Rising Sash Window

[chris riley]

Am-dram doing original play with frequent operation of 4ft 6in wide rising sash window. Not a proper sash with cord etc!

 

Cost effective method of the ups and downs of this is being researched. Timber guides for the frame come to mind, but engineering tolerance of softwood suggests that jamming will occur during the production if not at rehearsals even if silicone is applied to the sliding bits!

 

Four foot long drawer runners (mounted vertically) do not exist, and would cost the earth.

 

Any suggestions?

 

Kind regards

 

Chris Riley cjriley@cjriley.karoo.co.uk

[Tomo]

Look for the things used in sliding doors.

 

Cheap version is nylon covered pegs running inside steel "U"

 

More expensive is proper ball-bearing sliding door runners, which look similar to drawer runners but are much heavier duty and considerably longer.

 

Either way you want the real sash-window mechanism with the sash cords, pulleys and balancing weight.

[Storm_machine]

Unless you want to keep out weather? The frame can be as sloppy as you like - counterweight both sides or it will jam as one side will rise faster than the other. The weights can be on the outside of the frame on the back of the flat - think how it works not copying reality

 

C

[jayselway]

You could always make the frame out of wood, and then run some smooth metal strips down the runners to provide a suitable running surface. I have a diagram of such a thing from when I did an Am-Dram show involving a sash window - it worked pretty well :D

[obsoperator]

In my experience, jamming is not to be expected if the construction is good and the fit relatively tight. Unless the theatrical glazing (classically, scrim or bobinette, but often rigid plastic today!) is very heavy, you may have some success with spring steel strips (with a curve to them) that are intended for elderly and loose "real" sash windows. These are sold in U.S. hardware stores. They don't substitute for sash cords, but reduce rattling and add the friction you need to hold a theatrical sash up, without cord and weights.

[Malcolm Gordon]

Some thoughts on sashes are also included in this thread. We decided to have the 4' wide x 6' high (3' sashes) window and frame professionally made by a joinery firm, out of softwood (they're usually hardwood these days) and without weight boxes. We wanted it to be substantial and safe. As Storm_machine says, the weights are behind the flats. Because people were clambering in and out we also had a subframe made to support it, so the flats weren't taking the load.

 

Jamming was prevented by making sure the running clearances with the parting beads were adequate, being careful with the painting, adding a liberal application of candlewax and having equi-spaced lifting handles on the bottom rail. For remote operation we did without the operating lever suggested by Peter Tovey (we couldn't make it invisible) and simply lifted the sash weights each side (two operators) on cue, so that it fell under its own weight. We did use the stop pegs. A bit of noise was part of the effect.

 

Sashes of this size, particularly with sash bars, even without glazing, are fairly heavy and I would have thought that adding the friction necessary to support them without sash cord and weights would make actually opening the window quite a struggle.

[chris riley]

My thanks to Tomo, Storm machine, jayselway, obsoperator and Malcolm Gordon for your constructive replies.

 

Cords, pulleys and weights, handles positioned to cater for thrust moment, some wax, side guides - all these will be necessary to overcome the stress subjected by the cast. The cast think they have stress?

 

Village Hall audience will be most impressed. They are not used to incompetence.