Info re Bachmann K-27 from owners

Some of this I can answer, and some I can't, for reasons that will become clear....

First of all, the K is a great looking model. I happen to have the post wreck 455 version lettered for my own railroad. Stopped and posed someplace it looks, well, fantastic. All it needs is some weathering to take the shine off of some things, and accent some others, and folks will drool.

The problems come primarily when you want it to move.

There is what is now a well documented problem with the running gear. There was a machining problem with the counterweights on the first batch that required the shimming or replacing of the counterweights, and they did make counterweights availalble to those who could swing the replacement process themselves. Newer K's should have the replacements already installed.

There is an issue with the horizontal play in the axles on the locomotive. On mine, Dave Goodson was good enough to lock the first and fourth axles with washers. This solves the problem of the locomotive sliding sideways on curves and striking objects near the track because the whole locomotive tended to travel to the outside of the curve, but still allows the inner axles to slide, which helps the locomotive on tighter curves. Other people have come up with other solutions, or run theirs as-is, in some cases adjusting the clearance along their lines to accomodate the 'slide."

There is an electrical issue whereby the chuff trigger requires power for the light source in the optical chuff ... this makes the chuff inoperative at low speeds without modification. The chuff was also designed on a positive trigger instead of a ground trigger, which posed some problems with some existing control and sound systems. Those users who chose to use "auto chuff" of one kind or another avoided the issue entirely, and others installed circuits to power the light source, and invert the chuff signal. On mine, Dave Goodson installed a new chuff timer of the magnetic reed type on the rearmost drive axle, which works very well, and again circumvents the entire problem.

There are some questions as to the current handling capabilities of the on-board electronics. My locomotive is equipped with battery power and radio control, and most of the factory wiring (the ubiquitous "Super Socket") have been removed .... so I'm not in a position to comment personally on the extent of the problem. You might ask Bob Grosh, or other users who installed DCC equipment about their results with this.

There are some users who find the color of the marker lights and quality of the headlights is not what they wanted and replaced them with incandescent lamps. This is the case with my locomotive, and I'm very pleased with what it looks liike now.

Finally the motor and gearing produce some interesting problems. The locomotive has a large motor and very solid metal gears, which is good ... but the gearing of those gears is such that the locomotive behaves as if it were a truck stuck in third or fourth gear sometimes, and has some issues with acceleration (see: very steep (fast) curve) and a lot of power consumption in the higher ranges. That said, the locomotive will pull prototypically long trains nicely, and with a little practice on the throttle can be made to run well, however if you have grades on your layout, you will find it difficult to find a "cruise" speed and walk away from the controls, particularly with a long train. To date there is NO fix for this particular issue, but I understand that the speed control inherent to some DCC systems may deal with it somewhat.

Other than that, there's a fan in the top of the boiler that needs to be reversed (physically) or it sucks the smoke back down the stack (if you use smoke) versions with the plow need a whole new pilot deck if you plan to remove the plow, and the sun shades over the cab windows are quite fragile so you need to be careful with them, both installing and adjusting! But none of those are really a huge deal.

Mostly, I like mine VERY much ... it's the flagship of the Slate Creek fleet .... and now that it's been "K-Rexxed" it's a lot of fun to run as well. I say go for it, and work out the bugs... well worth it. 8' curves are a bit tight ... but from what I understand, if you don't have clearance issues, and can oil your flanges a bit, you'll make it.

Matthew (OV)

http://bp0.blogger.com/_3Hdj0jDlqqs/SISBg3FnHzI/AAAAAAAAADM/X_hkbtxjSfI/s1600-h/DSCN2565.JPG

Matthew.... Great response. Thanks for taking the time to cover all the bases for me and at great length. /DesktopModules/NTForums/themes/mls/emoticons/wow.gif I know it's a great looking loco from the pics in Garden Ry mag, but operation is more important. That'd be an expensive model to park on a library wall! Who is Dave Goodson and how does one go about getting him to modify all those design flaws? BTW, I won't need the loco until next May as my pike is at my summer home in Colo; maybe Bachman will fix some of the problems before then????/DesktopModules/NTForums/themes/mls/emoticons/whistling.gif As they say in Italian, "Speriamo!", i.e. let us hope! Thanks again!

