Bachmann 2-8-4 Berkshire/Kanawha in stock at M.B. Klein

[Iain]

If anyone wrecks theirs, I'll take the tender trucks! 

[Mark5]

I tested one of these in DCC this morning at MBK ...

I agree about the whitewall comments earlier in this thread. 

Sound is nice, given the budget speakers.

Runs nice ... once you get a little speed.

Unfortunately, the one I tested failed the slow speed operation test for me. I could not get it to (out of the box) run smoothly.

Win for wallet! Before I'll part with any $$, I'll wait to see if:

a) people I know report that it smooths out after "break in"
b) a reasonable "fix" is made known.

Mark

[jdcolombo]

I tested one of these in DCC this morning at MBK ...

I agree about the whitewall comments earlier in this thread. 

Sound is nice, given the budget speakers.

Runs nice ... once you get a little speed.

Unfortunately, the one I tested failed the slow speed operation test for me. I could not get it to (out of the box) run smoothly.

Win for wallet! Before I'll part with any $$, I'll wait to see if:

a) people I know report that it smooths out after "break in"
b) a reasonable "fix" is made known.

Mark

If you read this thread carefully, you will find your answers.

1.  Not really.   If you have uneven running at slow speed, it's not going to change.  The problem is a combination of mechanical and electrical, not some "tightness" that will go away with running.

2.  I have three of these, and all 3 suffered from exactly the same maladies, which were fixed by following the suggestions in this thread.  First, the "hitch" we all observe at low speed is because of a quartering mismatch between the 3d and 4th drivers.  The 4th driver isn't geared.  Fix: take your fingers or a pair of tweezers slipped between two of the spokes of the fireman's side wheel of the 4th driver and twist it just slightly (1/32 - 1/16") clockwise while holding the other driver steady.  Now test.  Hitch gone?  If not, twist a tiny bit more.  I know all the warnings that Max has given here, but this works, and the wheels are quite robust; you're not likely to break anything (if you could break it easily, I would have done so, because I wasn't exactly gentle with this maneuver).  If you are then worried about a wheel that will twist on the axle, use a drop of Loctite to lock it down - but I didn't do this, and mine are running fine.

After you've done this, then change CV's 209, 210, 213 and 214 as I noted in one of my responses above.  (I've settled on the values of 30, 180, 1, 3, respectively).  You may have to play with these values a bit, but I've found them consistent across the three units I have, so I'm pretty confident that entering these values will get you very close to optimum, and then you can do tiny adjustments if you are not satisfied.  The one that is most likely to need a bit of tweaking is the value in CV214 - start with 3, then try 1 and then 5 to see if you get improvement.   If not, leave it at 3.

My next project will be replacing the speaker for better sound and renumbering two of these.  But I'm now at the spot where I think that the engines are worth the $210 each that I paid for them.  I am particularly satisfied with the pulling power, which HAS improved with some running.  Each now easily pulls 30 of my NMRA-weighted cars (each of which is an ounce or more) plus a caboose with an axle retaining spring).  That's a fair amount of drag, particularly when the Berk is hauling this consist around a 180-degree 15"-radius curve that separates the two halves of my layout.

Finally, the Mars light on NKP 759 is a big plus.  I didn't know whether it would actually be an operating light or not, but it is.  From the factory, it is lit by a single LED that also lights the headlight.  But that's an easy fix - add a function-only decoder and a second LED to make it a REAL Mars effect.

Still some improvements to make, but all in all a happy ending - for me, at least.

John C.

[Mark5]

Thanks John,

I read the thread thoroughly.

I deeply understand that many of us have different ideas of what is acceptable slow speed performance, so I'll probably hold out until I can witness any fixes first hand.

Mark

[jdcolombo]

Thanks John,

I read the thread thoroughly.

I deeply understand that many of us have different ideas of what is acceptable slow speed performance, so I'll probably hold out until I can witness any fixes first hand.

Mark

OK.

Here you go:

/>

John C.

[powersteamguy1790]

Nice work John.

[nickelplate759]

Nice John!

I'm inspired to try and fix the bind in mine.

I notice that TopHobby has posted a video where they claim that a binding solution is to bend one of the side rods between the #1 and #2 drivers. Is that a different problem?

George

[jdcolombo]

Nice John!

I'm inspired to try and fix the bind in mine.

I notice that TopHobby has posted a video where they claim that a binding solution is to bend one of the side rods between the #1 and #2 drivers. Is that a different problem?

George

Different problem, though I've seen one other post about that over on Trainboard.  I didn't have that problem.

John C.

