Here is a side by side of my 2-6-6-2 and a AC-9.I bought the 2-6-6-2 because it looks cute on my layout next to my biggies, runs very nice, a bit noisy but the sound decoder covers the noise.I run it as a logger, 21 log cars and either a bobber or Drovers caboose. Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
DaywhitemtnsI understand that the model is a scaled-up version of the Uintah narrow gauge machine and thus no prototype exists for the mantua model.
IIRC that idea - that it's a scaled up narrow-gauge engine - came from a review in MR (or RMC?) when Mantua first brought out the engine 30+ years ago, but later was disputed, as apparently the model was based on (or at least "inspired by") a standard gauge engine. I can't recall for which railroad right now.
The October 1991 MR had a good cover story on making internal and external improvements to the 2-6-6-2 model.
erie 1068I am thinking of grinding about .025 on the inside of these drivers to see what happens.
The danger reducing inside width on a 'poley' is that it might drop outside a rail in some circumstances. This of course is less critical in an unsuspended model than an equalized prototype.
From the discussion, I can't help but wonder whether insulating some, or all, the width of the tread of the blind driver wouldn't be a better answer. That might be as simple as a coat of the 'right' sort of paint, or a turn of Kapton tape. Gentle reduction of diameter might be made to accommodate the additional 'thickness' if desired.
Interesting how the 'fix' for excessive hunting and guiding issues on the forward engine mirrors real-world practice on high-speed articulateds in the 1930s!
We have had a number of other duscussions regarding insertion of 'cut' washers on shafts as shims. There is no particular reason why this is not long-term suitable, as the 'lateral' load is usually insignificant in terms of force to displace the washer out or crush/tear it at the cut. I believe at least one contributor used PTFE (Teflon) for this with success.
My buddy at the club brought in a Mantua Clasic 2-6-6-2T which he had received as a gift. It ran poorly as it stopped on most turnouts. He inserted a ESU lokpilot v5 DCC decoder number 59620 and an ESU power pack mini keep alive 54671. After that installation, it runs very well and goes over turnouts without hesitation.
After reading all solutions offered I measured the width of the center flangeless drivers at close to .100. I am thinking of grinding about .025 on the inside of these drivers to see what happens. any thoughts?
Although I was quickly running out of things to do, the most obvious next step was to eliminate the side play in the four pairs of flanged drivers which also was excessive. I went to work with the Kadee washers to address that problem and, once back on the rails, the blind drivers no longer shorted out on the frogs. Apparently, eliminating the side play in all the drivers, coupled with limiting the motion of the front engine, seemed to solve the problem completely. Admittedly, this is a low-tech fix and some of you may think it's not an effective long-term solution that will hold up over time. I ran the locomotive on a continuous loop for one hour in both directions and the washers stayed in place and remained effective. The Kadee washers are tough and if the wedge-shaped opening in the washer is correctly made, after being forced on the axle it tends to stay in place. Even if the washers did wear over time, they are easy enough to replace. In any case, although replacing the blind drivers with flanged ones might also have resolved the problem, there is no guarantee they would fit because of potential flange contact. In any case, even if driver replacement would work, I'd still want to eliminate excess side play with the washers and the drawbar mod. I might add that my minimum mainline radius is 27" and my minimum radius is 24" which the locomotive, with reduced side play, has no trouble negotiating. My feeling is that it would tolerate even smaller radii but of course the lower limit would have to be tested. After all, it is a logger.
I now have a locomotive that I can use - one that runs well and looks good, in my opinion. I'm now encouraged to detail it to some extent, a process to which I'm looking forward. I hope my experience in learning how to make this thing run right will be helpful to others who may have purchased this engine and are having similar problems.
I still think the problems with this locomotive are due to a design flaw which apparently Model Power has no interest in correcting. Mores the pity.
I tried to post in the above blank panel but when I hit the post button my text disappeared. I don't know why but perhaps because the post was too long and there may be a limit on that parameter. I'll try again and this time break up the post into two, or more, sections.
I think I may have solved the problem of the blind drivers shorting across the wing rails of the frogs by using a low-tech solution that nevertheless seems to work and to hold up under long-term track testing. As earlier stated, I had felt the problem was due to the excess side play (slop) in the blind drivers coupled with the fact that the blind drivers' tread width is wider than that of the flanged drivers. My first attempt to remedy the problem involved eliminating this excess play by inserting Kadee red fiber washers (.125" I.D., .250" O.D., part # 208) on the axles, on each side, between the blind drivers and the frame. I accomplished this by cutting a wedge-shaped opening with a diagonal cutting pliers and then forcing it down over the axle with a pair of needle nose pliers. Once in place, the washers remain there and allow only enough play to prevent binding. Unfortunately, this did not seem to ameliorate the shorting problem.
