DaveS's Obsy Build Thread

[Rusted]

I like the perforated roofing plates for joining and spreading loads into solid timber. Absolute minimum of 2" or 40mm timber.
These plates are fairly inexpensive, come in all sizes and are galvanized against rust.

I also use the plates inside to reinforce potential security areas like padlock hasps and hinges.
Given enough screws you can't tear the plate from the surrounding structure without a JCB.

I also like perforated roofing strip. Often used to triangulate structures like roofs and lightweight walls.
This comes in long rolls and can provide a very strong fixing if you wrap it around the back of the anchored timbers before fixing all around with screws or nails.

A thin tension band is able to travel between widely spaced structures without needing solid [heavy] timber between them.
Timber ties don't work well in tension. Always use compression to avoid the nails/screws being literally torn out of the timber.

Special nails are supposed to be used with this "steelwork" but I often use lots of suitable Torx screws.
This helps to avoid splitting near timber ends and to provide massive reinforcement by using every fixing hole.
NOTE: Screws may not match building specs. The strips can be fixed to walls to tie down a fixed roof structure against lift. 
It is used, as such, on real houses to hold down the rafters/trusses to the walls.

[DaveS]

Thanks for the suggestions.

My tentative plans are to get the reinforcement sections in soon-ish, but leave this project until next year. At which point I hope to have built the imaging box around the platform telescope, taking note of all the suggestions in this thread so far. What I learn from doing that will be fed back into rebuilding the roof on the obsy, which will put it out of action while it's being done.

[DaveS]

Some progress today.

Managed to get the three remaining reinforcement sections in, though I had to remove the top length of roof cladding and cut a hole in the membrane underneath. Much use of the 4lb club hammer and liberal use of cuss words. There is now much less droop in the roof. Also done some fiddly easing around tight areas.

Hoping now for the roof panels to dry out enough that I can get the EPDM on tomorrow.

I now have a multi-way combination ladder that can fold out into a platform 1.2 metres high by 2 and a bit metres long, enough that I can work on the whole length of a side without having to move a ladder.

[DaveS]

I had to fudge the sizes of the reinforcement sections, as the roof battens might say 25mm on the Wickes site, but are actually 22mm . Result was, that instead of the 25mm x 3mm wall tube I wanted, I had to order 5 lengths of 20mm square x 2.5mm wall steel tube plus 5 lengths of 20mm x 3mm steel strip as packing, which I cut with an angle grinder.

Edited August 29, 2020 by DaveS

[DaveS]

I am in the process of getting the EPDM on. I have it stuck down to the roof, well, sort of a there are wrinkles in it due to my lack of eye-hand coordination (Almost zero) and really needing two people on a roof that size. Hope it will last until I rebuild the roof in a year or two.

Going to have lunch now, as I want to be able to take my time over getting the edge sealant on, otherwise I'll make a pig's ear of that too  .

Oh, and I have PVA all over my hands, been washing them but I think most will have to wear off.

[DaveS]

Time for another couple of photos

This has been a horrible fight, my eyes fight each other and are in a state of armed conflict with my hands.

Lots of wrinkles in the membrane, but I have it stuck down to the edges.

Until tomorrow, when it all comes loose again. Hopefully it will be rain proof anyway.

 

 

[DaveS]

Anyone remember a silly song, "When father papered the parlour"? That was what it was like. Hands covered in black gunk.

[Nigella Bryant]

It'll be worth it in the end.

[DaveS]

I think what I'll do tomorrow, look at those wrinkles on the leading edge. Maybe I can slice them with a sharp knife and stick then down flat.

But the garden is in dire need of attention as I have neglected it while working on the obsy.

[DaveS]

Another quick update.

Put a spare piece of EPDM over the exposed timber lip, and got the door furniture on the door. Trouble is, the door's so heavy that I have to give my back a few days off before hanging it. I think it must be over 18 kg as it's at least as heavy as the combination ladder I bought, which is 18 kg.

It's not so much the weight, but the maneuvering it into position.

