Lever Frames

Discussions of the prototypes and how to model them. Show us how you do it.
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Paul Townsend
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Re: Lever Frames

Postby Paul Townsend » Sat Jan 14, 2012 11:21 am

barhamd wrote:The servos I used were DYS0201 from Giantcod http://www.giantcod.co.uk/dys0201-micro-servo-torque-p-402575.html at £2.83 each.

The method of locking with a two lengths of of K&S tube, say £2 each for the length which did 20 levers, I made all the mechanics for the locking of 20 levers in an evening. There were also two lengths of 1/4 angle which had the short lengths of the tube in which the slotted lock rotates.

I reckon the total cost of the ironmongery was well under £10.

David


Ta for that.
It looks quicker to build than I expected so is very time and cost effective for Cbus users.
Those without Cbus would need to add servo driver electronics eg Merg Servo4f board at £5.50 for a kit for 4 servos + Merg membership + an evenings work + setting up time.

For these bods the solenoid route is a clear option as the sophisticated servo electronics is not required, even if DiY coils are too daunting or time consuming.
A quick search for cheap suitable solenoids in the market showed some options around £3...data being sought. ( Most commercial offerings like the MSE and RS ones mentioned are overpowered and overpriced for this light task.)
Andrews "mod. a relay option" may be easier for most bods than wind your own coil, assuming like him you have some freebie or cheap suitable relays to cannibalise

At least we now have several choices.

As a Merg member and regular Merg Forum visitor I forgot that I was in S4um in this thread so apologise for using Merg jargon. Cbus, Servo4f and CanAcc8 refered to above all refer to Merg ( Model Electronics Railway Group) kits for model railway electrics. For more info PM me or visit www.merg.co.uk

andrew jukes
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Re: Lever Frames

Postby andrew jukes » Wed Jan 18, 2012 7:50 pm

I think I need to know more about solenoids!

I managed to get the core out of my relay coil without difficulty, giving me a coil wound on a plastic moulding, overall length 20mm, overall diameter (of moulding) 10.5mm and with a bore diameter of 4.0mm. I think with careful trimming, it will be possible to mount a line of coils at 10mm centres. The resistance of the coil is 255ohms.

I have experimented with armatures and have the coil (using a 12V supply) lifting an armature/locking peg satisfactorily, though not with as much oomph as I would like. The better armature is made of old Meccano rod, 18mm long overall with 14mm at just under 4.0mm diameter and 4mm (for the locking peg) at 2.5mm diameter. What needs sorting out is:
- what is the best material for an armature?
- what should the overlap between armature and coil be for maximum lift?
- how does the trade-off between armature weight (4mm diameter steel rod is not light) and lifting force work? Would it be better with a much shorter length of 4mm diameter? (I will try it with half the length)
- could a hollow (tubular) armature give a better trade-off?
- what travel do we need? I would guess 2mm should be ample.

I need to get organised to include pictures.........

Andrew

andrew jukes
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Re: Lever Frames

Postby andrew jukes » Wed Jan 18, 2012 11:43 pm

A shorter armature is much worse.

Best results so far are with 19mm overall, 2mm locking peg section (2.5mm dia.) and with the 17mm of 4mm dia. section counterbored 2.6mm dia. for 12mm. It was made from a 2BA screw (so the finish on the 4mm dia. was not great!) but at least not much material needed removing. This gave an 8mm lift, so should be reasonably reliable if arranged to use (say) just the last 2mm of travel.

Andrew

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Paul Townsend
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Re: Lever Frames

Postby Paul Townsend » Thu Jan 19, 2012 6:30 am

andrew jukes wrote:I think I need to know more about solenoids!

I managed to get the core out of my relay coil without difficulty, giving me a coil wound on a plastic moulding, overall length 20mm, overall diameter (of moulding) 10.5mm and with a bore diameter of 4.0mm. I think with careful trimming, it will be possible to mount a line of coils at 10mm centres. The resistance of the coil is 255ohms.