It was also obvious that the front engine had an inordinate amount of side-to-side motion which caused the front engine to hunt on both tangent and curved track as observed from the front. I thought that limiting this movement might help prevent the blind drivers from shorting. The front and rear engines are connected by a drawbar that pivots at both ends and, as a result, not only can the front engine pivot but it can also move from side-to-side, even on tangent track. As described earlier, I locked the drawbar at the rear engine so that the front engine could only pivot for articulation purposes but no longer move from side-to-side. Back on the layout, the locomotive tracked considerably better, no longer hunted, and looked more prototypical in operation. No, it did not cure the shorting problem but it lessened it so that the blind drivers did not always short out when going over the frogs. This suggested to me that, at least, I was on the right track. I'll continue this in the next post.
Daywhitemtns,
I'm glad you got one of the issues,going for you..
Yeah!! M/P, definitely sucks. Still waiting,for a reply from them,about my friend in Manchester,UK. We were discussing that by E-Mail early this morning. Good Luck,with the axle's..
Cheers,
Frank
Glad you got the leading and trailing truck powered. I have recommended this to many folks and you are probably the first to actually do it.
I am wondering if you insulated the center driver by using tape between the bearing shell and frame. Or you could pick up a second driver and replace the powered wheel with a insulated wheel. You would be giving up one power pickup but the shorting may be fixed. Maybe wrap a little tape around a driver and give it a test.
The latest Mantua 2-8-2 and 4-6-2 with can motors are outstanding runners. I think with a little work this one can be made to run very well also.
I had high hopes for this product line when heard M/P was purchasing the Mantua brand. Its a shame someone else who actually cared couldn't have purchased them instead.
Jim
zstripe, although I didn't take the mechanism apart yet, from the parts list sheet that came with the locomotive it appears that the drivers have one piece axles, not split axles. The parts list sheet is printed in Hong Kong so I'm assuming that's where the locomotive is made, also. When I get a chance I'll order two flanged, non-geared drivers to replace the OEM parts - assuming there'll be enough clearance between the flanges to allow me to fit them in place. When I get around to this, I'll report to you the outcome.
I did however accomplish one last and final mod to the current pickup. In an earlier post I had erroneously reported that the rear engine was not live due to a faulty measuring technique on my part. After further checking I discovered that it is live and of course connected to the three rear engine drivers which pickup current from the left rail moving forward. This enabled me to replace the OEM outside frame trailing pilot truck with a brass inside frame truck that could pick up current. Rummaging around in my scrap box I located a brass truck which, after shortening the yoke and drilling a new mounting hole, was a perfect fit under the 2-6-6-2T. Now, four wheels pickup current on each side of the locomotive - 3-drivers and 1-pilot truck wheel. I don't think current pickup will ever be an issue here. Also, it looks more prototypical as all the articulated loggers I've seen photographs of have inside frame pilot trucks with spoked wheels. Unfortunately, I couldn't locate spoked wheels so I used solid wheel sets (insulated one side). Not quite right but still an improvement over the stock setup (at least in my opinion).
Now I'm more annoyed than ever with Model Power. Except for the blind drivers sparking across the frogs, all other aspects of the model are excellent. It has a good mechanism that runs extremely smoothly and with my installed Lenz Gold decoder it can creep along at an extremely slow speed. Perhaps the additional current pickup is helping, also. It's too bad that Model Power gave me the hustle rather than look at my complaint and attempt to resolve it. I guess they don't realize they have harmed themselves and their reputation much more than they have harmed me. After all, I may, or may not, be able to fix this on my own but I'll never buy anything from Model Power again.
Yes Model Powerless,is a trip to say the least,,,,,,anyway,doe's ''Sparky'' have split axle drivers? The kind that are two piece and go into the gear? The reason I ask,I had bought two Kato GP9's different #'s otherwise identical,one ran perfect the other would run stop,run stop,,it would stop,because it was shorting out,,so I watched closer and sparking was coming from one of the trucks..I checked the wheel gauge and they where all fine,so i took the wheel sets out and noticed,that one axle,had more showing on one side than the other,,,what they had done was to get it in gauge,they had pushed one side of the axle in further than the other,so any lateral movement the axles would touch slightly in the gear and short out..I'm wondering if yours is doing the same..If you do need new wheels,I would recommend NWSL (North West Short Line,great service there...Good Luck!!
zstripe, I'm sorry to hear that you've been having problems with Model Power, also. It's good to hear that there's a shakeup going on as they certainly seem to need one. Let's hope for the best.
