N Scale Concor Hudson 4-6-4 Secondhand

[brokemoto]

There are numerous complaints about the old mechanism's seizing after many hours of running.  It happened to mine.

[kiwi_al]

Well I have put this mechanism in a safe place and do you think I can remember where that is ................ NO!
However, the second one arrived a few weeks ago, had the same problem with the motor - ran extremely hot enough to burn my finger (I ran it out of the loco as I didn't want the shell damaged).
Managed to get the worm off the rotor arm and found that when I offered it to the new motor it fell off. I put it back on the original motor and it fell off. It appears Kato crimped the very end of the worm or reduced the worm diameter in the last millimeter so it would stay on the shaft. Go figure.
I have a couple of worms being sent from Tramfabriek, it'll take a while to get here. At least I'll get one running in the next few weeks or so.

[mmagliaro]

Does the worm fit on the shaft without actually rattling or wobbling on the shaft?  If it is just loose, it could have
been originally put on with a drop of LocTite instead of being a press fit.  I don't think I have ever come across a commercial loco that didn't have a press-fit worm, but you never know.  You could try the green loctite.  It isn't too awful hard to break free if you need to press if off later, but it will definitely hold the worm against the forces of an N Scale loco.

[wm3798]

Con Cor Hudson spotter's guide.
1st run, Kato built, metal side rods and no tender pick up (no wires between loco and tender)  Hot motor, poor electrical contact.  Often available at a much lower price than the later models.  Generally to be avoided.
2nd run and later Kato built, plastic rods, much better motor, wires present showing the tender is providing contact.  No headlight. Best version, in my estimation.
Rail Baron - Chinese knock off of the Kato drive, motor can be questionable, gearing can be less precise, plastic siderods and tender pick up. Available in a wider array of paint schemes, still pretty good, hit or miss on the QC, though.

Lee

[kiwi_al]

Does the worm fit on the shaft without actually rattling or wobbling on the shaft?  If it is just loose, it could have
been originally put on with a drop of LocTite instead of being a press fit.  I don't think I have ever come across a commercial loco that didn't have a press-fit worm, but you never know.  You could try the green loctite.  It isn't too awful hard to break free if you need to press if off later, but it will definitely hold the worm against the forces of an N Scale loco.

The worm wobbles slightly from side to side so if I want to use it, it'll be the loctite way Thanks Max

[kiwi_al]

Con Cor Hudson spotter's guide.
1st run, Kato built, metal side rods and no tender pick up (no wires between loco and tender)  Hot motor, poor electrical contact.  Often available at a much lower price than the later models.  Generally to be avoided.
2nd run and later Kato built, plastic rods, much better motor, wires present showing the tender is providing contact.  No headlight. Best version, in my estimation.
Rail Baron - Chinese knock off of the Kato drive, motor can be questionable, gearing can be less precise, plastic siderods and tender pick up. Available in a wider array of paint schemes, still pretty good, hit or miss on the QC, though.

Lee

Nicely put Lee!! I was sucked in by the second gen nice running Kato Hudsons that I have and didn't realise I was bidding on an earlier one. I must remember if the price is too good do your homework! They are going to get ATSFNScale Models tenders with pickup.

[mmagliaro]

The worm wobbles slightly from side to side so if I want to use it, it'll be the loctite way Thanks Max

If there is any wiggle at all that you can feel with your fingers when you slip it on the
shaft, I would not use it at all.  Loctite will hold it, sure, but it will not run true.  There's tolerances, and then there's
tolerances.  If you can feel it in your hand, that's too sloppy.  Try to get a worm that at least pushes on snug, even if it's
just finger tight and you can pull it right off.  Your only other option if you end up having to use that worm would be to bore it out  use a sleeve to make everything fit right.

[kiwi_al]

I'll wait for the worms to come in from the UK and go from there. They should be a snug fit but you never know until you get them.

[kiwi_al]

The worms arrived from Tramfabriek but they are too loose as well and a lot smaller. So I put the Concor / Kato worm on the new motor shaft and fixed it in place with Loctite. So far so good. Then I decided to test it - not so good.
I put the loco on the track and applied power and nothing happened. I flipped it upside down on the track and it ran fairly well. I put it back on its wheels and it shorted out. I got my DVM and did a continuity test and found that the frame halves weren't isolated. This is the 2nd Hudson that I hadn't torn down. I'm still looking for my other one.
This one will get torn down and some Kapton tape will be applied to both frame halves to ensure they can't short out.
Something else will probably bite me when I get this done.



EDIT: Well the shorting was caused by the positioning of the motor, I'll need to shim it and glue the back in place as it is a little narrower than the Concor one, at least I don't have to tear it down - time will tell

[kiwi_al]

I added some shims where the motor mounts to the frame and took it for a blat (run). It needs a bit more work but it is running on DC along a length of code 55 flex track. At least the motor runs cool . I ran the old motor by itself and it started shooting sparks occasionally. That motor is shot.

[otheym]

i installed new drivers but the wheels are still wobbly.  I have a 2nd generation locomotive.

[mmagliaro]

i installed new drivers but the wheels are still wobbly.  I have a 2nd generation locomotive.

Is this in the very first generation ?  (the one with metal side rods).   Honestly, I would not bother trying to rescue one of those.  They made so many improvements to it in the second go-around starting in the mid to late 70s (when the tender pickups went in).  Can you show some photos of the undersize with the plate off to show the axles, gears and bearings?
My guess is that the frame slots are just too sloppy.

[otheym]

i said it was a second generation. kato.  How do I fix the sloppy frame slots?  That seems to be the problem.

[mmagliaro]

i said it was a second generation. kato.  How do I fix the sloppy frame slots?  That seems to be the problem.

That model has bronze bearing blocks in the frame.  They generally do not get sloppy. You say the wheels are wobbly,
but I'm trying to understand what that means.  If you take all the rods off and the motor out, so you can push the bare frame with just the drivers in it down the track, does it wobble?

[otheym]

The bearing blocks are loose in the frame. The wheels are OK.