Kato GG1 Traction Tires

[Cajonpassfan]

Peteski, you're daMan!

Thank you! I will never call you de Snarkski again, or make fun of your avatar.
Appreciate you taking the time, truly.

Since good deeds never go unpunished, I have a more complex complex question for you as you like to tinker with mechanisms: do you think it would be possible to pull the wheels off their axless and replace them with a smaller diameter Kato (or other) wheels? Like plus/minus 40" diameter? In theory, it would lower the ride by only .053"....
(Hint: I'm looking for 20K gallon tender power for my big-drivered Hudson, see pic below. I would of course replace the power truck sideframes and cut off the GG1 frame just outside the power trucks).

Thoughts?
Otto K.

[mmagliaro]

Yikes...   off  topic, but...

Those geared axles in the GG1.. are those hollow axle tubes with the gear right in the center?
And do those gears on the axles have more than 22 teeth?

(He asked, realizing that if they do, they could drop into his 0-6-0 project and yield more gear reduction because
they are also mod 0.20 gears in the GG1!)

I cannot find those geared wheelsets as separate replacement parts for the GG1, but the power trucks are available.
My inquiring mind wants to know!

And .... Otto, if all this is true, I have a bunch of half-axles I've pulled out of geared wheelsets that go in the mid production
SD40-2, and they might just push right onto those GG1 tubes, giving you 40" diameter wheels)

[peteski]

Nice!  I give an inch and you want a foot! 
Now I'll have to take the loco and a truck apart!  I did notice that the axle gear is looks much larger than in locos with 40" drivers.  I'm also pretty sure that it follows the standard Kato design with gear/axle-tube and wheels on half-axles.  But I'll confirm that once I have it in pieces.   I'll even count the teeth for Max. 

I'm not sure if it is still on but Trainworld had a clearance sale on Kato GG1s a while back. They were selling for something like $60!  for that price, it is worth picking one up just for parts (which is what I did).

[peteski]

Peteski, you're daMan!

Thank you! I will never call you de Snarkski again, or make fun of your avatar.
Appreciate you taking the time, truly.

Oh Otto, I don't mind - call me Snarkski (which to me is a compliment) and make fun of my avatar (after all, I chose it for fun and for getting more respect points  )!  Just don't call me Al. 

[peteski]

Ok, here you go guys.  As expected, it is a standard Kato design. Half-axles are 1mm diameter.  The gear diameter is 0.234" which, if 40" wheels were to be used  would be very close to the track level and with 36" wheels would be below track level.  You also can't replace it with a smaller gear because those won't mesh properly wit the idler gears.

It is an interesting design. The trucks are removed without taking the frame apart. Actually the frame pieces cannot be separated without removing the trucks first!  But taking off the shall does make things easier.  The trucks have to be wiggled out by twisting them side to side. On reassembly the short drive shaft has to be nestled into the flywheel (which is actually easier than I thought), then the truck snapped back inot place (makign sure the metal pickup nubs are riding on the springy pickup strips.

To fully disassemble the truck is a bit tricky. Be extra careful not to bend the very delicate metal pickup plates.  First the leading truck needs to be snapped out of the truck (it needs some serious twisting and force to come out).  Then using a pair of open tweezers with each side of the tweezers slid under the edges of bottom cover I pried the bottom cover off by unlocking the little tabs on the gear case. Then the bottom cover/sideframes can be removed.  Be very careful on reassembly, again not to bend the delicate electric pickup plates.

Max, you can count the gear teeth yourself - I even drew in a dot for easier counting. 

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[Cajonpassfan]

Wow! I love this stuff

George: my sincere apologies for hijacking your perfectly good thread....it started with an innocent question and then Peteski took it to a whole another level.

Peteski, wow, I didn't expect you to dismember your loco for me ! Thank you, this very useful, kind of what I was hoping for. And perhaps Max finds this useful as well. Yes, the idea came to me when I saw the sale you mentioned and I was hoping for standard Kato engineering. You now confirmed it. The remaining question is whether the 40" wheels can work with the GG-1 gear; that's a tight clearance.

Max, could you please do me a favor and take a caliper to your ostensibly 40" wheels (here's hoping they aren't undersized which would kill this whole idea).

Thanks guys!
Otto K.

