# Why Bachmann Owners Keep a Wall Handy...



## rdamurphy (Jan 3, 2008)

So we have someplace to pound our heads...

K27 smoke

Robert


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## DKRickman (Mar 25, 2008)

I love the way they threatened to close the thread as soon as someone suggested that the models could be improved. That's why I don't participate in manufacturer hosted boards.


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## TonyWalsham (Jan 2, 2008)

They did close the thread. 
I actually agree with the Bach-man that yes, the fan was designed to cool the motor and not assist smoke. However, they obviously did not actually test it to see what happened. As it is the boiler shell acts as an air funnel and sucks the air back down the smoke stack. 
Even so, because the laws of physics say hot air rises I would have thought that having the fan suck the air up past the motor and blow it out of the stack, would result in better motor cooling anyway. 
By the same token, actually swapping the fan around is not that easy. You have to use different (as in shorter) length screws to hold it in place. Then comes the problem of getting the boiler shell back on. Very difficult unless you use the "chamfer the lower inside edge of the smoke box" trick.


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## rdamurphy (Jan 3, 2008)

Tony, I have two K-27's, one of the first run, that had to have the counterweights replaced, and one of the newer ones with the metal trucks. Bachmann installed the fan in the early model to blow down. In my other model, the fan is installed - by the factory - to blow up. It has different screws and is installed differently. 

So, now Bachmann is going to argue one is "right" and the other is "wrong?"

Huh?

And, let's be honest here, the only way the fan is really going to do anybody any good is if used with DCC - so it runs at full speed at all times. Or if wired up that way with RC. With normal DC, it stops when the loco does - which is when the motor is idle and needs the cooling help the most! Cars don't oveheat going down the highway, they overheat sitting still at idle... 

Robert


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## Ralph Berg (Jun 2, 2009)

Air cooled and water cooled are two different beasts. As are electric motors and internal combustion engines.
If the electric motor isn't turning, it's not generating heat. However, your car engine runs at idle and does generate heat.

Likewise, the electric motor doesn't care which direction the air flows to cool it. So the direction of airflow that makes the smoke generator work properly, would be the correct air flow.
Ralph


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## Greg Elmassian (Jan 3, 2008)

Not the same thing here. 

Electric motors create more heat under load, not stopped. 

A car does not stop it's motor when idling, cars get mega cooling by airflow when moving, when stopped they only have a fan.

This is not the case with the enclosed boiler. 

Greg


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## Dr Rivet (Jan 5, 2008)

Calling Chuck N 

Based on the Bachmann site, I guess your K-27 has probably deformed in the heat since the fan had to come out to fit in Rodney's gear box. We are DOOMED!! 

Most import thing I learned was that black engines get hot? So a green boiler version doesn't????? HUH!! 

Please respond at your earliest convenience, but stay away from the chemistry stuff. 

Still cleaning up after "Derecho".


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## chuck n (Jan 2, 2008)

I guess that I was lucky I still have a working engine after last Wednesday's running of my K-27 for two hours in 90 degree weather and pulling a train that weighted about 98 pounds. If the motor was going the heat up significantly, it should have done in Wednesday.

See July 26 post in the "Happy Camper..." thread. 

That post details Wednesday's test run. 

I have run the engine many times with Rodney's new drive and the only heat I notice is that from the solar radiation. 

Chuck


PS I had forgotten that we had to remove the fan to get the new drive into the boiler. 

In most of my engines, if it doesn't have a smoke switch, I will cut one of the wires leading to the smoke unit. I have put a small on/off switch in some of my LGB engines so that I could control the smoke. I did that after the smoke stack in one of my moguls deformed from running it without smoke fluid. Now I just cut the wire.


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## toddalin (Jan 4, 2008)

Posted By rdamurphy on 28 Jul 2012 11:07 PM 
So we have someplace to pound our heads...

K27 smoke

Robert



Far more satisfying to throw the train against the wall!

Unfortunately, that satisfaction is short-lived.


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## Curmudgeon (Jan 11, 2008)

One of the visiting designers of the K told me one why the fan was installed. And the external thrust bearings on the motor. And why it has 14.5:1 gearing. And the inverted chuff signal. 
I've been running mine with A) no fan at all, and B) no thrust bearings (or flywheel) since it was 3 weeks old. Still fine. 

