Hinged Alex Jacksons

[Penrhos1920]

I've just bought some Palatine AJ hinge plates (along with the bending jig and setting gauge). I'm a total newbie to AJ's and I don't find the Palatine instructions very helpful. I'm intending on using them on dogfish and similar hopper wagons mounted under the platforms. What sort of counterbalance weight will I need, 2g, 5g 10g? Am I right in thinking of using crimp on fishing weights? Can I glue the plate in place, or is there a good reason to use screws?

Thanks

[Andy G]

Hi Penrhos,
If you can let Ralph know what parts of the instructions you don't find easy to understand that would be great and he can then look at addressing any issues. I'm not familiar with your prototype wagons but I'll try and answer from the coupling point of view. The counter balance is purely to bring the coupling back up to height, i.e. it counterbalances the weight of the dropper on the otherside of the hinge. In the past I've used a small nail, one part for the dropper and the remainder for the counterbalance. You don't want too much weight or the magnets will struggle to pull the dropper down.
The screws serve two purposes, firstly (and obviously) fixing the plate to the wagon. However, the second, and the reason why I would advise against glue is that the by using a screw and the elongated hole in the plate the position of the coupling head can be adjusted without having to resort to bending the wire (which is a real PITA as it tends to have a mind of its own). The Palatine pivots currently available include a fold up base plate intended to bring the pivot into line with the bottom of the headstock (well just under it), you don't want to be pivotting from the wagon floor as that would mean that either the angles on the coupling head are out or you have an unwanted bend to get the coupling shank horizontal again.

I've just realised that you are looking to place the pivot under the platforms at the end of the wagon, correct? I could be wrong but this is probably one of the more awkward locations for positioning and pivots may not give enough downward movement to couple/uncouple. I know that Norman had successfully experimented with a hinged version coming back on itself and thus using half the length otherwise required but I still think you are going to be short of space and perhaps the coiled version would be the best option for this situation. You have got the book on AJs haven't you?

There is more on the hinged version of the coupling on the MMRS web site, http://www.mmrs.co.uk/technical/ajcoupling4.htm. Please note that the photos show a wagon with multiple bends on the coupling shank - they don't need to be like this!

Any further questions just post them here and I'lll keep a look out for them.

Andy

[davebooth]

[quote="Andy G"]Hi Penrhos,
If you can let Ralph know what parts of the instructions you don't find easy to understand that would be great and he can then look at addressing any issues. I'm not familiar with your prototype wagons but I'll try and answer from the coupling point of view. The counter balance is purely to bring the coupling back up to height, i.e. it counterbalances the weight of the dropper on the otherside of the hinge. (Snipped here)

That's not strictly true Andy. The counterbalance must have enough mass not only to balance the dropper but also to overcome the sliding force of each wire against the other when uncoupling. If the counterbalance simply matches the dropper mass, then as one coupling is pulled down by the magnet these sliding forces will pull down the second coupling too and uncoupling does not then take place.

For what it's worth Penrhos, I have now standardised on using 1mm x 25 mm veneer pins (try http://www.screwdix.com). Cut off a 9mm length below the pin head and saw a diametric slot at your cut face with a piercing saw; (this slot to slide over the 0.011" wire where you solder the two together). the remainder of the pin, with the point removed, will usually provide sufficient mass as the counterbalance. Have a look at the pics on Manchester MRS web page; they're also in MRJ55&56 and in the Scalefour Digest sheets. As Andy said, come back if all does not then become clear.

[Andy G]

Penrhos,
The coiled AJs were apparently covered in Snooze number 153.
The veneer pins shuld be available from your local DIY shop (much more preferable), or as Dave said http://www.screwfix.com, but not http://www.screwdix.com

Andy

[Edit:Looks like screwfix have been clever and bought bought srewdix as well]

[Penrhos1920]

I'll try to explain to Ralph my problems. Looking at MRJ has helped a bit. But if I didn't have the book, MRJ or the MMRS web pages I'd be totally lost. The instructions don't really say how to use the parts, just what the advantages of hinge plates are over the traditional design. Here are some specific problems that I'm having.


Is this a good place to put the hinge plate?...

Genesis herring, similar to cat & dogfish

P5060081.JPG (100.71 KiB) Viewed 3238 times

.....I don't think I've got many other options except vertically on the end of the hopper? Or have I got it the wrong way around? I'm surprised that there isn't a tab on the front to set the coupling height.

How would you fit AJs to this beast?

MCA with a typical freight bogie and nowhere to mount an AJ?

P5060082.JPG (222.61 KiB) Viewed 3236 times

How about these Bachmann wagons where there is very little height between the axle and 'floor', or there is a big screw lug in the way?

Bachmann wagons

P5060083.JPG (191.95 KiB) Viewed 3232 times

Thanks for your help,
Richard

[Tony W]

Hi Richard

Is there any chance of a wider view of your first picture. I'd quite like to see more of the wagon floor but from the photo posted the hinge plate does look as if it will cause a few problems in that position. Bogie stock is another issue altogether and one where attention will be focussed in the future. Since most bogie stock doesn't need to be uncoupled automatically that often it is sometimes better to fit fixed AJ's, which in your case would probably be close to the centre of the bolster.

