robsmorgan
Registered
Been searching through my old postings to give credit to the person who inspired this structure on my trackwork, but sadly can?t find it - Sorry! His words were along the lines of ?Go for a lift bridge? so here is a brief history of the work involved. I decided not to post this update before it had proved itself through the winter.
Rationale: I needed to be able to get access to the inside of the loop section. The track is approx 18? above the ground, I am not tall and like everyone, I?m getting older, so clambering over could have been dangerous to both me and the track.
The gap is bridged by 6? x 2? treated timber (8? wide used for the rest of the system track base) n.b. the lift section timber is cut at 20deg from vertical angle at both ends of the bridge to allow a clean lift without jamming.
I used two 1 metre stainless steel rules (from a local cheap store) as the hinge mechanism, pivoting through the factory-hanging-up-hole (indicated by the use of an old drill bit in this photo)
Aligning took some careful measurement, but the most critical being the distance from the fulcrum of the hinge to the opening point. The 20 degree angle compliments the 9mm (3.5 inch) radius.
The covered bridge is modelled on the Vermont Fall covered bridge. I decided to try using standard A4 corrugated plastic display card to simulate tin sheeting fixed to a series of wooden arch frames. This would be easy to work with and keep the weight to a minimum for lifting. Apart from some problems with the ?No-Nails? type adhesive being useless in the heat of the summer sun and the plywood frame being susceptible to absorbing water following rain it worked well. I therefore dismantled the structure, cleaned and dried everything and then sealed the woodwork with several coats of paint and re-assembled using ?Evostik? ? no problems since!
The following photos show some of the scratch building process. I decided not to build the whole structure as in the prototype, but instead cut holes to take the wooden ?window? shapes with simulated framework. (n.b. the waste material from the opening was re-cut to hold the ?timber? frame in place whilst glueing and subsequently removed)
This photo shows the internal arch framework braced at the top by fixing to an old broom handle.
So now to the seasonal trials?? Last Autumn it looked reasonably similar to the Vermont Fall bridge
And it survived the heavy snowfalls of December 2010.
Hope to report that is stands up to the hot summer we must be getting this year!!!!
Rationale: I needed to be able to get access to the inside of the loop section. The track is approx 18? above the ground, I am not tall and like everyone, I?m getting older, so clambering over could have been dangerous to both me and the track.
The gap is bridged by 6? x 2? treated timber (8? wide used for the rest of the system track base) n.b. the lift section timber is cut at 20deg from vertical angle at both ends of the bridge to allow a clean lift without jamming.
I used two 1 metre stainless steel rules (from a local cheap store) as the hinge mechanism, pivoting through the factory-hanging-up-hole (indicated by the use of an old drill bit in this photo)
Aligning took some careful measurement, but the most critical being the distance from the fulcrum of the hinge to the opening point. The 20 degree angle compliments the 9mm (3.5 inch) radius.
The covered bridge is modelled on the Vermont Fall covered bridge. I decided to try using standard A4 corrugated plastic display card to simulate tin sheeting fixed to a series of wooden arch frames. This would be easy to work with and keep the weight to a minimum for lifting. Apart from some problems with the ?No-Nails? type adhesive being useless in the heat of the summer sun and the plywood frame being susceptible to absorbing water following rain it worked well. I therefore dismantled the structure, cleaned and dried everything and then sealed the woodwork with several coats of paint and re-assembled using ?Evostik? ? no problems since!
The following photos show some of the scratch building process. I decided not to build the whole structure as in the prototype, but instead cut holes to take the wooden ?window? shapes with simulated framework. (n.b. the waste material from the opening was re-cut to hold the ?timber? frame in place whilst glueing and subsequently removed)
This photo shows the internal arch framework braced at the top by fixing to an old broom handle.
So now to the seasonal trials?? Last Autumn it looked reasonably similar to the Vermont Fall bridge
And it survived the heavy snowfalls of December 2010.
Hope to report that is stands up to the hot summer we must be getting this year!!!!
I recon that Ross has the ideal answer to your power requirement (better than soldering flexible cable links to the track!)
