Anyone add weight to a Bachmann 4-6-0?

[Dave V]

Did some grade testing on my Bachmann 4-6-0...  At 3% and 10" radius (I know, a tough climb) she couldn't haul two boxcars without slippage.  in fact, she slips a little without anything behind her.

My 4-6-0's pulling power is still not what others have reported.  I thought my thinned bullfrog-snot on the traction tire driver would have solved the problem, but no.  My hope is 3 boxcars and a caboose, though I'll take 2 and a caboose.

For those who have added weight, where is there room inside this little thing?  Did you use tungsten putty or something else?

Am I missing any other opportunities (i.e., journal shims or the like) to squeeze a little more tractive effort out of her?

Oh, and since threads are better with pictures, here:

[Lemosteam]

Hi Dave the shell is quite tight to the chassis, there may be some space in the domes for some hammered lead or tungsten disks.  the cab although nice inside may be another option hidden with curtains.

The other option since you have not laid tracks is to glue a 3/32" stranded cable from the hardware store between the cork (flush with the top), just through the graded portions and add one or two thin rectangular rare earth magnets (I can suggest some item numbers) to the drive gear cover with some CA, especially near the TT driver.  The magnet has to clear all of the frogs, etc. but this will work, this video is a two axle homemade loco with NO TT.  Ballast and such will not affect the magnetic downforce at all.

[Dave V]

Wow!  Way to science!  Makes me wonder, though...  If I ever went DCC (I intend to at some point once I have more than one loco), would all that B (magnetic) field screw around with the decoders?

[Chris333]

Cab is really the only place. I haven't added any weight to mine. Lead is heavier than tungsten putty.


Will any other steam like a Bachmann 2-8-0 make it up the hill?

[Lemosteam]

Dave those are physics questions that my little mind cannot handle.  But....

If you look at the size of the magnets, and the fields around them that the manufacturer specifies, you will realize quickly that the field is so small that a decoder placed in a tender would never notice.  When i made that loco, i was concerned that the field would affrct the armature and motor performance.  It did not affect that one bit. 

In the video, the magnet had to be within 0.070" of the wire to even attract a downforce.  Of course as the ferrous material got bigger, from 045 wire to 3/32" cable the more force the magnet exerted.  The last experiment I did with the multi-strand cable improved traction even more, plus the magnet could be farther away.  I even tried just thin sheet metal under the entire track and the downforce was to great the loco could not move!  believe it or not, track nails would stop the loco in its tracks too!

this also works through switches.  you just diverge the cable down the center of the diverging route.

You actually have nothing to lose in trying it.  If it doesn't work you ballast will simply makke the wire disappear.  I can mail you two of the same magnets I used for free.

[eric220]

John, I actually gave some thought to using that system in my helix. Very cool solution.

[mmagliaro]

Dave,
Mine can pull 10 cars up my 1.7% grade (just tested it).

How many can yours pull on level track?    That way we can get a similar comparison.
That 3+ % grade of yours may be too much for it, and remember, with the TT driver on the front
on that engine, climbing a steep hill shifts more and more weight toward the back, which is not good
for where that tire is.

I would not be looking to add weight as long as you have a fundamental difference in behavior between what
yours does and what mine can do (and anyone else's).    There must be something else wrong, and adding weight
may compensate a little, but won't solve that problem.

So, how many on level track?
Does your front driver slide freely back and forth?  Let's start there.

[Dave V]

I went with 3% because 2% would not have really fit, and 2.5 is not commercially available (to keep the weight down and to avoid uneven grades I went with WS risers).  So 3% it is.

I'm at work so can't vouch for side play on the drivers or what else can climb the grade (my Bachmann 2-8-0 is inop right now) but I had her doing 5 cars on the level.

So yeah, less than what she should.

[victor miranda]

will it pull going backwards up the grade?

[peteski]

Wow!  Way to science!  Makes me wonder, though...  If I ever went DCC (I intend to at some point once I have more than one loco), would all that B (magnetic) field screw around with the decoders?

Nope, you should be fine. But strong cosmic radiation might affect the internal memory cells of the decoder.

If this loco has no traction tire, it soundsl like adding a real traction tire to this tiny gem (after figuring to which driver first) woudl do wonders for its pulling ability.

[mmagliaro]

It does have a tire, on the front drivers.
So I like Victor's theory... Try it backing up the hill.

I asked about the driver sliding because if it is somehow static or can't float a little, maybe
something is out of whack with the way that axle is placed in the frame and it can't keep both wheels down on the rails.

5 on level track is very low.   I threw 17 on it, and it pulled them with ease on level track.  It could surely pull more.

Let's back up and start doing all the rest of our experiments on level track to eliminate the confusion of grade or curvature,
since the overall pulling is way low.    When we get that number higher on yours, then we can go back to
the grade.

[peteski]

It does have a tire, on the front drivers.
So I like Victor's theory... Try it backing up the hill.

Then it sounds like the loco is not balanced well, or the traction tire driver is not suspended low enough to bear any appreciable weight (so no additional traction).  Maybe shimming the TT driver bearing (to lower it) would simply do the trick.

[Dave V]

Then it sounds like the loco is not balanced well, or the traction tire driver is not suspended low enough to bear any appreciable weight (so no additional traction).  Maybe shimming the TT driver bearing (to lower it) would simply do the trick.

This was my thought.  Shimming the TT journal on the light 4-8-2 about doubled the power.

But let me get home from work first (snowing like crazy) and then I can start testing.

'Cause honestly, 3 cars and a caboose or a baggage & coach is all I ever see pulling up the branch anyway....  Anything more wouldn't fit the little passing siding up there.  Get me to 3 cars and a caboose and I'll give you free beer if you come visit Colorado Springs!  Oh, hell, I'd do that anyway...

[Dave V]

OK, she can pull 7 50s-era cars around a 13.75" radius curve on the level.

She has what seems like the correct amount of side-play in the TT.

She slips just as much in reverse climbing the hill.

And now the valve gear has been seizing up in reverse...

I kinda wish I'd gone with my gut and gotten the MDC/Athearn 2-8-0.

EDIT:  'Nother coat of snot on the TT and now she pulls the 3 cars and caboose, but she sounds angry.  Something's binding somewhere...

[victor miranda]

what is the current and voltage?