Increasing Traction on Spectrum K4

[kchronister]

Okay, I've been an advocate of Spectrum as a good mid-priced brand. But now I find myself confronted with the reality that the Spectrum K4's don't 'zactly pull worth a hoot (okay, maybe I got spoiled by my BLI K4...).

So how to add traction. Bachmann doesn't offer traction tires for it (that I know of). Weight over the drivers is obvious, but I can't for the life of me see where to fit any... Any other brilliant ideas? Or, alternately, I'll happily hear why I'm wrong about the points I raised...

Thanks ahead,

Kris

 

[MasonJar]

Other than weight on the drivers, I think clean, dry wheel treads is the only other thing that will help you (unless you can get a working sand dome...!).

How does the Spectrum compar with the BLI? Can you give us some numbers?

I have a number of different locos that pull nothing along the lines of what the prototypes could do... And in fact, my ~30 year old 2-6-0 outpulls everything on my layout, including bigger, newer engines!

Andrew

 

[Gary Pfeil]

Don't have the model so don't know where weight can be added. But a big factor in tractive effort is the balance of weight. Which is to say you want to try to get the loco to balance on its center driver set when you place it on say a pencil. Most locos are back heavy, which results in the front drivers barely touching the rail. Adding some weight as far forward as possible (maybe behind, or inside, the cylinders) Inside the smokebox. Under the pilot. Sometimes removing some weight from the rear, or moving it forward will help. A stiff spring pushing the loco up from the trailing truck may help get the front drivers to bear more weight. Good luck.

 

[wjstix]

I was hoping that had changed with the more recent K4's, I have one of the first ones from the eighties and it can't pull too much - runs well but not much pull. Course one good thing is the PRR often doubleheaded them, guess that might work til you can get em to pull better.

Does Bowser make a re-motor/chassis kit for the K4 like it does some other Bachmann engines (like the N&W "J")??

 

[George D]

Does Bowser make a re-motor/chassis kit for the K4 like it does some other Bachmann engines (like the N&W "J")??

Yes Bowser does make a mechanism for the Bachman K4. I've got one in my "to do" stack. Anyone have experience with it?

George

 

[jim currie]

if there is a electric motor rebuild shop in your area they might sell you some balancing putty it can be shoved in odd places.

 

[kchronister]

Thanks, all. Several ideas here I'll try and report back... (But don't hold your breath, probably a few weeks before I can get to it)

 

[XavierJ123]

[size=-2]Here's an interesting tidbit about adding weight that I thought might interest you..[/size]
[size=+2]Genesis ~ is it "as real as it gets" ?[/size]
[size=-2].[/size]Before...........[size=-1]click to enlarge[/size]..............After

[size=-1]photo's by Bob Boudreau[/size]​

added 3 oz. of weightpaint drive linkageworking front couplertriangular number boardair tank on pilot deckmove bell, add handrailsallweather cabfeedwater heaterlight weathering

There were many things I was not satisfied with on this engine. My biggest complaint being poor traction. I added a KD and coupled it to the little 7 car train my IHC Pacific pulls nicely on my 3% grade. Uh oh, it starts spinning only half way up the grade !

Here are some comparison tests results :
Engine# carsEngine# carsAthearn sw 150014Proto sw 9/1222Proto 2000 FA240Proto 1000 f345IHC docksider 0-4-014Bachmann [size=-1]Consolidation[/size]19IHC Pacific14IHC Mountain20Proto 2000 0-8-016Athearn 2-8-25.
I send an email to Athearn, the fiasco that followed is "another story" One way to make this engine haul a proper sized train. The engine runs perfectly with 2 ounces added to the front !

[size=-2].[/size]

[size=+1]I am not the only nut around here ![/size]
[size=+1]What does one do on a wet July day ? FIX my 2-8-2 ......[/size]

[size=+1]Carefully study the exploded view diagram, and disassembly notes that can be found on Athearn's website.[/size]

[size=+1]From an old lead wheel weight, I filled both steam domes. I thought about taking the drive apart to get at the steam chest, but changed my mind. In the front I managed two ½ oz. pieces of lead between the wires.[/size]
[size=-2].[/size] [size=+1]My engine is supposed to be a Canadian National. "As real as it gets"[/size] [size=+1]NOT ![/size]

[size=-2].[/size]
[size=+1]The only thing CN about it is the decal. To look like a CN, the engine needs a triangular number board, a feedwater heater where the bell is and a tank on the pilot deck.[/size]

[size=+1]I made the tank from a lead weight, added a KD to the front, made the number board and installed a feedwater kit. I did not follow Athearn's instructions re installing the handrails as I know better from past experience building MDC and Bowser engines. I slipped the stanchions on the handrails, then pressed each in order into the boiler. [/size]

[size=-1]Click image to enlarge[/size]..............................​

[size=+1]In all I have added 3 ounces of weight and this engine will now pull 25 cars on my grade.[/size]








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[kchronister]

Interesting...

I've managed to add 3/4 oz. by the simple expedient of gluing weights underneath between the drivers. This had a modest improvement on pulling, but nothing to write home about (e.g. the loco can now pull 2 rather than 1 Rivarossi passenger cars up my 2% grade). For comparison's sake, my BLI K4 can pull 8 up with ease, and would probably pull more if I had 'em... My Rivarossi Hudson can pull 8 easily as well (though it has traction tires...)

I think my next step is to get some of that balancing putty mentioned earlier, disassemble the thing and fill up the steam dome and any other open space I can find inside...