[Richard Johnson]

QUOTE (Donone @ 4 Oct 2008, 14:19) <{POST_SNAPBACK}>My 'point' poliss was that with peco it should have been possible with one motor and mechanics, not four.

***Peco point motors are incredibly inefficient (they draw approximately 4 amps at the time of throw) and unless they are close to perectly aligned when installed on the point, have difficulty throwing one point, let alone 4. There is no way you can reliably control several with one PM unless you modify the points.

To be honest why you'd want to mve multiple points except in a crossover or scissors I have no idea, as its neither good for operational flexibility or prototypical, however, I do appreciate the need to save cost where possible.

But - you cant do it with Pecco points as they are... If you want to move multiple points with one motor, then you will have to modify the points to remove the latching spring.... and use a latching type motor as per seeps offering OR go to motor drive.

The lowest possible cost method is in fact a series of cranks, linked to a return spring and pulled "off" using a simple lever and string or similar + pulleys. This method will work but it requires good mechanical expertise and realtively high maintenance.

You say you are a hands on person and OK with electronics/electrics, so here is a possibility: It is cheap enough for one per point even on the lowest budget if you are OK at scrounging bits & bobs here and there....

(1) remove the spring from the peco point and use the softest possible return spring to hold the blades at their most commonly needed rest position/route position.

(2) wind your own electromagnetic single solenoid coils from fine winding wire, with an impedance high enough that it will not overheat if latched "on" for an extended period. I'd suggest the static impedance of the coil should be more than 150 ohms to be safe - thats a lot of turns of wire so use a drill to wind it. (better to connect a DC conctoller to a battery drill so you can slow it down enough so that you can guide and lay the wire very evenly on the bobbin)

(3) Use a bit of steel rod or part of a 4" nail for a slug and a bobbin made up from a length of plastic tube & end caps.

(3) link this to the other end of the points throw bar

You can then use a simple SPST switch for control.

final option:

look at old floppy disc or CD drives and similar geared motor drives.... they are easily adapted if you are good with your hands nad understand the fundamentals of electronic control.

Richard

 

[Richard Johnson]

QUOTE (Donone @ 5 Oct 2008, 14:51) <{POST_SNAPBACK}>If anybody is going to suggest that binary coding cannot be used in mechanics, then look at the 'Teletype' If you remember the old fashioned football scores on Saturday evening. The keyboard is entirely mechanical and by operation of some, say 60, keys, 8 bars encode this at right angles into binary movement, i.e. which combination of the eight bars move. This is done with cutouts in the top of the slider bars.
No that won't work here but, something a little simpler and smaller and more limited??
A mechanical decoder.

***

Your primary question is neither new nor unique, and the answers already provided give you most practical options if you choose to pursue them.

but your follow on posts simply cloud things:

To be honest, looking across all your posts, the problem you have is nothing to do with point control at all... It is aspiration and budget allocation really - sacrifice the purchase of one loco and coach set and you have most of your budget problem solved

....Actually if as you have as indicated in other posts just bought an ECOS before solving this issue then you never had a budget problem in the first place... only a budget control or timing problem really

.

--------------------------------

As to simultaneous control via mechanical links, why not simply make up a test and try it your way.

I think that you will find that as a simple experiment on a test bard it will work but as a concept applied to a layout in place, your cost in dollars saved for solenoids merely becomes huge increase cost in time, engineering and precision set up or manufacture to mechanically automate multiple turnouts that are a good distance apart...followed by increased maintenance compared to electromechanical options... and to buy the quality of parts needed, budget will not really be saved long term!

So... is it really a saving: I do not think so.

(and yes of course loops are of course a positive example of possible simultaneous throw, except that a passing movement as often used on real railways in single track territory requires each end to be independent, and that a loop in prototype is actually more often than not a minimum of three turnouts, as on double track territory the exit end will be protected by a third turnout which directs an overruning train to a dead end lead, and on single track, there is likely to be a dead end lead BOTH ends....).

Certainly winding coils will take far far less time, frustration and money than purchasing parts for mechanical linkages.

and:

Re winding a simple coil: If your skills are good enough for reliable mechanical links or even to consider making a mechanical matrix based control then you will have absolutley no trouble modifying a common low cost level-winding fishing reel to wind your solenoids nice and evenly ...and easily for you!

Any "hands on" true Audiophile can do it perfectly, so I guess as an "electronic engineer" as you introduced yourself you should have no trouble at all.

You said "If anybody is going to suggest that binary coding cannot be used in mechanics etc etc..." What is that all about?

Frankly nobody would bother suggesting anything about mechanical encoder possibilites - of course they aren't new and did and do still exist - and why would anybody care to dispute it or bother with your comment... I thought it was help and advice you were looking for.

(by the way, the electromechanical (old world) or electronic (current) device that takes very few wires and makes them do many things is an encoder, not a decoder - MERG have an excellent kit for one, available to members).

