Kato NW2 switcher weight

[TimF]

I bought a nice model of a Kato NW2, It runs louder than other Kato locomotives and its tractive effort is really low... 6 Atlas 90-ton hoppers on straight, level track and it is crying for a helper!
Is there a way to put more weight into this tiny unit?

Also, the light is only flickering, what may be the problem?, Is this a decoder equipped unit? Its my first NW2, the seller told me that it would be factory new...

Tim

[ryan_wilkerson]

Tim,
That appears to be a Digitrax decoder dn123k3. If you'd like to try a DC board, I could send you one and you could try it out.
-Ryan

[larry p mahoning division]

I tested my unit with DCC and it pulled 14 properly weighted cars thru a flat yard. However the cars have FVM metal wheels.

[peteski]

While Kato models are generally excellent runners, this one was is a bit unusual design, and it was prone to a split gear problem.  That could result in the shaft slipping on the gear. Maybe the problem with extran noise and poor pulling ability is due to that split gear?  I don't have any more info on that, but it is likely documented somewhere out there.

[jpf94]

My NW-2 with TCS decoder pulls 16 cars with MT trucks and wheels.  Had heard the comments it does not pull well, I am quite happy with the performance I have.  Yes it is louder, I think that is due to the frames not being screwed together, but rather held in place by the motor mount only.   The unit is lite, but overall I have no complaints. 

[Teditor]

Look to me like a section of the chassis holding the PCB is broken, could it have been dropped or otherwise damaged.
Ted (Teditor) Freeman

[tehachapifan]

Look to me like a section of the chassis holding the PCB is broken, could it have been dropped or otherwise damaged.
Ted (Teditor) Freeman

Good eye! I agree that one of the frame tabs appears to be broken off. This could possibly be causing an intermittent connection as the shell on these do apply some downward pressure on these decoders (evident by the shell sitting slightly higher towards the front vs. with the stock light board). This downward pressure could already be causing a spotty connection and the broken frame tab may be exacerbating it.

[peteski]

It might be also possible that the truck power pickup strips in the chassis are not properly installed.

The green arrow points to a correclty installed strip, while red is incorrect.

[TimF]

Look to me like a section of the chassis holding the PCB is broken, could it have been dropped or otherwise damaged.
Ted (Teditor) Freeman

Eagle Eye!!! Yes, there is a small part broken, this must be the reason why the guy sold it for such a low price...

[randgust]

Obviously your conclusion is based on when the locomotive appears to be slipping.

Take a really, really good look down at track level to see if the wheels are actually slipping or if you hear the motor running and the wheels aren't moving.   Because if it does have a cracked gear, it is most likely the one off the end of the motor; so both trucks will loose power at the same time (unlike some other split gear designs).
It's just like a clutch failing, it isn't all that obvious unless you study it.   I had split universals on one end of an Atlas C630 and it was kind of a surprise, particularly on watching it 'spin out' going uphill when in reality that was just enough to make the split result in loss of rpm.

For its size, the NW2 has proven to be just as good as the LL SW8 for pull, even without weight in the cab.   You could add more there, but I'm still suspect that your problem is elsewhere.   I have cut up about a dozen of these into custom SW1 rebuilds by modifying the frames, and while I've never seen a cracked gear on one, others have so I believe in it.   

[peteski]

While that chipped frame likely indicates that  the loco was dropped (and possibly has other mechanical issues due to that), it wouldn't affect the electric contact between the decoder and the frames. Why? Because there is another set of contacts on the front of the decoder which engage undamaged tabs on the front of the frame.

If the loco fell, the contact strips I mentioned and shown could have slipped in the frame, and then there is the possibly cracked gear.  The only good way to investigate and look for all those problems would be to take the mechanism apart. Unfortunately this screw-less design is not the easiest to deal with when it comes to disassembly.

[tehachapifan]

While that chipped frame likely indicates that  the loco was dropped (and possibly has other mechanical issues due to that), it wouldn't affect the electric contact between the decoder and the frames. Why? Because there is another set of contacts on the front of the decoder which engage undamaged tabs on the front of the frame.

If the loco fell, the contact strips I mentioned and shown could have slipped in the frame, and then there is the possibly cracked gear.  The only good way to investigate and look for all those problems would be to take the mechanism apart. Unfortunately this screw-less design is not the easiest to deal with when it comes to disassembly.

But the shell, IIRC, presses down on the decoder or at least makes contact with the taller components on the decoder. I wonder of this might break and/or cause spotty contact as I believe the frame contacts on that decoder are only along the top of the decoder. I can't recall right now if I added some solder to some or all of the decoder contacts on mine to improve contact (warning, probable warranty buster), but I do recall using a Dremel inside the shell to add some more clearance for said components (you may notice there are some pretty deep depressions inside the shell where some taller stock lightboard components sit). I did this primarily so that the shell would seat down better over the decoder. All this said, I really can't recall now if pressing down on the decoder definitely caused frame contacts to lose contact or have spotty contact. Might be worth investigating further though.

[TimF]

The NW2 is running good on DC and also on DCC.
A good friend told me that he could make me two halves from steel so it would get more weight, I'll give him a try.
Testing on a very long Kato Unitrack oval showed that the NW2 pulls 12 NMRA weighted 40' Boxcars, this will be a good sized train.

Have a nice weekend

Tim

[peteski]

The NW2 is running good on DC and also on DCC.
A good friend told me that he could make me two halves from steel so it would get more weight, I'll give him a try.
Testing on a very long Kato Unitrack oval showed that the NW2 pulls 12 NMRA weighted 40' Boxcars, this will be a good sized train.

Have a nice weekend

Tim

Casting the frame halves out of led or brass would make it even heavier.

So just to clarify, is that your loco, or his (with a steel frame) that pulls 12 cars?

[TimF]

Casting the frame halves out of led or brass would make it even heavier.

So just to clarify, is that your loco, or his (with a steel frame) that pulls 12 cars?

Pete, the NW2 pulls 12 cars after I put it together and cleaned the wheels with a MiniTrix wheel cleaning brush.
Lead or brass sounds good, I'll ask him if he could make frame halves of that material