Re: [7mm NGA] Re: Electro magnets and KDs
- At 10:58 2012-02-07, you wrote:
>Ken and others,Joe:
>I'm here in the U.S. and I _think_ the NMRA recommended practice
>works out very close to 1 ounce per inch. That's become a standard
>for all of my HO modeling friends. For 4" to 6" long cars/wagons,
>that's "close enough". Recent advances in truck/bogie technology
>have resulted in extremely free rolling cars, making the unintended
>uncoupling problem worse.
>I have another friend who's been using hinged magnets for his giant
>home layout (~35' by 70' with 10' high clearance ceiling in his
>basement - he's building a "mushroom" style layout). He uses a
>single Tortoise slow motion machine attached to fishing line to
>raise/lower all the magnets in a town, at the same time. Further, he
>cuts his #308 magnets in half (cutting across the width, to form
>nearly square magnets). While this reduces the under-track "area"
>for uncoupling, it's a money saving move that still works fine. I
>forget what he uses as a hinge but I can ask.
>Secretary/Keystone Chapter of European Train Enthusiasts
Pretty close. The NMRA RP for car weighting is here
The initial weight and additional weight per inch vary with scale but
if you look at HO as being reasonable for 7mm NG the initial weight
is 1 ounce with an additional 1/2 ounce per inch of car.
Barrie, Ontario, Canada
Life Member NMRA
Member Scale 7 Group Gauge 0 Guild 7mmNGA
Member Bird Studies Canada Ontario Bird Banding Association
Brereton Field Naturalists' Club Simcoe County Banding Group
- --- In firstname.lastname@example.org, "stephen" <stephenjhowe@...> wrote:
>Many thanks to all who contributed to this topic. We have subsequently carried out a more forensic examination of the problem (three blokes watching intently as trains pass through various parts of the layout) and have concluded that a combination of weight (lack of or too much) and vehicles that are too free-running is largely the problem. Also persistent offenders were taken out and in all cases were found to have steel axles whose attraction to the permanent magnets was enough to cause a jerk at a critical point creating a de-coupling.
> We have the KD permanent magnets on Gweek North Quay, but we find even with careful setting up that vehicles can become detached when passing over them. Often this is traced to a 'jerk' (not one of the operators) caused either by stock passing through a turnout crossing in close proximity to the magnet, or a disparity in the weights of the vehicles. This slight jerk at the critical moment is enough to activate the couplings and open them.
The solution has begun with the free-runners; small pads of foam rubber glued under the axles and just bearing on them has made a marked difference. This treatment applied to steel axle-ed vehicles also seems to work. Some wagons have recieved extra weight to bring them to an average of 2 oz overall. I am now looking at filling the crossing vees with plasticard strip to try and alleviate the dropping which despite checking the back to back, still persists - the Peco "universal" standards again!
Thanks to those who made themselves known at Shepton, by all accounts the crew had a great time.
- Hi all
Following the various comments about Wrightlines, I spoke with Adrian Swain last evening.
He told me that the next narrow gauge exhibition he will be attending is Swanley on October 27th - http://expong.org/
Hope this helps members sort out orders etc - and it's a great show too!
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