Key Imports PRR I-1

[mike_lawyer]

Thanks for the info Max, it will be interesting to test those Mabuchi motors.  I still have not completely given up on using a Faulhaber with the gearhead, but it will be very tight if it fits.  I need to play with it some more.  Obviously, the Faulhaber is the A answer, but if I can't use it, the Mabuchi is probably the best bet. 

One of the projects I need to do before I remotor is to figure out how to smooth out the siderod motion.  There clearly is "tightness" in the rotation where it is harder for the motor to rotate the drivers.  Not sure if one of the drivers or more is slightly out of quarter or what.  With only one driver geared and the rest driven by the siderods, any driver out of quarter can cause problems.  Is there a quartering jig available in N scale? If anyone has any other ideas on how to diagnose siderod rotation issues, I am all ears.

[mmagliaro]

There is no N Scale quartering jig.  There have been a few obscure ones that I've seen mentioned in places like the 2mm Society in the UK, but actually finding any of them for sale was a blind alley.  And on brass locos, I wouldn't count on all the drivers being quartered correctly anyway. They could all be set at 85 degrees instead of 90, or be set at 90 with some filing and reaming just to get them go around however they could.  Unfortunately, that is a fact of life with brass.  Mark (spookshow), reports a slight bind at one spot in the rotation in his review of the engine,  and looking back at my notes on one I repaired, I wrote that it also had a bind in its rotation, so I bet it is a common problem on all of them.  I did not fix that problem on my repair subject because the owner was happy enough with it and it would have taken more time and money to dig into it.  Getting 5 drivers to go around all on the rods in an N Scale model is going to be "challenging" to say the least.   Make sure the valve gear aren't bent in and the crossheads do not bind at all as they slide back and forth in the guides.  I have seen that make the drivers bind up just like a quartering problem.

I came across one other option for your motor.  Do you have 13mm of width in there, or are you stuck with only 10?
The Maxon RE series 13 x 20mm motors  are monsters for power and you could couple one up with the rubber tube.  Maxon
makes a version with a  1.5mm shaft.    Motor 118414.  You can buy it direct from Maxon on line for a pretty penny
if you really want to do this.  (77 Eur or about $82 right now).     I also have a stash of some older-generation A-max series
Maxon 13mm x 20mm.  The motor output shaft has a pinion on it, but that could be pulled off.  PM me if you are interested.
I'll sell them cheap because I don't have any use for them and I have too many anyway.  They are not as powerful as
the RE series, but they are still really powerful.

[mike_lawyer]

Max, I measured with a caliper and I have 12.5 mm to play with.  So that Maxon won't fit.  I suppose I could try to find a Maxon 1017 or a straight Faulhaber 1016, those would fit.

As far as the slight bind, I tested it on my work bench tonight, and I think it is really more of a function of the three pole stock motor.  At low voltage, it simply lacks the "girth" to keep everything moving smoothly.  Once I get it up to even a slower steady speed, you do not notice any issues at all.

I am going to test out the 5 polers that I have coming over from China, and also continue to see if I can somehow make the Faulhaber + gearhead work.  There might be barely enough room in there for it.
 

[mike_lawyer]

Max, I was able to score a Mashima 1220 for a good price, and it fits nicely inside the boiler.  It looks like I will have to fabricate a bracket to hold the motor.  What size steel would you recommend for fabricating a motor bracket?

[mmagliaro]

Max, I was able to score a Mashima 1220 for a good price, and it fits nicely inside the boiler.  It looks like I will have to fabricate a bracket to hold the motor.  What size steel would you recommend for fabricating a motor bracket?

As thick as you can stand it!  LOL!
But seriously, it has to be something you can bend without resorting to a sledge hammer, yet still be rigid so that it
won't cave one way or the other over time.  I think a 1/16" thick strip should be plenty.  How thick is the bracket that's in there now?  Just go with that. 

[peteski]

As thick as you can stand it!  LOL!
But seriously, it has to be something you can bend without resorting to a sledge hammer, yet still be rigid so that it
won't cave one way or the other over time.  I think a 1/16" thick strip should be plenty.  How thick is the bracket that's in there now?  Just go with that.

1/16" ?!  That is seriously thick!
I would think that 0.020" or 0.032 (1/32") steel (or even brass) strip would be plenty strong. I have some steel blank PCI slot covers I saved when I build my PC, and those are 0.030" steel. Plenty stiff.

[mike_lawyer]

1/16" ?!  That is seriously thick!
I would think that 0.020" or 0.032 (1/32") steel (or even brass) strip would be plenty strong. I have some steel blank PCI slot covers I saved when I build my PC, and those are 0.030" steel. Plenty stiff.

I removed the stock motor tonight and looked at the bracket and holes.  By sheer luck, the holes on the Mashima 1220 line up perfectly with the holes on the existing L-bracket.  So it doesn't look like I need to fabricate a new bracket after all.

After removing the motor, I was able to move the drivers by hand.  No binding or anything, it is smooth as silk. So I suspect some of the jerkiness at low speed may be a combination of a 35 year old 3 pole non-skew wound motor and electrical pickup issues.

So the only thing I need to do is cut down the two shafts on the Mashima motor to fit.  I assume the best was to do that is to use a Dremel to cut them down?  Or is there a better way?  I don't want to risk fouling up the motor itself.