I purposefully held off writing this post because I wanted to test a similar type of locomotive and compare it with "Sparky" (my new name for the Mantua 2-6-6-2T), first. I happen to have a United Sierra 2-6-6-2 imported by Pacific Fast Mail (my only brass locomotive). It was bought new by an old hand friend of mine, sometime in the late 50s, early 60s I believe, at a cost of US $60 from a dealer. Doesn't this price make you want to cry? It's a beautiful model (still unpainted) and runs very well even with its original open-frame motor. At some point my friend gave it to me as a gift and I plan to eventually install in it a can motor and DCC. Since it's identical in wheel arrangement to Sparky, I thought I'd do a comparison. The only mods I've so far done to it have been to spring the lead and trailing trucks and to build a centering device for the lead truck so that it actually guides the front engine in and out of curves, similar to the prototype. As you can imagine, it tracks very well. Additionally, the side-to-side driver play is much less than on Sparky and all drivers are flanged. So how did it perform out on the road? In a word, flawlessly - absolutely no sparking. It's kind of pathetic to see a 50-some year old locomotive outperform an almost brand-new one, but there it was.
What are my options now? I'm guessing that I could eliminate the frog-shorting problem if I replaced the blind drivers with flanged ones. The problem is that I might not be able to do so because of lack of clearance between the drivers. It looks like replacement might not be possible because the flanges may make contact. I'm not sure but, since replacement drivers are relatively inexpensive, I just may go this route and give it a try. If clearance is a problem, it's possible that the flanges of all the drivers could be turned down but this is way beyond my capabilities, skills, and pay grade.
Another alternative would be to coat the ends of the wing rails in the frogs with Dullcote or similar laquer-based coating. Because this is the only loco that has this problem, I imagine the insulated coating would last a long time. I really don't want to do this for only one locomotive and this would increase the dead zone around the frog which I certainly don't want to do.
If all else fails, I suppose I could empty it of its fuel oil and water and put it out for static display so my model railfans could come to view it. Speaking of fuel oil, I removed the spark-arrestor from the stack as being inappropriate for an oil burner. Too bad because it's real cool looking.
Apart from the problem, I like the locomotive. It has a very smooth mechanism, I like its appearance and it would be relatively easy to detail.
If any of my fellow modelers and forum members have any ideas or suggestions, please feel free to inform me. Just don't tell me to send it back to Model Power to see if they can fix it. Lol.
I understand your frustrations,with Model powerless,I have been dealing with them for quite some time now for a Forum member from the UK,,THAT HAS TO BE THE WORST RUN CO. ever,,no one knows,whose job is what over there,,there is supposed to be a shake up going on now to hopefully get it going right...I believe it is a shame too,,,,,it's not Mantua's fault.
It's now time to continue my tale of woe. To recapitulate, I sent the 2-6-6-2T back to Model Power for evaluation and repair. During its sojourn there, I sent them one unanswered email and then spoke to them twice on the phone. During the first conversation, after reminding the technician of the reason the locomotive was there (not very confidence-inspiring), he said that he would replace the blind drivers with flanged ones which, I believed, would cure the problem of shorting across the wing rails of the frogs. After another week with no news I called again and was told the locomotive was ready and would ship to me the following day. By now, it had been over a month since Model Power had the locomotive at there repair facility. This they did, however, since I received the locomotive back three days later.
With great expectations and high hopes I eagerly opened the box and removed the model. When I noticed that the blind drivers were still in place, my heart sank and a flicker of apprehension passed through me that, after all this time, nothing had been done to resolve the problem. Quickly placing the model on my layout, I ran it through turnout after turnout watching the blind drivers sparking their way merrily over the frogs' wing rails as they shorted the two opposite polarity rails together. Needless to say, I will never, ever, buy a product from Model Power again. I figured there was no point in contacting them again (I know when I've been hustled) and that it was up to me to resolve the problem on my own, if it was resolvable. I do believe that if I had never contacted them they would never even have sent the locomotive back to me. Maybe they figured that I would just forget about it. Ultimately, I think there is a serious design flaw in the locomotive and I don't think they'd ever admit to that.
