Bachmann spectrum 4-4-0 pilot truck derail problems

Started by CBR, September 13, 2020, 07:16:52 PM

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CBR

Front truck constantly derails usually around corners & changing grade. Have tried adding some weight to the front wheels of pilot & then both but neither solution is perfect. Seeking ideas for a better solution. Thanks
Colin - Okotoks AB

Greg Elmassian

#1
If weight did not solve it, you need to improve your trackwork, vertical transitions, track warp, etc.
Visit my site: lots of tips and techniques: http://www.elmassian.com

CBR

Thanks - have given lot of attention to grade (<3.5%) & ensured track is level (rail to rail) especially around all curves.  Just wondered how much weight to add?  Appears that adding weight over front wheels then rear lifts but adding weight to both wheels creates & I'm back to square one/

Loco Bill Canelos

Colin,

It is most likely the track.  I had the same problem many years ago.  Your grade is very steep. When you transition from level to a grade on a curve is where most of the problems occur.  I actually raised the outside of my curves when transitioning from level to a grade.  Make sure the transition from level to grade is very gentle, especially on curves.  If there are no mechanical problems with the front truck, it can sometimes bind on a curve where the transition is not gradual enough.  Once I finally reworked the track several times, I did not need any weight on my 4-4-0 front truck.  Adding weight can be part of the problem if it sticks up too high and hits the frame at transition points.  While there are many problems another possibility is that your curves are too tight and the front truck is forced to the limit and jumps the track.  I would mark all the spots where it jumps the track, Then do a video with you phone.  Enlarge it and play it back at slower speeds, and watch carefully to see what is going on.  Do it with and without the weight, and also from different angles. 

I do have to agree with Greg that the problem is the track.  In my own case, a friend kept telling me it was the track. Until I took it seriously and worked on my track my problems continued. I had every problem mentioned above!!!

It can be very frustrating I know, and can ruin your fun, but keep at it and you will succeed. 

Loco Bill
Loco Bill,  Roundhouse Foreman
Colorado & Kansas Railway-Missouri Western Railway
Official Historian; Bachmann Large Scale
Colorado RR Museum-Brakeman-Engineer-Motorman-Trainman
There are no dumb or stupid questions, just questions!

CBR

Hi Bill - thanks - really like the suggestion to take videos of the problem areas. I acknowledge I have a reluctance to blame the track, given the amount of time I've recently dedicated to it,  & that there are no problems with any other locos. Figured I'd reach out to give this loco one last before it gets left on the shelf  forever - that won't happen I like this loco too much! However I also know that I can improve the grade transition on one specific problem curve.

Understand the concern with the grade, note that's the absolute max & majority of grade is 2% or less, there are no tight curves.

Defintely agree, I'd prefer not to have to add weights at all but obviously it would seem others have had the same problem over the years (https://forums.mylargescale.com/27-masterclass-articles/15693-bachmann-spectrum-4-4-0-pilot-truck-issues.html) & that Barry Olsen had designed & built specific pilots to specifically address the problem. Unfortunately Barry is no longer with us.

What does concern me with the design of this pilot is...
1) the degree of play/side to side movement of the wheels, which seems far too much (wouldn't limiting this to 1/8" to 1/4" be better?). (but is no different that the 2-6-0)
2) there are no pilot turn limit/guide pins on this loco (wrong terminology) as on the 2-6-0 pilot;
3) the spring tension appears to be very weak & not well positioned to keep both axles on the track again far less than the 2-6-0 design.

Guess I was looking for a simpler answer to the solution to implement quickly but sometimes it's just more time & graft that's required, probably have to wait until next year now.

Cheers - & really appreciate your feedback.

Colin

Loco Bill Canelos

Colin, 

Don't feel bad, Your 2 % grades are definitely better than many I have seen. The MLS thread does have some good ideas and like a lot of things I had forgotten about that post.  I have the utmost respect for Kevin Strong.  His knowledge and tricks have been helpful over the years. His trick might just be worth trying, but will involve much trial and error to get it right.   Too much one way would take the weight off the drivers.  Same possibility exists with too strong a spring, because that too could lift weight off the drivers. I have had some luck at ACe Hardware, and Home depot with their spring assortments, but most are too strong.The video method I mentioned has helped me trouble shoot problems with freight cars that continually derail as well.  When I had my outdoor railroads, maintenance of critical areas was often ruined after a few days rain.   Now that I am an 80 year old man with a indoor large scale layout, I thought problems with track would go away.  I was definitely wrong.  Transition points were still affected by heat and humidity in the unheated basement, although not nearly as bad as outside. 

When there is no allowance for track expansion in critical areas, things can go bad as well. When outside my trackwork was subject to vast ranges of humidity, temperatures, and frost heaves in the winter, as well as the summer washouts.  In all my years in the hobby,  messing with track issues was the least enjoyable part of my fun, but at the same time critical to me having fun!!  In my old club I was often called on to troubleshoot problems on members layouts.  99.5 percent of the time it came down to the track.  In one case a members diesels were running perfectly(mostly B+B), but he couldn't keep his steamers on the rails. Diesels can handle bad track way better than steamers.  Steamers are definitely in need of extremely good track because of the long wheelbase and associated pilot trucks.  His trackwork was plainly poor and too rough. I explained what I thought needed to be done and He was insulted that I thought his track work needed improvement. I almost lost a friend over it.  In the end some good old leveling and ballasting and longer transitions from level to grade and careful work on the transitions that took place on curves did the trick and he was having fun again.  Three years later during a club visit to his home his track was so bad he could only run eggliners!!

I just ate the goodies and enjoyed the meeting and said nothing!!!!

Enough blah blah for today.

Keep having fun!

Bill

Nonetheless I am still very happy with Large Scale and all it's many facets. 
Loco Bill,  Roundhouse Foreman
Colorado & Kansas Railway-Missouri Western Railway
Official Historian; Bachmann Large Scale
Colorado RR Museum-Brakeman-Engineer-Motorman-Trainman
There are no dumb or stupid questions, just questions!

CBR

Cheers Bill,  I'm a relative newbie to G scale outdoors - this is my 3rd summer of full operation. Like many others I've learnt the hard way & now understand the importance of track maintenance & design  But putting in the extra effort has definitely increased reliability & the fun.  I'm challenged by the relatively small footprint, the GR magazine had been a key source of very useful information & helping me avoid the same errors of those more experienced folks. Gonna miss not having the magazine in its old format.
The hobby has been far more challenging than I first thought but the fun its given me, especially with my grandkids, has been simply awesome.

Thanks again
Colin