A while back someone here at MLS was having trouble with his K derailing. I made some measurements on mine and discovered that there was a small gap between the engine and the tender on 8' diameter curves and a much larger gap on 10' diameter curves. Extrapolating those measurements I've concluded that the engine (cab) and the tender would touch on curves between 7 and 7.5'. Tighter curves would require a longer drawbar. I also thought that there was no lateral play in the drivers on the 8' curves. Any tighter curves would most likely cause excessive wear on the track and drive wheels.

I have two of the K-27s (#453 and #455). I received 453 in early January, by mid-January I had to shim the drivers, no problems since then. When I bought 455 in April I ask the vendor (Caboose Hobbies) to fix the drivers before they shipped the engine to me in Virginia. The engine has run perfectly since I received it. I have not added sound or batteries so I cannot answer any of your questions along that line.

There are the minor problems that others have mentioned, the dim head light and the reddish marker lamps, but I'm not planning to do anything about that at the moment.

My roadbed isn't the greatest. It took me 2 years of tweaking the roadbed and my Accucraft K-28 before it would go around the track once. The Bachmann K has great suspension and handles my roadbed like a good mudhen should.

It's a very good engine and it pulls nicely. If you want a reasonably priced K, I can strongly recommend it.

Chuck N

I'm beginning to lust after the Bachmann K-27 but have several concerns that you pioneering owners might be able to help me with. I am in a small town in the mountains of Colo and do not even have access to a hobby shop to look at one. From reading the threads, it appears that Bachmann has now solved most if not all the serious design issues. 1) Am I correct on this?

Unfortunately, I have several curves on my layout where I had to use 8' diameter track. 2) Will the K-27 easily take 8' diameter without larger diameter transition track?

Finally, I had to quit using a Bachman Annie on my Aristo stainless 4 years ago as I am convinced that some sort of electrolysis occurred between the cast drivers on the Annie and the stainless track: required serious cleanup every 10 minutes of operation to the point of serious frustration. (I had no problem with the turned steel drivers of my LGB locos.) Of course, that was just on DC, not DCC which I am presently using. 3) Does the K-27 have power pickup thorough the drivers or throuch a 'shoe' a la LGB? 4) Are the drivers of the K-27 cast rather than turned? 5) Has anyone with stainless track experienced unusual black deposit on stainless while using the K-27?

6) Any recommendations of DCC decoders for ease of installation on the K-27?



I can perhaps answer all your questions. I currently have 3 K27 models on my layout. I have both stainless and brass track, run both DC and battery power, and have numerous LGB 1600 turnouts (which are gradually getting replaced on the main line)

I should note that I did provide some thoughts to Bachmann prior and post release and and this locomotive is clearly my favorite locomotive on my railroad.

The very early first production locomotives had loose counterweights. While there are likely a few of these models still in the market with this issue, Bachmann replaced all the ones that Dealers notified them on. If you get one of these Bachmann will supply free replacements which can easily be replaced.

The power pickups are through the drivers and work exceptionally well in both DC and DCC. With one K-27 I have installed Hybrid Drive so that I do not have to clean wheels or track. My others have other boards at present and work fine but these do have to have their wheels cleaned from time to time like any locomotive. As an aside installing Hybrid drive on your Annie will completely solve the issue you were having with the wheels.

The K27 has the expanded Aristo Craft socket which is identical to the one Aristo has been using for about 10 years. You asked about DCC use. QSI and ESU have DCC sound boards that plug into the socket. The ESU board supports all the functions including sound with no modifications. The QSI board requires a simple inversion transistor should you wish to use the on board chuff circuits rather then the boards auto chuff feature. There is one chuff sensor in each cylinder triggered at the half way point.

Perhaps it would be useful if I also commented on some of the comments that Matthew provided.


There is an issue with the horizontal play in the axles on the locomotive. On mine, Dave Goodson was good enough to lock the first and fourth axles with washers. This solves the problem of the locomotive sliding sideways on curves and striking objects near the track because the whole locomotive tended to travel to the outside of the curve, but still allows the inner axles to slide, which helps the locomotive on tighter curves. Other people have come up with other solutions, or run theirs as-is, in some cases adjusting the clearance along their lines to accomodate the 'slide."