Actually, given the style of some posts and the comments quoted above I wonder really if you aren't just fishing already...

Richard

 

[Richard Johnson]

QUOTE (Donone @ 5 Oct 2008, 20:16) <{POST_SNAPBACK}>Despite your last comments, that is an interesting innovation. Unfortunately in my case, I require non-manual control, but it does show what can be achieved.
Thanks

***Don't get excited.

I can't be bothered with arguments.... I offer advice all across the day every in several world time zones and do so to be helpful, no more, no less. I generally hard practical advice and answers devoid of bulls**t, and while I do have an occasional short fuse or twisted sense of humour on I generally simply can't be bothered playing word games... Its my way.

If you need automation + low cost mechanical then you really are very limited in possible applications: If you really don't want to wind solenoid bobbins, and can't geet your head around reworking old drive mechs, then the most likely low cost option that will fit the bill for you is definately memory wire, which should be less than 2 GBP per point.

All it needs is low current with a little regulation so it can't be overheated - an easy project, mainly mechanical and CAN be used for more than one turnout at a time.

You can get it at reasonable cost from here http://users.skynet.be/pro-rail/ukindex.htm

There is another example of use here http://home.cogeco.ca/~msmodels/memwire/

Richard

 

[Richard Johnson]

QUOTE (Lancashire Fusilier @ 6 Oct 2008, 11:40) <{POST_SNAPBACK}>Hello all, I decided to take up the challenge here and provide hopefully enough of an idea that then anyone who is actually serious about exploring electro-mechanical point control using just one point motor can actually get on and do something.

Concept is taken from a turntable with indexing to align a point motor with its appropriate wire in tube partner. I have shown 5 but if you really want to do 40 I can see no problem with that either.

Hopefully the plan view sketch (5 seconds work) will make the idea / concept fairly plain to see.

The LEDs shine up from under the disk and through the hole only when the hole is aligned over the correctly lit LED. This means that when you make Wire in Tube (WIT) target number 2 (press button, DCC, PC, whatever) this sets the motor off rotating the disk until the hole falls over the LED and the light shines through and hits the Light dependant resistor thus cutting the motor drive circuit. This has aligned on the opposite side a point motor of some sorts ( I have shown a coil / solenoid type but if it is only one it could even be a Tortoise and still remain at the GBP40 budget). I trust this makes some sense. Go and build it and report back I say

The target size and shape can be adjusted for any innacuracies in the LED/LDR combo.

PS, to save even more money you could mount the LDR directly over the hole on the disk saving on LDRs.

***Nice ... very neat idea.

I love a challenge:

LDRs work fine and I like them for detection of many things but here's an easier option which is also easily switched: deletes all WIT, solenoid and all LDR and replaces with one microswitch + 5x basic memory wire mechs.

each WIT 1 to 5 replaced by simple on/off memory wire mechanism.

each can be active closed (or passive closed - its up to you) - whichever U choose, its option states are to insert and withdraw a small "plug" (bit of rod) thru hole in turntable side centred for each exit track... (one state = flush with side of TT, other is withdrawn).

plug can be anything running in any plastic tube at all. A bit of small reticulation pipe or a cheap ballpoint pen pen barrell with any old easily workable material for the plug would probably do. Fancy boys can use brass tube and rod.

Turntable deck has matching rod lightly spring loaded to pop into any available non plugged hole that acts on a microswitch to turn TT motor on and off... this has tiny wheeled tip or smooth ball end end surface which rubs gently on turntable side wall as it rotates.

when hole it is in already is activated then the memory wire mech pushes the plug/plunger in the deck out and therefore closes the microswitch and starts the motor. ie it closes a microswitch and starts the turntable rotating.

The deck is no longer held by the pin which is now free of the hole and the motor is running.

To auto index, activate the track it is at to start it for a moment, then activate whichever track you want it to stop at to make that track memory wire mech withdraw its plug.

When deck reaches hole, plug drops in to lock it and the microswitch turns off TT motor at the same time.

Benefits: basic so simple tools to make it. just holes, screws and a bit of ingenuity. very low cost. You could even turn ball end pin in a battery drill if needed. failsafe + uses only on off switches + low cost mem wire mech's. very positive action for track alignment
downside. Need to be very accurate in hole layout. definately install radial tracks after install TT in place!

Have fun

Richard

 

[Richard Johnson]

QUOTE (Lancashire Fusilier @ 6 Oct 2008, 15:48) <{POST_SNAPBACK}>Nice one Richard. I knew there must be a memory wire solution however I got stuck on the 40 units side of thing.

Well Donone, over to you now to run with it I reckon as there is enough conceptuals here to actually provide exactly what you asked for in your first few posts - single mechanism point control for 40 points at less than AU$2.50 per point. Time to get building hey?

***Time U dropped by for a cuppa Paul

Richard