[JamesF]

1 minute ago, DaveS said:

It's not so much the weight, but the maneuvering it into position.

This is, I think, a secret skill that is passed between chippies on pain of being fed feet-first through a planer/thicknesser if they ever reveal it to anyone outside the trade.  I've certainly never worked out how they manage to make it look so easy.

James

[Peter Drew]

Wedge some shims under the door to lift it to touch the top of the frame, then fix the hinges.  The door will always drop a bit when the shims are removed but not enough to foul the bottom.    🙂

[DaveS]

I have some wedges in addition to a spare length of timber the same thickness as the sole plate, so I should be able adjust the height of the door.

Just waiting now for the lower half of my body to recover enough for lifting heavy masses. Hint: It's not just the back  

[Rusted]

Wedges to hold and a crowbar to lift.

[DaveS]

Don't have a crow bar unfortunately.

Maybe another trip up that long river place.

[carastro]

Quote

Anyone remember a silly song, "When father papered the parlour"? That was what it was like. Hands covered in black gunk.

Yes l remember that.  I am conjuring up a picture of your endeavours. Lol

Carole

[DaveS]

Yep, pretty much lol.

[Xsubmariner]

Great to see your observatory up and sealed. Having just read this thread from the start it is clear you have risen to the many challenges presented during the journey. Your dedication and perseverance is a great example for anyone thinking of building their own observatory. Now looking forward to reading about your automation and commissioning experiences. 

[Xsubmariner]

Have you considered a drive system for opening and closing the roof. With my ROR I utilised a sliding gate system. With some straightforward modification of the motor assembly I mounted the motor on the ROR wall top. The metal drive rails were mounted to a mild steel rail which I had attached to the observatory roof. To Gide the toothed rail through the motor drive I used the sliding stop that came with the kit. There are 2 remote controls which also come with the gate system, you can also fit a push button switch.

I removed the gate built in stop switch and fitted 2 roller switches that stop the motor when the roof is fully open and closed, you can stop the roof at any point in-between by pressing the start button again.

The gate system comes with an inhibit function on the motherboard so I utilised this feature with a wire loop that goes to a mini roller switch on the mount RA arm and a magnetic reed switch on the DEC arm. Only when the mount is in the parked position will the circuit complete and allow the roof control to function.

In summary the kit consisted:

Gate automation system £139 ( motor/ control system, steel drive rails x8, 2x remote)  (just seen a similar new system on a bidding site for £126)

Roller switches x2 £20 (first cheap ones were rubbish) get good quality.

Reed & mini roller switch (came in pack or 3 so some spares) £10.

Already had some mild steel rails that I welded together.

Here are some pictures of the system fitted, it works great and was relatively cheap compared to a specialist system. Hope this is of some use to you.

 

 

 

 

[DaveS]

This is what I'm using, terrifyingly and stupidly expensive, but as I lack Gina's expertise I'm pretty much stuffed.

Talon ROR Automation.

It interfaces with the AAG cloudwatcher and ASA Sequence software.

[Xsubmariner]

Nice bit of kit you have there. I assume it works with Ascom drivers. I have a used  Hitec observatory controller that I need to integrate into my system to ensure the mount is parked to allow the roof to close. Was waiting on a plug-in for SkyX to complete, unclear if plugin will be available now FLO is Hitec, must ask David.

[DaveS]

I still have to get it fitted and set up, but I've had to wait until I had the roof waterproof. May have a go tomorrow.

[DaveS]

I'm pausing my build for a couple of days, even though I have the stuff I need, as the garden is in desperate need of attention. So that's what I'll be doing.

A bit boring perhaps, but necessary.

[Nigella Bryant]

12 minutes ago, DaveS said:

I'm pausing my build for a couple of days, even though I have the stuff I need, as the garden is in desperate need of attention. So that's what I'll be doing.

A bit boring perhaps, but necessary.

A pause is sometimes good. 

[DaveS]

Well, I ran the hedge trimmer over one short hedge, and pulled / dug out some long tree suckers, now my back hurts. Giving it a rest for a few minutes.