So is there a fix out there to improve the Walthers Berkshire anemic pulling?

[u18b]

Lemo,

I also don't own one..... but a few things.

1.  How long will the tape last before it comes off.

2.  And when it comes off, how is it going to foul the running gear.

3.  Based on your before shot and the wear pattern.... it almost makes me think the middle two drivers are too high and the loco is running on mostly the outside two drivers.   Could that be the real (mechanical) issue?

[Lemosteam]

Ron, it's so thin I dont think there will be anything left to be honest.  I had one strip get tangled in the connecting rod while I was installing it to no ill effect.

It looks more like a dirty driver than a traction tire.

 I'm going to do some before and after pull tests like I did with my Mike TT add. 

Maybe JD knows what happens when it comes off?

I was thinking the exact same thing about the wear pattern.  Wonder I if anyone else can share a similar wear pic?  Maybe it is simply a bearing pocket height thing and the main geared driver never gets pressure on the rails?

[Lemosteam]

Finally uploaded the inaugural run of the entire PE consist after adding the tape to the rear driver coming up the grade:

[randgust]

As one of 'those guys' that does a CSI investigation every time something doesn't seem to work quite right....

It's a combination of design and execution flaws.   The big one is the driver material - it's quite slick.  I haven't done my usual adhesion analysis but it appears to have the same super-hard alloy that Atlas diesels do on the drivers.

The second interesting killer is the placement of the  split 'post' on the rear of the locomotive for the drawbar to the tender.   If you put the locomotive at full slip, you'll notice that the high/rear placement of that 'peg' causes a jacking of the front of the locomotive, putting all the weight on the rear driver and in severe cases, actually lifting the front.  And on curves, it also torques the locomotive toward the outside of a curve. 

Compare that with the drawbar design on the Kato Mike, and a couple others, that pull through the trailing truck,  so that the pivot for the trailing truck right behind the rear driver is 'forward and low' so that this lifting and torqueing phenomenon doesn't happen.  And I'm not talking 9 3/4" curves here, mine was climbing off of 13".  With deeper flanges you might never notice, but with smaller ones it's possible.

That's why I modified my drawbar location, loaded up the front of the smokebox and pilot with weight, etc.

I suspect, but can't exactly prove, that you'll beat the adhesion problem with an additional TT, BFS, or what have you and it should work fine on the rear drive set and dig in pretty well.   Just beware of that other issue.   It's fixable, have photos of what I did if anybody else hits it.

Your train looks great, particularly the car lighting.

[jdcolombo]

Ron, it's so thin I dont think there will be anything left to be honest.  I had one strip get tangled in the connecting rod while I was installing it to no ill effect.

Maybe JD knows what happens when it comes off?

I've had tape on my Berks for more than 8 years.   It's never "come off".   What will happen, eventually, is that the tape will just wear through to the driver.  When that happens, you will notice a decrease in pulling power, and I take the engine, invert it, pull off the old tape from the drivers with some tweezers, and put on new tape.   But the tape will take a lot of abuse; I don't know what 3M is using as the substrate for the tape, but whatever it is, it's very strong for its thickness, and it is also just "rubbery" enough that it makes a nearly perfect "traction tire". 

I've also found by experimenting that more tape isn't better - that is, I tried putting it on the 3d and 4th drivers; and on the 3d and 2d.   Doing that didn't improve the tractive effort noticeably, and further degraded the electrical pickup.   One set of drivers appears to be enough.

I do believe there are issues with the Berk in terms of its weight balance and how well the drivers all stay in contact with the rails.  These issues are not simply those of the Berk - it's why Kato went to an "equalized" (sprung) design for the GS4 and FEF - to keep the drivers in contact with the rails at all times.   But as Randgust has noted, the Berk has a significant tendency to lift the front drivers.   This tendency seems worse on some than on others - I have 10 of the Berks for my NKP layout, and I'd say about half of them are prone to the driver lift, but the other half are not (or not as much).  I haven't tried Randgust's approach of moving the connection point for the tender, which I suspect would help a lot.  Mine work for me as is, so I'm probably not going to try that, and in the meantime I'm waiting patiently for the Bachmann version of the Berk, which will FINALLY have the Mars light on the front of the boiler that was ubiquitous for the NKP Berks in the 1950's.   If the Bachmann Berk is as good as the 2-8-0 or the EM-1, I suspect my LL Berks will see an early retirement.

John C.

[Lemosteam]

I've also found by experimenting that more tape isn't better - that is, I tried putting it on the 3d and 4th drivers; and on the 3d and 2d.   Doing that didn't improve the tractive effort noticeably, and further degraded the electrical pickup.   One set of drivers appears to be enough.

