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Re: Electro magnets for AJs

Posted: Fri Jan 26, 2018 8:00 am
by RobM
martinm wrote:So what do people do with unfilled track?
Surely it should not be above rail level?
The droplets certainly must always be above rail level!
martin


Although I use Dingham's I think the same principle applies. On Manston Brewery I have a section of infilled track with an electromagnetic just below rail level and it works fine. You can just see it between the wagon and the loco on page 1, 2nd photo down. https://www.scalefour.org/forum/viewtopic.php?f=101&t=2819 The electromagnets are those supplied by Dingham's.
Rob

Re: Electro magnets for AJs

Posted: Fri Jan 26, 2018 9:23 am
by steamraiser
For AJ's I was mulling the problem over with Gordon Gravett.
The problem with infilled track is that there is no space for the coupling dropper to be pulled down into when uncoupling.
I was thinking of having a couple of manholes with the covers off to create the space.
GG's answer is to bring the magnets up to the top of rail level and shorten the dropper on the AJ.

Gordon A

Re: Electro magnets for AJs

Posted: Fri Jan 26, 2018 10:07 am
by Paul Townsend
steamraiser wrote:The problem with infilled track is that there is no space for the coupling dropper to be pulled down into when uncoupling.

I was thinking of having a couple of manholes with the covers off to create the space.
Gordon A


Wouldn't they would have to be mighty big manholes if you wanted to shunt across the uncoupler magnet to get the 2 hits.

steamraiser wrote:GG's answer is to bring the magnets up to the top of rail level and shorten the dropper on the AJ.
Gordon A


So you have to have a few special wagons for this.
OK for GG's latest model with minimal stock but when you have 50+ wagons running this feels a bit limiting for playing trains type operation. Viable for a disciplined timetable I guess.

I seek a definitive solution to this as I need to apply it in the next few months!

Re: Electro magnets for AJs

Posted: Fri Jan 26, 2018 1:19 pm
by steve howe
I thought the specification for the AJ was such that the dropper did not descend below rail level? I don't have any infilled track on my current project but I do have a road crossing immediately adjacent to a magnet, in tests only one wagon fouled the crossing when under magnetic influence and on inspection I found the dropper length was 10mm instead of the specified 9mm. All other vehicles pass over OK.

Steve

Re: Electro magnets for AJs

Posted: Fri Jan 26, 2018 4:52 pm
by steamraiser
Steve,
I find with the couplings at rest the droppers clear the rails, but when passing over a magnet the droppers go below rail level.

For Pauls objections you could have a short dropper on one end of the wagon with a standard dropper on the other end.
If you come up with a workable alternative I would be interested, unless you go for three links.

Gordon A

Re: Electro magnets for AJs

Posted: Fri Feb 02, 2018 5:29 pm
by steve howe
Lots of good practical stuff here:

http://www.lbscrmodels.co.uk/aj1.html

Steve

Re: Electro magnets for AJs

Posted: Sat Feb 03, 2018 9:42 am
by Terry Bendall
steve howe wrote:Lots of good practical stuff here:http://www.lbscrmodels.co.uk/aj1.html


Yes there is but if you read to the end you will find that Barry Luck has given up on using AJs and he explains why.

The book published by the Society on using AJs has on page 17 some useful drawings with dimensions. This section is a reprint from MRJ No 55 so if you don't have the book you might have the relevant copy. According to the drawing, for a wagon with 12mm dia. wheels, the horizontal wire should be 10mm above the rail. The end of the dropper, when at rest should be 1.5mm above the top of the rail and will move down by 3mm when the current is applied to the magnet. That would seem to cause problems with inset track.

I don't use AJs and probably never will but perhaps there is a need for some changes to cope with inset track. Perhaps an experts in the use of Ajs has the answer.

Terry Bendall

Re: Electro magnets for AJs

Posted: Sat Feb 03, 2018 2:12 pm
by steve howe
I do sympathise with Barry's point - I think there is an element of 'Holy Grail' with the AJ, and its devotees may be a little too emotionally attached to achieving the un-achievable - that is a perfect, reliable and realistic auto-coupling system, to overlook its shortcomings. As we've discussed here before, there are many approaches and each have their drawbacks; the AJ scores in its discretion, but misses on many other counts, particularly those discussed in Barry's epilogue.

For myself I'm up to 20 odd vehicles and three locos now fitted with AJs and am embarking on the long and tedious process of testing each one 'live' on the layout, which is very different to achieving 100% reliability on the test track. Mine is a simple shunting plank with small locos and mainly short freight stock, I'm not sure I can be sold on the AJ in the longer term if ever a more ambitious project were to be undertaken. Its been a long and interesting (and at times downright frustrating) learning curve which is not over yet!