Sorry if you found the Jig instructions unhelpful. They were never intended to be a complete treatise on AJ Couplings and I had to cut them down considerably from the first draft to get them to fit on a manageable piece of paper.

Dave's quite right about the size of the counterbalance but I notice in your original posting that you mention specific weights. Please don't get hung up on measuring the weight of the counter balance. I've never measured one yet and have no intentions of doing so but use the advice Dave has given and you shouldn't be too far out. You want to be aiming for a nice positive action but there are other variables to consider such as length of coupling and strength of magnet used. The beauty of the hinged AJ is that if you've done it wrong it lets you know on the first trial. And just to let you know we've all done wrong at some time or other!!

Regards

Tony

[Andy G]

Richard,
You pick some awkward ones to get started with don't you? I'll start with the last ones as those are probably the simpler and most similar to what I'm working on at the moment - Bachmann 16 tonners. First thing I did was to chop off that big lump that the screw passes through and used to attach the NEM coupler - keep the screw though. If it is the same as used on the 16 tonners then it can be used to affix the plate to the chassis floor. Slightly widen the slot in the plate with a small file so that the screw can slide more easily. Once you have established where the plate is going to go then use a 1.4mm drill through the plastic chassis, with a little bit of force behind it the screw will then tap itself into the chassis, but you may then need to shorten the screw as it will now push up into the wagon body. I'm screwing the plate directly to the bottom of the floor and the coupling will be bent so that when the coupling side of the wire is horizontal the counter balance side is bent down sufficiently so that it has enough room to move upwards such that the coupling can move down and uncouple (needs to have at least 3.5 mm movement but not sufficient that the dropper digs into the ballast). If this isn't clear let me know and I'll have another go at explaining it.

So where to position the plates? Well I've positioned mine approx 30mm behind the buffer heads and such that the pivot in the middle of the plate is approx on the centre line of the wagon (thus positioning the shank down the centre line of the wagon). I would then position the counter balance so that it is mostly concealed behind the wheels at the other end of the wagon - this may enable you to use a lesser weight as you will have greater moments due to the extra length you have, but you may also need to experiment.

The proximity of the floor to the axles is not an issue as even if the floor was in its usual place the coupling should be just below the solebar (actually 10mm from rail height).

As for the herring - 'is this a good place to put the hinge plate?' - errr not ideal. I presume that vertical piece can not be moved, otherwise I would say move it about 10mm further inboard. Another possibility would be to move the plate the other side of the divide and cut a slot in middle of the divide for the coupling to move up and down through.

The MCA is a typical example of why the coiled version was developed. However, are these wagons not normally formed into fixed rakes? If so then consideration would normally be given to having fixed AJs (i.e. as you would on a loco) in the middle of the rake and functioning ones on the outer ends.

Andy

[Penrhos1920]

Richard,
You pick some awkward ones to get started with don't you?

Not to start with. TOERAG had an AJ making session a couple of weeks ago and I'd finished a Bachmann NE GBV by the end of the meeting and made 8 more sets ready for the simple conversions. I've also got a couple of coaches with MJT bogies, so they'll be easy. The problem that all of the stock runs on Awrhyllgwami Quarry and most either have hoppers or other awkward features. We found that 3 links were a pain at S4um and we quickly lost our viewers when we struggled to couple up. So we've decided to go to AJ after one of the members brought along a couple of wagons already fitted with AJs.

Is there any chance of a wider view of your first picture. I'd quite like to see more of the wagon floor but from the photo posted the hinge plate does look as if it will cause a few problems in that position.

Yes here it is together with dogfish. I was thinking of running the counterbalance down the side of the Herring hopper. I think the coiled AJ is the only solution for the Dogfish?

Herring (bottom) & Dogfish

P5070090.JPG (306.14 KiB) Viewed 3183 times

Fortunately all of the wagons only need an AJ at one end as the run in semi -permanent rakes.

The MCA is a typical example of why the coiled version was developed. However, are these wagons not normally formed into fixed rakes? If so then consideration would normally be given to having fixed AJs (i.e. as you would on a loco) in the middle of the rake and functioning ones on the outer ends.Andy

Correct. This is one of a rake of four, can't fit the prototypical 5 in the fiddle yard (However, now that Dapol have announced the wagon I might buy a few more and run them around Penrhos just to show what it might have looked like if the Beeching axe had fallen in a different place). The inner wagons are coupled with Kadees with the tails removed as they are probably as close to working buckeyes as you can get. But the outer wagons need working AJs so that they will uncouple from the loco, which has a fixed AJs.

Another view of one the Bachmann wagons. There is exactly 2mm between the axle of bottom of the weight.

Bachmann MFA

P5070091.JPG (136.66 KiB) Viewed 3184 times

[davebooth]

Hi Richard
Snipped beyond recognition! :-

......................................... And just to let you know we've all done wrong at some time or other!!

Regards

Tony

"Some time or other"? Just about every time for me, but perseverance overcomes even Alex' Chinese puzzle!