[Cajonpassfan]

And .... Otto, if all this is true, I have a bunch of half-axles I've pulled out of geared wheelsets that go in the mid production
SD40-2, and they might just push right onto those GG1 tubes, giving you 40" diameter wheels)

Max, thank you, if this is doable you bet I'll be very interested in six sets of half-axles!

[mmagliaro]

Ok, here you go guys.  As expected, it is a standard Kato design. Half-axles are 1mm diameter.  The gear diameter is 0.234" which, if 40" wheels were to be used  would be very close to the track level and with 36" wheels would be below track level.  You also can't replace it with a smaller gear because those won't mesh properly wit the idler gears.
...

I very much appreciate that dot, Pete!

28 teeth.  Diameter of 0.234

mod x (numteeth + 2 ) = outer diam, so    0.2 x (28 + 2) = 6mm  =  0.236"

Good heavens, it is a mod 0.2 28 tooth gear.  And in a 51" drivered engine (the 0-6-0) the drivers are 0.320"
so the gear is still plenty smaller than the wheels and won't bottom out.
4x28 = 112:1   instead of the 80:1 I have now.

I would have to change my idler gear to a smaller one, and then find a larger diameter worm to re-mate with the new
idler.  I wish I had known about that GG1 gear before.


Otto:
I measured the SD40 wheelsets I have.  They scale out to 40.6" on the tread (0.254") and their half-axles are 1mm.
The bad news is I only have 6 (6 wheels w/half axles which would only do 3 complete axles).
But if you want them, PM me.

[Cajonpassfan]

Max, thank you for the good news/bas news. Appreciate the offer, but before I take you up on it, it sems I need to find a set of six, and not knowing much about more modern power, what kind of half axles/ wheels am I looking for to fit the GG1 gear/hollow tube? A mid-production Kato SD 40-2? Any other Kato half axles fit the bill?
Thanks, Otto K.

[mmagliaro]

Max, thank you for the good news/bas news. Appreciate the offer, but before I take you up on it, it sems I need to find a set of six, and not knowing much about more modern power, what kind of half axles/ wheels am I looking for to fit the GG1 gear/hollow tube? A mid-production Kato SD 40-2? Any other Kato half axles fit the bill?
Thanks, Otto K.

Well, the ones I have came from a mid-production SD40-2.  But parts for those are hard to find.  I am not sure, but I think a lot
of Kato diesels use the same 40" wheels with 1mm half-axles.  Peteski will know better than I.

[peteski]

I'm pretty sure that most Kato diesels use 40" wheels . Not sure about the newer GEVO units.  I think that these should work for you (40" wheels and 1mm dia. half-axles).
http://www.modeltrainstuff.com/Kato-N-Low-Profile-Geared-Wheelsets-p/kat-932090.htm

These might be 40" too:
http://www.modeltrainstuff.com/Kato-N-Low-Profile-Geared-Wheelsets-p/kat-932090.htm

I might have some of those in my stash - I'll have to look.

[Cajonpassfan]

Hmmm, thanks for pointing me to these Peteski; somehow it didn't occur to me that offset gear axle tubes might work I assume that the half axles are the same length regardless of gear placement?

So now it's a question of total axle length to fit the GG1 pickup cups. Is that a standard dimension for Kato?
Looks like a need to start hunting for a GG1
Otto

[peteski]

Hmmm, thanks for pointing me to these Peteski; somehow it didn't occur to me that offset gear axle tubes might work I assume that the half axles are the same length regardless of gear placement?

So now it's a question of total axle length to fit the GG1 pickup cups. Is that a standard dimension for Kato?
Looks like a need to start hunting for a GG1
Otto

Yes, the lengths of both half-axles (on all Kato wheelsets in locos and cars which use plastic tube axles) is the same on both sides. Otherwise it would be a pain do deal with.  All the axle tubes are hollow all the away through.  The half-axle lengths appear to be identical for all the wheelsets (I haven't actually measure them).   I also didn't not measure how far the pointed axle ends protrude out of the wheels - I assume that is a standard dimension too.  If not, you should be able to adjust them (I use small arbor press to do that).

[Cajonpassfan]

Thank you Pete!
Otto

[chicken45]

Hey @tom mann ! Does this qualify as a Best Of?