I decided to carry out a step-by-step approach to see if I could ameliorate the situation. Noting that the blind drivers had an inordinate amount of side play, I cut wedge-shaped openings in four Kadee no. 208 insulating washers (.015" thickness) and forced them down behind each blind driver with a pair of precision needle nose pliers. They stayed in place and eliminated virtually all of the excess slop. Unfortunately, that did not resolve the problem as the sparking continued. I also noted that the tread width of the blind drivers exceeded that of the flanged ones which I guess is contributing to the problem.
It was also obvious that the front engine had much more side-to-side movement than seemed necessary to me, at least for my track radii. Running the locomotive on tangent or curved track and observing it from the front, the front engine constantly hunted R/L when it should have been tracking more-or-less straight, particularly on tangent track. It occurred to me that if I could limit that movement it might prevent the blind drivers from shorting. The front and rear engines are connected by a drawbar, part no.MO185, that pivots at both ends. With this arrangement, there is so much play that not only can the front engine pivot but it can also move from side-to-side on tangent track. I decided to lock it up at the rear engine end so that the front engine could only pivot for articulation purposes but have any other motion constrained. I accomplished this by cutting two lengths of Evergreen .100 x .100 x 3/4" and affixing them to the rear engine retainer plate at both sides of the drawbar with ACC. Additionally, the lead driver pair of the front engine also had extensive side play so while I was at it I also fitted Kadee washers there which removed virtually all excess motion. Back on the layout, the locomotive now ran straight and true, no more hunting, and it looked much more prototypical. Did it resolve the shorting problem with the blind drivers? No it did not, it didn't even minimize it! BTW, my minimum mainline radius is 27" and my minimum radius is 24" so this procedure may not be suitable for those with very sharp curves.
At this point, I observed that the locomotive didn't seem balanced across all the drivers of both engines. Specifically, it seemed a little light over the rear pair of drivers on the rear engine. Whereas the front engine drivers pressed solidly against the rails due to the spring and pin boiler support between the bottom of the boiler and the front engine frame, provided by the factory, only very little force was required to lift the rear drivers from the rails. It seemed to me that additional spring tension was needed to press the rear of the engine and its drivers more firmly against the rails. Fortunately, by moving the front engine as far to the side as possible I was able to slip Mantua's conical spring around the pin, providing additional spring tension - just enough to balance the superstructure correctly. The conical spring is the same one Mantua uses for the pilot trucks on the 2-6-6-2T but I happened to have some spare ones on hand from past projects (part no. 7008R1). And no, this modification didn't do a thing to eliminate the shorting problem either.
Well, now the locomotive runs beautifully and looks good while doing it provided I just run it on tangent track, or curves, and keep it off the turnouts. In my next continuing tale of woe I'll discuss some possible solutions to the shorting problem and look at their feasibility.
Soo Line fanModel Power is clueless.
DaywhitemtnsThey have one of the worst customer relations policies I've ever experienced and I'm beginning to wonder if I'll ever get my loco back. At this point, I'm very doubtful that I would ever buy another product from them again.
Guess I wasn' kidding but this is nothing to gloat about. Rather sad really, a once great product line with no customer support
Another update but again nothing new to report. I never received a reply to my email so I called Model Power about a week ago and finally managed to talk to the repair technician, Michael Sicurelli. He told me that he had received the 2-6-6-2T but hadn't written it up so forgot what had to be done. When I reminded him of the problem, he said that perhaps replacing the blind drivers with flanged ones would cure the problem, a solution to which I agreed. He said he would get on it and, I assume, send it back to me when the conversion was accomplished. Since then, I've heard nothing from him and so I called Model Power again today, asked for the repair department and was told it was closed today and to call back tomorrow.
Now, my loco has been at Model Power since Friday, August 23rd and I had never heard from the company until I called them, and since then, nothing. I don't know what's going on but I'm rapidly losing confidence in Model Power. They have one of the worst customer relations policies I've ever experienced and I'm beginning to wonder if I'll ever get my loco back. At this point, I'm very doubtful that I would ever buy another product from them again. Let's hope that I can get through to them tomorrow.
Thanks for the links, more good information. The brass products are very tempting, for sure - I'm still trying to wrap my head around the notion of their prices. I have talked with Model Power's support people a number of times in the recent past - they seem sincere. I hope you get some satisfaction.
Wilton.
