Lemon Locomotives

[VonRyan]

Since these locos were used (and supposedly modified), is is possible that the seller was simply told by the personhe bought the locos from that they were re-motored, and he simply didn't take them apart to verify that?  While this doesn't make things any better for you, at least it wouldn't make him a lier.

There you go again speaking words of wisdom.

Now how about how to troubleshoot this thing? I got a meter, but don't know how to use it.

[mmagliaro]

Post a pic of the meter.  That will help folks dictate which jack to use and what setting to select on the dial.

You have a brass F3 that gets hot, and one that doesn't.

1. Take the shell off and flip the one that doesn't get hot on its back on the workbench.  Hopefully you have something soft that can
cradle and support it upside down.

2. Set up a power pack, turn it up about halfway, attach clip leads directly to the motor to get it to run. 
Just make sure you've got this working before you go on.

3. Now, let's call those leads "+" and "-"  from the power pack.

4. Set your meter on a current (amps) range that can go up to at least 0.5 AMP (not 50 mA, or uA, or anything like that....
If it reads up to 500 mA, that's okay (500 mA is = 0.5 AMP)
THIS IS IMPORTANT.  If you don't set a decent higher-current range on the meter and hook it up to read motor
current, you will blow an internal fuse in the meter and then you will need to take that apart to replace the
fuse before you can use the meter any further.  (or, if there is no fuse, kiss the meter goodbye)

5. Connect the "-" lead from the throttle to one  motor terminal

6. Connect the "+" lead from the throttle to the "+" meter lead (clip them together)

7. Connect the "-" meter lead to the other motor terminal.

In other words, the meter is "in line" with one lead from the power pack to the motor, like so:



Now, turn up the power pack slowly.  The motor will start to run.  Read the current on the meter.
My guess is that in an engine like that, with a motor like that, you should see something between
100 mA and 300 mA   (0.1 A  and 0.3 A)

----------------
Now, repeat the test with your "hot" engine.   Most likely, you will read a much higher current, like
500 mA (0.5 A), but whatever, we expect it will be much higher.

-----------------
Now, you really should remove the motor from the problem child, and test it by itself, out of the engine.
If it still reads high, then either:

a) There is carbon or oil build up in the commutator slots (and we'll get to fixing that later if this is the case)
b) The motor has a shorted winding, in which case, it goes in the trash and you need to find another motor.

If it does NOT read high when it's out of the engine, you have a serious bind in the drive mechanism somewhere that
is killing the motor with a heavy load.   Since you have the motor out, you need to see if the trucks and gears
roll free all on their own.  Then put the motor back in and see if you can gently turn the motor armature by hand
freely.  Compare it to how freely the "good" engine is.
Either you've got junk in the gears like hardened grease, or a gear mesh is too tight.  Could be other things to.

[VonRyan]

I can't take the motor out of the engine. It is glued in with some mind of black glue. Probably E6000.

[peteski]

At work now holding the meter. Says Fluke 87 true rms multimeter.

Chris,
this meter still have separate low (mA) and high (A) current terminals for measuring current.  From its user's manual (https://physics.ucsd.edu/neurophysics/Manuals/Fluke/87______umeng0800 ):

Autoranges to the 40 mA or 400 mA range when
using the mA mA input terminal, or to the 4000 mA or
10A range when using the [A] input terminal

So it will auto range in each range, but not between all the ranges.  Just like the cheaper multimeters.

[mmagliaro]

I can't take the motor out of the engine. It is glued in with some mind of black glue. Probably E6000.

Can you post a photo of what this thing looks like inside?  You say it's not like the ones on Spookshows loco encylopedia
site, so we should see what we're dealing with here.

(By the way, I noticed that you didn't take my advice to focus on the Kato F3's first      I still recommend doing
that before working on these brass thingies

[peteski]

I can't take the motor out of the engine. It is glued in with some mind of black glue. Probably E6000.

Can you post some photos?  If you can't remove the motor then it will be more difficult to determine whether the problem is caused by the motor itself or by binding gear train.  Also, if the motor is glued in then the loco was most likely re-motored by the previous owner - I don't think that factory-installed motors were glued in.  I'm also not sure how you arrived at the conclusion that it is not a Sagami motor - Sagami makes open frame and can motors.

[victor miranda]

usually one side of the motor is to chassis.
take the loco off the tracks. clip a wire one rail to chassis
put the meter from other motor lead to other rail.

hot will be over about 300 ma.
it is a question of how long it takes to get hot.

fixes will be getting the worm bearings loose
and then gear bearings.

victor

[Chris333]

Chris,
this meter still have separate low (mA) and high (A) current terminals for measuring current.  From its user's manual (https://physics.ucsd.edu/neurophysics/Manuals/Fluke/87______umeng0800 ):

Autoranges to the 40 mA or 400 mA range when
using the mA mA input terminal, or to the 4000 mA or
10A range when using the [A] input terminal

So it will auto range in each range, but not between all the ranges.  Just like the cheaper multimeters.

