Tweeks of the Trade needed to make Brass Engine run smooth

[Paul3]

Another thing to check is if the drivers are on the axles squarely.  I've seen some that are on crooked, and it makes the loco "hunt" going down the track (shift side to side).

As for general tweaks, make sure you try to balance the loco over the center of the drivers.  IOW, put a triangle or a pencil on the table, and (in the case of 4-8-4) put the loco on the pencil in between drivers 2 & 3.  In a perfect world, it should balance.  Usually, brass steam is tail heavy due to the motor and a large firebox.  Add lead to the smokebox end until it's more balanced, and your brass steam will pull a lot more.

I have one friend who tweaks his brass steam by putting upsidedown in a cradle, then running it with the bottom cover off while the loco is connected to a digital ammeter.  He then shims each driver with brass strips while it's running all while he's monitoring the ammeter.  When the ammeter drops, he knows he's just made the loco a little more square as it now has less resistance.  If it increases, he knows he's made it worse.  Once he does all he can, he permanently fixes the shims in the journals.

Paul A. Cutler III
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Weather Or No Go New Haven
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[twhite]

Fergie--

Disassemble the gearbox cover so that the the worm gear is not connected to the driving axle. Put the locomotive on a flat piece of glass and push it back and forth.  If you have jerky movement, it could be that your side-rods or eccentric valve gear are hanging up someplace.  If so, you can cure side-rod hangup by VERY GENTLY using a circular file to 'open them up' a little.  Or, in 'spreading' the two center drivers, you might have put one of them slightly out of quarter--most brass wheelsets are pressed on.   And frankly, since it's a Northern, the Mfgr might have put those center drivers just a little narrow to enable it to take sharper curves without binding (yes, it happens, my M-67 4-8-4 has center drivers just a little narrower.  I left them alone, as it doesn't affect the tracking abilities at all. 

Now, if it's running freely after disconnecting the gearbox, re-assemble the gearbox and turn on some power to the mechanism.  If it's still running jerky, you may need to do the following:   

Check the connections on the shaft between the motor and the gearbox--a 'floating' gearbox is pretty standard operational procedure with a lot of brass manufacturers, so there should be no trouble there.  If it's a neoprene shaft connection, it might need a little adjustment either back or forth to eliminate 'surge'.  If it's an adjustable NWSL/Hobbytown-type connection, with a 'slider' between the shafts, it may also need adjustment.  There should be a very small screw on the motor shaft housing to do this. 

Hopefully, one of these should help cure the jerky running.  As I've said before, brass is VERY forgiving to work with, but it does need 'tinkering'. 

Hope this helps.

Tom      

[CAZEPHYR]

I finally got my CPR 4-8-4 to run yesterday but can't say I'm overly happy with it's running. It's a Samhongsa built in the late 70's. I've cleaned it, lubed it and checked the wheels to make sure they meet NMRA guage standards (Drivers 2 and 3) had to be "spread as they were a tad tight. They are quartered but... The engine runs as if it was hobbled as it has a slight wobble and odd occassional stutter to it. I noticed the gear box on axle three is free floating unlike my Samhongsa 4-6-4 would this mke a difference? I also notice that the alignments in Drivers 2 and 3 are slightly out and were out before I spread the wheels. by the looks of the wear I think this Locomotive has less then 100 hours on it and that may even be a liberal amount of time as there was no tire wear just a small bit of crud on the wheels. The srings under the bearing boxes are all present.

 

Fergie 

Anyway yhe question is what are the steps to get a brass engine running smoother 

Fergie

The first Samhongsa models were hit and miss when it came to good running qualities.  The details on the early models were fair, but the soldering quality was less than great also.  Samhongsa really started to build quality brass in the early to mid 1980's and continued to build quality models until they got out of brass manufacturing three years ago. 

I hope you are able to correct the problems and enjoy the model.   The gear box should not be free up and down if that is what you mean.  That would indicate the springs are missing in the main driver and would cause a lot of running problems, since it would be out of alignment with the other drivers.  

 Cheers

 

 

[dinwitty]

a couple or so of things, make sure no side rod action is binding on anything, and the motion everywhere looks good.

The other issue is quartering. Have one siderod full up or down then look at the other side, if it looks like a wheel iss slightly off 90 degrees, it will need quarting. If you have NWSL's quarterer you will be fine.

 

  

[arkansasrailfan]

It appears that some part has bent, most likely the frame. Some axles may be bent, and new springs need to be in stalled

[Fergmiester]

I finally got my CPR 4-8-4 to run yesterday but can't say I'm overly happy with it's running. It's a Samhongsa built in the late 70's. I've cleaned it, lubed it and checked the wheels to make sure they meet NMRA guage standards (Drivers 2 and 3) had to be "spread as they were a tad tight. They are quartered but... The engine runs as if it was hobbled as it has a slight wobble and odd occassional stutter to it. I noticed the gear box on axle three is free floating unlike my Samhongsa 4-6-4 would this mke a difference? I also notice that the alignments in Drivers 2 and 3 are slightly out and were out before I spread the wheels. by the looks of the wear I think this Locomotive has less then 100 hours on it and that may even be a liberal amount of time as there was no tire wear just a small bit of crud on the wheels. The srings under the bearing boxes are all present.

 

Fergie 

Anyway yhe question is what are the steps to get a brass engine running smoother