Developing a Manual Point Control System.

Discussion in 'Workshop Benches' started by gormo, Sep 11, 2020.

  1. gormo

    gormo Staff Member Administrator

    Messages:
    4,090
    Likes Received:
    1,306
    Joined:
    Dec 5, 2015
    G`day Folks,
    I have started developing the Little Bardfield section of my layout on Great Chesterford Junction.
    This area of the layout has been overlooked for too long and it`s about time I made it fully functional.
    The mental barrier holding me back has been twofold. Firstly how to make the points operational and secondly how to wire the section for independent operation as well as allowing a shuttle service to run independently if I wish to be occupied with other sections of the layout.
    Now, I do know how to do all this stuff, but the drive to do it has been easily brushed aside in favor of working on other parts of the layout and sometimes, just running trains instead.
    I guess I have been just putting it into the too hard basket, knowing that one day I will eventually have to face it and complete it.........the curse of the Mojo.
    So I started the other day by changing the track flow. You can see in the pic below, the difference between the old flow ( the black squiggly lines ) and the new recently moved track.


    DSC09583.JPG

    This section of the railway sits on 18mm ply baseboard and it is very narrow. The baseboard framing is quite deep so consequently the access is limited. In saying that, the baseboard is hinged and folds upwards from the front for access, however, once the various jobs have been done to complete the section, I don`t really want to open it up anymore. Just get it working and leave it alone.
    Relaying the track has definitely cured my Mojo problems related to this project, and I have found that once you make a start, some sort of flow ,or the next logical step seems to fall into place. It`s a matter of solving one problem at a time and slowly moving forward to a satisfactory conclusion.
    The next logical step is point control. As you probably know, I have a manual control system on the main part of my railway. There is plenty of room to accommodate it, which helps when negotiating awkward angles and also the plentiful room allows more than one operating area.
    Not so with this little section. I considered going with Peco point motors for the restricted space, however all the points would need adapter bases, which tend to get a bit sloppy over time.
    So back to the manual system. I need to refine it and make it smaller but still pretty much maintenance free.
    The short runs between points will allow me to use wire in tube and a more light weight bellcrank system so, how to go about it...??????.....and keep the cost down.?????
    I have started with the bellcranks.....or... start from the point and work backwards. I still have a plentiful supply of my original point levers, so I just need to work out the rest of the line to the point.

    The bellcranks that will throw the points are an adapted tile spacer. Nylon material that is extremely tough and I have used them thrown by Peco point motors on my main fiddle yard for years without failure.


    DSC09591.JPG


    The less than a millimeter wire that goes to the point is bent into a tight " U " shape and threaded through two holes in the tile spacer whereupon the short arm of the 'U" is then bent back onto the top of the tile spacer to keep it firmly in place.


    DSC09592.JPG

    A 20mm x 1.4mm Flat Head Wallboard nail is used as a pivot / mounting for the bellcrank and a short offcut of tile spacer is impaled on the nail and Superglued to the tile spacer to act as a spacer between the bellcrank and the underside of the baseboard


    DSC09594.JPG

    Holes are drilled into the three available arms to offer a mounting point choice for a connecting wire to throw the bellcrank. This would leave two arms available for operating micro switches for frog polarity and or connecting to a second point.


    DSC09595.JPG



    DSC09593.JPG

    So that`s the first part sorted out and I will add more in the development as we carry further on.

    :tophat:Gormo
     
    Last edited: Sep 11, 2020
  2. Walkingthedog

    Walkingthedog Full Member

    Messages:
    198
    Likes Received:
    152
    Joined:
    Jul 30, 2020
    Gormo I love the idea of using a tile spacer, I have hundreds of them and wondered if they would ever be used again.
     
  3. gormo

    gormo Staff Member Administrator

    Messages:
    4,090
    Likes Received:
    1,306
    Joined:
    Dec 5, 2015
    Well that`s the thing..........they are as cheap as chips, and as as I stated above, I`ve had them in use for years as bellcranks connected to Peco point motors. The Peco motor has what I would call a severe throw, or at least it gives that impression, and yet the tile spacer takes the forces without any noticeable changes over approx. 7 years of use.
    They can be drilled quite easily with a pin vice or mini electrical drill, so no great technical skills required, just a little perseverance and careful assembly.
    Some pics of them with Peco motors driving them.

    E RailwayConstruction (90).jpg


    E RailwayConstruction (91).jpg

    :tophat:Gormo
     
    Jim Freight and Kimbo like this.
  4. Walkingthedog

    Walkingthedog Full Member

    Messages:
    198
    Likes Received:
    152
    Joined:
    Jul 30, 2020
    How clever is that. Brilliant.
     
