Are All Scale Speed Motors Interchangeable?

[MK]

Going back to the Atlas motors, while a gray plastic end bell is pretty reliable indication of scale speed motor, I also recall either Paul or Cory from Atlas mention that more recent models have scale speed motors which are produced with black, not gray plastic.  I can't find the specific post here, but I could have read that on the Atlas forum which no longer exists.

I have read this on a few places too but can't specifically say where at this point.  I am 99% sure it's a true statement.

[davefoxx]

Going back to the Atlas motors, while a gray plastic end bell is pretty reliable indication of scale speed motor, I also recall either Paul or Cory from Atlas mention that more recent models have scale speed motors which are produced with black, not gray plastic.  I can't find the specific post here, but I could have read that on the Atlas forum which no longer exists.

FOUND IT!

If you've purchased a locomotive from us within the past 10 or so years, it has a "slow speed" motor in it. The motor casings went back to black when we changed suppliers.

DFF

[peteski]

FOUND IT!

DFF

Thanks Dave.  I was searching for "scale speed" when he called "slow speed".   Just so nobody thinks we are making it up, here is a link to Cory's Post: https://www.therailwire.net/forum/index.php?topic=38738.msg469998#msg469998

For those who do not know, Cory was an Atlas employee, so the info he provided was coming directly from that proverbial horse's mouth.

[rrjim1]

Thanks Dave.  I was searching for "scale speed" when he called "slow speed".   Just so nobody thinks we are making it up, here is a link to Cory's Post: https://www.therailwire.net/forum/index.php?topic=38738.msg469998#msg469998

For those who do not know, Cory was an Atlas employee, so the info he provided was coming directly from that proverbial horse's mouth.

Funny, right on the Atlas parts catalog they are listed as scale speed motors.    https://shop.atlasrr.com/p-1625-n-u25b-motor-flywheel-assemb-scale-speed.aspx
The slow speed motor is the one with the silver housing. https://shop.atlasrr.com/p-3058-n-gp-motor-flywheel-assembly.aspx
The fast speed motor looked about the same as a Kato motor, couldn't find a picture but I still have a few in a part draw.

[mark.hinds]

@rrjim1

You mistakenly reversed your links above (a/o 7:05pm CST on Monday, 11/4/2019; assume you will edit to correct...). 

MH

[peteski]

Funny, right on the Atlas parts catalog they are listed as scale speed motors.    https://shop.atlasrr.com/p-1625-n-u25b-motor-flywheel-assemb-scale-speed.aspx
The slow speed motor is the one with the silver housing. https://shop.atlasrr.com/p-3058-n-gp-motor-flywheel-assembly.aspx
The fast speed motor looked about the same as a Kato motor, couldn't find a picture but I still have a few in a part draw.

Funny?
Not sure whether you are trying to disprove what Cory wrote, or just stating that "slow speed" and "scale speed" names are interchangeable?  Cory is human - maybe he wasn't accurate in his description. Scale-speed and slow-speed to me seem mean the same thing.

There is a major and very visible difference between Atlas and Kato motors. Kato motors have straight-wound, while all Atlas motors have skew-wound armatures.

You seem to be quite an expert on electric motors - maybe you could buy few of those cheap eBay motors, run some tests on them, then post your findings here?  If those truly are same (or very similar) to the Atlas slow-speed/scale-speed motors, we would have a really inexpensive source of those motors.

[narrowminded]

At this point I'm comfortable saying that the gray brush end housing is a scale speed motor and not all black housings aren't, especially later issue.  I have several "newer" DCC ready units that are scale speed and also are black brush housings.  When I get some flywheels this can be put to final rest, tachometers, 5 pole skewed armatures, and volt/ ohm meters be damned.

The flywheel dimensions that I know will fit, measured from a motor assembly that installed and operated properly, are .351" dia. x .278" length x .155" deep hex.  There is room for generous tolerance in those dimensions and larger could be machined to make fit if necessary.  It's the female hex part that is really needed as that would require tooling made that goes way beyond the value of this venture.

[rrjim1]

Funny?
Not sure whether you are trying to disprove what Cory wrote, or just stating that "slow speed" and "scale speed" names are interchangeable?  Cory is human - maybe he wasn't accurate in his description. Scale-speed and slow-speed to me seem mean the same thing.

There is a major and very visible difference between Atlas and Kato motors. Kato motors have straight-wound, while all Atlas motors have skew-wound armatures.

You seem to be quite an expert on electric motors - maybe you could buy few of those cheap eBay motors, run some tests on them, then post your findings here?  If those truly are same (or very similar) to the Atlas slow-speed/scale-speed motors, we would have a really inexpensive source of those motors.

Funny, in my first Atlas locos with this type of motor there was a High Speed Motor straight wound, two different versions. These motors turned about 30,000 rpms, not much torque at low speeds. Then Atlas went to the skew wound sliver frame slow speed motor. It improved the loco's starting speed but still turned 30,000 rpms at 12 volts. I can still remember getting a couple Atlas C420s and how different they ran. They had the gray end bell motors, better starting, slow and top speed. I then went on to replace most of my Atlas and Kato motors with the Atlas gray end bell motor. That motor is call by Atlas a scale speed motor and is very different than what Atlas called there Slow Speed Motor. Scale speed and Slow speed might mean the same to you but were talking about Atlas motors and there is a huge difference between them. I also call a Atlas loco an Atlas no matter who manufactured it. Yes, I also know that the latest scale speed motors have a different color end bell.
 

[rrjim1]

At this point I'm comfortable saying that the gray brush end housing is a scale speed motor and not all black housings aren't, especially later issue.  I have several "newer" DCC ready units that are scale speed and also are black brush housings.  When I get some flywheels this can be put to final rest, tachometers, 5 pole skewed armatures, and volt/ ohm meters be damned.

