Preferred height for Kadee couplers on UK 4mm scale models

[Ravenser]

I haven't got any lead sheet (and the builder's merchants are shut) but I have found my bag of lead shot, it is marketed as 'Fluid Lead' with a spec. diameter of 0,5 to 1,0 mm. Still wanting to try this (instead of lead strip), I stripped the grey open wagon in my last post, took out the steel weight and put a puddle of dilute pva into the underframe. For this particular moulding (Bachmann), there is nowhere for it to run out. Then I filled it level with the lead shot, and used a cocktail stick to clear the area around the fixing holes for the bosses on the underneath of the body (photo).

 

The result is quite dramatic: the original wagon (with shortened steel weight) weighed 21 g; it now weighs 31 g. The steel weight weighs 5 g, so the lead must be three times as much, 15 g. Above all, the wagon now 'feels' a whole lot better, tho' I suppose it will now wear out its axle bearings more quickly and someone will tell me I will have to fit brass ones. I am very pleased so far. (The wagon is probably the one in my post number 73 on 15th June, but I'm not sure).

 

DSCF9917.jpg

Richard:

 

A word of warning - correspondence in MRJ in the last year has revealed that PVA is acidic and promotes corrosion of lead very nicely . Especially as the surface area of lead shot is so much greater than an equivalent weight of leadsheet

 

Lead corrosion does 2 things . Firstly the corrsion products have greater volume so everything swells (as with rust) Various finescale modellers who happily filled the boilers of their etched brass kit locos with lead shot in pva have reported with horror that the boilers have started to swell and burst as the lead shot corrodes and expands inside them. This will probably happen inside your chassis moulding over the next 2-4 years 

 

Secondly the corrosion product of lead is white lead, a highly toxic heavy metal product , which takes the form of dust - easily inhailed. When the Victorians used white lead in paint it did serious harm to those producing the white lead, and to painters , and there are very strong warnings today about using masks and avoiding sanding and dust when stripping old painwork which may use  lead based.pigments

 

Use superglue, use araldite, but don't use pva with dust shot....

[47137]

Richard:

 

A word of warning - correspondence in MRJ in the last year has revealed that PVA is acidic and promotes corrosion of lead very nicely 

...

Use superglue, use araldite, but don't use pva with dust shot....

Thanks for this, just in time before I did the whole fleet. A bulging and broken model is one thing, white lead dust is serious ... I have added a warning above my last post.

 

There are some graphic photographs here:

http://www.lner.info/forums/viewtopic.php?f=3&t=2737

 

Superglue works well and makes for a quicker job. For the wagons I have done: well, the quantity of lead is relatively small, at least smaller than a 7mm model; perhaps I will get away with it. It is probably easier to buy a new wagon, and take the wheels and couplers across, than unpick everything.

Edited June 30, 2013 by Richard1962

[Dunsignalling]

Thanks for this, just in time before I did the whole fleet. A bulging and broken model is one thing, white lead dust is serious ... I have added a warning above my last post.

 

There are some graphic photographs here:

http://www.lner.info/forums/viewtopic.php?f=3&t=2737

 

Superglue works well and makes for a quicker job. For the wagons I have done: well, the quantity of lead is relatively small, at least smaller than a 7mm model; perhaps I will get away with it. It is probably easier to buy a new wagon, and take the wheels and couplers across, than unpick everything.

If you haven't long done it, hot water will probably loosen the pva enough to get it out fairly easily.

 

John

[47137]

If you haven't long done it, hot water will probably loosen the pva enough to get it out fairly easily.

 

John

I had done six wagons by the time I read Ravenser's post . I have stripped down three of them, with some warm water to remove the remains of the residue, and reworked them with fresh lead and super glue. The other three I shall put some red paint underneath as a reminder, I glued up the brake gear too well.

 

Changing the ballast from steel to lead has made next to no change to the behaviour of a wagon over a Kadee no. 308 uncoupling magnet. I like the idea of non-magnetic axles, but I would like to try lowering the magnet first ... many of my wheels are steel discs, not just steel rims. As it happens, the track bed is 5mm foam board, and the magnet is glued into a hole below the track on top of a second piece of foam board. With luck it will drop out from below the track and I can then try fixing it say 2mm lower. The Kadee surface mounted permanent magnets are a lot weaker and work better, at least for me so far.

 

Another idea would be to ballast over the no. 308 with the lead dust shot?

[Dunsignalling]

I had done six wagons by the time I read Ravenser's post . I have stripped down three of them, with some warm water to remove the remains of the residue, and reworked them with fresh lead and super glue. The other three I shall put some red paint underneath as a reminder, I glued up the brake gear too well.