  5. gormo

    gormo Staff Member Administrator

    Messages:
    4,090
    Likes Received:
    1,306
    Joined:
    Dec 5, 2015
    Next stage I guess is to build a lever frame.
    This will follow the same theme as others I have built, however I must admit I am considering something slightly different.
    Instead of mounting the lever frame below baseboard level, it could also be mounted at baseboard level. This would be a significantly simpler build although a departure from the theme of the railway. The jury is out on this one at the moment, but I guess common sense demands that we follow the original theme / concept for the sake of completeness.
    So I will have to ponder it for a while but in the meantime, as it makes no difference to the first stage of the lever assembly, I will undertake to build it as the next logical step.
    Here we have the parts required.
    The levers I have laser cut to my design, however the rest of the parts are readily available at your local hardware store. You could make your own levers from 10mm x 3mm Aluminium Flat Bar.
    Parts required.......3/16th Threaded Rod, 3/16th Nyloc Nuts, 3/16th Flat Washers and Spring Washers, Terminal Block Brass Inserts, 3mm short Black Screws, 3mm Washers, 20mm Right Angled Brackets ( not shown ), Loctite Thread Locking Liquid.


    DSC09596.JPG


    Insert the Black screw into the lower hole on the lever and fit a 3mm Flat Washer to the other side.


    DSC09599.JPG


    Add a drop of Thread Locker to the inside thread of the Terminal Block and then connect to the lever by screwing home the Black Screw. The screw should be only tightened lightly to allow the terminal block to rotate freely.


    DSC09600.JPG

    We have five levers in this frame, so all terminal block connections need to be completed before moving on.


    DSC09603.JPG


    To start assembling the frame we first add two Nyloc Nuts, two Flat Washers and two Spring Washers onto some 3/16th Threaded rod with a 20mm Right Angled bracket sandwiched between them. The nuts should be fully tightened and then mount the bracket with rod into a vice to hold it securely.


    DSC09604.JPG


    Next the levers are added, but with the parts in the following order.
    Spring Washer, Flat Washer, Lever, Flat Washer, Spring Washer, Nyloc Nut and then repeat.


    DSC09606.JPG


    The Nyloc Nuts lock reasonably well, however I like to assist the process by adding a drop of Loctite just prior to bringing the nut to the lever.
    It is also important to test each lever for movement as you tighten the nut. You want no sideways / horizontal movement whatsoever, but at the same time achieving a forward and backward movement with all levers having approximately the same amount of friction. The friction will ensure that points without center locking springs can be held securely and won`t move until required to do so. Therefore this is a friction system.


    DSC09607.JPG


    Once the levers are fitted, a bracket is fitted to the end to complete the frame. Make sure the brackets sit flat on their backs before final tightening.
    The excess thread can be locked into the vice and trimmed flush to the end nut with a hacksaw.


    DSC09609.JPG


    And there we have it.....:thumbs:


    DSC09610.JPG

    More to follow as we progress.
    :tophat:Gormo
     
  6. gormo

    gormo Staff Member Administrator

    Messages:
    4,090
    Likes Received:
    1,306
    Joined:
    Dec 5, 2015
    Next I have cut some Aluminium angle to length and drilled appropriate holes to match up with the brackets on the lever frame.


    DSC09611.JPG


    The angle will be a backstop to limit the throw of the levers forward, or away from the operator. If the levers can travel all the way to a backboard, it`s difficult to get your fingers in behind them to pull them out again. It`s not impossible, but we are going for convenience here and ease of operation. There will be sufficient travel backwards to accommodate the point throw.


    DSC09612.JPG

    I am currently working on and preparing a cavity in the baseboard framing that will allow a lever frame box housing to be fitted in under the baseboard.
    Great Chesterford Junction Part Two
    I am keeping with the theme on the rest of the railway. More work involved but there you are......if I didn`t do it I would regret it.....its as simple as that....:scratchchin:
    More to follow.
    :tophat:Gormo
     
    Last edited: Sep 15, 2020
    York Paul, steve and Mr Porter like this.
  7. Toto

    Toto I'm best ignored Staff Member Founder Administrator

    Messages:
    14,693
    Likes Received:
    3,209
    Joined:
    Dec 5, 2017
    I've seen you do this before and will never tire of it. A first class bomb proof installation that works and looks great.

