Con-Cor 4-6-4 modification

[SkipGear]

Victor,
  That should work. Dubro also has small silicone fuel tubing that size available. Any shop that carries RC should have it or be able to get it for him.

[mmagliaro]

+1 on the Dubro small silicone tubing.  Works great.

http://shop.dubro.com/p/2-ft-super-blue-silicone-tubing-small

I have actually given up on the NSWL dogbone and put the tubing in there instead on some engines because,
inexplicably, they ran smoother. You'd think it would be the other way around.

[peteski]

+1 on the Dubro small silicone tubing.  Works great.

http://shop.dubro.com/p/2-ft-super-blue-silicone-tubing-small

I have actually given up on the NSWL dogbone and put the tubing in there instead on some engines because,
inexplicably, they ran smoother. You'd think it would be the other way around.

Why not?  Any sort of hard plastic universal will have undesired slop in it. Soft tubing OTOH provides a nice damping effect, which makes the mechanism run smoother.  But the length of the area with hollow tubing is also critical - if the hollow tube is too long, there will be too much damping and the loco will start to misbehave.

[mmagliaro]

Why not?  Any sort of hard plastic universal will have undesired slop in it. Soft tubing OTOH provides a nice damping effect, which makes the mechanism run smoother.  But the length of the area with hollow tubing is also critical - if the hollow tube is too long, there will be too much damping and the loco will start to misbehave.

Because with a pair of cups and a dogbone, there is some lateral freedom between the worm and the motor.
It lets the worm move freely in its bearings and the motor armature
move back and forth against its own bearings, each without affecting the other.  With the silicone tubing,
any thrust against the worm teeth causes pushing back and forth on the motor armature.  I would expect the
driveline to work better if the worm and the motor are free to slide back and forth just a hair between their own
bearings without imposing forces on each other.

[Doug G.]

I have used silicone tubing in several old steamers to replace the original plastic coupling and it quieted them right down. Unless those couplings are pretty precise, there is too much slop and whatever and it allows vibration to develop.

Doug

[nickelplate759]

Dubro tubing ordered.  However, it claims the "small" size to be 1/16" ID (0.0625") - and the shaft diameter is 0.060" (1.5mm).  Hope that still will work out.       It's way easier to try tubing first, and ball-and-cup later if the tubing doesn't work out, but from what you all say I should be happy with the tubing.         Put brass screws in the frame to attach the Red and Black decoder wires to tonight, and cut grooves to run decoder and headlight wires in.  To think this all started out as a simple shell replacement!

George

One surprising discovery tonight - when I completely stripped the mechanism, it turned out that the motor was glued in place with something resembling rubber cement!

[victor miranda]

I suspect the tubing is much the same across the brands

the one I picked was because it was what I had.
the size declared is the size of the brass tubing it fits
I think it will not grab firmly onto 1.4mm and will not hold 1.2mm
I recall trying it on an old rr/atlas pacific.

victor

[mmagliaro]

Dubro tubing ordered.  However, it claims the "small" size to be 1/16" ID (0.0625") - and the shaft diameter is 0.060" (1.5mm).  Hope that still will work out.       

...
...

That's the size I always use and it grips a 1.5mm shaft very nicely.  Never had a problem with it. 
And by the way, I have replaced the rotted, hardened ConCor 4-6-4 tubes with that very stuff.

[victor miranda]

yeah I agree Max, I shoulda said that...

what I have holds onto 1.5mm nicely.

victor

[nickelplate759]

I'm pleased to report that the Dubro tubing does indeed work just as well as you all said it would.  The bind between the motor and worm is gone!   On to the next step - getting the gear train working smoothly.  I noticed that the idler gears seem pretty sloppy in the frame (they can skewy off-axis) and am wondering if it's worth trying to constrain that, maybe with a plastic shim on the frame.

George

[mmagliaro]

I'm pleased to report that the Dubro tubing does indeed work just as well as you all said it would.  The bind between the motor and worm is gone!   On to the next step - getting the gear train working smoothly.  I noticed that the idler gears seem pretty sloppy in the frame (they can skewy off-axis) and am wondering if it's worth trying to constrain that, maybe with a plastic shim on the frame.

George

If they wobble that much, it may not really be correctable, but a shim washer is worth a try.  (i.e. the
gear may stop wobbling, but if the hole was big enough to allow that much wobble in the first place,
the gear won't be spinning true around the pin, even if you shim it).   Like I said though, it can't
hurt and it's worth a try.    I would be inclined to use the nice thin phosphor bronze NWSL washers rather than a plastic shim, unless you have some Delrin or other "engineering plastic" shims.   Styrene isn't a good bearing surface for a gear rotating up against it over and over .... and over.  If you use metal, make sure you can place it so it doesn't short the two frame halves together.

[nickelplate759]

Next question!   I'm also converting this to DCC.   It's easier to install the decoder (in the boilder) now,  'cause the motor is sandwiched in the frame,  than after I get everything together.  However, as I reassemble the drive train I want to test it on DC.   Once the DCC coder is wired in, can I still apply DC directly to the motor brush holders to test things (by attaching leads from a DC power source) or will that hose the decoder (TCS M1 if it matters)?    Note that in this scenario the engine will NOT be on the track, it will be upside down in a cradle.

George

[victor miranda]

from all I understand about decoders....
do not apply power to the motor leads.

use the decoder to run the motor.

victor

[peteski]

Once the DCC coder is wired in, can I still apply DC directly to the motor brush holders to test things (by attaching leads from a DC power source) or will that hose the decoder (TCS M1 if it matters)?

You will fry the decoder!
But all the decoders currently on the market will run under DC power.  That mode is usually enabled by default. If not, you need to set come CVs to enable that functionality.  Then just put the loco on its back and stick a 9V battery to the wheels to see if it will run.  That is how I test my DC and DCC locos.

[nickelplate759]

Problem!   While installing the decoder, I somehow touched an idler gear with my soldering iron  (the gear had fallen out of the frame and I didn't notice).  It's a about 1/2 gear and 1/2 blob now. I don't think I can rescue it.       The other idler gear is just fine, so at least I have a reference part.

Not my best night at the workbench.

I now need a replacement idler gear for a Chinese-made Con-Cor Hudson.    Besides calling Con-Cor and hoping for a minor miracle, any suggestions?  Anyone got one in their junk-box they'd be willing to part with?

George