As shipped the drivers of the K27 locomotive can go around 5 ft curves.(the total locomotive an tender need a little more then a 6 foot diameter). This is accomplished by a design with has an inner and outer axle with side play. Many of us have layouts designed for smaller locomotives and the K27 is rather large by comparison. Because of the locomotives size and design the side to side play can cause clearance problems on many layouts. As noted Dave Goodson developed a method to reduce the side to side play by locking the 1st and 4th axles. I did this on one of my K27s. Because of the subsequent tendency to derail I quickly altered the approach. One can accommodate 90% of what Dave was trying to accommodate and improve the locomotive tracking at the same time by locking the 2nd and forth axles. Locking the axles will indeed reduce side to side play but will increase the radius required. With this mode the locomotive will still easily handle LGB 1600 curves This after market improvement is totally optional. I should note that over time I have adjusted my layout to accommodate a greater side to side play and have not decided if I will do this mode to my other K27s.

Note that if you have the snowplow version you will have to do a minor mod for Aristo manual turnouts to prevent the plow from hitting the manual throw mechanism.


There is an electrical issue whereby the chuff trigger requires power for the light source in the optical chuff ... this makes the chuff inoperative at low speeds without modification. The chuff was also designed on a positive trigger instead of a ground trigger, which posed some problems with some existing control and sound systems. Those users who chose to use "auto chuff" of one kind or another avoided the issue entirely, and others installed circuits to power the light source, and invert the chuff signal. On mine, Dave Goodson installed a new chuff timer of the magnetic reed type on the rearmost drive axle, which works very well, and again circumvents the entire problem.


Perhaps I can correct this observation a little. Low track voltages not low speed. Most sound boards designed for DC use require a battery to run at low track voltages. The K27s motor will start at a slightly lower voltage then the chuff circuit. A pair of diodes on one motor lead (the LGB approach to allow the electronics to activate before the motor) or coupling the locomotives and battery circuit both solve this issue. DCC or RC users will not see this issue. The second issue raised is the need for a chuff inversion for many but not all sound systems. The ESU plug in board for DCC users works fine and the RCS plug in board for RC users has the required inversion built in. If you want to use a sound system that requires the inversion it is very simple to add.


There are some questions as to the current handling capabilities of the on-board electronics. My locomotive is equipped with battery power and radio control, and most of the factory wiring (the ubiquitous "Super Socket") have been removed .... so I'm not in a position to comment personally on the extent of the problem. You might ask Bob Grosh, or other users who installed DCC equipment about their results with this.



I try to follow all reported problems for this locomotive and I am not aware of any current handling issue if the stock electronics are used.. I run my railroad at 21.5 volts DCC and have many hours on my K27s


Finally the motor and gearing produce some interesting problems. The locomotive has a large motor and very solid metal gears, which is good ... but the gearing of those gears is such that the locomotive behaves as if it were a truck stuck in third or fourth gear sometimes, and has some issues with acceleration (see: very steep (fast) curve) and a lot of power consumption in the higher ranges. That said, the locomotive will pull prototypically long trains nicely, and with a little practice on the throttle can be made to run well, however if you have grades on your layout, you will find it difficult to find a "cruise" speed and walk away from the controls, particularly with a long train. To date there is NO fix for this particular issue, but I understand that the speed control inherent to some DCC systems may deal with it somewhat.



An issue you will likely never encounter. The K27 has a top speed that is very similar to other plastic models built by companies such as Aristocraft, LGB, Charles RO and others. This top speed is twice a K27 prototype speed and much faster then many comparable brass models. While the prototype modeler likes the slower speeds, the market still demands the faster speeds. Most of us use the after market electronics we have chosen to adjust our top speed to suit our preferences.