    This is the model rail equivalent of bling. :avatar: true eye candy.:thumbs:

    Toto
     
  8. gormo

    gormo Staff Member Administrator

    Messages:
    4,090
    Likes Received:
    1,306
    Joined:
    Dec 5, 2015
    :avatar::avatar:...well if you say so Toto.
    As far as bomb proof goes, it is pretty close to it.
    I think I have had about three minor adjustments in about seven years. One of those was a bell crank that failed, however it takes about 10 minutes to replace a bell crank, so no big deal. The others were just a slight repositioning of parts due to a screw becoming loose.
    Otherwise.... it just works......:thumbs:
    :tophat:Gormo
     
  9. gormo

    gormo Staff Member Administrator

    Messages:
    4,090
    Likes Received:
    1,306
    Joined:
    Dec 5, 2015
    OK Folks,
    Time to build a box for the lever frame.
    I have some basic measurements to match if I am to follow the theme of the other boxes that I have made.
    The most crucial measurements to observe are the thickness of the side walls (15 mm), the depth of the side walls (30 mm) and the height of the box ( 116 mm).
    The width of the box is determined by how many levers there are , however there is a 30mm space between the end levers and the neighboring side walls.
    Staying with these standard measurements will keep the visual continuity going on the railway.
    You may think it`s too much trouble, but for me it adds to the overall look of the thing and helps somewhat in my search for perfection.....it`s far from perfect but I like to aim high if I possibly can...it`s better to aim for 100% and achieve 95%, rather than set your target low in the first place. Yes it takes more time and fiddling about, but once it`s done, you`ll think
    " that wasn`t so bad !!"???.......:scratchchin:

    Here we have the timber for the Little Bardfield Lever Frame.
    The large piece will be used for the back and is an old drawer front 20mm thick and way more than I need. This is timber that could be thrown away, but why do that when you can put it to good use and help preserve the environment.
    The other piece with the painted edge will be the sides for the box. It was originally cut from a much larger length and width and it is left over baseboard framing. At the moment it is rough cut and has a few dings and nail holes in it, but I will put it through my thicknesser to take it down from 35 x 20mm to 30 x 15mm. The reduction process will also dress the timber.


    DSC09616.JPG


    Don`t be put off by how it looks now rough sawn........this will come up beautiful once it`s been put through the machine.


    DSC09617.JPG


    The timber is now dressed and I need to take time out to rebuild the box in my head. Measure everything twice and double check before committing saw to timber.


    DSC09618.JPG


    A close up of the timber once dressed. It has a nice tight, straight grain and should polish up rather well I think.?


    DSC09619.JPG


    It looks a bit rough at the moment, but once the side walls are rounded off and the ends of the front panel are rounded as well, it will have a visual slimming effect on the whole thing.


    DSC09620.JPG

    So it`s quittin` time out in the shed for the day.........it`s getting a little late to be making much noise, so I will retire to the indoors and see what SWMBO has got lined up for me.

    :tophat:Gormo
     
    York Paul likes this.
  10. Toto

    Toto I'm best ignored Staff Member Founder Administrator

    Messages:
    14,693
    Likes Received:
    3,209
    Joined:
    Dec 5, 2017
    Lovely stuff.
     
  11. gormo

    gormo Staff Member Administrator

    Messages:
    4,090
    Likes Received:
    1,306
    Joined:
    Dec 5, 2015
    Thanks Toto.........:thumbs:
     
  12. gormo

    gormo Staff Member Administrator

    Messages:
    4,090
    Likes Received:
    1,306
    Joined:
    Dec 5, 2015
    Minor advancement this morning with the making of the angle that will sit on the front lower removable panel.
    The point lever combing will be fixed to this angle, plus it can be padded out to create a backstop for the levers by adding packing behind it.
    Once the length of this angle was determined, I could then also cut the timber for the removable panel.
    So, in a nutshell, the width of the lever frame box has been determined.


    DSC09622.JPG


    DSC09623.JPG

    I now need to head off to Bunnings some time today to replenish my supplies of face plate sanding disks and also an assortment of sand paper sheets for hand sanding.
    The back board can also now be cut due to the final box dimensions being sorted.
    Those dimensions mentioned will in turn determine the dimensions ( length ) of the rockers arms ( 5 ) that will be mounted behind the back board. The rockers will transfer the movement of the levers up to an under the baseboard top ready for connection to the wire in cable system. the rockers will be cut from 10mm x 3mm Aluminium Flat Bar......note to self.." must check supplies of flat bar before going to Bunnings.?"
    More as it happens
    :tophat:Gormo
     
    York Paul likes this.
  13. Kimbo

    Kimbo Staff Member Moderator

    Messages:
    2,674
    Likes Received:
    1,623
    Joined:
    Dec 13, 2015
    Neat idea Gormo :thumbs:
     
