I'm experiencing a situation with a number of my locomotives since I pinned my track down to foam where by they seem to Jam / stick or bounce (however you wish to look at it) as the travese accross the points. The problem doesn't seem to occour so much if they are travelling straight through the point, and, it doesn't de-rail the train completely, but the power to them is interrupted, and if travelling at an excessive speed they will derail.
This situation doesn't affect all my locos, but certainly the newer longer / heaveir ones (I'm operating 00 Gauge) and Bachmann ones too.
Please can soeone advise how I can stop this happening, it seems that the points are riding higher than the other pieces of pinned down track.
Have you pinned down the points affected? I have found that the whole format of peco points can be easily distorted by heavy handed pinning. Having foam either side and not pinning the points however , can lead to uphill profiles into the point from all directions . If you place an engineers rule along any track you should be able to see any horizontal deviation with the aid of a torch shining behind the rule.
Most of my similar problems have been traced to failure of power pick-ups ( bad contacts) on the locos which cause hesitation at speed when transiting uneven sections followed by over-running of the train and subsequent derailment.
Graham Kendall said the following on 14/04/2006 19:53:
The clue might be in that sentence. Which points are you using? It may be just that you are using clunky code 100 points that newer locos don't like. Have you checked the back-to-backs of locos that derail, compared to locos that are OK?
The points I am using are either the small Hornby ones - or the equivalent PECO Set-track ones, as that's what I had to work with. Please can you explain the term "Back - to - back" as I don't know where you mean to be measuring.
Graham Kendall said the following on 18/04/2006 13:12:
I'm pretty sure (but maybe someone else can confirm) that newer stock doesn't like set-track points, Peco or Hornby.
The back-to-back measurement is the distance between the back faces of the wheels. For OO, I think it should be 14.5mm, and it does seem as if there is variation between manufacturers. For set-track points, that back-to-figure might need to be less, but you can't usually adjust it that way.
I'm trying to keep this thread alive so that someone with more RTR experience can help! I model in P4 and S4n2, so have a whole different set of problems!
This doesn't seem to be the case where the stock is checked for accurate B2B and where the front bogies are correctly aligned. Our layout uses all set-track points and slips [well over a hundred]. We run our mainline locos approximately nine [full scale] miles per day, usually pulling long rakes, so they are well tested [also regularly well serviced]. We run on code 100 as it takes the curve wear better for our particular purposes. However we also allow our volunteers to run their own stock from time to time and in line with your comment, there have been some major problems while running non serviced straight out of the box locos with less than accurate wheel geometry ex works.
A very wide variation and not necessarily between manufacturers but quite often between individual locos from the same stable .
Not wishing to muddy the waters, but we measure and adjust all wheel spacing from the inner wheel face to opposing outside face as we get a more accurate result, with the actual precise measurement depending on the wheel type and manufacturer. While this might seem overkill, It's essential that in our case we act to pre-empt running problems as a pile up of up to 40 wagons per rake with four main lines operating plus the yards, while in full view of the public and with only two operators present is not at all amusing :o( We also replace all of our rolling stock plastic wheels with decent ?? metal types. We have found very little variation between various batches and between individual items of Peco code 100 set-track. The locos and some items of rolling stock seem to be the main problem. We won't even mention Virgin Voyager coupling bars :o(
Recently with one well known manufacturer's wagon chassis, the plastic used was of such appallingly poor quality [brittle and springing] that the chassis actually began to twist. This caused us no end of problems until in desperation we made up a jig to accurately test each chassis level and alignment. The manufacturer replaced all of the defective units free of charge of course and without quibble. However I have developed an abiding hatred of Kadee couplings that still remains :o)
I was trying not to muddy the waters :-) The "check gauge" is actually the more important measurement where you have variations in flange thickness, but is a little harder to measure. This is where a fixed set of standards such as used in P4 or EM, or even the oxymoron that is FS-OO, is of massive benefit. It seems to me a bit bizarre that in all the decades that OO has been around, there is still no fixed standard!
True! The kids of course love it. Nothing funnier [when one is not involved personally that is] than watching the two operators each blaming one another to the accompaniment of the various 'witty' comments from the onlookers. Only last Saturday after a minor accident and a shunting derail, a little blonde angel of about six years old proclaimed quite loudly to the whole assembly [some thirty or so people] "My daddy always says 'Oh shit' when that happens and then throws things about". Her mother was mortified and dad quite sensibly beat a hasty retreat :o)
Many Thanks again Paul, I think I see where you're coming from and so what is going on. Does that mean then, that if I shaved a small amount off of the broadness of the plastic checkrail, on the side that sits between the plastic check rail and the outer running rail, I would overcome my problems??
Roy, Are you sure you mean 'set-track' ? The pictures of your layout look more like Streamline to me and I admit, like Paul, to going by hearsay but I believe there is a difference in the flageway standards. Keith
Now that is well outside my experience - I haven't used commercial pointwork for years. It might also be the case that you need to add a shim of plastic to reduce the gap, rather than increase it. This might be OK for newer models, but then your older models may have problems.
It could do but I haven't done the maths to see just how much the effect could be. On the curved road of a turnout, raising the height of the check rail will tend to have the effect of reducing the back-to-back of a set of wheels. If the back to back measurement of your wheels was on the tight side on a straight road, then on a curved road, they would be tighter, and with a raised check rail on the curved road, they would be tighter still. If your back to back measurement becomes too tight at check rails, then you will get a derailment.