DIY Standing Desk with Linear Rails

[Jades1]

Hi all,

I'm trying to make a desk that will move up and down on linear rails. There will be two stop collars to stop the cartridges holding the monitor as well as a pulley system. Then there will be a desk below, that will be on another set of cartridges. The issue I'm experiencing is a lot of racking, such that it is very hard to move the cartridges in concert because they quickly become no longer parallel. Is there a fix that you can think of? Would two pieces of steel in x shape going to each cartridge solve the issue?

Thanks,

James

[toprecycler]

An x brace will help the racking a lot. Are the main rails fastened to the wall? If so, are they parallel?

You might still have problems, unless you rig up some sort of cable and pulleys so both sides will raise together.


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[Jades1]

Thanks...yes they are fastened to the inside of the window frame, butting up against a ridge (so they should both be parallel).

I do have a double pulley and then a pulley on the table, such that they should both be lifting at the same time. Isn't there any way to get it perfect? I'm not great with pulleys and couldn't find a lot of information out there for this purpose.

Best,

James

[digger doug]

Look at a garage door torsion spring set-up.
Qty (2) winding drums, one on each side of door, connected by a shaft to keep them timed.

[arizonian]

You need two cables and four pulleys. The cables form an X as it crosses the center of the mechanism. Think old school drafting table.

This guy has some thoughts on a problem with a range of motion similar to yours, but way more complicated. About the four minute mark is where his problems and solutions start to appear.

[Shade Tree Welder]

Originally Posted by digger doug

Look at a garage door torsion spring set-up.
Qty (2) winding drums, one on each side of door, connected by a shaft to keep them timed.

Oh no that is not complex enough, he should run balanced
hydraulic cylinders, at a minimum of 3000 psi.

[Shade Tree Welder]

Originally Posted by arizonian

You need two cables and four pulleys. The cables form an X as it crosses the center of the mechanism. Think old school drafting table.

That but I think you need longer linear bearings. You are calling them
cartridges, they are the linear bearings or double the number of them and
mount them on a board or frame that is co-planar with your guide rails, If you
go with the doubling of them have them mounted at least 6" apart on center.

[digger doug]

Originally Posted by Shade Tree Welder

Oh no that is not complex enough, he should run balanced
hydraulic cylinders, at a minimum of 3000 psi.

You forgot to put a computor on it sir.....

[digger doug]

Originally Posted by arizonian

You need two cables and four pulleys. The cables form an X as it crosses the center of the mechanism. Think old school drafting table.

This guy has some thoughts on a problem with a range of motion similar to yours, but way more complicated. About the four minute mark is where his problems and solutions start to appear.

I forgot all about that system.
It would be the easiest.

[Lew Hartswick]

:-) 2 lead screws geared together. :-)
...lew...