  14. gormo

    gormo Staff Member Administrator

    Messages:
    4,090
    Likes Received:
    1,306
    Joined:
    Dec 5, 2015
    Thanks Kimbo....:thumbs:
     
  15. gormo

    gormo Staff Member Administrator

    Messages:
    4,090
    Likes Received:
    1,306
    Joined:
    Dec 5, 2015
    Ain`t it just the way of things...???
    I go to Bunnings to get some more face plate sander disks .....the adhesive ones....yeah...you guessed it...they don`t do them that way anymore.......I had to get a velcro adhesive adapter pad to fit my machine and then get the sanding disks to suit the velcro system. I must admit it will be much easier to change a sanding disk, however because I now have a velcro pad plus a sanding disk stuck to the face plate, I had to pad the lower guard plate out with washers because it was rubbing on the disk, which in turn meant the little adjustable work top had to be adjusted as well.
    One adjustment leads to another......but in the end, I`m set up very well until somebody decides to change the system again.....:thumbs:

    The back board is now mostly complete. It still needs the rocker frame fitted to the back but I have not made the rockers yet. The cut out gives more clearance and throw for the bottom end of the levers.


    DSC09635.JPG

    The mounting point for the lever frame brackets has been established and sorted


    DSC09636.JPG

    The side walls can also be fitted, although everything is temporary at the moment. It will all have to be taken apart to allow the backboard to be drilled once more on the drill press. It could be done by hand but the drill press is far more accurate.


    DSC09637.JPG


    This is the back of the removable front piece, which also doubles as a fixed mounting for the lever frame combing.


    DSC09638.JPG


    And the front with rounded ends now and ready to go.


    DSC09639.JPG


    Careful measurement was initially required to ensure the placement of the levers matched the height of the Aluminium angle on the front removable section. Necessary to allow the combing to sit flat.


    DSC09640.JPG



    DSC09641.JPG


    A view from the back showing the clearances


    DSC09642.JPG



    DSC09643.JPG

    Yes we are now heading for home on this one. I need to make five rocker arms and set them up in a frame. Make sure it all works properly when connecting rods are fitted between the levers and the rockers, and then strip it down for varnishing and also make the combing.
    The combing and lower parts of the levers will also need airbrushing with some flat Black paint.....but that`s a little way off just yet.

    More as it happens
    :tophat:Gormo
     
    jakesdad13, steve and Peter Cross like this.
  16. Walkingthedog

    Walkingthedog Full Member

    Messages:
    198
    Likes Received:
    152
    Joined:
    Jul 30, 2020
    That is one of if not the best posts I have ever read on a forum.
     
  17. gormo

    gormo Staff Member Administrator

    Messages:
    4,090
    Likes Received:
    1,306
    Joined:
    Dec 5, 2015
    Thanks Walkingthedog.....:thumbs:
    Crikey....that`s put the pressure on me now......:scratchchin::avatar::avatar:

    OK...moving on.....this afternoon I managed to cut out five rocker arms from 10mm x 3mm Aluminium flat bar. Careful measuring and cutting required as you`ve got to try and get them all as close as possible to the same length. Cheating is allowed, by any means you can think of to achieve consistent results. I usually cut just a little over length and then stack them and hold them tight and square them up against the face plate sander.


    DSC09644.JPG


    We now need a 3mm hole drilled at each end of the rockers. I have a wide timber table that I have fitted to my drill press. It has a timber adjustable fence that can be set up with end stops for consistent drilling. It takes a little bit of setting up and checking your measurements, however once it`s set, you`re good to go and it actually makes the job a lot quicker and more accurate.
    You have to be a bit methodical and sort out your drilling order and even use some of your smaller holes as pilot holes for a larger drill bit when required.
    Basically, you have to be patient and think it through before you start drilling.


    DSC09645.JPG


    Once the Aluminium is drilled, you invariably finish up with burs. These have to be removed completely, even a small Donut like this one is not good enough, because we need a totally flat surface for this system to work as well as it possibly can.


    DSC09646.JPG


    A typical bur below......we have to get rid of this. These pieces of Aluminium have to be drilled again and if they have burs on them, they will not sit flat on the drilling table and we`ll finish up with holes drilled at all sorts of angles.


    DSC09647.JPG


    This is how we prove the accuracy of the drilling. Drill bits the same size as the holes will only line up and pass through the bar if all is aligned correctly.
    Stacking and holding the rockers this way will also make the next lot of drilling much easier.


    DSC09648.JPG


    The center holes, or the fulcrum, now need to be drilled accurately. The drill bits will hold everything together for the most part. The end stop has been set to get us to the center of the bar.


    DSC09649.JPG


    However, we need some insurance. We don`t want this lot to move, so I`ve also clamped it as well as I can prior to drilling.