The issue seen on the BM forum is endemic to at least that brand, and why I will never, as in ever, buy another BM unit. That is sort of arguable, since I have more on-site than I will ever need, but attitudinally I cannot deal with them or their visiting dyslexic designers any more. 

Motors being fan cooled. 
Let's try to understand that. 

It's a Pittman. 

There are no holes in the motor case or ends to allow cooling air to flow. 
Additionally, there are no cooling fins attached to the case of the motor. 
How effective is the fan, especially at low speeds, track power, climbing a 4% with 12 cars? Is the fan just slowly circulating hot air? 

I am no longer interested in doing any testing to have data to tell you....but think about it. 

On a Mabuchi with holes in the case and vents in the ends, maybe, but not a sealed, smooth cased unit. 

The question was on smoke. 
Yet, the folks who run the dis-information service at BM made it a bad thing to discuss. 

Makes one wonder. 

In automobiles, on a radiator, does it make any difference if the fan is sucking air through from the back side or blowing it through from the front side? 

You would be surprised at the answer, wherein British cars experience less cooling efficiency with the water pump mounted fan removed and an electric fan mounted in front of the radiator that stock. 

Obviously, since later units have the fan reversed, BM/Kader/visiting engineers found it made no difference. 

With the recent revelation that Chairman Ting (the younger) just resigned at Kader, being replaced with Chairman Ting (the elder), if someone finally realized there might be an issue with consumer confidence? 

We'll never know, other than possibly a visiting engineer telling us we don't understand. 

Yes, someone directed me to this thread. 

After I finished laughing, got up off the floor, and re-attached the parts that fell off, I decided to post, then log out again! 

TOC


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## rdamurphy (Jan 3, 2008)

Actually, I was using the gasoline motor as an example, I realize they're different, somewhat of an metaphor. I didn't really think about the Pitmman being a sealed motor, but an open frame motor will cool better while it's running. 

Like TOC said, it would take an awful lot of research to figure out if the fan really works. And where. If you live in the desert, or at altitudes over 5000 feet, air cooling isn't really a good idea. Just ask any VW owner in Denver on a hot summer day. They're easy to find, they're stalled on the sides of the highway. 

BTW, the plural of "it" doesn't use an apostrophe. (BTW,


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## chuck n (Jan 2, 2008)

Without Bachmann's quality control (?), I wouldn't have had the opportunity to meet or learn about three very knowledgeable and help full individuals. Thanks to TOC, Barry and Rodney, I have a Connie and two K-27s that I really enjoy running. Their suggestions and improvements are great.

Thanks guys!!!

Chuck


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## Steve Stockham (Jan 2, 2008)

Chuck, I couldn't have said it any better! Those three have made my K and Connie two of my absolute favorite engines! 
By the way, I stopped over at the Bachmann site. Who's this "Yardmaster?" He sounds like he came over to Bachmann from the Aristo site! 
There are ways for people to get information but the factory sites aren't it!! (Sheesh.... "This thread is very close to getting shut down!")
You have the first issue with the fan going one way and the second issue with it going the other(??!!) Umm... I'll keep my mouth shut cause
I don't want to offend someone at Bachmann!


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## Greg Elmassian (Jan 3, 2008)

Hmm... changing production to reverse the fan kinda admits it was basically "wrong" in the first place. 

Yeah, manufacturers sites are the wrong place to get unbiased helpful information... I was Lewis' "pet engineer" until I wrote up about all the problems in his "prime mover"... then I had to promise to never say anything negative again the rest of my life in order to stay... 

Greg


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## rdamurphy (Jan 3, 2008)

I must say, the quality issue certainly does allow you to meet new people! My second K had two wires reversed on one of the circuit boards, meaning it wouldn't go forward. Or reverse. It did, however, just sit there and look awfully pretty! Stan Ames - and others - helped me troubleshoot it. I've also had to learn how to compensate for the fact that Bachmann wired the chuff triggers in exactly the opposite way of everyone else on the planet. I would say "wrong", however Bachmann doesn't seem to like the word "wrong." Since the provided wiring diagrams don't exactly tell you where the wires go, I had to locate the ones on the 'net that are more usefull. 

I could go on, but then again, why would anyone point out that we had to replace our counterweights on the early models, not because the original ones were "wrong" but, hmm, why did we replace them again? 

