Make that roof ROLL!!!

[pmrid]

TenChain Hill Obs has a 4 x 5 metre roof that rolls off on to the west. The existing bottom rails (50x50 box section 11 metres long have 15 Bunnings rollers per side and the roof is centred by sections of 50mm angle iron on the outside of both top rails. That was fine for a while but we have had an extended wet and this means too much time to think and re-invent the wheel.
So now we are well under way with the "New" roof system.
This time, the rollers will be attached to the roof and not the bottom rail - it'll keep them out of the weather. And the rollers are in fact pulleys with high-precision bearings in them and there will be ten to the side.
The bottom rail will be 50x50 square section with a vertical flat bar rail running the full 11 metre length and the pulleys will roll along this bar. The pulleys each have a side-pushing spring so the pulleys will be self-centering and will be able to handle a bit of deviation as it rolls out and back.
The attached photo shows the upper sections with pulleys fixed in place and a couple of sections of the bottom sections with the flat-bar rail.
All going well, I ought to be able to move the roof by hand without blowing a valve every time, or throwing my back out. And the boat winch I use occasionally will not have to suffer a hernia every time.
Next step is to get the rails in place. That'll be fun.

Peter

[steve000]

cool! i look foward to more piccys

[DavidTrap]

Now that looks a little bit fancy!

DT

[Tandum]

How are you going to get these in pete? I'm guessing by jacking up the roof somehow?

[RobF]

Heck its green out there now. I've got to get out again sometime.
Hope you sort the roof out Peter, and hope the gear is safe in the meantime!

[ballaratdragons]

That's a cool looking bit of work there Peter :thumbsup:
The metal wheels might be a bit noisy though, running metal on metal.

And pleeeez cover up your avatar :rofl:

[pmrid]

Avatar? What Avatar? The image is inspired by the James Joyce novel "A portrait of the artist as a young man." HaHa. Not really, but I couldn't resist the grossness of the image when I spotted it.

As for the noise of steel on steel, my nearest neighbour is about 1/2 km away and the obs is about a km back from the front of the place anyway - so there's only the cows and the koalas to be annoyed.

Peter

[pmrid]

I'm going to weld then to the existing rails (with a liberal sprinkling of bolts to assist) and then just knock out the shafts on the existing Bunnings wheels and remove the wheels themselves so there should be no movement at all. That's the plan - but I know that Murphy's Law is always lurking around somewhere.
Peter

[gregbradley]

That looks very good. Very clever.

I am about to renovate my observatory as well. My wall has bowed out slightly making opening and closing the roof harder than what it was.

A bit of steel angle iron screwed to the top beam should pull everything back to straight.

Greg.

[Lester]

Hi Peter, be careful welding on the same side of steel to fix the rollers to the roof as it will contract at the weld and bend the steel. I had the same issue when building my observatory and had to do equal welds on the other side of the RHS to get it straight again.

All the best.

[pmrid]

Yes. Welding that flat bar on the bottom section was like that - had to alternate sides all the way - and still there was room for a little "persuasion" with a mallet.
Peter

[ChrisM]

Peter, looks like a neat design and a neat job. Keep the construction pics coming.

Chris

[pmrid]

Well, major progress today - despite raining non-stop. Never knew how much fun welding in the rain can be.
In answer to tandum's question about raising the roof - it was a job for the does-everything farm tractor - with a little help. Did one side at a time and didn't drop it once.
Here's some before and after shots of the old rollers that have been replaced by the "after" photo rollers and rail system. I can now move the roof with two fingers - yahoo.
I've included a "detail" shot.

Peter

[ozstronomer]

Peter

Great work, That should make the roof easier to open now!!:)

Geoff

[Tandum]

MATE ... Definately looks like a winner.
You should be able to drive it with a wiper motor now, if it's that easy to move.
Tack on a rain sensor to shut the roof, set limits on the mount to stop it when it should, then feet up and wait for the results :)

[pmrid]

Another big day yesterday and the job is largely done - minor fiddling only remains. Here are some pics showing the roof fully retracted and the stiffening I had to improvise to stop the exterior rails sagging under the weight.
Now I have to start putting all the scopes, computers etc back in. Joy.
I'm heading offshore tomorrow for a week for work so I can have a good think about how it should all hang together.

Peter