Best Of The TP56/TP70 Kitbash thread N scale

[rodsup9000]

 Will a Kato GG1 truck, part# 929360 work for doing one of these???

[peteski]

Will a Kato GG1 truck, part# 929360 work for doing one of these???

The GG1 wheels are larger than the needed 40" wheels.  The wheel spacing will also  most likely bee too wide.

[u18b]

Here is a comparison of photos.
Same angle, same shot.

Chassis 1. 
Kato SD40-2 early truck
5 pole motor
runs well.  Motor almost certainly too tall.




Chassis 2. 
Kato SD40-2 mid truck
Kato 11-105 motor
runs well under DCC.  Motor may stick rearward too much.  Could be moved 1 mm closer.



Chassis 3. 
Kato SD40-2 mid truck
Kato 11-105 motor, worm mounted on motor shaft.
runs fairly well  analog.  Could run better.




Bearing is superglued to truck.

[peteski]

See Ron, worm attached directly to that motor shaft is a viable solution. Nice job! 

[delamaize]

What is in this space?

[ Guests cannot view attachments ]

Could it be carved away, and the motor attached on the other side, keeping it in the footprint of the truck?

[tehachapifan]

What is in this space?

(Attachment Link)

Could it be carved away, and the motor attached on the other side, keeping it in the footprint of the truck?

Sure seems like this could be good a possibility.

[Chris333]

Just saw this on youtube:

[Philip H]

That big gear one sure has good speed control.

[central.vermont]

and it even comes with sound!

[u18b]

Just saw this on youtube:

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Yep.  You beat me to it.

I was going to say..... that what we are doing becomes a CINCH in HOn3.  (I assume that this is what's meant by HO  and some Japanese characters and 9 mm track).
The space becomes HUGE when dealing with HO.
Bigger motors.
More control.

[u18b]

What is in this space?

(Attachment Link)

Could it be carved away, and the motor attached on the other side, keeping it in the footprint of the truck?

Great question.
The answer is.... sort of nothing.

But right at the center of your blue circle.... you will see a nub that is a latch.

So the gear cover locks on here..... there is a low latch at the back (toward the motor) and a somewhat high latch where you circled.

So the point is....... if you cut off the space... then the latch is gone and the worm cover cannot be retained any more.

This is of course possible, but I'm not convinced it is best (yet).

So before I destroy the truck and cut that part off, I'm now waiting for those motors mentioned above that have the longer shafts.

[u18b]

See Ron, worm attached directly to that motor shaft is a viable solution. Nice job! 

Yes.... but not easy and I'm not convinced it is best (yet).

1.  It was not easy to get the worm on.  This motor does NOT have a shaft that comes out of the rear end.  There is a kind of wall there.

So that means when you beat (tap) on the worm with a brass hammer.... where is the force going.  On a traditional motor with a rear shaft... you place that shaft on a hard surface and so as long as the shaft does not bend, ALL of the force goes to the worm and it taps down.

But here.... things are moving around inside.  And it may not be good.

I have not taken apart this motor, but many motors have the commutator and the poles as separate pieces.  So if you are not careful, when you beat something onto the shaft, the poles may MOVE down on the shaft closer to the commutator than they should be.  You change the configuration of the motor slightly.   I fear that is happening here.

2.  And for the sake of clarity at previous suggestions..... you cannot place a shaft extension in there so you can use both bearings in the holder.

That's because most (including this one) worms are NOT uniform on the inside.
My experience is that ONE end of the worm bites and holds onto the shaft. 
But only one end.

So the other end allows the shaft to slide in.... but does not bite the shaft.

Thus this worm only goes onto the short motor shaft ONE way.   The tighter biting end is toward the motor.

All worms may not be like this, but I have experienced this phenomenon a lot when kitbashing/modifying mechanisms over the years.

So back to the point, any extra shaft extension would just flop around in there.

3.  In spite of the fact that gluing the bearing onto the holder worked..... it doesn't run as well as the others.

Now I tried to get the motor at just the right angle (see the slight space between the teeth of the gears) and this was not easy.  The shim must be angled since the top of the gear housing is not flat but angled.

So I don't know if my positioning could be better....

Or if the motor was slightly damaged as described in #1 above.

But this version is not as smooth at low speed as the others.

The one that runs best has everything stock with a u-joint between.

[peteski]

I did not comment on why you didn't mount the motor on the inside of the  truck because I thought you wanted the motor sitting in the loco's cab.  But if that was not the reason then I would have tried to mount the motor on the opposite side.
I would trim the gear case and the worm retainer clip, and also find a way to positively attach the partially trimmed clip to the gear case. Probably by pinning it in some way.

I woudl push the original worm shaft out enough to be able to push the motor shaft in (on the larger opening side of the worm). You worried about the loose fit of the motor shaft in the worm and also about not damaging the motor by pressing the worm onto it. Well, if you install the motor shaft in the larger worm hole and use Loctite then both problems are eliminated. Loctite will be plenty strong to hold the worm on the shaft.

Then I would use just a single bearing on the outboard side of the worm shaft (in the style of your Beardenizing method).

Since this strictly theoretical design on my part (based on your photos of all the pieces) I'm not sure if it is a workable solution, but that is how I would approach this.

[u18b]

This is an interesting little addition.

Chessiefan came over today and asked if I had any drawings/mock up made yet.

I said yes, but not finished.

So we printed out what I had.

I took this side-on shot.




And drew this over it.




And then scaled it to N scale.  My estimation was that the pilot faces is 30 feet.  (33 feet coupler pulling faces)

And then placed my chassis on top of the drawing- the truck measuring out properly--- so this is pretty close.

Hmmmm.  Looks like I have a good deal of room.  More than I thought.




And this chassis -- which runs the best--- has the motor sticking out too far.



Given this info, I have high hopes that the motors on their way to me from Asia with the long shafts will work out just right.

[Chris333]

So that means when you beat (tap) on the worm with a brass hammer....

 

You ream the worm out till it slides onto the shaft then secure it with Loctite or super glue. I have a set of 5 mini reamers like this:
http://www.ebay.com/itm/Mascot-Precision-Tools-MPTH311-Mini-Reamers-Broaches-Set-079376003113-/371979835625?epid=1600129741&hash=item569bb9d8e9:g:yOgAAOSwXXxZPsqT

The smallest one even fits inside a #80 drilled hole