Robert


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## TonyWalsham (Jan 2, 2008)

Bachmann, to their credit, did replace the counterweights without any argument whatsoever. 
Not only that, but they also fixed that problem for the second run and at the same time made a huge improvement to the tender trucks. 
Sure the chuff signal is back to front, but it is a really easy fix that costs all of 5 cents in parts. 
I haven't seen a sample where the fan has been reversed but I don't doubt that they have. 
Having converted dozens of them to battery R/C without needing to gut the wiring, I can honestly say there has never been a wiring mistake or failure in any I have seen. 

That just leaves the gearing...............


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## chuck n (Jan 2, 2008)

Steve:

Thanks for the positive comments. I think that it would be nice if others who have benefited from the BIG THREE, might add some comments. They have save many locomotives from being shelf queens to valuable running locomotives. Perhaps someone at Bachmann might see it.

Chuck

PS I try to add constructive comments to the Bachmann site, but more often, than not, the beginner who asked the question never responds to anyone's comments.


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## rdamurphy (Jan 3, 2008)

Tony, you make some good points. In reality, I wouldn't give up my K's for anything, my wife asked me if I wanted to be buried with them. The link I posted is just a really bad example of customer service. If there's a problem, admit it! And then come up with a fix. As you mentioned, there's a no-so-simple fix for the inverted chuff signal. Sure, it' may only cost a nickel (I paid $.50 a piece for my transistors) but it does require understanding a wiring diagram and soldering. And, if you screw it up, I suspect it would void the warranty. You could also fry an exensive decoder. Why not fix it on subsequent runs? 

Robert


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## chuck n (Jan 2, 2008)

deleted


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## norman (Jan 6, 2008)

Hi TOC and folks: 

I guess it could be argued that the metal case of the Pitmann motor acts as a heat sink and that the fan is used to move the radiating heat? 

Non issue for me as the K-27 is too large a loco for myself. The 4-4-0 is my size limit. 

Have folks looked at the Train World Bachmann current pricing of the K27, the forney and the E&P 4-4-0 now at 550.00 ( was once as low as 250.00 ) ? 

I really do not see much of a future for Bachmann large scale loco sales at those prices. 

The upgraded Aristo Craft C-16 is still affordable. But the majority of folks want 1:20.3 . 

The Bachmann Annie is affordable. But how many locos of that style does one want to buy? 

I think that eventually we will all look back to the days of when Bachmann trains had design and assembly problems but that at least their locomotives were once extremely affordable. 


Norman


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## Greg Elmassian (Jan 3, 2008)

Not argued, it is basically the heat sink, but with so little surface area it works poorly. (Also, internally the pitmann motor does not have a good path for getting heat to the outside). If you go to their site, and you have an engineering background, or even just a scientific background, it becomes readily apparent that these are instrumentation motors, designed for intermittent duty, and while they can handle high current and voltage for a short time, extended running will destroy the motor. 

I have personally melted one solid. 

As much as the Pittmann motor is touted, the motors that Aristo makes with the cooling fan and ventilation slots are far superior for our use. 

Greg


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## rdamurphy (Jan 3, 2008)

Fascinating, Greg. But it makes perfect sense. I suppose since the Pittmans are readily available and "fit" voltage and anmerage wise and have a good reputation, they've become a defacto standard in miniature ferroequintology. Maybe, along with regearing the K's, we should work on a replacement geartrain/motor combination? 

Robert


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## Greg Elmassian (Jan 3, 2008)

If you should ever be curious, you can see the actual graphs of voltage, current and torque for each motor. 

My first in depth experience was my AML K4, and it would not pull well. It had a very "tall" gear ratio. I got a lot of information from TOC about this also. So as I tried to get it to pull more, I had slipping drivers... 

So I added more weight... I think I added 5 or 7 pounds, and finally it would pull a decent passenger train, but now I was pulling peaks of up to 5 amps... literally melted the motor solid inside (plastic insulators, etc.) 

Went back to the graph on the pittman site... shows torque and voltage and current where I was operating, so was pretty confused. 

Then looked closely, part of the graph is shaded... in the footnote below it said "operation in this area is not possible, the curves are theoretical only, damage to the motor will occur if operated in this area" or something really close. 

Then I finally looked at the "legal" part of the graph... my motor was only rated at 7 TENTHS of an amp max !!! So running at 5 amps, or 50 tenths, was death. 

Most motors in our stuff will run at a couple amps all day... 

Pittman got a great name for ball bearings and quality construction, but the models chosen are not always appropriate. I know the Bachmann one is heavier duty, but still, no fan, no cooling slots... just plain goofy. 

Greg


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