3/4" Scale Little Engines 4-8-4 Rebuild

[H&NERY]

I finally got to spend some time in my shop yesterday and began working on my 3/4" scale Northern. It ran on air when I purchased it but the valve gear was poorly made, so now I am in the process of rebuilding the running gear. About a year ago I purchased another one of these off of the for sale section on this board so I am Kit bashing so to say and going to make one out of two. I am working on cleaning the frame and drivers up for reassembly. The 1st locomotive I had was not roller bearing equipped on the drivers but the second engine I bought was, so I am using that frame with the roller bearings.
Yesterday I dropped out the drivers and cleaned the frame up in the blast cabinet at the shop where I work. Today I am going to press the drivers off the axles so I can clean them up and inspect the bearings and races. Then it will be time for a new coat of paint before assembly.
Marty Knox built me a new boiler for this engine last summer, I have posted some pictures of my progress.

[Andypullen]

Looks good Henry...Almost looks like the old photos from locomotive shops of olde...

Andy Pullen

[H&NERY]

Work on the 4-8-4 continues slowly, the frame and drivers have been sand blasted and painted, Now they are ready for assembly. Watching all the other progress on this site helps keep me motivated, I just wish I had more time to spend on this, I can't wait for winter to get here again, it's the most relaxing thing I have found to do. Thanks, Zach

[KidAmato]

Henry,
Very nice job! Keep at it, I´m sure it will turn out to be amazing! Good luck with your bash/build, can´t wait to see more progress on it!!!


Best wishes,
Nico

[H&NERY]

I managed to find some time to spend in my shop yesterday. Working on fitting the Roller Bearing journal boxes. One question, what is the proper way to get lubrication to these bearings?

[RET]

Hi,

I'm not sure, but it looks like the bearings you have are tapered roller? If so, tapered roller bearings are probably not the best choice for this application unless there were two opposed bearings in each axlebox to take the bearing thrust load, otherwise it is difficult to avoid end float between the cup and the cone.

Anyway, whatever they are, the most important thing with any rolling element bearing is to keep the dirt out. If you can do this successfully, they should last forever. Grease lubrication would be my choice because like car lubrication, the new grease forces the old grease out and any dirt is carried with it. A working locomotive chassis is a dirty environment and the bearing internals must be protected from that environment.

This is just my recommendation. Best of luck, looks good.

Richard Trounce.

[kenrinc]

tapered roller bearings are probably not the best choice for this application unless there were two opposed bearings in each axlebox to take the bearing thrust load, otherwise it is difficult to avoid end float between the cup and the cone.

It was standard practice on the LE 3/4" Northern if I remember correctly. They are shown in my old LE catalog (circa 80). There was an interesting way of adjustment from the inside. Hard to see in these pics.

Ken-

[H&NERY]

To adjust the bearings there are 4 little tabs that fasten to the bolts that hold the journals together, and when you tighten them is pushes the race closer to the bearing, pretty ingenious, but I think I need to fabricate some kind of seal for the bearing.

[RET]

Hi,

Yes, you should add some kind of sealing to keep the dirt out. What I would suggest is to put some kind of shield plate on each side of the bearing; it doesn't have to seal perfectly but it should extend beyond the bearing a bit on each side. If you put a grease fitting in one of the two plates, either inside or outside and use it to pump the bearing full of grease, that should work OK. This way, the new grease will push the old grease and any dirt out of the bearing and keep it clean.

A few years ago I bought a part built 7 1/4" scale "Dart," an 0-4-2 English Tank engine. I'm slowly continuing on with it. It already had the axle ends drilled with cross holes where the bearings were for oil lubrication a la Martin Evans in Model Engineer (Dart is one of his designs).

I thought this was a very good idea but that grease should be used instead of oil. I used 1" dia. needle bearings (rated for 2,000 lbs. ea.) running directly on the axles and the engine ran very freely on air. When I pumped the bearings full of grease, initially it didn't run as fast, but after a few minutes, it ran even better than before. When you pump the grease in, it comes out on both sides of the axlebox, thus any dirt would be forced out at the same time.

Hope this helps.

Richard Trounce.

[H&NERY]

I have been working on my 4-8-4 some, got the fame back on its drivers but I can't get the spring rigging to equalize the weight on the drivers. 1 and 4 seem to have all the weight on them. Any advice would be much appreciated. Thanks, Zach. I'll post some pictures tomorrow when I get to my office.

[H&NERY]

Here are some pictures.

[Rwilliams]

Always nice to see a big locomotive in 3/4 inch scale. Even in 1 inch scale a Northern is not that common.

Years ago a friend wanted more than a Pacific in 1 inch scale and proceeded to convert a Little Engines Pacific he was building into a Northern. He immediately discovered he had the same problem the full size shop forces had when trying to equalize the spring rigging. Some research at that time hinted at dumping the straight equalizer arms and making them in a slight U or V shape. A look at some full size Northern drawings in a locomotive cyclopedia helped to guide us in the new direction of equalizer arms.

The new equalizer arms helped along with shorter spring hangers going up to the ends of the leaf springs. Eventually we got it to work but never did get it to the desired level of equalization.

A better look at late steam blueprints shows the use of coil springs on the bottom of the end spring hangers to give some more adjustment. The combination of leaf springs and coil springs made the late model steam locomotives ride much smoother that their earlier counterparts with nothing but leaf springs.

Study some drawings for locomotives such as a UP, SP or N&W 4-8-4 and that will give some good ideas on how to perhaps fix your equalization issues.