I have experimented with armatures and have the coil (using a 12V supply) lifting an armature/locking peg satisfactorily, though not with as much oomph as I would like. The better armature is made of old Meccano rod, 18mm long overall with 14mm at just under 4.0mm diameter and 4mm (for the locking peg) at 2.5mm diameter. What needs sorting out is:
- what is the best material for an armature?
- what should the overlap between armature and coil be for maximum lift?
- how does the trade-off between armature weight (4mm diameter steel rod is not light) and lifting force work? Would it be better with a much shorter length of 4mm diameter? (I will try it with half the length)
- could a hollow (tubular) armature give a better trade-off?
- what travel do we need? I would guess 2mm should be ample.

I need to get organised to include pictures.........

Andrew


The coils are probably better performing than any DiY attempt for the given size but 10.5mm OD with a 4mm hole and 255 ohms implies athinner wire than my DiY attempt with 40swg. The pull will be a bit marginal especially vertically for a 20x4 armature.

Best material is softest iron you can get, meccano axle will be mild steel similar to the bolt. Nails is usually softer. Flower wire better still.
Try a plastic tube with od to clear hole and a thinner nail inside...this will be lighter.
The length should be similar to coil length so most is in the coil when off and is drawn to be all in coil when on. I agree 2mm move should be enough, but would perhaps design for 3mm to allow some losses. However the initial pull will be least and it increases as the armature disappears into the core.
Not sure about steel tube, but worth a try if you have some ....not stainless steel though as most grades are non-magnetic....oops seen your described homebrew tube...looks good on 8mm lift!

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Paul Townsend
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Re: Lever Frames

Postby Paul Townsend » Thu Jan 19, 2012 6:36 am

andrew jukes wrote:I managed to get the core out of my relay coil without difficulty, giving me a coil wound on a plastic moulding, overall length 20mm, overall diameter (of moulding) 10.5mm and with a bore diameter of 4.0mm.
Andrew


As mentioned earlier I found a chinese listed solenoid at around £3 which is reasonable price. Size is about right but the supplier doesn't quote a resistance and ignored my query for the ohms.

It may well be cost effective for others to cannibalise relays as you are doing, and you are getting good results with hollow screw core. What is the source /type/price of relay?
If unknown, can you put up a piccie of the relay before carving up?

frizby

Re: Lever Frames

Postby frizby » Thu Jan 19, 2012 12:26 pm

Could you cannibalise Peco point motors (£4 on the web) giving 2 coils each?

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Russ Elliott
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Re: Lever Frames

Postby Russ Elliott » Thu Jan 19, 2012 1:16 pm

Andrew - does your locking peg fall (by gravity) into your tappet when the solenoid is unenergised?

andrew jukes
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Re: Lever Frames

Postby andrew jukes » Thu Jan 19, 2012 1:22 pm

The relays were purchased about 20 years ago for a long-since abandoned project. Fortunately, I have enough for my likely needs - provided I rip some off some pcbs I spent ages making. They almost certainly came from Maplin, who had a really useful catalogue in those days.

Pictures below showing intact relays, the coil and the best so far armature, the relays in close up and a picture giving some railway context. The lettering on the relay reads DARO55000.
IMG_0098.gif

IMG_0090a.gif
IMG_0090a.gif (117.65 KiB) Viewed 35811 times

IMG_0099.gif

Frizby - Peco point motor coils could probably do the job but would take something like ten times the current my RPC outputs would allow.

Russ - It falls against the work surface with a nice clunk, but not yet tested with a slide with holes.

Andrew

ps Getting the pictures attached and in the intended order has been a nightmare and I still can't get the first to show as a picture in 'Preview'
Last edited by grovenor-2685 on Thu Jan 19, 2012 8:16 pm, edited 1 time in total.
Reason: fix problem image- kn

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Russ Elliott
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Re: Lever Frames

Postby Russ Elliott » Thu Jan 19, 2012 1:32 pm

frizby wrote:Could you cannibalise Peco point motors (£4 on the web) giving 2 coils each?

