I just finished cutting my track that goes across the lift up bridge section of my layout. It is a double main line, HO scale. The bridge section consist of 3/4" plywood, 2" foamboard. The track is laid on WS foam roadbed. The track at the hinged end of the bridge binds when I attempt to lift the bridge to the point of bending and deforming the track if lift the bridge section. The only solution I can see is to leave a big gap between the rails leading up to the bridge, but this would render the the bridge useless as no train could go over such a wide gap in the track without derailing. What can I do to correct this, any thought to making it a duck under section would not work as I am disabled and unable to do so. I need to have this bridge open if I want to continue with the layout.
With the ‘hinge’ at the upper part of the ‘bridge’ - You are going to have the problem you describe. Can it be hinged to drop ‘down’? I rather complex ‘lift, then rotate’ hinging scheme will work, but might be rather expensive to implement. he other idea would be to hinge the liftout section a couple of inces away, so that the liftout rotates downand away. All of this will require ‘re-engineering’ on your part.
Jim
woodman.
If you cut the track, roadbed and sub-base at an angle so that the bridge lifts up and away from the stationary part of the track it should work OK.
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Solid Hinge Bridge Solid track section track
As indicated, the hinge is on the left side of the bridge and the right side would rest on a support so that the track is level.
Just my thoughts.
Blue Flamer.
The hinge pivot needs to be above the top of the rails.
Try the below link for some helpful information. It is a PDF file.
http://mysite.verizon.net/vzescsbb/HO_MRR/Room%20Access%20Lift%20Bridges.pdf
Yes, that’s your solution unless you want to swing it down or sideways. The hinge pivot is ALWAYS the innermost part of the arc. Nothing at the joint can protrude past it.
Thanks, I think I realize what I did wrong. When I built the bridge section, I made sure that the hinges were above the board. I mounted them on 1 1/2" blocks. Everything worked great. Then I laid 2" foamboard down on my entire layout, including the bridge section. I then put down the foam road bed and track, this cause my track to be about 3/4" above the hinges. I will increase the blocks the hinges are attached to 3". Hopefully this will correct my problem. Thanks
I have four swing ups and in my personal openin they are very efficient to use…
The hinge on this one is under the plywood. Note the hinge point is in from the end thre or four inches and the fixed roadbed and swing up has a 45 degree miter accross the end, this and the back set on the henge gives it clearence. The backset also holds it upright when in the over center up position.
This has a double crossover in the middel of the span
Hope these help a bit, Take Care… John
Wayne,
I must apologise for my reply to your posting. I totally misunderstood the content of your reply. Please accept my apology.
I understand placing the hinge above the track height. Does it matter exactly where the hinge is placed. Is the hinge centered over the adjoining section of the layout? Thanks for all your help
The key is for the place where it mates to not be perpendicular.
Not necessarily. I have one hinge point that is out on the lift up section a little bit. However, I try to center the hinge pin directly over the gap in most cases.
Another method is to place the hinge pin about 1" off center onto the fixed section so if the hinge is 4", 3" will be on the fixed section and 1" will be on the movable section. This is shown in the “764 Helpful Hints for Model Railroaders” by Bob Warren 1970 edition.
John, excellent solution for hinge placement. Great idea, also allows for any minor adj by riser placement.