Key Imports PRR I-1

[mmagliaro]

If you really want to use just the motor with no gearhead, here's a Key M1 (not the I1, I know), with a Maxon 1017 mounted on the existing L Bracket. 



I would not recommend this.  My experience with this is that while it runs better than the original, even the coreless cannot make enough torque on its own to keep the engine from slowing down on curves and hills.  If you don't mind that, then you can use the bare motor like this.  The Maxons are stronger motors than the Faulhabers unless you can find a Faulhaber 1016 SR, which is much rarer and expensive.

I reamed out the hole in the bracket, and then tapped the big hole in the bracket so that the screw threads on the motor nose would screw right into the bracket.  I put some JB Weld on there just to keep the motor from coming unscrewed (could have also just used LocTite).
The thread on those motor noses is weird.  It is M5.5 x 0.5, but can buy a tap for that thread, even though it's pretty impossible to find nuts or bolts in that size ( https://www.amazon.com/M5-5%C3%970-5mm-Metric-Thread-Round-Right/dp/B071L2CKPZ ).
At least I've never been able to find any.
This would depend on what kind of nose is on your Faulhaber motor.  They don't all have threads.  You could also just ream out the hole until it is close to the right size, and kind of force-screw the motor into it, so the motor's threaded nose acts kind of like a tap and cuts its way through.  Not very motor-friendly, but I've done it.  And once it is in, add some Loctite to keep it from coming loose.

[kiwi_al]

Something around 12,000 rpm or even lower might work well.  Got anything in mind?

This but have a look at what Max has posted cause he is SuperMax! 

https://www.aliexpress.com/item/4000591437881.html?gatewayAdapt=4itemAdapt

Aliexpress is where I get most of my motors from - I've got about 40 odd at the moment all 12 volt with varying sizes and rpms.

Edit: Here's another:

https://www.aliexpress.com/item/1005002684017609.html?gatewayAdapt=4itemAdapt

[mike_lawyer]

Max and Al -

Thanks for all your help on this.  Here is a picture of the underside of the boiler.  The stock motor barely fits:



So I don't think a Faulhaber 1016 and gearhead will fit without reaming the inside of the boiler.

Running the engine stock this late last night and this morning, I am having trouble with the locomotive derailing at a couple of  points where I have a 15 inch radius.   EDIT - I figured out the problem - I had reassembled the pilot wheel upside down, and it was causing derailment.  It will track well without derailing on all my curves now.

So now, back to square one.  The question becomes how to repower the loco for good torque at low speeds.  Basically, I need something that is 10 mm wide by no more than 23 mm long. 

Mike

[mmagliaro]

On those aliexpress motors... just make sure you don't buy any with a "15" or "17" as the 1st two digits of the motor number.
Those are 15mm or 17mm diameter and are much too big for most N Scale.

As for that I1 space... it looks like there is just a flat plate across the underside at the back.  Is that really important?  Can you just cut that out of the way with a Dremel so the shell would drop over a longer motor?

[mike_lawyer]

Max, that plate is the floor of the cab of the locomotive.  There is vertical piece at an angle that has the cab firebox interior on the other side.  I don't really want to Drexel out that area.

Another possibility might be to shorten the distance at the center gear post.  Would it be possible to cut down the shaft extending from the worm to the plastic connector piece?  That might save a few millimeters there and let the Faulhaber fit.

[mmagliaro]

Darn.  Hoping that wasn't the case (that the plate was the bottom of the cab interior).
Yes, from the photos, it definitely looks like you could cut the gearbox shaft a little shorter, but I sure wouldn't do that until I had
the Faulhaber with gearhead in hand to hold in there, to CONFIRM that it would fit if you cut that shaft.

So let's try the other approaches first.  Do you have any skew-wound Atlas/Kato motors?   The Atlas scalespeed ones (with the gray plastic brushcap section) probably have lower RPM than the motor that's in there.  Whether it will have enough power to make it run the way you want, I can't say.

Another option is Mabuchi FT-010SA-07300.  These are all over the internet.  You can find them on eBay and aliexpress
if you just look for Mabuchi 010SA.  When you look at any of the sellers, sometimes they offer it in two versions "12v" and "24v"
If they list it that way, you want the 24v version (because it will run slower at 12v and below).  Sometimes they
show the whole motor number and will show the 07300 part, which is what you want.
These are still 21,000 RPM (no load) motors, but they are smooth and powerful.  And don't get hung up on them being 3-pole motors.  Their form factor can probably be easily adapted to that L bracket, too, because they have a metal plate end that you
can drill and tap for the screws.  The motor can be easily disassembled to allow for safe drilling and tapping if you don't want
to do it while assembled and risk crashing through the plate into the armature with your drill bit.