I'm not sure those coils are good enough for 'continuous' rating, but I suppose they might be good enough for the few seconds it would take to make a lever frame change sequence.

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grovenor-2685
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Re: Lever Frames

Postby grovenor-2685 » Thu Jan 19, 2012 4:55 pm

ps Getting the pictures attached and in the intended order has been a nightmare and I still can't get the first to show as a picture in 'Preview'

The seccret to this is to use the "place inline" button which puts the image wherever the cursor is, and you can then move it subsequently by Cut and paste.
I just had a go with yours. There does seem to be a problem with IMG_90.gif, I'll have another look at that when I get home.

The image seemed Ok when I downloaded it, so I cropped and resized a bit. On the whole its best to use .jpg for photos and keep .gif for line drawings.
Regards
Keith

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Paul Townsend
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Re: Lever Frames

Postby Paul Townsend » Thu Jan 19, 2012 7:49 pm

andrew jukes wrote:The relays were purchased about 20 years ago for a long-since abandoned project. They almost certainly came from Maplin,


Ta for piccies.
They look very similar to what was an industry standard family of 2 or 3 decades ago. Generally called continental cradle relays, they were made by the likes of ITT et al. Because they were shrouded and not sealed they had some maintenance issues and have long since disappeared from the electronic mainstream.
I looked for them in Farnell, RS, Rapid, Maplin & Ebay.

Someone is flogging a few on ebay but limited numbers so not recommended for you all to rush.

The best bet seems Rapid who do a similar probably chinese version at £1.77 each ( !!) or £1.46 over 25 ....code 60-0905
These are spec. as 12volt 220ohms and the size looks suitable. At that price the contacts are probably crap but as we will throw those away....

A trial is required to see if they dismantle and meet our needs ....not me for a while, but I would be optimistic that if the fixed core is removeable they will do the trick; certainly easier than DiY winding and more robust.

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Paul Townsend
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Re: Lever Frames

Postby Paul Townsend » Thu Jan 19, 2012 7:52 pm

frizby wrote:Could you cannibalise Peco point motors (£4 on the web) giving 2 coils each?


These will draw nearer an Amp than Andrew's and my concept of a 50-100mA device, they are overkill for oomph

JFS
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Re: Lever Frames

Postby JFS » Sun Feb 12, 2012 10:25 pm

I used the SHAG frame and fitted locking to it.

It is not really designed to be suitable for such things, but it can be done and it looks very nice!

Frame finished.jpg


the locking came from some custom etched I had made.

I am currently working on a 25 lever version.

Pannier Tank
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Re: Lever Frames

Postby Pannier Tank » Mon Feb 13, 2012 7:53 am

JFS wrote:I used the SHAG frame and fitted locking to it.

It is not really designed to be suitable for such things, but it can be done and it looks very nice!

the locking came from some custom etched I had made.


I've not seen a vertical locking frame (in model form), how did you link the levers to the locking frame?
Regards

David

JFS
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Re: Lever Frames

Postby JFS » Mon Feb 13, 2012 8:06 pm

Hi David,

It is pretty well a direct copy of the Great Western Vertical tappet locking -

So there is a cam plate thus:-

Drive cam-1.jpg


It results in a reduced tappet travel which makes the locking design easier.

Not for me this electrical locking stuff - even the sequential locks are mechanical using a lifting tappet.

i will upload a pic of the 25 lever frame when i get a mo.

Good Luck!

Howard.

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Paul Townsend
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Re: Lever Frames

Postby Paul Townsend » Tue Feb 14, 2012 7:42 am

JFS wrote:Not for me this electrical locking stuff - even the sequential locks are mechanical using a lifting tappet.

i will upload a pic of the 25 lever frame when i get a mo.
Howard.