The K27 has a very large motor and some electronics in the market have problems powering the motor/gear mechanism. Comments such as a sluggishness, poor acceleration or stuck in third gear are an observation of a poor marrage between the drive and the electronics. Other electronics in the market is designed for high efficiency drives and the power is smooth across the speed range. I have used Lenz, QSI and ESU drives in my K27s. All have high frequency back emf as part of their design and none have any of the problems reported by Matthew. In fact several sound manufacturers had to slightly alter their software to accommodate the ultra slow performance that is achievable by this model.

Hope that helps.

Stan Ames
http://www.tttrains.com/largescale

I stand corrected, Stan.

With #1 and #4 axles locked, I have never had a derailment with my K-27 except on one occasion when I ran a switch set against me. But you're right; locking #1 and #4 axles won't work on 4' radius curves. It will work on a #4 switch with a reverse curve, but then I've never asked it to go around a 5' diameter curve, so that capability may be lost when one locks the axles. Of course, it never occured to me to ask my locomotive to take a curve radius that was less than its length... shame on me. You're right again.

And, you're right. I misspoke. the optical chuff does not come on at low speed, it comes on at low voltage. You're right. How utterly silly of me. Part of the confusion arises from the fact that people running the locomotive on DC power (track or battery) achieve low speeds by using low voltages. And, you're right.... our sound systems come with batteries to power themselves during times of low voltage (which, entirely coincidentally (apparently) is when the locomotive is moving slowly.) I think I must have forgot that on the K-27 there is hardly any slow speed, even at low voltage, but let's address that seperately, shall we? For the moment, I'm glad to see you agree with my assessment that if you use auto chuff, you can use a QSI decoder without modification, or modify the chuff circuit and use the chuff timer. It's kind of like where I said I wasn't aware of any current problems with the socket, even though there had been some reports, and to address the question to someone (like Bob Grosh) who uses the socket with DCC equipment. So "Correct" my assessment all you want ... on track power if the locomotive is unmodified and moving slowly, you're not going to hear anything from the chuff timer unless you have the mod from Phoenix that uses the sound system battery to power the light source, and thereby requires the smoke unit be disabled to avoid depleting the battery entirely. But you're right, it's low voltage, not low speed.

As to the gearing being an issue "most people" will never encounter, excuse me but PHOOEY. My original assessment of the situation was that the locomotive is geared too high. I would say that twice prototypical speed is TOO HIGH. My part of "the market" (whatever that is) does not demand a K-27 that can run at eighty miles per hour, and I have NEVER heard anyone anywhere complain that a K-27 should be able to achieve highway speeds. You say that the marriage of the electronics and the drive is a poor one, and I AGREE. I cannot believe that anyone with any concept of how to power a model locomotive would design a drive mechanism in such a way that every current battery and track powered system currently in use marries poorly to it, and that only a DCC decoder with back EMF, constant track voltage over 20 volts can compensate for the elephantine problems caused by YOU not understanding the material you submitted for the gearbox that halved the gear ratio. Perhaps if you really WERE a consultant for Bachmann, you'd catch errors like that before you submitted them to become part of the design of an otherwise fantastic model.

Everyone ... I surrender. Listen to this guy Stan, and you won't go wrong. He's got five K-27's running on DCC, and they can all run over a stick. He's never had a problem, and everything's wonderful. Because of his innovations, all of the K-27's produced to date have run wonderfully right out of the box, and to date, I've just been a part of a conspiracy of mean spirited phillistines who have abused a nice guy for no reason. I just made up the rest of this to be difficult.... none of it's true, and actually, I'm going to rip out all my batteries and track power and install a full on DCC system next week so I can take full advantage of all the hobby has to offer.

And... the lobotomy hurt a great deal less than I'd feared.

Anyone whose experience with the K-27 differs from Stanley Ames' expert opinion feel free to contact me OFF BOARD and I'd be happy to talk about my imaginary success with imaginary modifications and imaginary fixes that solved all of my imaginary problems. I'm tired of being called a liar, or a misguided child every time I try to help.... so my discussion of anything Mr. Ames has ever had a hand in stops as of this post, unless it's "What a great model, it runs great, I love it, and wish they'd make more." Promise. To the new guy who started this thread, I apologize.... it's not always like this here, except when politics gets in the way of reason. To the moderators, I've said my piece, I'm done, save your ammo.....

With my compliments....

Matthew (OV)