I figured it's time for an update although I have nothing new to report. As already stated, my 2-6-6-2T arrived at the Model Power Service Center in Farmingdale, NY on Friday, August 23rd. As of yesterday I had received no word from them on the status of the repair and consequently sent them an email asking for a progress report. I have so far not received a reply. I hope I will hear from them this coming week and will share the outcome with you as soon as I've been notified.
oregon shay,
Thanks very much for the links. Although I already knew of the Logging Mallets site, the second one is new to me. Since we're both interested in super-detailing our loggers, I also found some photos that could aid us in this quest. The first site contains photos of an earlier NWSL brass 2-6-6-2 built by TOBY and based on Weyerhaeuser's #105.
http://www.brasstrains.com/classic/Product/detail/036909/HO-Brass-NWSL-TOBY-Weyerhaeuser-Timber-2-6-6-2T-105
The second site is Precision Scale's home page and by scrolling down you will find photo of a prototype Rayonier 2-6-6-2T which supposedly serves as the basis for their forthcoming models.
http://www.precisionscaleco.com
My Mantua logger arrived at Model Power's service center this last Friday so perhaps I'll hear something this week.
I thought you might like to be aware of some prototype information about the Mantua 2-6-6-2t locomotives. My plan is to super-detail the Mantua logger loco that I purchased. Digging around on the old innerweb I found some relevant data on it that you might be interested in. As you know, Baldwin Locomotive Works made locomotives like the models Mantua sells. The Mantua item# 353103 is their version of an actual Baldwin loco, the White River Lumber Co. #7, which is Baldwin's builder # 58272. Because I need some accurate photographic references to correctly detail my loco, I was able to find some decent pictures of Baldwin's locomotive in operation. Check out the web link that follows - scroll down to March 1925 and follow the link for some photos of this locomotive.
http://loggingmallets.railfan.net/list/list.htm
I also found a link to a company that produces this loco in brass - the White River #7 is the last product listed at the bottom of the page.
http://www.railmodel.com/search/CatalogSearch.asp?pj=1320
Let me know if you are able to access this data.
Lets hope they do not send it back NTF........................
Thanks for all the advice and words of encouragement from Soo Line fan, oregon shay and PHARMD98233. Some of your ideas I will try in the future. I did receive a prompt response from Model Power to my email detailing the locomotive's problems and the tech person who answered me told me to send it back to him and he would check it out for me. He also wrote that no one else has contacted him with a similar problem with this loco but that he would see what he could do. Curious! I'm sending it out to him today and I will keep you posted about further developments. It seems that the simple purchase of this locomotive has turned into a real Odyssey. Let's hope that its resolution doesn't take as much time as Homer's account covered.
One of these came to me last year. As an experiment, I tried out a TCS Keep Alive add on capacitor set in addition to the TCS decoder. It worked astonishingly well. Since room is very limited in the cab and bunker, use a separate decoder and place in the bunker and place the Keep Alive capacitor set in the cab near the roof. I did not have the courage to try adding sound.
I am also the owner of one of these Mantua 2-6-6-2t logger DCC ready locomotives. I purchased DCC ready with the intention of installing a Tsunami sound decoder and speaker into it. I could have purchased a DCC version, but desired the Tsunami over the factory-installed MRC decoder. It required removing some of the boiler weight and inner boiler plastic body to get that Tsunami in there.
I fought with poor power pickup from the time I removed this locomotive from the factory packaging, and discovered as you (and likely numerous other modelers) did the nature of the power pickup design. My solution was to heed the advice of several of my more learned forum members, and add additional power pickups using wipers, on both rear drivers.
BIG difference in power pickup performance, needless to say, but still not perfect. I thoroughly lubricated the side rod pivot points and wheel bearings with a conductive model lube, and that helped even more. As has been mentioned, this model's design is very challenged in the power pickup department, and will never be my smoothest runner. I purchased this locomotive because I desired this particular wheel arrangement and look, and couldn't embrace the cost of a brass version. Every desire and "must have" comes at a price. Wilton.
BIG difference in power pickup performance, needless to say, but still not perfect. I thoroughly lubricated the side rod pivot points and wheel bearings with a conductive model lube, and that helped even more. As has been mentioned, this model's design is very challenged in the power pickup department, and will never be my smoothest runner.
I purchased this locomotive because I desired this particular wheel arrangement and look, and couldn't embrace the cost of a brass version. Every desire and "must have" comes at a price.
Thanks for taking the time to do such a detailed write up and root cause. The common game plan with these engines seems to be the return for refund option when a problem is found.