A good looking job!
Will this appear at an exhibition where we can all admire and feel it?
If it works as well as it looks would there be a market for your etched components, through S4Stores perhaps?

While all my instincts and experience lean me to an electric solution, if someone like you has done all the hard bits of design, then a mechanical solution also looks attractive; "just like the real thing".

Yes I know of the three commercial systems out there, mentioned higher in this thread, but a set of components to allow DiY assembly to ones own needs might be cheaper, and look better than some.

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Dave K
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Re: Lever Frames

Postby Dave K » Tue Feb 14, 2012 7:54 am

paultownsend wrote:A good looking job!
Will this appear at an exhibition where we can all admire and feel it?
If it works as well as it looks would there be a market for your etched components, through S4Stores perhaps?

While all my instincts and experience lean me to an electric solution, if someone like you has done all the hard bits of design, then a mechanical solution also looks attractive; "just like the real thing".

Yes I know of the three commercial systems out there, mentioned higher in this thread, but a set of components to allow DiY assembly to ones own needs might be cheaper, and look better than some.

I totally agree with Paul a superb piece of work and like him I hope it can be made available to a wider audience because if so I for one would buy it as it makes the perfect addition to the SHAG frame which is currently installed on by layout.

JFS
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Re: Lever Frames

Postby JFS » Tue Feb 14, 2012 2:55 pm

Dave, Paul,

Many thanks for the kind words! I am considering making the etches available - but there are a couple of points to remember - firstly, because they are etched in .7mm NS they are by no means cheap! Secondly, even with the etches, it is not even nearly a shake the box job - there remains an fair bit of "fit and fettle" - but it has to be said that if you can make a tidy job of building the frame, you are probably handy enough with the files to put the locking together.

BUT the hardest part of it all is designing the thing so that it not only works, but fits efficiently into the available space (8 trays and 32 bars) and can be assembled without being a 3D Chinese puzzle. Here is a quick snap of the 25 lever frame and locking trays. It is at the stage where (I think) I have fitted everything together, and I am testing it in the trays before fitting the trays to the frame. You can see my "working drawings" - it took at least twice as long on the drawing board (well in Microsoft Powerpoint - which is not a good CAD tool but is good at manipulating shapes!) as it did on the bench. But the locking IS complete, including the FPLs (which stand "in") all the conditional locks, the starter "holding the road", the sequential locks, plus all the (complicated) locks for the ground discs - not everyone would want or need to go to town like that.

Regarding getting to an exhibition, it will be going to our Nottingham Area Group meetings from time to time - I am sure all would be welcome (not all at once!)

25 Lever frame.jpg


And here is a close up of some of the cleverer bits - you can see some of the loose and swinging pieces for the conditional locks.

Locks Close up.jpg
Locks Close up.jpg (134.71 KiB) Viewed 35553 times


For those interested in what it is doing, here is the Box Diagram - if you are wondering what I mean about conditional locking, just consider the locks on 4 and 18 - bearing in mind that they both read to / from 4 different routes, and that the FPLs are required N for the facing moves but EW for the trailing ones. (Here I have 'some' sympathy for an electrical solution!)

Minories Box Diagram.jpg
I bet C J Freezer never had this kind of nonsense in mind when he published 60 Plans for small Layouts!!


The Treadles, by the way, are because it is Sykes "Lock and Block". (and before someone points it out, I know you COULD do the sequential locks using the Sykes instruments but...)

If you want to see the track work underway, there is a thread in the Nottingham Area Group forum

Best Wishes,

Howard

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Paul Townsend
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Re: Lever Frames

Postby Paul Townsend » Tue Feb 14, 2012 5:16 pm

Phwoar! :D

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newport_rod
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Re: Lever Frames

Postby newport_rod » Thu Feb 16, 2012 12:50 pm

JFS wrote: I am considering making the etches available ...

