# Bachmann 2-4-2T Questions



## auburnrails (May 31, 2012)

Hello,

Well, I have a used Bachmann 2-4-2T in the Coal Creek Lumber company scheme. It has ran pretty well but twice it seems like it may have been pushed too hard. Both times it seems to grab and surge, grab and surge, like it's binding at a certain spot. It is more noticable on the curves (4'). The first time the problem went away but this time it hasn't. I did try to take the bottom off so that I could see inside (not sure what I'd be looking for lol) but can't figure out how to remove the bottom to get inside.

I do have a decent grade (don't know the percentage) so I'm guessing I've overstressed it or something. I'm just wondering if anyone has any suggestions or feedback for me? 

On a sidenote, I'm looking at getting either a Bachmann 0-4-0T Porter or a Bachmann Davenport Gas Mechanical. Any recommendation for which would be better with a grade or with reliability in general? 

Thanks!

-Dave


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## lownote (Jan 3, 2008)

I've ever owned one of those, but the drive mechanism doesn't have a good reputation. Bachmann recently re-issued tat model with a vastly upgraded drive mechanism. You might get some help from Bachmann on it--maybe some of the plastic parts could be replaced. I'm not sure--other folks here will probably know more


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## Pete Thornton (Jan 2, 2008)

can't figure out how to remove the bottom to get inside 
If I remember rightly - and it's a long time since I took my "Lyn" apart - you twist off the dome(s) revealing the screws that hold the body to the chassis. Remove them and all will be revealed ? 

I do recall the wheels are just press-fitted into the central gears from each side - only the flanges stop them falling out when the loco is running! If one is binding, you may get the surge effect. 
It sounds to me like one of your wheels isn't tightly fitting into the gear in the center of the axle. I would put it somewhere flat where you can look at both sides, and check that both wheels on each side are identically placed - same alignment, same width between flanges, etc.


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## Amber (Jul 29, 2011)

If it's a colombia type 2-4-2, with a tender, it might have a cracked drive gear. That seems to be a common problem on the older colombia type Bachmann engines.


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## auburnrails (May 31, 2012)

Thanks for the replies. I'll try to disassemble it again tomorrow. My first thought was a gear issue based on previous comments but could it go back and forth between working and not working like it's done? 

Also, I can't remember if I asked about this before but I am using a Tech 3 power pack currently and so even downhill it isn't screaming along while the throttle is on high. It doesn't have a "Amps" register, per se, but it has "Track Current" - is this the same thing? It usually is around 1 or a little over but it swings way up to 3 when binding and then goes down to maybe two for a moment before then binding and swing high again. 

I'm pretty ignorant when it comes to electronics (among other things) so I'm not sure what to read into this. 

-Dave


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## Pete Thornton (Jan 2, 2008)

Posted By auburnrails on 08 Aug 2012 02:46 PM 
Thanks for the replies. I'll try to disassemble it again tomorrow. My first thought was a gear issue based on previous comments but could it go back and forth between working and not working like it's done? 

Also, I can't remember if I asked about this before but I am using a Tech 3 power pack currently and so even downhill it isn't screaming along while the throttle is on high. It doesn't have a "Amps" register, per se, but it has "Track Current" - is this the same thing? It usually is around 1 or a little over but it swings way up to 3 when binding and then goes down to maybe two for a moment before then binding and swing high again. 

I'm pretty ignorant when it comes to electronics (among other things) so I'm not sure what to read into this. 

-Dave Dave,

Yes, [Track] Current is measured in Amperes, or Amps. 1 amp or less would be normal, 3 amps not surprising if the drive is binding ( = "stall current".)

Once you get the chassis out of the frame, you could remove the fake outside frame (2 screws, I think) and the coupling rods between the two wheels (and tape them up somewhere out of the way.) I think you may have to pry them out of the wheels ? As I recall it, the wheels will just pull out - they are push fitted in the central gear.

The motor has two worms driving the axles, so it will work without the external stuff. See if it still binds.


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## auburnrails (May 31, 2012)

Ok, thanks Pete. I do think I need to get a higher power (more amps) power source, but for now I guess this one will do. 

-Dave


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## Pete Thornton (Jan 2, 2008)

Posted By auburnrails on 09 Aug 2012 12:17 PM 
Ok, thanks Pete. I do think I need to get a higher power (more amps) power source, but for now I guess this one will do. 