I "think" what I meant to say was millivolts not amps. It will change the voltage range automatically. oops 

[Chris333]

OK I guess I will put this here since it will also help Cody...

I while ago I think it was back when Max built his 2-10-0 from Kato parts. He put a 6volt motor plus gearhead in it and I tried to follow his lead. Either here or at Atlas he showed how he worked out any binds by checking the amp draw. At the time both Max and Victor tried to explain all this to me. First it was found that I had a very old, not so good working pocket meter so I ran out and bought the one I have now. I forget the details then, but I couldn't figure it out and though you guys just had much better $400+ meters or something like that. I gave up on the meter thing, but my 2-10-2 runs just fine

Just now I ran downstairs and hooked up the meter to the layout. I was pulling 20 cars with a LL Berkshire and got this:


It reads 0.16 .

So after you all roll your eyes let me know what that means or what I did wrong. 

[peteski]

LOL Chris!  You are in a 10 Amp range and the meter indicates a current draw of 0.16A (which is 160mA - you just move the decimal 3 places to the right, since "milli" means "thousandths").

That seems quite reasonable for N scale loco pulling a 20 car train. Some Kato locos have their current rating indicated on the back of the box. IIRC, it states 12V, 250mA max current.  That is operating (not stalled) combined motor and headlight current.

I don't see anything wrong with your use of the meter.  I suppose that you could have plugged the positive lead into the other terminal, then selected the 200mA range. But that set of ranges is fused with a fuse (probably 250mA fuse). If your loco stalled and started consuming more current (over 200mA) then the fuse would have blown.  So, you did very well! 

[alhoop]

I'm flabbergasted at the number of modelers who do not keep track of how much current each of their locomotives draw under normal
operating conditions.http://www.tonystrains.com/technews/cmc_wiring.htm
When a  PM DC motor draws excessive current the motor magnets are heated and weakened which leads to more current draw which leads to
more overheating which leads to more current draw which leads to..... ad infinitum.
I had a Hallmark FT unit(bought off Ebay) where this happened - part of the trace where the trucks make contact  was burned away and yes the
 motor magnets were severely weakened. Such a motor will appear to run normally under no load but will slow down and draw excessive current under load.

Al

[brokemoto]

Since these locos were used (and supposedly modified), is is possible that the seller was simply told by the personhe bought the locos from that they were re-motored, and he simply didn't take them apart to verify that?  While this doesn't make things any better for you, at least it wouldn't make him a lier.

It may not make him a liar, but it makes him at best, irresponsible; at worst, something less than honest.  If I sell something at a show or on FeePay that somebody supposedly modified before I received it, I state that the person from whom I acquired it said that he did whatandsuch to it, but that I have not or can not verify that.  The seller should have told VonRyan that the person from whom he acquired "stated" that it received new motors, but that he had not verified it or was not able to verify it. 

If someone tries to sell me something that he states has had an "upgrade", if I can not verify it, I ask him if he has or is able to verify it.  If I can not receive a satisfactory answer, I decline to spend my money.  If he is willing to refund my purchase price should I be able to verify that the claim is inaccurate, I MIGHT open my wallet, but even then, I would have to think hard about it.

Some people will tell you anything to get your money, especially when it comes to a millstone such as N scale brass.  Many people in N know that it brass is pretty, overpriced, poorly operating HOON-kay.  For that reason, they will not buy it.  I bought it once, that was enough. 

The sad thing for vendors is that they can not cut the price of brass too far, as they get little, if any, price break on it.

[LV LOU]

OK I guess I will put this here since it will also help Cody...



Just now I ran downstairs and hooked up the meter to the layout. I was pulling 20 cars with a LL Berkshire and got this:

It reads 0.16 .

So after you all roll your eyes let me know what that means or what I did wrong. 

 Chris,that's just about what you should be seeing.My lowest draw stuff runs maybe .09,the worst,like a 3 unit set of old Arnold FA's,might draw .35 or so if all is well.

[mmagliaro]

Yep, 0.16 ...think of it as 0.160, or 160 thousandths, or 160 milliamps
I agree with Victor, that I start to get suspicious of excess bind or polluted commutator slots, at around 300 mA,
but 250 is not uncommon for a normal engine.   Many older Kato diesels draw that, Con-Cor Hudsons draw that,
and even Kato Mikados surprisingly draw that much (although a little tweaking on them usually gets it down under 200).

Yes, good tip on clipping one lead to the frame.  On that brass loco, one motor lead is surely tied to the frame.

[Chris333]

A Bachmann 44T pulling the same train was 0.03 so 30 milliamps.