NSR 4 gate level crossing

Discussion in 'Buildings & Structures' started by Andy_Sollis, Aug 6, 2018.

  1. TimberSurf

    TimberSurf Full Member

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    I am having none of it!
    So, the road lock block of the distant inter governor testicles of the clear check loop with the reverse 1st of the roding regulator causes the balance of clear to depress the normal?:facepalm:
    Yeah I totally get it! :headbanger:

    :lol: Haha, I kinda guessed it was something like that, had no idea it was so complicated, but "interlocking" gates with the signal does make sense, sort of pre electronics safety relay logic. Definitely sound's like an O gauge gig!
    Thanks Paul
     
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  2. York Paul

    York Paul Full Member

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    Well such rules from the Ministry have come about through 150 years of experience, mishaps, accidents and major incidents such as the Qintenshill disaster, one can make light of such if you wish but railwaymen and former railwaymen such as myself would have taken a dim view to the flouting of safety. Now if you think that is complex I can elaborate with topics such as Permissive Block Working, Sequential Interlocking or the golden rule itself and cardinal sin if you break it Rule 55 ... detention of Trains on Running Lines, as the old saying goes " during fog and falling snow" :avatar:
     
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  3. Andy_Sollis

    Andy_Sollis Full Member

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    Other than what Paul has said, I’ll explain more with some drawings next week. Then I will have a go at making them work from a servo. Hopefully the whole thing will work off two servos only for gate locks and also the gate swing...

    Andy
     
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  4. Andy_Sollis

    Andy_Sollis Full Member

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    Hopefully these bits and bobs will help explain...

    Here are the gates working - although at this point, it just my hand pulling one of the chains under the board.



    here is how the 4 gates are linked by chains - still to add the servo link.

    IMG_9307.JPG

    And here is a drawing re the road stops. The back stop is raised from the signal box by the lever, the counter weights lift the front stops, which depress when the metal gate foot goes over them and locks in the gap. when the line is clear and to reopen to traffic, the lock is released and the gates swung the other way to open to road traffic again.
    all this sits below the road level.

    IMG_1592.JPG
     
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  5. TimberSurf

    TimberSurf Full Member

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    Ah, now it sinks in, its to allow the back stop (cus it's a double gate) to drop, so you don't rip the underside out of the vehicles!
    I am still not convinced one servo and chains is the best approach, keeping all four in sync is going to be a nightmare. (or do you plan to overdrive it to reset positions when it hits the road lock?)
     
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  6. Andy_Sollis

    Andy_Sollis Full Member

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    Here it is in its model form, drawn for O gauge.

    Road stops 1.jpg

    block is approx. 8mm wide, by 15 long.
    Road stops 2.jpg
    Here I have cut away the side to show internally what there is. the two green weights have to work separate otherwise one gate my release the second.. the red road stop when placed in the up position allows the green weights to swing down and raise their sloped backs.

    Road stops 3.jpg

    bringing the red stop down by 1.8mm also retracts the green stops, pivoting them on the blue bar by 27degrees.


    The intention is when one set is up, the other is down. so open to road or open to rail.
    hope this helps ?
     
    Last edited: Aug 12, 2018 at 10:15 PM
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  7. Andy_Sollis

    Andy_Sollis Full Member

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    they are all fixed to the capstans under the board now, so they all swing together... powering the servo off the "lead gate" may just make it lead in either direction. Its trial and error - each figure 8 loop also has a tension spring in the line and they are superglued to the capstans.
     
  8. TimberSurf

    TimberSurf Full Member

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    Wow that is small and fiddly even though it's in O gauge! Will it be plastic or brass or a mix?
     
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  9. Andy_Sollis

    Andy_Sollis Full Member

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    At the minute, its printed in Frosted Ultra detail from Shapeways, so all plastic, but I suspect the red rod in the above cut away will be replaced with a bent paper clip or similar, once I work out how to change the direction of the servo from a horizontal to vertical push\pull.
     
  10. York Paul

    York Paul Full Member

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    The backstop raises twice, in the first position the backstop extends above the road metal by no more that the height of the front stops (gate lever placed in the Check Lock position), at this point the stops are extended no more than about a couple of inches out of the road and are easily depressed by a vehicles road wheel without physically affecting the underside of a car. Now after the gates are placed across the road and the gates have ridden over the front stops and landed in the locks the back stop is further raised to its second position which is another inch or so higher. The second position occurs when the gate control lever is moved from the Check Lock position in the lever frame to the Full Normal Lock position, at this point the stops cannot be depressed and are thus proving the gates locked, now all road traffic has to stop. However I do know a certain ex signalman who Andy also knows whose regular box was Stallington Crossing, this chap wound the gates one morning and caught a motorcyclist by his front tyre as the gates were closing, the poor biker had to sit bolt upright on his twisted steed until the Longport tanker train and the Up Derby had passed. :avatar::avatar::avatar: The motorcycle wheel was completely bent and the chap had a long walk to work which must have been the local Mental Hospital about a mile up the lane.
     
    Last edited: Aug 12, 2018 at 11:26 PM
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  11. TimberSurf

    TimberSurf Full Member

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    You might get some idea's from my linear movement here, tube in tube works well, although my crank screws may be replaced by RC Model Linkage Servo Screws Nuts (now in stock, for further development)
     
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  12. Andy_Sollis

    Andy_Sollis Full Member

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    Actually. Yes. now there is food for thought. Just need to wok out how 1 servo can work 4 locks in 2 different directions (2 on up stroke and 2 on down but in an + shape.)

    doesn't help by fact its 1.8mm travel. I need to also work out some leverage calculations.
     
  13. TimberSurf

    TimberSurf Full Member

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    I'm not sure why you are hung up with minimising the quantity of servo's (because you need things to drive them?). With my new found understanding of Arduino, at least 6 servo's can be driven easily (at £1.50 a pop) from one Arduino (£3).
    I was wondering about 1.8mm! Immediate thoughts would be a double crank linkage to make a dividing balance lever! Lots of mechanical pain! So how about a cam?
    You could design a conjugate cam in 3d so it pulls as well as pushes and gives linear movement all in one!
     
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