More lightweight baseboard construction observations

 A useful feature to have on a micro layout is a sector plate. The ability to turn a train through a 90 degree arc in the length of a train can be a great space saver. 

Creating the pivot point for a sector plate in a wooden baseboard presents no problem. However, should you need to put a sector plate pivot into a foamcore baseboard you may have problems. The very nature of the foam core of the board mean to will likely compress and wear away at the hole making it larger and a sloppy pivot point.

At least that is what I was finding in early experiments with my baseboard. My first attempt at solving the problem, so far seems quite successful and I share it here. It's quite simple.

I had been using a wire T pin for my pivot. It was easy to push through the foam and create the pivot with no problem, and the top of the pin sits down below the sleepers/ties of the track rendering it invisible. 

I have plenty of styrene tubes of various sizes in my modelling supplies, so I looked for a diameter tube that would be a snug fit for the T pin wire. I found it in some Plastruct 2.4mm Butyrate tubing. I cut two pieces. Each to the length of the base board that they would pass through. With the location of the pin already established by the hole previous, locating the tube was a simple push fit. It was then glued in place using my chosen adhesive for foamcore board. Exterior grade woodworking glue.

I made sure the pin, tubes, and holes all lined up to make the sector plate pivot accurately. Then left everything to dry. Which due to pressures of life was several days. 

What has followed has been some intensive testing; i.e. lots of pivoting of the table, fast, slow, delicate, and clumsy. So far the pivot remains its proper position.

I think this may be deemed a success. 


Can you see it? The Butyrate tubing in place on the baseboard at the pivot point.

A close up

Same goes for the pivot on the sector plate

The pin and the tube close up









Comments

  1. Hi Ian,

    The issue with a pivot in foamcore is simply the forces of the sectorplate being operated, being applied to the foamcore over too-thin a surface area. Think like how 1 kilo of "stuff" (flour?) in a bag is "relatively lightweight" sitting on a surface, but that same 1-kilo of gravity-downforce applied to the surface via the thin-edge of a knife-blade and it will cut the surface easily...

    In my case ("ChicagHO Fork" https://forum.mrhmag.com/post/500-layout-contest-chicago-fork-design-12194532), the solution to making the sectorplate pivot-surface bigger, and thus spreading the forces applied to the foamcore, was to:
    - recess a cheap "608" skateboard/roller-blade bearing into the layout benchwork surface
    - recess a small piece of MDF into the (foamcore) sectorplate
    - and mount a suitable (8mm or 5/16") bolt thru the MDF plate, so it protrudes down thru the benchwork-captive bearing

    Hopefully this picture, as linked from Model-Railroad-Hobbyist forum, will make the explanation clearer... ;-)
    https://d28lcup14p4e72.cloudfront.net/259338/7354680/pivot_03.jpg

    Now, admitedly, "ChicagHO Fork"s sectorplate is pushing 2' long,
    and has to take the weight of an HO scale Atlas GP40-2 + two cars,
    but the concepts hold (have done for over a decade now, wow... ;-) ), and show no signs of wearing-out or damaging any of the component parts...

    Happy Modelling,
    Prof Klyzlr

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