The flywheel dimensions that I know will fit, measured from a motor assembly that installed and operated properly, are .351" dia. x .278" length x .155" deep hex.  There is room for generous tolerance in those dimensions and larger could be machined to make fit if necessary.  It's the female hex part that is really needed as that would require tooling made that goes way beyond the value of this venture.

I hope they are scale speed motors, I still have three motors for spares so I don't see a need for any.  I just wanted to let you know that from the description they would not be a Atlas scale speed motor. Great price if the description is incorrect.   Like I stated I have some flywheels and lots of crappy high speed Kato motors. The flywheels I have measure .353 X .275 two different styles using the inside hex.

[NtheBasement]

I have some old Atlas Kato engines that no longer run smoothly, presumably due to the motor, not the gears.  I would be very interested in re-motoring them.  Could someone describe what it would take to change motors if I get one of these scale speeds?  Particularly how do you swap flywheels?  Never done that - special tools needed?

[MK]

I hope they are scale speed motors, I still have three motors for spares so I don't see a need for any.  I just wanted to let you know that from the description they would not be a Atlas scale speed motor. Great price if the description is incorrect.   Like I stated I have some flywheels and lots of crappy high speed Kato motors. The flywheels I have measure .353 X .275 two different styles using the inside hex.

Hording!     

[rrjim1]

I have some old Atlas Kato engines that no longer run smoothly, presumably due to the motor, not the gears.  I would be very interested in re-motoring them.  Could someone describe what it would take to change motors if I get one of these scale speeds?  Particularly how do you swap flywheels?  Never done that - special tools needed?

I use these tools that I made.

[peteski]

Funny, in my first Atlas locos with this type of motor there was a High Speed Motor straight wound, two different versions. These motors turned about 30,000 rpms, not much torque at low speeds.

In my recollection, the first time Atlas locos used that type of a motor were RS-3 and RS-11 locos (Made for Atlas by Kato)
So, weren't those early Atlas motors simply Kato motors (or at least direct Kato clones)? And there were 2 versions?  Maybe Kato-made and Chinese-made clones?

I also call a Atlas loco an Atlas no matter who manufactured it.

Ah, that answers my earlier question: You consider the Kato motors as Atlas motors.
Yes, I also know that the latest scale speed motors have a different color end bell.

Then Atlas went to the skew wound sliver frame slow speed motor. It improved the loco's starting speed but still turned 30,000 rpms at 12 volts. I can still remember getting a couple Atlas C420s and how different they ran. They had the gray end bell motors, better starting, slow and top speed. I then went on to replace most of my Atlas and Kato motors with the Atlas gray end bell motor. That motor is call by Atlas a scale speed motor and is very different than what Atlas called there Slow Speed Motor.

I'm confused.  So you are saying there are multiple versions of the motor with gray plastic end bells?!

Scale speed and Slow speed might mean the same to you but were talking about Atlas motors and there is a huge difference between them.

Ok, how then one tells the difference between scale-speed and slow-speed motors?

I know  that I would, and I'm sure others here also would consider it very useful if you were to post photos of all the versions of Atlas motors and describe ways they can all be identified, if they are identical visually.

As I mentioned, you seem quite knowledgeable about the motors, and have the means to evaluate them. I ordered those motors from eBay with gray plastic end bells. I could send you couple so you could evaluate them and let us know whether they are the same as one of the Atlas motors, or something totally different.  Let me know if you are up for this.

[mmagliaro]

These are worth a try if you feel confident in your ability to switch the flywheels to a new motor: https://www.ebay.com/itm/DC-12V-24-46000RPM-High-Speed-5-Pole-Rotor-Motor-6mm-Dual-Shaft-DIY-RC-Car-Boat/123356124760. You will want to by several as not all of the motors are good but they're cheap enough that it's not a big deal. I have used these to repower several Atlas locos with high-speed motors.

I have ordered some of these from eBay before.  There are many sellers on eBay with the same motors.  None of the ones I received would turn anywhere near 46,000 RPM.  I'm pretty sure that's a bogus label.  They seem to top out at around 12,000, and my guess is they are the "scale speed" ones.  There are also black housing ones on eBay.   I bought 3 of each.  The black ones turned faster... cannot remember my measurements now... darn.
I also recall that one of them was "wonky"... it had slightly unstable speed, especially at higher revs, so it  kick up and down between around 10,000 and 12,000.   These could be seconds, or untested outcasts from a production run.  I don't really know.    But for the price, you can buy 10 and pick out the best ones.  Overall, I think the gray housing ones are equivalent to the Atlas scale speed motors - skewed armature, and 12,000 rpm.

[rrjim1]

I have ordered some of these from eBay before.  There are many sellers on eBay with the same motors.  None of the ones I received would turn anywhere near 46,000 RPM.  I'm pretty sure that's a bogus label.  They seem to top out at around 12,000, and my guess is they are the "scale speed" ones.  There are also black housing ones on eBay.   I bought 3 of each.  The black ones turned faster... cannot remember my measurements now... darn.
I also recall that one of them was "wonky"... it had slightly unstable speed, especially at higher revs, so it  kick up and down between around 10,000 and 12,000.   These could be seconds, or untested outcasts from a production run.  I don't really know.    But for the price, you can buy 10 and pick out the best ones.  Overall, I think the gray housing ones are equivalent to the Atlas scale speed motors - skewed armature, and 12,000 rpm.

That's what I wanted to hear that the motor would not turn faster than 12,000 rpms. I could not see any indication that they are balanced like an Atlas motor?   I don't really need any but for that price I went ahead and ordered some any way.