) trick will take care of that.

Also I found a very slight bind when hand-turning the mechanism.  It went away when I disconnected the valve gear.  It's hardly noticeable, but I know where to look during the reassembly process.

Thanks for the great advice so far.

Regards,

Jonathan

[GN.2-6-8-0]

Jonathan
If you have or can find a July 1991 issue of Model Railroader you'll find a great artical called Diode Lighting Made Easy,in it there is a piece on tender back up lighting using 2 Diodes and a bridge Rectifier to light a 1.5v bulb,you will have to insulate the drawbar pin but thats not to difficult.
I've used this circut and it worked like a charm on my GN.PFM 2-8-0

[jonathan]

I will most assuredly look for the article.  I like lights.  Thanks.

Here's the gearbox all clean:



Turns like silk in my hand.  Hopefully, the loco will like it, too.  Note the added thrust washers.  Really made a noticable improvement.

While I decide on the right motor,  I'll start on the smokebox next.  It needs the most attention.



Regards,

Jonathan

Addendum:

The frame is pretty much down to parade rest:


I scrubbed all the parts, including removing the paint off the spokes.  The marks on the inside of the tires are sharpie marks so I'll know which side is the right side.

The frame is soaking in vinegar as we speak.  My intent is to paint the frame, and the underside of the tender, grimy black.  I'm hoping the paint will stick, even if I don't get all the tarnish off.  The other trick will be to file paint off the parts that need to conduct the current to the motor.  OK, I need to take the weekend off from building.

R, jev

Now we're getting somewhere...

[jonathan]

A little update:

With a needle file, I removed the paint so the wheel bearings can carry the current to the frame:



I used a tiny drop of gear oil to hold the springs in place.  This provided just enough stickem so I could put the wheels back in place, all in one shot.  Still, it was a bit tricky getting the springs lined up just right.



Here's the underframe all put back together:




Regards,

Jonathan

[J3a-614]

Black frame, tires, and rods--she's looking good already!

I was looking at the original photos, and was wondering how you were going to mount a front coupler.  An engine like this needs one, and I wasn't sure I saw how it was supposed to go on.

[J3a-614]

Just a tiny, tiny nitpick--I'm not sure, but it looks like you may have one rod set on upside down or something.  The rods on the left side have their grease cups (small extensions on the rods at the crankpins, this simulates the grease cups used for crankpin and rod bearing lubrication) facing downward.  These would normally face upward.

Still, looking forward to seeing what you get to do with this veteran. . .keep it up.

[jonathan]

J3a-614,

Thanks.  I marked the rods on the back, when I removed them. When I remounted, I thought I got it on right, but I'll check again. To tell you the truth I can't tell up or down on the rods. Both sides look the same to me. The "cups" appear to be on the top AND bottom. Will revisit...

The front coupler area does have two holes for mounting a KD coupler box like the tender.  I tapped 'em for 0-80 screws. I used some leftover crankpins. Looks like it will work:



OK, here's a big question, for which I need some advice.  I have looking at how to mount a new motor.  I understand silicon is the way to go, but you need something to put the silicon on, so...

Here's one I idea where I mount ON TOP of the motor. The advantage is I can fashion some sort of bracket to attach to the gearbox. You see, with a universal type connector, you need to counteract the rotating force on the gearbox (back and forth). The disadvantage is I only have 40mm of length from the mounting screw to the gearbox axle. Like this:



The more traditional method has the mounting bracket on the bottom. Then I still need to fashion a separate bracket (torsion bar?) to brace the gearbox. Like this:



Of course, electrical isolation is critical, and I'm keeping that in mind. Oh, the motor brackets are pieces of an old Pittman motor I took apart, just out of curiosity. Never throw anything away... ever.  

Thoughts?

Regards,

Jonathan

p.s. I could keep doing the rubber tube connector, but that's a last resort.  jev

[Woody Elmore]

Jon - you reassembled the engine before I could give you a suggestion about the frame springs. It was common practic to put a piece of sewing thread through the spring. This was helpful because the springs had less opportunity to fly away. Once seated with the driver the thread was pulled out. The other tip you already did - put something sticky on the spring to hold it in place. Years ago they used Pliobond or Walther's goo. I doubt if they still make the stuff.

I suggest you try the mounting made from the old motor. You have nothing to lose if it doesn't work. The problem is lining up the motor armature with the gearbox. I also second the suggestion of using model airplane fuel line. The stuff is indestructable and a few feet will be enough for all your future projects. Oh sorry - this is your last engine project (until the next one!)

Merry Christmas to you and yours (and to all those who follow Jon's adventures!)

[J3a-614]

I always thought Walthers' Goo was one of those products that had the most appropriate name:

http://www.walthers.com/exec/productinfo/904-299

Pliobond is still around, too:

http://www.walthers.com/exec/productinfo/255-49101

http://www.walthers.com/exec/productinfo/255-49102

And thanks for the Seasons Greetings, and Merry Christmas to all as well. . .

[RAM]

Years ago they had small bottles of pliobond.  Then I think they took that off the market.  Can you buy small bottles now?

[Doneldon]

jonathan-

I have a cheapie ultrasonic jewelry cleaner which I use to clean models before painting.  It enhances the effectiveness of just about any process you might use to clean, degrease or etch a to-be-painted surface.  Harbor Freight sells two of these.  One is too small for other than the smallest models but the larger one will hold most HO locomotives and freight cars.  Longer locos and passenger equipment might need to be bathed half and half.  I doubt if these machines (well, I have only the larger one) would stand up to regular use in a jewelry store or something, but they're fine for the occasional bauble or train project.
                                                                                                                                                                                                          -- D