John C.

John, thank you for this tip.

I was thinking of doing just that.  To be clear, you have never experienced a tape-to-driver adhesion issue where the tape begins to, and then completely separates intact from the driver.  You have always had to remove the remains and replace it?

Hmmm,  I might have to do a one to one Kato Mike test, I have two old version replacement mechs.  One with a TT driver and one with the tape on my pull-o-meter.



Maybe I'll call 3m to see if they can make a 1.2mm wide roll of this tape for me! 

[jdcolombo]

John, thank you for this tip.

I was thinking of doing just that.  To be clear, you have never experienced a tape-to-driver adhesion issue where the tape begins to, and then completely separates intact from the driver.  You have always had to remove the remains and replace it?

Hmmm,  I might have to do a one to one Kato Mike test, I have two old version replacement mechs.  One with a TT driver and one with the tape on my pull-o-meter.

Maybe I'll call 3m to see if they can make a 1.2mm wide roll of this tape for me! 

I had the tape separate from the driver once in 8 years - it came off and I found it in the middle of the ties.   I knew something had happened because the Berk (pulling a 30-car reefer train at the time) suddenly stopped and started spinning its drivers.  That is literally the only time in 8 years over 10 different Berks that I've used this technique on where that has happened.  Otherwise,  I've always had to remove what's left after it wore out (it will leave a tiny bit of residue on the driver after you take it off, by the way.  I clean the driver with 90% alcohol before putting on a new strip).  Now understand that I don't run the Berks for hours around a layout; they typically get used for about 15 minutes at a time running a mainline train in an operating session.  I probably don't put more than 4 hours of run time PER YEAR on one.

If you get that roll of 1.2mm-wide tape, sign me up for one, too!

John

[victor miranda]

yeah when you write to 3m tell em it is for making architectural models
your mullions will not stay on....

don't mention trains.

victor

[Lemosteam]

Victor,   

Ya got me on that one! and thats not a bad idea either.

[Cajonpassfan]

John (Lemosteam that is),
your pull-o-meter is interesting, didn't know there was such a thing.
How sensitive/useful is its range for N scale?
Thanks, Otto

[Lemosteam]

Otto, you be the judge, I felt I got some fairly good comparison data from these tests, although I have never equated the force to the total number of cars the could pull (I always wanted to):

I think Micro Mark still sells it:

http://www.micromark.com/digital-pull-meter,9577.html

[mmagliaro]

  John,
 I don't have a berk, but I think the 3rd driver is the geared one and THAT is the one you should use for the added traction. If these are like the mallets, running it the way you have it, will wear out the driverod pin holes, the added force with the traction is going through the rods.

 BTW your PE looks very nice.

This comment forced me to go look at mine (with the groove cut in driver #4).  As it turns out,
BOTH drivers 3 and 4 are geared, so there's no worry putting traction tires, or snot, or tape on
the rear driver.

Other notes... While I had the gear cover plate off from underneath, I observed that there is a large amount
of open space between the frame halves that can easily be reached from under there.
Some packs of tungsten sheet or disks, glued to a thin sheet of styrene (like .005") so they don't touch the frame
halves to cause short circuits, could be put up in there, especially between the frames by drivers 1 and 2,
where this engine really needs weight.    I had already put tungsten disks up front anywhere I could fit them,
but it could still use more.

It is far too tail heavy.

I haven't run this thing in quite a while.  Boy, with some rubber on the wheels, it pulls great.  30 cars over
my hills, no problem.

[rodsup9000]

Thanks Max for looking.
It's good to know.
I wish that they (Lifelike) would the gearing like that on the 2-8-8-2's.

[garethashenden]

Other notes... While I had the gear cover plate off from underneath, I observed that there is a large amount
of open space between the frame halves that can easily be reached from under there.
Some packs of tungsten sheet or disks, glued to a thin sheet of styrene (like .005") so they don't touch the frame
halves to cause short circuits, could be put up in there, especially between the frames by drivers 1 and 2,
where this engine really needs weight.    I had already put tungsten disks up front anywhere I could fit them,
but it could still use more.

Instead of styrene, use cigarette rolling paper. It's very thin, strong, and takes superglue well. Gives you more space for lead or whatever.

[Chris333]

Tungsten?   

I wacked the front of the frame down on my Berk and put a piece of tungsten welding rod in there.

This is also the Berk with a traction tire slot so one day when I put it all back together it should be a puller.