I'd be interested!
Rod

HighlandRailwayman
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Re: Lever Frames

Postby HighlandRailwayman » Thu Feb 16, 2012 1:21 pm

Me too! would definately want some of those for my layout/plank in progress!

I do design for 12":1' lever frames as part of my day job and i am still in awe of your frame! Very nice work.

Pannier Tank
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Re: Lever Frames

Postby Pannier Tank » Fri Feb 17, 2012 7:57 pm

JFS wrote:Hi David,

It is pretty well a direct copy of the Great Western Vertical tappet locking -

Howard.

Hi Howard,
That's a pretty impressive Interlocking System, may well be interested in your brass etches!
Regards

David

JFS
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Re: Lever Frames

Postby JFS » Sat Feb 18, 2012 4:58 pm

Many thanks for the kind words chaps.

I shall certainly be looking at making the etches available - though there is a fair bit of development work still remaining.

In the meantime, I have managed to get an hour or four to assemble and test the frame. All seems to have gone well.

Testing only revealed one mistake. My method of providing 12 locks 14 resulted in a false lock of 3 Locks 12. Luckily, I was able to correct this without any serious dismantling. Removing the old lock only involved removing a drive pin from a top-side bridle, and providing the new lock only involved cutting a single port and the there was a spare tray into which a new bridle could be fitted. But that was luck! Mistakes like this are much easier to put right on the drawing board than after the event!!

One learning point - on a frame this size it is a Good Idea to number the levers before you try any testing - I have lost count of how many times I have investigated a "jam" only to discover that I was trying to pull the wrong lever... That remains a To Do job.


Minories Frame 1.jpg
View from rear showing how I use the back end of the cam plates to provide a mechanical drive to the rodding - something which the original SHAG design does not really provide.


Minories Frame 2.jpg
View from the front



In the pics, the frame is set up for some parallel moves as follows:-

- arrival, Up Main to Platform 1 (main arm)
- departure loco spur to Down Main
- Shunt Carriage Sidings to Platform 3.

(The design follows LBSC practice so FPLs stand "in")

Keith and other experts, will have already spotted that the frame contains at least 4 "Pull Betweens" (ie where the signalman has to pull a lever between two others already reversed - a good route to a hernia!) which would not be allowed on the Real Thing, but which are unavoidable in this case where we a have to economise on levers by having no "spares".

Hope this is of interest,

Best wishes,

Howard

JFS
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Re: Lever Frames

Postby JFS » Sat Feb 18, 2012 5:22 pm

LesGros wrote:
James Moorhouse wrote:For a description of a model mechanically interlocked frame see this video: clickable Youtube link

Well worth a look if you are thinking about a plan to build interlocking. The presenter has an easy conversational style as he describes the layout, tables and charts. A note pad will be useful to capture relevant gems of information.
The slide lever mechanism he employs has the virtue of compact mechanical simplicity, with the complexity of the locking stemming from the layout requirement being relatively straight forward to follow
Also worth noting is the teamwork element, in that the locking chart was prepared by an expert in the subject, and the layout builder is, clearly, a skilled and imaginative 4mm modeller.

one question arises, who is the builder?


Well, it is not for me to reveal a name, but you can "see him" in person here:-

http://www.youtube.com/watch?v=HfGUaVqSsKE

I, on the other hand, am not visible in the video, but I did write the computer simulation referred to in the text which is "driving" the box (bells, train movements, T/Cs whistles etc - by comparison with which, creating a mechanically locked frame is quite easy!

Best Wishes,

Howard.

Pannier Tank
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Re: Lever Frames

Postby Pannier Tank » Sun Feb 01, 2015 3:26 pm

Some very nice examples of the Society's Lever Frame in this thread.

I would appreciate some advice on the best technique in laminting the 3 piece Lever Handles and advice on solders / fluxes to use etc.
Regards

David


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