 

Changing the ballast from steel to lead has made next to no change to the behaviour of a wagon over a Kadee no. 308 uncoupling magnet. I like the idea of non-magnetic axles, but I would like to try lowering the magnet first ... many of my wheels are steel discs, not just steel rims. As it happens, the track bed is 5mm foam board, and the magnet is glued into a hole below the track on top of a second piece of foam board. With luck it will drop out from below the track and I can then try fixing it say 2mm lower. The Kadee surface mounted permanent magnets are a lot weaker and work better, at least for me so far.

 

Another idea would be to ballast over the no. 308 with the lead dust shot?

Have you installed the steel intensifier plate under the magnet?

 

If so, taking it out will reduce the strength of the magnetic field.

 

John

[298]

Another alternative to the Kadee permanent magnets are small round Neodymium magnets from eBay, positioned between the sleepers either side of the rails. Their field is much smaller so stopping in the right place is critical, but will have less effect on unwanted uncoupling or affecting exisiting stock with steel weights or wheels & axles. 

[Pacific231G]

Another alternative to the Kadee permanent magnets are small round Neodymium magnets from eBay, positioned between the sleepers either side of the rails. Their field is much smaller so stopping in the right place is critical, but will have less effect on unwanted uncoupling or affecting exisiting stock with steel weights or wheels & axles. 

I know some people have reported good results with these but must admit that my experimens with them have had very little joy. The Neodymium produce a strong but very focussed field but I found this  was too strong where you didn't want it and weak where you did. I found that they tended not to attract the pins enough to open the knuckles but when they did pulled them hard over.  They probably warrant further investigation. 

I've been using Kadees on my French H0 layout for years and with the surface mounted permanent magnets haven't noticed any problems with steel axles. I guess that the field strength at axle height is simply too weak and these magnets do depend on being very close to the ends of the pins.

Edited July 1, 2013 by Pacific231G

[47137]

Another alternative to the Kadee permanent magnets are small round Neodymium magnets from eBay, positioned between the sleepers either side of the rails. Their field is much smaller so stopping in the right place is critical, but will have less effect on unwanted uncoupling or affecting exisiting stock with steel weights or wheels & axles. 

This ought to work well, with the flux pulling the pins sideways rather than the whole wagon downwards. Perhaps two longer 'strip' shaped magnets would be better. Could you post a photo? I tried one of the 'button' magnets (about 10mm dia x 4 mm thick) on edge between the rails, it works as an uncoupler but not a delayed uncoupler, and if there is any slop in a coupler mounting, it pulls it downwards not sideways.

[Pacific231G]

This ought to work well, with the flux pulling the pins sideways rather than the whole wagon downwards. Perhaps two longer 'strip' shaped magnets would be better. Could you post a photo? I tried one of the 'button' magnets (about 10mm dia x 4 mm thick) on edge between the rails, it works as an uncoupler but not a delayed uncoupler, and if there is any slop in a coupler mounting, it pulls it downwards not sideways.

DSCF9921.jpg

I'll be very interested to see the results you get from this.

[tender]

If you want to see the use of Neodymium magnet strips in use have a look here:

 

http://www.rmweb.co.uk/community/index.php?/topic/60560-pwllheli-next-stop/page-2&do=findComment&comment=950234

 

I've bought some of these to try out on my own layout but havent got around to fitting them yet, but from what CambrianCoaster shows in his video they look a pretty good alternative.

Ray

[Ramblin Rich]

I did see this and it looks very useful, but I wonder if the magnets are too strong - it looks like, if a train is shunted/pushed over, they might just pull every pair of couplings over into delay mode position, so a train shunted into a siding would effectively have all the vehicles separated.....?

[298]

I did see this and it looks very useful, but I wonder if the magnets are too strong - it looks like, if a train is shunted/pushed over, they might just pull every pair of couplings over into delay mode position, so a train shunted into a siding would effectively have all the vehicles separated.....?

 

Kadees don't work that way, the knuckles have to be separated (aka the Kadee shuffle) to be in the delayed position. If a train stopped over the magnet and then proceeded in the other direction then they would separate, but there is a school of thinking that says this is less likely as the magnet area is less.

[Welly]

Is it possible to use Kadees without the magnetic hooks for semi-permanently coupled rakes of coaches and wagons?

[298]

Is it possible to use Kadees without the magnetic hooks for semi-permanently coupled rakes of coaches and wagons?

 

Of course, you simply cut the excess off. You could argue that the pins might resemble air hoses, but otherwise they don't have a prototypical use. Since I chose to not fit magnets to my HO layout and rely solely on an uncoupling tool, I don't need the trip pins.

