Help with newest GS-4?

[mmagliaro]

Thank you, Tony.  That's what I figured.  Once the plating is gone, the magnet is doomed.  Neodymium is amazing stuff, but not if it is exposed to the air.

[carlso]

Wow, Max I did not realize that it was 7 years ago, boy does life go fast. Anyway here is the last image that I made :


Let me say that yes it did run although a tad too slow for my likes. I ran it, I think twice, on the club layout and it crapped out. If I remember correctly the worm wore down the worm gear. Not sure why because I used the stock GS4 gear tower and worm hold down clips. I used NWSL parts and had the shafts aligned. The only thing that might have been the problem is that the loco was a 1st run unit and the drivers may have wobbled causing it. I abandoned the project. The motor is in my Key Challenger.

Hey, thanks for remembering my thread. If I ever get my two bash jobs finished I would like to try another re-motor job. Actually as far as I am concerned KATO can drop the Big Boy project and put out a new GS4 based on the FEF mechanism.

[Albert in N]

   Earlier in the thread, Peteski noted "GS4 motor is the same motor used in the NW2 diesel".  I wonder if Kato had NW2 motors updated after first run.  I own an early (2007) CB&Q switcher and a later (2013) Burlington Northern unit.  Both are standard direct current and I use an MRC Tech4. The BN starts with less voltage, runs faster, and seems to run more smoothly.  At a large train show (in 2012 per memory), Kato had a booth and was showing the new Burlington Northern NW2 along with their Nebraska Zephyr set.  I was super interested in the BN NW2 and was told that it was improved over their earlier NW2 since customers complained.  The Kato rep told me that the newer version had stronger U-joints and other improvements.  Judging from this discussion and my two NW2s, I wonder if the motor was updated with coated rare-earth magnets??  I have no criticism of either one since I do not multi-unit them. 

[Chris333]

There was a gear in the NW2 that would spin on it's shaft. They probably just knurled the shaft for the improvement  ( just a guess).

[peteski]

There was a gear in the NW2 that would spin on it's shaft. They probably just knurled the shaft for the improvement  ( just a guess).

Exactly, the gear slipping on the shaft was a problem with the initial release of NW2s.  That made them perform very poorly.  I doubt the motor was reworked (but I have no proof either way).  Maybe @nightmare0331  would know if the motor was redesigned?

[nightmare0331]

Exactly, the gear slipping on the shaft was a problem with the initial release of NW2s.  That made them perform very poorly.  I doubt the motor was reworked (but I have no proof either way).  Maybe @nightmare0331  would know if the motor was redesigned?

Ah the NW2. The motor itself was not redesigned.

The idler gear that sits below the motor is a shaft with a gear in the middle and two dogbone joints on it.  On each end of the gear was a bearing (either bronze on the original one or engineering plastic on later units).  The trucks would bind up for whatever reason, torque the shaft and the bond would break between the idler gear and the shaft.

The later run units didn't feature a knurled shaft...they redesigned the gear so it was tighter, but I still saw those fail.  I had a small bag of revised gear assemblies that the factory sent me after one of the later production runs of NW2's, but those were mostly gone by the time I left Kato.  Not sure what they're offering as a solution at this point (if anything).

At one point I did experiment with scuffing the middle of the shaft a bit and applying a hair of Loctite.  I recall it working at the time, but no idea on the longevity of that solution.

Enjoy!

Kelley.
www.dufordmodelworks.com

[Dwight in Toronto]

I’ve had an ‘original run’ GS4 since 2012.  I ran it quite frequently with 12 Daylight coaches, using the original drop-in dcc decoder, right up until February of this year.  It always ran as smoothly and reliably as all of my other Kato locomotives. 

In February, I swapped out the original decoder and put in that ESU “Japan” sound unit with a speaker from an iPhone.  Bought a LokProgrammer and downloaded the GS4 sound file.  Getting the chuff rate properly synchronized was an adventure in learning (endless thanks to a bunch of great folks on the io.groups ESU site), but the end result is wonderful. 

Speed step 1 has to be seen to be believed … it is SO impressively slow and smooth.  The entire performance spectrum is top-notch.  I couldn’t be happier with it … fingers crossed that it delivers the goods for another 10 years.