Parallel linkage roof?

[900SL]

As a structural engineer, I'm interested in home observatory designs and likely to build my own next year. Has anybody used a parallel linkage roof before?

The design effectively lifts the roof up as it opens. The force required depends on the geometry but is around half the roof weight. It could be opened by hand or screw jack. With appropriate stops and cleats it can deal with wind loads without issue, and weathering details are straightforward

Any examples out there? 

 

 

 

[Skipper Billy]

Mine is a slight nod in the direction of your design.....

https://www.flickr.com/photos/113316085@N05/albums/72157663274320360

https://www.davidbanksastro.com/micro-observatory

When I was planning it I avoided a flat roof as I could imagine issues with weather sealing - ponding water that could end up in the observatory when the two halves are parted to open up. Also snow loading issues - we are in the Scottish Highlands - it may not be an issue where you are 😉  We often get winds of >100mph and whilst I add storm straps when storms are forecast they have never been required to do anything - yet!

The only downside I have thought of is that in its current format it would be difficult to motorise it if I wanted to.

 

 

 

 

 

[900SL]

24 minutes ago, Skipper Billy said:

Mine is a slight nod in the direction of your design.....

https://www.flickr.com/photos/113316085@N05/albums/72157663274320360

https://www.davidbanksastro.com/micro-observatory

When I was planning it I avoided a flat roof as I could imagine issues with weather sealing - ponding water that could end up in the observatory when the two halves are parted to open up. Also snow loading issues - we are in the Scottish Highlands - it may not be an issue where you are 😉  We often get winds of >100mph and whilst I add storm straps when storms are forecast they have never been required to do anything - yet!

The only downside I have thought of is that in its current format it would be difficult to motorise it if I wanted to.

 

 

 

 

 

That's a nice bit of work Billy. The roof sections presumably are not too heavy as a dead lift?

I'm planning on using a nominal pitched roof to shed rain but I'll design it for snow and wind load, size is 2.4 X 2.4m (8' square). 

 

My day job is stuff like this so I might try to get a bit architectural 😉

[Skipper Billy]

4 minutes ago, 900SL said:

That's a nice bit of work Billy. The roof sections presumably are not too heavy as a dead lift?

I'm planning on using a nominal pitched roof to shed rain but I'll design it for snow and wind load, size is 2.4 X 2.4m (8' square). 

 

My day job is stuff like this so I might try to get a bit architectural

Each half of the roof is only about 15kgs so it's fairly easy to open and close.

Good luck with the day job!!  

[wimvb]

1 hour ago, 900SL said:

My day job is stuff like this so I might try to get a bit architectural 😉

I've heard of/seen truss tube telescopes, but never truss tube observatories. 😉

Seriously though, good luck with the build. I'll keep following this thread.

[900SL]

So with some playing around with radii and linkages I have v2, pitched roof opening gull wing. The maximum force a person is supposed to apply horizontally (for opening) is 220N or 22kg, I think I can get below that with a lightweight roof using a stressed plywood skin and a linkage gearing of 2 to 1

 

 

[900SL]

Oh my... I've just found the sacred '4 bar linkage' and the free software for linkage animation... 'Linkage'

 

Example, not obviously for roof application but this looks like the nuts