DaywhitemtnsBecause of the excess side play, I was able to move the driver so that it contacted both rails of opposite polarity at the same time, thus shorting out the system and causing the spark. Whenever the locomotive went over the frog, shorting and sparking would occur depending on the relation of the blind driver to the opposite polarity wing rail.
This happens to other engines as well but the owners do not understand it is a partial short as opposed to a stall.
DaywhitemtnsI'm toying with the idea of replacing the blind drivers with flanged ones except that due to size of the flanges there may not be enough clearance to accomplish this.
Try moving a flanged one from another position to check for clearance.
DaywhitemtnsAt the very least the excess play has to be removed but I'm not sure how to do this without pressing one of the drivers off the axle, adding shims, and re-quartering it on assembly - a task that is probably beyond my skills at this point.
This is not that hard of a task. Scribe a couple of marks on the axle and wheel for reference and use a NWSL puller. A good test prior would be to add some slip in shims. I would try to get a thin washer and slot it for a temporary fix. Then install it and see. A fiber or brass plumbing washer might be a likely candidate.
Daywhitemtns I sent an email to Model Power detailing the problem and asking for their help in its resolution. When I get a response I'll report back to you.
I sent an email to Model Power detailing the problem and asking for their help in its resolution. When I get a response I'll report back to you.
My personal dealings with Model Power have been less than satisfactory. They are a far different company than Mantua was, with the way they handle parts. Mantua had a woman who was dedicated to the job of mailing out parts and honoring their lifetime warranty. She had parts labeled and bagged for immediate shipment.
Model Power is clueless. I emailed them requesting a parts listing. I got a return email asking for 5 dollars for the listing. Later when I did not respond, they actually mailed me a bill with a second request for 5 dollars prior to sending me the parts listing. So I did without their parts list. Somehow Kato, Atlas, Bowser and others are able to list parts for free but MP cannot even have a PDF available on the web?
Let us know the out come and welcome to the forum. We need more folks like you willing to take the time to actually repair their locos.
I'm sorry folks but after giving such high marks to the locomotive I've discovered what I believe to be a design flaw that should give pause to anyone considering its purchase. After determining the current path pickup in the locomotive and changing the lead truck, I tested it by running it back and forth on a tangent track section of my layout devoid of turnouts. It was based on this paradigm that I reported it was a good runner. Then, I put it to work which of course involved running it through turnouts. It was at this point that I noticed the locomotive would sometimes balk going through the turnout or even stop and require a push to start up again. It seemed that this always occurred when the drivers hit the frog. After continued inspection I saw that the middle (blind) driver of each engine sometimes sparked as it went over the frog. This never happened with the flanged drivers. Next, I noticed that, compared with the flanged drivers, the blind drivers had an inordinate amount of side play, probably designed to enable the locomotive to negotiate ridiculously tight curves. At the wing rail of the frog, the two rails of opposite polarity are closest together so I placed the blind driver over this point and, using a toothpick moved the blind driver from side-to-side. Because of the excess side play, I was able to move the driver so that it contacted both rails of opposite polarity at the same time, thus shorting out the system and causing the spark. Whenever the locomotive went over the frog, shorting and sparking would occur depending on the relation of the blind driver to the opposite polarity wing rail.
My turnouts are all Peco insulfrog (Nos. 5, 6 and 7 curved) and all of my other locomotives, steam and diesel, run through them without a problem so it is definitely due to excess play in the blind drivers that is the culprit here.
This leads me to believe that the problems with current pickup of this locomotive reported by other users of this locomotive may have actually been due to blind driver slop causing shorting and erratic running. Obviously, this excess play is a design flaw and should have been corrected at the factory as certainly they must test their models before offering them for sale.
Since my mainline radius curves are 27" and my minimum radius is 24", I'm toying with the idea of replacing the blind drivers with flanged ones except that due to size of the flanges there may not be enough clearance to accomplish this. At the very least the excess play has to be removed but I'm not sure how to do this without pressing one of the drivers off the axle, adding shims, and re-quartering it on assembly - a task that is probably beyond my skills at this point. My first step will be to contact Model Power in an attempt to resolve this problem. I shall certainly let you know of their response.
With 50" drivers, blind middle ones, and the relatively short rigid wheelbase, I don't see where extreme middle driver slop is necessary to negotiate even very sharp curves.
I'm sorry I jumped the gun and hope that my favorable review didn't cause you to make a purchasing decision you may come to regret.