Re: Electro magnets for AJs

Posted: Sat Feb 03, 2018 2:23 pm
by Le Corbusier
steve howe wrote:I do sympathise with Barry's point - I think there is an element of 'Holy Grail' with the AJ, and its devotees may be a little too emotionally attached to achieving the un-achievable - that is a perfect, reliable and realistic auto-coupling system, to overlook its shortcomings. As we've discussed here before, there are many approaches and each have their drawbacks; the AJ scores in its discretion, but misses on many other counts, particularly those discussed in Barry's epilogue.

For myself I'm up to 20 odd vehicles and three locos now fitted with AJs and am embarking on the long and tedious process of testing each one 'live' on the layout, which is very different to achieving 100% reliability on the test track. Mine is a simple shunting plank with small locos and mainly short freight stock, I'm not sure I can be sold on the AJ in the longer term if ever a more ambitious project were to be undertaken. Its been a long and interesting (and at times downright frustrating) learning curve which is not over yet!


Didn't Iain Rice develop his own simpler version of the AJ coupling. How does that measure up? or is it regarded more as a curiosity?

Re: Electro magnets for AJs

Posted: Wed Feb 07, 2018 7:46 am
by Flymo748
Le Corbusier wrote:
steve howe wrote:I do sympathise with Barry's point - I think there is an element of 'Holy Grail' with the AJ, and its devotees may be a little too emotionally attached to achieving the un-achievable - that is a perfect, reliable and realistic auto-coupling system, to overlook its shortcomings. As we've discussed here before, there are many approaches and each have their drawbacks; the AJ scores in its discretion, but misses on many other counts, particularly those discussed in Barry's epilogue.

For myself I'm up to 20 odd vehicles and three locos now fitted with AJs and am embarking on the long and tedious process of testing each one 'live' on the layout, which is very different to achieving 100% reliability on the test track. Mine is a simple shunting plank with small locos and mainly short freight stock, I'm not sure I can be sold on the AJ in the longer term if ever a more ambitious project were to be undertaken. Its been a long and interesting (and at times downright frustrating) learning curve which is not over yet!


Didn't Iain Rice develop his own simpler version of the AJ coupling. How does that measure up? or is it regarded more as a curiosity?


I feel it remained the latter. Very much hand made, and not something that I recall having been taken up elsewhere. I think he described it as something like "an inverted tension-lock, in wire".

Of course, the incompatibility won't matter if you only run your own stock on your own layout, or don't have any visitors contributing stock either. Or you have converter wagons ;-)

Cheers
Flymo

Re: Electro magnets for AJs

Posted: Thu Feb 14, 2019 12:04 am
by steve howe
Seems the best place to ask this:

Having replaced all the old H&M point motors on 'Watermouth' with Cobalts, I am looking at the pile of old motors and thinking the coils would make good electro-magnet uncouplers for AJs.....

Just wondering, (what with being electrically illiterate and all), if one coil would be sufficient or is there any advantage in yoking two together? (we do have an awful lot of redundant H&Ms!)

Steve

Re: Electro magnets for AJs

Posted: Thu Feb 14, 2019 12:29 am
by David Knight
I used half of an old point motor to work my Dinghams. The only catch was that I had to make up a new core section as the existing one was too loose and would fly out when the coil was activated :oops: . That said, a single coil has enough oomph to work the coupling. I use about 6 VDC from an old power supply with a push button to activate.

HTH

David

Re: Electro magnets for AJs

Posted: Thu Feb 14, 2019 10:27 am
by steamraiser
I use Gaugemaster electro magnet EM1 for AJs.
For some reason they are listed for N gauge use.
They are not cheap and come with a push button switch that I am not impressed with, but they do the job.

Gordon A

Re: Electro magnets for AJs

Posted: Thu Feb 14, 2019 1:24 pm
by steve howe
David Knight wrote:I used half of an old point motor to work my Dinghams. The only catch was that I had to make up a new core section as the existing one was too loose and would fly out when the coil was activated :oops: . That said, a single coil has enough oomph to work the coupling. I use about 6 VDC from an old power supply with a push button to activate.

HTH

David


Yes, the H&M armature is too short and loose to be much use, I am thinking a cut down 4" nail with the head forming the exposed part would do the job. Interesting to know that one coil is enough.


Steve

Re: Electro magnets for AJs

Posted: Fri Feb 15, 2019 3:02 pm
by CDGFife
The other bit of "blindingly obvious when you think about it" I'd add here is that if you're mixing magnet sources on the layout this can cause a problem if they have differing strengths. All my magnets on Cadhay are EM1s from Guaugemaster as mentioned by Gordon above. I've got pretty reliable working now on most of my stock but some others stock which works fine with different magnet systems often fails to drop well enough with the EM1s on Cadhay. Equally mine over-drop on some other layouts! I would say magnet strength and positioning being consistent is another of those key things to get right.

Chris

Re: Electro magnets for AJs

Posted: Fri Feb 15, 2019 5:49 pm
by steve howe
Agreed, I tried Dinghams and DG and found a marked difference between them, the DG ones (from Andrew at MSE) being markedly stronger. I will try some experiments with H&M coils and report back - no breath holding now!

Steve