Kato GS4 Driver Replacement Tutorial

[mmagliaro]

I suspect that an awful lot of people just run them with the original drivers, and when they crack and fail,
they just give up and put the engine in a drawer or on a shelf.

For the record, I did have to put the U bracket on driver #2 on at least one other GS-4. I may have had to do it on a second one.  I can't remember now.
Carl's didn't pop out when I test ran it here, so I didn't add it on #2 on his. 
But those bearings are dicey, so I guess I'm not at all surprised
that it could have happened after he got it back.

From now on, if I do another one of these, I'm putting blocks on #2 and #4, just as a matter of course.  It's not
worth the risk.

[carlso]

Victor
Max

I can't help but think about how many you guys have speculated may have been repaired plus however many may have been sent to KATO for repair. I think I remember a fairly small number was guessed and who knows how many GS-4's KATO made between the three paint schemes of Daylight, war baby, and Freedom Train. I watch the bay some but have not seen very many, if any at all, listed. If they are some of them will most likely be posted as " near new ", what a joke, in some cases. But again, I am afraid the majority of guys or gals will just put them up to look at. Actually, how many of these lookers were sold to collectors initially? I know a man who had one of each paint schemes and possibly two of the Daylights, just purchased as a collector. He was a major player in the days of old and the Micro Trains collectors. So, how many GS-4's may be sitting in a collectors box somewhere and have never been run ?

All of the discussion regarding the GS-4 makes me concerned about the FEF. Has KATO solved their driver problems on steamers ? Why do I ask this, because they had a driver/pick up problem with their initial Mikado locos and came out with a set of "replacement" drivers. I have those in my Mike. They have done the same for the GS-4 and will they be doing the same for the FEF ? How long will it require for a short coming to rear its head on the FEF ? Will it be a driver/pick up problem, undersized motor problem ? Who knows and I plan on enjoying my 844, for sure. One other thought, do they have these nagging, ever present problems with their Japanese style locomotives ?

Actually, I suppose these are all mute issues regarding the Mike and GS-4. Shucks, you can't get repair parts for them now. The Mike pages show most everything as "discontinued" and not much available for the GS-4 either. I know what they are up to, they are going to re-release the Mike and GS-4 with all new updated mechanisms ala the FEF. Ya, when pigs fly. They will play the FEF card for a long time with all the possible paint schemes.

Carl

[victor miranda]

I find Kato is very hard second guess.

I am pretty sure Kato will not do a repeat of the mikado as we know it.
If they do something close
it will be re-tooled.  that seems to be how Kato does things.

the FEF is likely to be re-issued a few times.
I can't believe they will skip the grey paint.
(oh my poor wallet....)

the GS-4...
I doubt they will re-issue it.
like the Mikado they will re-tool it...
 I think they will change the frame and mounting the shell
so the tender may not be re-done.

If Kato does another us Steam engine...

I'd think they'd do a niagara on the front of the 20th Cent limited....

oooof

now while everyone is responding to that...

I am hoping that Kato has learned its lesson to put metal around the plastic insulating tubes
a la kato mike and FEF axles.
one can do it as the original gs-4, and even that requires at least rings/collars to hold
against cracking.
what so irritates me about all this cracking is that after I came to know the b-mann
white gear cracking...
I remember thinking Well... at least Kato knows better than to build axles like that.

funny what gets revisited.

victor

[peteski]

To directly answer the question, I don't think that FEF-3 will ever exhibit the same problem with the axles as GS-4 did. I wouldn't worry about that.  Kato learned their lesson and decided that increased friction from the larger axle bearing on the FEF-3 was worth the price to pay for not having the axle tubes crack with lower friction small diameter axles on the GS-4.  Plus the faceted axle in the FEF-3 makes it impossible for the drivers to get out of quarter (similar to the Mikado design).

[peteski]

Since I just took apart my almost-new GS-4, here are my findings.

It was from the 2nd run (DCC friendly) and it only has few hours of running time. It was also handled very gingerly by me.  #1 and #2 axles have cracks. The other ones are ok.

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[mmagliaro]

Yep.  I think that is pretty typical.

I keep wondering if, when they are cracked but still functional like that, if a swipe of a hot soldering
iron to melt over the crack would keep it from worsening.  I am thinking that once it has cracked,
it has relieved some of the pressure, and it may not need much to hold it from spreading.