[nickelplate759]

So I got brave (for me) and went ahead and started tweaking the quartering in D4.   On straight track it will creep at about 1/4 RPM, but there's still a slight bind.  I found that tiny adjustments are pretty much impossible though, so I'm tempted to leave it alone.

Max is absolutely right - the driver is way too easy to slip around the axle.  Definitely will need loctite.

Then I put on John's BEMF CV values.

Next question - there's not much difference between 50% and 100% throttle.  I'm using DecoderPro3, and for some reason it won't let me set the Maximum and Midpoint Voltage for this engine (it does for others), only the Start Voltage (which is already fine).

Might that be because I didn't start from the right template for this engine?  I didn't have a correct one, but the Bachmann HO 2-6-0 entry seemed close, so I've started with that.


George

[Mike C]

 I tried the driver fix also last night . The driver is real tight , not sure if I moved it any or not . Anyway afterwards I adjusted the EMF CV's . It runs really smooth in forward now . BUT while it runs fairly smooth in reverse , the Loco seems to vibrate in the first 4 speed steps . I don't know enough about BEMF  to know what I should adjust to get rid of the vibration.....
 The other thing , the whistle is supposed to be playable. With my Powercab all I get is a set long when I use the horn button . I can get a set short blow if I use F2 . But from what I understand I should be able to "play" the whistle using the horn button???????

[Chris333]

I know it worked for me, but I doubt every locos 4th driver is out of quarter.  Look first before messing with it.

[jdcolombo]

So I got brave (for me) and went ahead and started tweaking the quartering in D4.   On straight track it will creep at about 1/4 RPM, but there's still a slight bind.  I found that tiny adjustments are pretty much impossible though, so I'm tempted to leave it alone.

Max is absolutely right - the driver is way too easy to slip around the axle.  Definitely will need loctite.

Then I put on John's BEMF CV values.

Next question - there's not much difference between 50% and 100% throttle.  I'm using DecoderPro3, and for some reason it won't let me set the Maximum and Midpoint Voltage for this engine (it does for others), only the Start Voltage (which is already fine).

Might that be because I didn't start from the right template for this engine?  I didn't have a correct one, but the Bachmann HO 2-6-0 entry seemed close, so I've started with that.

George

The Tsunami does not implement CV's 5 and 6.  Instead, there is a separate CV (CV 25) that implements a speed curve, or you can set it for "user defined" to use a full 28-step speed table.   I really, really recommend that folks read the Tsunami Steam User's Guide here:

http://www.soundtraxx.com/manuals/tsunamisteam_users_guide.pdf

But remember that the Bachmann "stripped down" version doesn't implement all of the CV's of the regular TSU.   For a list of the CV's that you get with the Bachmann version, the best I've been able to come up with is this:

http://www.soundtraxx.com/factory/OEM_pages/bachmann/ho_2-6-0_sv.pdf

Note that CV 216 is the BEMF Reference Voltage.   The default in this CV is 140.  This is not a CV that is implemented in the "regular" Tsunami, but in other decoders with this kind of CV, if you have a situation in which the top half of the throttle doesn't do much, you reduce the value in this CV.   I haven't tried playing with this yet, but I may do so - I've got the same issue with the top half of the throttle doing very little.

John C.

EDIT - I tried reducing CV216 to 100, and this seems to "stretch out" the throttle response.  I still get nothing above about 75 on my Digitrax DT402R, but that's better than what I had before.   Notice that adjusting this CV doesn't make the locomotive run faster; it just moves the maximum speed up the throttle range and stretches out the throttle response.

[jdcolombo]

I tried the driver fix also last night . The driver is real tight , not sure if I moved it any or not . Anyway afterwards I adjusted the EMF CV's . It runs really smooth in forward now . BUT while it runs fairly smooth in reverse , the Loco seems to vibrate in the first 4 speed steps . I don't know enough about BEMF  to know what I should adjust to get rid of the vibration.....
 The other thing , the whistle is supposed to be playable. With my Powercab all I get is a set long when I use the horn button . I can get a set short blow if I use F2 . But from what I understand I should be able to "play" the whistle using the horn button???????

Try adjusting CV 214 up a bit to see if you can smooth out the vibration without getting a hitch.  You might not be able to.

John C.

[nickelplate759]

I tried reducing CV 216 from 140 to 70 and indeed the control range is better.  I don't claim that 70 is the ideal value, but it helps!

George

[victor miranda]

I am....attempting to adjust my berk...

I have jmri and a pr3.

I should use the 2-6-0 decoder option for this decoder?

I do not have CVs above 105 with the b-mann sound decoder.

victor