    DSC09650.JPG


    The center holes have worked well and I`ve also counter sunk the end holes to accept the mini 3mm screws that will hold the brass terminal block inners.


    DSC09651.JPG


    So we`re almost ready for the hardware, but the the ends of the rockers have to be rounded first to allow the brass inners to swing through a 180 degree arc....same as the point levers.


    DSC09652.JPG

    At this time of the day, I have a self imposed noise curfew to keep the neighbors happy. The rounding of the rocker ends will make a bit too much noise I think.?
    More to follow on another day
    :tophat:Gormo
     
  18. gormo

    gormo Staff Member Administrator

    Messages:
    4,090
    Likes Received:
    1,306
    Joined:
    Dec 5, 2015
    The rockers have now been rounded off and cleaned up ready for fitting the hardware.

    DSC09653.JPG


    Hardware fitted and now we need to wait for the thread locking compound to dry out completely before disturbing the hardware too much.


    DSC09654.JPG



    DSC09655.JPG


    Then we start building a frame for the rockers following exactly the same procedure as the the one for the levers.


    DSC09656.JPG

    And once completed the frame looks like this.


    DSC09657.JPG

    More as it happens
    :tophat:Gormo
     
    Dr Tony and Toto like this.
  19. Walkingthedog

    Walkingthedog Full Member

    Messages:
    198
    Likes Received:
    152
    Joined:
    Jul 30, 2020
    Can’t wait. :thumbup:
     
  20. gormo

    gormo Staff Member Administrator

    Messages:
    4,090
    Likes Received:
    1,306
    Joined:
    Dec 5, 2015
    Onwards and upwards folks,......:thumbs:

    The assembled rocker frame has been now fitted to the back of the lever frame box.
    It is important that the bottom of the rockers matches the bottom of the levers. If you were to hold a straight edge under them, the straight edge would be horizontal.
    Accurate positioning also applies to the vertical plane, whereby the rockers should not only be as close to the vertical as possible, but also should be centered as best as can be achieved on the back of the box.
    Given that the rockers are assembled from the same materials as the levers, they should be an almost exact match for the levers dimensions and therefore, if aligned properly, everything should move in harmony.


    DSC09658.JPG


    The tops of the rockers shown in the pic below will sit approx. 5mm below the top of the box frame. This was taken into account in the design stage, so that the tops of the rockers will not rub on the underneath of the baseboard top when they are being used.
    To determine the length of a rocker arm, you should measure the distance from the top of the box frame to the bottom of a point lever sitting in the vertical position, then deduct 5mm.
    That assures you, that if you position the rockers correctly lined up with the bottom of the levers, they will have sufficient clearance at the top of the box.


    DSC09659.JPG


    Next we need some connecting rods to transfer the movement of the levers to the rocker arms.
    I am using wire coat hanger wire here. It has been straightened by securing one end of it into a vice and securing the opposite end into my electric drill chuck. You then pull it tight and turn on the drill.
    The twisting of the wire straightens it beautifully. A method passed on to me from Keith who moderates on this forum.
    In the pic below, I am determining what length of wire will be required. The point lever is pulled all the way back and the rocker is moved to it`s maximum travel position.
    We won`t cut the wire flush, but rather leave an extra 10mm or so for future adjustments or tweaks. The extra won`t be seen, so it does no harm to have some insurance built in.


    DSC09661.JPG


    In this case we`ve finished up with about 60mm for each connecting rod.


    DSC09662.JPG


    So now we fit each rod in turn.....1 to 5...the lever is pulled all the way back to it`s maximum travel.


    DSC09663.JPG


    And the rocker is placed at it`s maximum travel position.........note the clearance below the top of the box as mentioned above.


    DSC09664.JPG


    The logic behind doing it this way is twofold. Firstly, it gives you plenty of clearance to access the locking screws that secure the connecting rods, and secondly the parts are ultimately set at their maximum travel, which is far more than required and can be reduced if necessary.
    It`s quite easy to reduce the travel distance, but finding more movement above the travel limits of the parts is a rebuild or re-design I`m afraid.?


    DSC09666.JPG


    Here we now have all the connecting rods fitted and we have a potential working lever frame.


    DSC09667.JPG


    A view from underneath


    DSC09668.JPG

    I have a short video of it working, although not fitted to the layout yet. The frame has to be varnished and tarted up with a signal box diagram and some little signs and point numbering etc. and of course the combing has to be made.......much to do before we put it to bed.



    More as it happens
    :tophat:Gormo
     
    jakesdad13, Dr Tony and Keith M like this.

Share This Page