[peteski]

Yep.  I think that is pretty typical.

I keep wondering if, when they are cracked but still functional like that, if a swipe of a hot soldering
iron to melt over the crack would keep it from worsening.  I am thinking that once it has cracked,
it has relieved some of the pressure, and it may not need much to hold it from spreading.

But since the grip of the cracked (and melted) sleeve around the axle is not as tight as the un-cracked sleeve, IMO the wheels might get out of quarter much more easily.

[mmagliaro]

But since the grip of the cracked (and melted) sleeve around the axle is not as tight as the un-cracked sleeve, IMO the wheels might get out of quarter much more easily.

Welllll, they might.  But my conjecture here is that if they have been running fine for a while with that crack in there,
they are probably tight enough.  And the only thing we have to worry about is preventing the crack from getting
any worse to the point where the tube loses its grip.
I think if I owned one, I would do it and see what happens.   If it never slips, and the crack never reappears
after melting over it, then I'd call it a "fix".

[victor miranda]

Hi Max and peteski,

the swirling dance is a joy to watch...

I think taking a soldering iron to the plastic sleeve a bad idea
because of the possibility of misalignment of the axle when it cools.

I suspect it would work otherwise...
cause there is not that much axle loading.

I saw that peteski has a metal lathe...
are you going to make collars and install them?

oh an before I forget.
remarkably good photos!

victor

[peteski]

Hi Max and peteski,

the swirling dance is a joy to watch...

I think taking a soldering iron to the plastic sleeve a bad idea
because of the possibility of misalignment of the axle when it cools.

I suspect it would work otherwise...
cause there is not that much axle loading.

I saw that peteski has a metal lathe...
are you going to make collars and install them?

oh an before I forget.
remarkably good photos!

victor

Thanks Victor!  My 15-year-old Nikon is still great for macro shots.  These are cropped version of 3Mp pictures taken with the subject less than couple of inches from the camera.

I do have a Sherline lathe and mill but on this instance I'm going with the Kato replacement drivers.  I'll have to fabricate the spacers Max described in this thread (but my version of them).

[mmagliaro]

Thanks Victor!  My 15-year-old Nikon is still great for macro shots.  These are cropped version of 3Mp pictures taken with the subject less than couple of inches from the camera.

I do have a Sherline lathe and mill but on this instance I'm going with the Kato replacement drivers.  I'll have to fabricate the spacers Max described in this thread (but my version of them).

I think it would be really cool to mill the U spacers out of a solid piece of Delrin.   
They could be molded and made available as a spare part if somebody (cough, cough, KATO) were so inclined.

[peteski]

Exactly - U-shaped spacers.  But I don't see any advantage of using Delrin, since the axles or other parts will not continuously rub against it  Styrene or acrylic  should be good enough.  Even resin, like you mentioned, should be good.

[Mike C]

  Victor , Peteski , Max , I read all of your rebuilding / improving comments on different locos with great interest . You always seem to find innovative and practical solutions to the problems . What I am wondering , and I'm sure you probably covered it somewhere , is why not use a drop of CA in the crack . Seems to me it would work , but I'm guessing there is a reason not to ?

[peteski]

  Victor , Peteski , Max , I read all of your rebuilding / improving comments on different locos with great interest . You always seem to find innovative and practical solutions to the problems . What I am wondering , and I'm sure you probably covered it somewhere , is why not use a drop of CA in the crack . Seems to me it would work , but I'm guessing there is a reason not to ?

For starters nothing (even CA) will adhere well to the plastic from which the tubes are made from.  Since the glue won't hold, the integrity of the tube has been permanently compromised (since the glue is not really holding the crack together). Rough handling of the model that with an unbroken axle tube could survive that stress, with a cracked axle that same rough handling could cause a complete tube fracture, causing the half-axle to come loose.  Even if the tube remains partially cracked, the half-axle on that side can easily be twisted and the drivers will go out of quarter.

These are all worse case scenarios mind you.  Some of these cracked tubes might just stay as they are and if the model is handled gently it might keep on running for years.  But the perfectionist in me can't let this kind of problem left untreated. 

EDIT: clarification.

[Mike C]

 Thank you , I figured there was a good reason !