Richard, I suspect that you have actually pulled out of your stock all the wagons that you knew would cause problems to us at Manchester MRS

I think that in nearly every case you have shown us, high levels of personal ingenuity are required, and that a standardised answer is most unlikely.

I would start by looking at the coiled spring AJ, rather than the hinged version, and see how that type can be applied; probably just forward of the axle.
But I doubt if any one can give you a simple "here's how to do it" answer, unless some forum member reading these pages has already actually successfully fitted AJs to the type of wagon you have problems with.

Referring to P5070091.JPG :-
Those weights are definitely in the way. Must they be there?
If they were removed, then the picture implies to me that the hinge mount would nicely fit on the wagon's centre-lines, exactly the best place for them. Even countersinking the screw fitting could possibly help a little.
Again, without the weights there then a coiled spring version would sit nicely in that area.

[dave k]

I think the coiled AJ is the only solution for the Dogfish?

Althought I have not used AJ's myself, yet, I seem to remember a picture in a MRJ, I think, where someone had bent the AJ around the hopper bottom of a wagon. The AJ were attached to the opposite end in convential style

[davebooth]

I think the coiled AJ is the only solution for the Dogfish?

Althought I have not used AJ's myself, yet, I seem to remember a picture in a MRJ, I think, where someone had bent the AJ around the hopper bottom of a wagon. The AJ were attached to the opposite end in convential style

That idea does on first view sound reasonable but there is need to remind yourself that the bit of bent 0.011" wire must cope with the tension forces set up by the train behind that particular vehicle. If that wagon is next to the loco which is hauling thirty or forty wagons, it's extremely unlikely that the bends around the hopper will stay as they were originally bent. Also, if there is a derailment and the derailed vehicle locks up, then damage is almost certain.
OK, most of us will never have our wagons in such long trains but I don't think any of us genuinely expect to get by without the occasional derailment!
If bending the wire around an obstacle is the only possible answer then please think in terms of support pillars which will absorb some of the excess forces developed in these cases and stop the wire straightening out under tension.
Both the hinged version and the coiled spring version are of course bent, but they are also supported against tension at the bend or bends.

[Penrhos1920]

Richard, I suspect that you have actually pulled out of your stock all the wagons that you knew would cause problems to us at Manchester MRS

I think that in nearly every case you have shown us, high levels of personal ingenuity are required, and that a standardised answer is most unlikely.

Never. How dare you suggest that. I've think I've solved or avoided most of the problems and I'll report next week after the show. But there is a difficult one left. It's an Oyster. Very similar to the standard Shark brake ballast plough. How do I get a wire through the ploughs? It cannot be a fix AJ as it needs to be shunted by locos with fixed AJs. Last night I stopped short of cutting a vertical slot in the ploughs but I can't see any other way of getting around it.

See Paul Bartlett gallery for pictures of Oysters: http://gallery6801.fotopic.net/c820141.html



Thanks

Richard

[Andy G]

Hi Richard,
I think you may be right about cutting a slot being the only option, unless you look at Nigel Cliffe's DCC operated hook.

Andy

[nigelcliffe]

The rotating method on my Coronation class shunter might work if the wagon can be easily chipped. Pickups are the main issue with chipping a wagon. Once the chip is installed, map the function to a convinient number, and then run the wagon in a multiple unit with the loco; then the loco function keys will operate the wagon coupling.

There is some info on the Coronation on my blog -
http://nigelcliffe.blogspot.com


- Nigel

[Penrhos1920]

Well he's how I managed on the MCA with it's freight bogie and apparently nowhere to put an AJ:

MCA AJ.JPG (225.28 KiB) Viewed 2900 times

It ran well this weekend, the only problem being that it is hinged and cannot by uncoupled from another hinged AJ.

[Andy G]

Well he's how I managed on the MCA with it's freight bogie and apparently nowhere to put an AJ:

It ran well this weekend, the only problem being that it is hinged and cannot by uncoupled from another hinged AJ.

Richard,
Well done, but do you know why it wouldn't uncouple from another hinged AJ? There should not normally be any reason for it not to uncouple from another hinged version, unless you've forgotten about that extra little bit of counterbalance weight that I had earlier! I assume that it would uncouple from a 'traditional' version.

Andy

[davebooth]

Well he's how I managed on the MCA with it's freight bogie and apparently nowhere to put an AJ:

MCA AJ.JPG

It ran well this weekend, the only problem being that it is hinged and cannot by uncoupled from another hinged AJ.

Congratulations Richard; your own ingenuity sorted how best to apply Alex' idea. Your confidence has no doubt risen.
From inspecting the picture I'm fairly sure that the reason for the inability to uncouple is more related to the distance of the hinge fulcrum from the axle than to the mass and position of the counter-weight.
The axle is acting as a limiter to vertical movement (as it should do), but in this case, because the axle is so close to the fulcrum of the hinge, it is limiting that movement too greatly.
Try moving the hinge closer to the bogie pivot point therby increasing the distance of the hinge from the axle. This will result in more vertical movement and I think you can achieve sufficient to make the couplings uncouple OK.