-Dave


Dave, If it will run your trains and deliver 'stall current' if called upon to do so, it is perfectly adequate.

Train speed is not related to amps. The voltage output is what drives the train. Most large scale trains need at least 14 and often 18 volts. LGB uses 24 volts as do Aristo, etc. Most Bachmann locos are happy at 18V, and I recall the 2-4-2T isn't very fast anyway.


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## auburnrails (May 31, 2012)

Posted By Pete Thornton on 09 Aug 2012 01:39 PM 
Posted By auburnrails on 09 Aug 2012 12:17 PM 
Ok, thanks Pete. I do think I need to get a higher power (more amps) power source, but for now I guess this one will do. 

-Dave


Dave, If it will run your trains and deliver 'stall current' if called upon to do so, it is perfectly adequate.

Train speed is not related to amps. The voltage output is what drives the train. Most large scale trains need at least 14 and often 18 volts. LGB uses 24 volts as do Aristo, etc. Most Bachmann locos are happy at 18V, and I recall the 2-4-2T isn't very fast anyway. 



Well, on full throttle it doesn't move very fast, but maybe that's just how they are. It seems to be drawing 12v-18v at any given time, usually somewhere in the middle. 
Of all the things I've done so far in this new experience, having a grade has been the absolute biggest mistake. Even after leveling it some from my original plan, it is simply too much for the engine to cope with. I'm pretty wedded to this layout for this year as I've planted things and used up most of my budget getting to this stage, but I think I'll need to look at relocating it down the road. 

-Dave


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## Greg Elmassian (Jan 3, 2008)

If you are drawing close to 3 amps and you used a higher current supply, you might overheat the motor... not many motors will handle 3 amps continuous. 

It would not be a bad idea to measure the grade (inches of rise over inches of run) and see if you aren't asking the impossible. 

The Tech 3 packs are inadequate for much of anything other than level track and light duty motors... I gave mine away disappointed. 

Greg


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## auburnrails (May 31, 2012)

Thanks Greg. The pack was a leftover from my N scale set up. I also have a PowerCab so eventually I might go DCC and do the booster, etc. For now, it'll need to get me by. 

I think tomorrow I'll have to find some string and get the grade figured out. It doesn't seem overly steep but I'm not sure how to quantify "overly" without actually measuring it.  

-Dave


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## auburnrails (May 31, 2012)

Well, I measured the grade today and from what I can tell it's in the 4%-5% range. I say "range" because my string had a lot of elasticity and the level I have is a 30 inch thing that doesn't exactly balance on the string well. The main challenge with my railroad is that it's built on a gradual slope from right to left. I excavated the right side as much as I could but some surface tree roots sort of set the floor, if you will. On the left I did build it up a little but obviously not enough. I just got back from Lowes with another 7 bags of paver base that I use for the subgrade. My plan is to build up the left end enough and blend it to the right so that the grade is more like 2%-ish. 

In the interim, with no progress made on the 2-4-2T problems, I've ordered a Bachmann Prospector set as I've had a train crush on the little 0-4-0 for a while now. ha ha I think that by leveling the grade and using some smaller equipment on my tight curves, I should have a better experience. I hope to get the 2-4-2T going again at some point, but summer in Seattle doesn't last forever and it's been disappointing not being able to run a train for perhaps the two best weeks of the summer. If I get it going eventually, I'll have the little Prospector consist and also the logging consist to play around with. 

Oh, and I am adding a short "branch" of about 12' or so to my line that will be used for unloading the ore cars - at least in my head. It should add a visual element to my line and give some more interest when operating. 

Thanks for the feedback and advice. 

-Dave


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## toddalin (Jan 4, 2008)

If it is the old style 2-4-2 Lyn, the power pick-up from the wheels to the contacts is very poor and causes jerkiness.

It is worse if the siderod slips off it's mount. These are held to a squared area by a plastic push-pin. Once the push-pin comes out enough to let the rod slip off the square, there is no easy way to get it pressed back tight enough. But there is another way. You can use a screw and the hole for the push-pin is actually threaded (or at least will accept a threaded screw), though I don't know the thread count.


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## auburnrails (May 31, 2012)

Thanks Toddalin! 

-Dave


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