[47137]

I have found I can easily cut a Kadee no. 308 magnet using a knife, and then break it into strips ... and that the strips are barely magnetic at all.

 

Having put the pieces to one side, I tried the arrangement below and it works really well. This is a pair of 10 x 4 mm "button"  magnets, positioned with their top edges about 5 mm below the tops of the rails. I am lucky I chose a track bed I could alter easily, but I think this will take a cosmetic rebuild without altering the performance. The delayed uncoupling is perfect, and the tendency for wagons to centre themselves over the magnet has gone. I don't know the name of the magnet manufacturer/distributor, possibly 'Centurion', they were in a pack of two in an ironmongers. Happy.

 

[Pacific231G]

Is it possible to use Kadees without the magnetic hooks for semi-permanently coupled rakes of coaches and wagons?

Yes if you remove the trip pins they still couple perfectly well and you can uncouple them from above by twisting something like a cocktail stick or the uncoupling tool that Kadee supplies in the knuckle.

I gather that a lot of American modellers now prefer to use them this way especially on the type of large layout where operators are switching trains at a number of local yards as they find it more realistic to be the brakeman (or whoever uncouples cars on American trains) cutting out cars anywhere rather than doing the Kadee shuffle over a magnet.  The only problem I can see is that for coaching stock with corridor connections it would be quite hard to get at the couplers to release them but that doesn't matter if they are semi-permanent rakes. . 

[BR60103]

Having tried to uncouple coaches with gangways, I'd leave the pins on and use the stick to pull them sideways.

[Dunsignalling]

I have found I can easily cut a Kadee no. 308 magnet using a knife, and then break it into strips ... and that the strips are barely magnetic at all.

 

Having put the pieces to one side, I tried the arrangement below and it works really well. This is a pair of 10 x 4 mm "button"  magnets, positioned with their top edges about 5 mm below the tops of the rails. I am lucky I chose a track bed I could alter easily, but I think this will take a cosmetic rebuild without altering the performance. The delayed uncoupling is perfect, and the tendency for wagons to centre themselves over the magnet has gone. I don't know the name of the magnet manufacturer/distributor, possibly 'Centurion', they were in a pack of two in an ironmongers. Happy.

 

DSCF9922.jpg

Looks a very neat job, Richard. I'll be keeping a look out for some of these.

 

Did you install the magnets as a pair to get greater force or in opposition (trying to repel each other) so as to get effectively the same force pattern on each side? I am guessing the latter and, if so south to south or north to north?

 

John

[47137]

Did you install the magnets as a pair to get greater force or in opposition (trying to repel each other) so as to get effectively the same force pattern on each side? I am guessing the latter and, if so south to south or north to north?

At the moment this is a lash up. The magnets are holding themselves together, i.e. opposite poles touching.  It would need some very strong glue to hold them 'in opposition', they will spin round and fly over a foot on the workbench when they get near each other. They are sitting on one of those self adhesive foam 'grab tabs' on the block of wood. I fancy fitting some thin card below the sleepers to hold the ballast, and fitting the magnets to a length of thick dowel so they can be moved up or down, or even swapped out for some different ones, from below the baseboard. It might be worthwhile to put some small steel washers between them, to put them further apart, this needs experimentation. I would like to work through my stock, to see if I can find a coupler that does not uncouple properly, before I do anything permanent.

[47137]

On my own models, I generally add extra weight to r-t-r wagons and, with 9/10 foot wheelbase stock I aim for 40-45 grams, long wheelbase vans, 60-70 and bogie stock at least 100. A bit lighter than the NMRA standard, but quite adequate empirically. However, consistent mass produces consistent running whatever couplings are in use. In my case it has less to do with overcoming the buffing force than reducing the tendency of vehicles to move under the power of uncoupling magnets acting on their axles!

 

With open wagons, I really recommend using lead flashing rather than shot - there are no air gaps so you can get more weight in a given space. I'm still recycling old stuff that came off my roof when it was re-done a few years ago but Builders Merchants sell it off rolls about 6" wide so it shouldn't be too expensive to get a foot or so that will do lots of wagons.

 

Open wagons without loads can be a real problem - I make the new weight to fill as much of the chassis as possible without interfering with the wheels. It is easily cut with a small pair of snips (or even a large pair!). Cut away any unnecessary part of the moulding to make room (e.g. the little tubes that are often provided to accommodate the ends of straining rods if the chassis is used under a tank wagon but are otherwise superfluous. 

Backtracking to last weekend and to three weeks ago, I now have an offcut of flashing from my local builder, it is a lot less messy to work with than lead shot dust. My first application (photo) was almost too much: a strip 23 mm wide, folded to a double thickness with a hole for a fixing boss weighs 35g. It replaces a strip of mild steel which weighed 7g, and it takes the total weight of the wagon up from about 25g to 53 g.