[peteski]

So the only thing I need to do is cut down the two shafts on the Mashima motor to fit.  I assume the best was to do that is to use a Dremel to cut them down?  Or is there a better way?  I don't want to risk fouling up the motor itself.

Yes I use a cutoff wheel in a Dremel.  First I wrap the motor tightly with masking tape. On the end where I'll be cutting, I push the shaft through a piece of tape and I wrap the that piece of tape tight around the motor.  That way none of the metal particles from the cutting operation will get into the motor.  most of the shavings will likely concentrate on the surface of the tape around the motor's magnets.When done I take another piece of tape, and with its adhesive side I pick up as much of the shavings as I can.  Then I carefully remove the tape wrapped around the motor.  I might be a bit anal, but I don't see anything wrong with being cautious.

[mike_lawyer]

Update - I installed a Mashima 1220, and unfortunately it is too wide to fit in the boiler.  It will fit in part of the compartment, but not far enough forward.

The good news is that the jerky and clogging at low speed is definitely caused by the stock motor.  The Mashima was very smooth at low voltage.

I received 4 Mabuchi FT-010SA 24 volt motors.  I think I might try to install one of them, but I will have to modify the L bracket that holds the motor.

The stock motor is a 3 pole straight 1020.  The Mashima 1020 would be a perfect replacement, but they are very hard to find.
 

[mmagliaro]

Drat.  So close, but yet so far.
I would like to add one tidbit to Peteski's very good description of cutting off a motor shaft.  I also wrap the motor with some masking tape.
(and after I start putting those super-strong neodymium magnets into Rivarossi motors, that became IMPERATIVE because wow, do those magnets pull in anything metal!  The masking tape shield is positively coated in metal dust after I cut off a shaft.  But I digress...)

Be sure to use some small needlenose pliers to hold the motor by the shaft you are cutting when you do this.  Ideally, grip the shaft
close to the motor, and make the cut on the other side of the pliers, away from the motor.  The shaft gets burning hot very quickly when you cut,
and that heat can damage the armature.  The pliers act as a heat sink, keeping the shaft from heating up so much.

[mike_lawyer]

Max -

Any recommendations on a 5-pole skew wound motor that is 10mm x 20mm?  You said the Mabuchis are 3 powers, I didn't know if it might be preferable to a 3 poler. 

[mmagliaro]

Max -

Any recommendations on a 5-pole skew wound motor that is 10mm x 20mm?  You said the Mabuchis are 3 powers, I didn't know if it might be preferable to a 3 poler.

Whether they would be better than the Mabuchi, I have no idea.  That little Mabuchi starts at about 3v and runs very quietly and smoothly, just as-is.  It has a 1.5mm shaft and a rectangular frame which makes it easier to mount than a round can.  But I don't know how it would actually perform in your engine.  I only steal the armatures out of them for Rivarossi rebuilds.

There are some 10x20 coreless from Tramfabrik (you can find them online and on ebay).  Never tried them, but they are not expensive and might do the job.  There are a number of "knock off" 10x20 coreless motors around on eBay, but I have no idea if they are durable enough for loco use.  Particularly, the brushes in a lot of low-end coreless motors don't stand up well (as in, burn out in 10-20 hours of use).   And mounting one will require some sort of home-made bracket.  You will also have to sleeve up the shaft as most of these, if not all, have 1mm shafts.

There are some Mashima 1015's around on the internet.  They aren't cheap, typically $40 - $50.  That would fit, according to what you are measuring, and won't have the power of a 1020 or 1024, but still should be a lot better than what was in there.

The 5-pole open frame motor from the pre-2017 Bachmann 2-8-0 was a very good motor.  You can still buy them from Bachmann's website for about $15.   I don't know the dimensions of it off-hand.  Maybe somebody else here with a spare one lying around can measure it.

 

[mike_lawyer]

I wish if there was some reliable data on all the motors from Cina on Ebay.  Most don't say how many poles the motor has, and many don't give much info on the rpm speed at 12 volts.

It's too bad Mashima is no longer made, they were excellent motors and you could find good data on them.  With the motors on Ebay, it is kind of a shot in the dark.

[kiwi_al]

I wish if there was some reliable data on all the motors from Cina on Ebay.  Most don't say how many poles the motor has, and many don't give much info on the rpm speed at 12 volts.

It's too bad Mashima is no longer made, they were excellent motors and you could find good data on them.  With the motors on Ebay, it is kind of a shot in the dark.

if you look for the motors on Aliexpress they usually publish some or all the details you are after, some are better than others at doing this

[mike_lawyer]

Received a Mashima 1020 in the mail yesterday.  That motor is really smooth, and I like it.  The only problem is that it is still geared pretty fast.  Ideally you would like to have the top speed be about 1/3 of the current top speed.  It's really too bad a Faulhaber 1016 with a 4:1 gearhead will not fit in this locomotive.

One thought I had was whether it might be worth trying to regear the locomotive for a better gear ratio.  I have not calculated the current gear ratio on the locomotive, but I am betting it can be improved.  I know NWSL sells main gearing replacements.  Has anyone used them before for N scale brass locomotives?