Requiring more home-brewing to mount it, but a whale of a small motor, look for the Minebea 10mm square motor.
Ebay and aliexpress seem to have exhausted their dumps of them, but Amazon still has some.
https://www.amazon.com/Passion-Exceed-Precision-Square-10x10mm/dp/B074SGJMWQ
It's only a 6v motor, so you will need to stick  zener diodes or resistors in there.  But I've tested these and they are amazingly
powerful.  Top RPM is only about 14,000

[randgust]

I'm glad you got the derailment problem fixed.

As I'm reading about the PRR Dec's for my own project, I came across a 'whaaaaa?' in Staufer's "Pennsy Power", page 66.

"To get them over some of the more crooked branches, as well as around Horseshoe and Muleshoe Curves, only the two end pairs of driving wheels were flanged, the three center pairs being blind".

Wow.   Just sayin.   I did that stunt with my Hallmark 3751 brass 4-8-4 to get it to run consistently on 15" radius and took up ALL the lateral on the drivers with nylon "C" washers, and it still works great.  I turned the flanges under power with a diamond file.  Not the smartest thing I've ever done (photos available) but it worked quite well.

But if there was another locomotive class in widespread use with THREE BLINDED DRIVER SETS I've never heard of it.

[mmagliaro]

I'm glad you got the derailment problem fixed.

As I'm reading about the PRR Dec's for my own project, I came across a 'whaaaaa?' in Staufer's "Pennsy Power", page 66.

"To get them over some of the more crooked branches, as well as around Horseshoe and Muleshoe Curves, only the two end pairs of driving wheels were flanged, the three center pairs being blind".

Wow.   Just sayin.   I did that stunt with my Hallmark 3751 brass 4-8-4 to get it to run consistently on 15" radius and took up ALL the lateral on the drivers with nylon "C" washers, and it still works great.  I turned the flanges under power with a diamond file.  Not the smartest thing I've ever done (photos available) but it worked quite well.

But if there was another locomotive class in widespread use with THREE BLINDED DRIVER SETS I've never heard of it.

Oh yes... most definitely.  The I1 had 3 middle blind drivers.  And they made drivers 2,3,4 with wider tires than drivers 1 and 5, so the inner drivers wouldn't drop in off the rails on curves and then get "stuck" trying to climb back out.   But on a model layout, this isn't practical because even our "broad" curves are ridiculous.  So blinding all those drivers is probably going to cause the engine to get hung up on curves.  I only blinded the center one on mine.

[mike_lawyer]

I only blinded the middle driver on my I1, and it worked great.  I think any more than that would cause tracking issues around curves.

[Teditor]

Sort of off topic but related, in Australia during World War II we had what was known as the Australian Standard Garratt, they had blind lead drivers and funny enough had derailment problems.

Ted (Teditor) Freeman

[dem34]

Sort of off topic but related, in Australia during World War II we had what was known as the Australian Standard Garratt, they had blind lead drivers and funny enough had derailment problems.

Ted (Teditor) Freeman

The more I hear of Garratts the more of an Enigma they are to me.

[bbunge]

If you visit the surviving I-1 in upstate New York, you can see the flangeless wide tires on the center drivers have a 1 inch deep or so groove about 2-inches wide carved out the steel.  It's quite impressive to see first hand. 

Bob

[Cajonpassfan]

That's where the traction tire goes..
Seriously, very impressive machine!
Otto K.

[mike_lawyer]

I ordered some of the Mabuchi 1015 motors off Ebay.  I specified the 24 volt version.  Not sure how much speed reduction you get when you drive those motors at less than 12 volts, but we will see.

[mmagliaro]

I ordered some of the Mabuchi 1015 motors off Ebay.  I specified the 24 volt version.  Not sure how much speed reduction you get when you drive those motors at less than 12 volts, but we will see.

I use the armatures out of those motors for my Rivarossi can motor rebuilds.  The motors themselves run pretty nicely on their own as delivered.  They spin at 12v like your typical Kato motor, like 15,000 or more rpm.  So I don't think you'll get speed reduction
from them.  But they might be more powerful than what's in there.  They are skew wound, so they don't cog as much as your typical 3-pole motor.
It's either that, or a 1220 or 1224 Mashima, which also has the metal case with screw holes in it.  You would just have to
make new holes in the L bracket to line up and put the screws in.  But good luck finding those these days.  The Mashimas all spin slower than Kato/Atlas motors, more like 12,000 RPM with no load, and they have more power.