 

I agree small open wagons are a lot harder to squeeze enough lead in, and I am reconciling myself to the idea that a 32 g wagon is going to run a lot better than a 26 g one, and be content with that. Some wagon loads would make the task a lot easier. I am still experimenting with magnets; but the 'leaded' tar wagon with its steel axles still finds the magnets too easily.

 

[brossard]

Yes if you remove the trip pins they still couple perfectly well and you can uncouple them from above by twisting something like a cocktail stick or the uncoupling tool that Kadee supplies in the knuckle.

I gather that a lot of American modellers now prefer to use them this way especially on the type of large layout where operators are switching trains at a number of local yards as they find it more realistic to be the brakeman (or whoever uncouples cars on American trains) cutting out cars anywhere rather than doing the Kadee shuffle over a magnet.  The only problem I can see is that for coaching stock with corridor connections it would be quite hard to get at the couplers to release them but that doesn't matter if they are semi-permanent rakes. . 

 

David, I've been doing this for some time with my UK stock (and most of my clubmates go along - we ripped up magnets in disgust some time ago due to unwanted uncoupling).  Trip pins on unfitted wagons look very much out of place (even if the Kadees don't!).  As for coaches, my approach is to use semi fixed rakes.  The outer coaches are fitted with Kadees for coupling to the loco.  The coupling system for the rest of the coaches is copied from something I saw in Right Track 4 where Tony Wright fashioned home made hook and bar couplings from NS wire.  It takes a bit of effort to set up but works well.

 

John  

[47137]

Here is a working solution. I modified the coupler on the loco so it opens further. This means removing the spring, filing away at the end stops top and bottom, and putting the spring back in. I cut the trip pin off the coupler on the wagon. This works over my 'button' magnets (photos) and also on the Kadee no. 321 surface uncoupler. So you can have a train of unfitted wagons without unsightly trip pins, and still detach the loco using magnets ...

 

 

[Dunsignalling]

Richard1962, on 05 Jul 2013 - 22:15, said:

Backtracking to last weekend and to three weeks ago, I now have an offcut of flashing from my local builder, it is a lot less messy to work with than lead shot dust. My first application (photo) was almost too much: a strip 23 mm wide, folded to a double thickness with a hole for a fixing boss weighs 35g. It replaces a strip of mild steel which weighed 7g, and it takes the total weight of the wagon up from about 25g to 53 g.

 

I agree small open wagons are a lot harder to squeeze enough lead in, and I am reconciling myself to the idea that a 32 g wagon is going to run a lot better than a 26 g one, and be content with that. Some wagon loads would make the task a lot easier. I am still experimenting with magnets; but the 'leaded' tar wagon with its steel axles still finds the magnets too easily.

 

DSCF9924.jpgDSCF9925.jpg

I only used a single thickness on my tar tank wagons. Be careful not to go too heavy - it's likely to wear the axle holes in the chassis. It can even cause problems on (plastic) kit built wagons with brass bearings, not through wear but by the axleguards gradually splaying outwards under the weight.

 

I was operating on a mate's layout last week and he has working tail lamps on all his brake vans - the pickups prevent unwanted movement over magnets but whether adding mechanical drag to all wagons would be viable will depend on the train lengths you wish to run.

 

Another friend suggested scribing lead flashing to represent planking and fitting it into open wagons as dummy floors. A chunk that size would be too heavy for my liking (getting on for 40g on its own) and I think its thickness would be noticeable in anything lower than a 7-plank wagon. Certainly no good in a Lowfit!

 

However, the basic idea is good, so does anyone know of a source of thinner lead sheet, say 1.5mm or less?

 

John

 

EDIT: Just found that Eileen's Emporium list 1mm lead sheet so I'll get some next time I see them (Railwells?). Probably not quite enough on its own, but good to top-up the thicker stuff hidden underneath.

Edited July 6, 2013 by Dunsignalling

[47137]

...

However, the basic idea is good, so does anyone know of a source of thinner lead sheet, say 1.5mm or less?

 

The lead sheet I have measures 0.053 inches (1,35 mm), I expect it is left over from roof flashing.

 

EDIT: The weight of my 7.5 x 10.5 inch offcut is 740 g: about 9.4 g per square inch (if you excuse the mixed units!)

Edited July 7, 2013 by 47137

[Dunsignalling]

The lead sheet I have measures 0.053 inches (1,35 mm), I expect it is left over from roof flashing.

The stuff I've been using (and never measured until today) is 0,087 in. / 2.2mm thick - which explains why I didn't need a double thickness in the Tar wagons.....

 

John