Help with a Kato Mike

[wm3798]

Converted my first Kato Mike to DCC last night.  The installation went smoothly, and I was test driving it on the layout, when after a few laps it slowed down significantly going forward, then I threw it in reverse, it obtained the desired speed, but then I heard a click, and the wheels locked up.

My best guess is that during the re-assembly, the valve gear got hosed up, or I managed to un-quarter the wheels.  I think I got the wheels where they're supposed to be, but I think the eccentric gear on at least one side is not oriented the way it should be, because she still just sit there and hums, apparently due to the rods being locked up..

If somebody out there can take a close up photo of the valve gear of a healthy Mike, I can make sure I've got all the bits and pieces where they should be.  Preferably there would be a straight on shot of each side, with the wheels in the same position in both (don't run the locomotive to shoot the other side...)

I'd appreciate any help you can provide.

Thanks.
Lee

[71jeep]

Hi Lee..

I have been ripping apart a few of these lately and I can say for sure that all valve gear on mine are oriented the same way with the eccentric to the center on the wheel in that square hole and the second two are different valve gear I know but it is the same eccentric and the wheels were never moved.



Its not the best pic but you can see eccentric points the center of the wheel.



Allen......

[sizemore]

If that pic doesnt help let me know I'll grab Hi-Res pics tonight for you.

The S.

[wm3798]

Hi res with a little extra light, please...
Thanks!
Lee

[SkipGear]

Lee,
 It's really hard to get a Kato Mike out of quarter. All the axles and eccentric rod socket are square so that they can only be installed at 90 degree relations to each other.

Here are some shots with a little better contrast that may help:




Make sure the steam chests are pushed all the way back on the posts on the frame. Also make sure wiring hasn't pinched against the flywheel if you are running wires between the tender and loco.

[wm3798]

I was careful avoid pinching the flyweel by running the wires around under the sides of the cab.  I'm pretty sure the eccentric gear is the culprit.  When I took off the gearbox plate I accidently dislodged the drivers, and I may have spun one of the eccentrics out of position.  So the drivers may be lined up, but one of those little elbows is "hyperextended" and causing a bind.  The photos are a great help.

It's also helpful that the side rod is only physically connected to the main driver and the lead driver, which isn't geared.  So once I get them situated and eccentrics straightened out, the problem should be solved.

...should be (he said hopefully!)

Lee

[victor miranda]

 ;D ;D ;D

lee,
the eccentric crank on the Kato is squared off, as I recall.

set it into the driver close to center.
it should lean slightly forward when the main crank is at the bottom.

an eccentic crank being mis placed will cause most n-scale locos to stall.
the way I test is to reverse the loco. If it backs up it is quite often
the valve gear.

rare on a Mike, sometimes the front crankpin grabs the connecting rod and stalls the loco.
usually this happens in a sharp curve.

v

[wm3798]

Also a strong possibility...  I noticed the problem about 4' after the engine went through the sharpest turn on the layout, a roughly 13"r arc.  It was running counter clockwise in a forward direction, and if memory serves (I'm not at the workbench at the moment) the side giving trouble is on the engineer's side...  Heading home for lunch now to further diagnose.

Lee

[wm3798]

Got it running after aligning everything per the photos provided.  I started by removing the two wheelsets that aren't tied in to the siderods, then adjusting till it fired up (1, maybe 2 adjustments)  Once I was satisfied that it was running smoothly, I put the other two drivers in, making sure the counterweights were aligned, and put it all back together.  Runs just fine now.  Now I just have to install all the jewelry, and find a Z scale coupler for the pilot (got any laying around?... you know how I feel about Z scale!! ;D)

Thanks as always, for the technical support!

Lee

[David Leonard]

I'm experiencing a variation on this problem, and I have a solution, but I'm wondering if there might be a better way.

My Mike is now a GHQ PRR Mikado, and the pewter air tank on the fireman's side is displacing the valve gear hanger to the side, with the result being a slight cogging like behavior. There's not room to move the air tank further back. It pushes down and outward on a small (non-functioning) detail on the top of the hanger.

I'm thinking of just removing that bit of detail from the hanger. It's not the correct valve gear for a Pennsy L1 anyway, but does this seem like a reasonable solution? Is that what you did, Allen?

[71jeep]

Hi Dave...

I soldered the tank on then clearanced the back until it was not interfering with valve gear anymore.

I coud get you pic if you would like???



Allen.....

[SkipGear]

David,
 Without pictures, it's hard to say for sure but I would guess a little trimming for clearance wouldn't hurt anything.

[David Leonard]

SkipGear, if you look at 71jeep's photo above, you can see how the air tank almost touches the top of the valve gear hanger. The detail on top of the hanger on his model is in back of the air tank. Since it is not all that visible, I think I'll just trim it off. I can always glue it back on if I change my mind later.

Is this Forum great or what?