StarShed Goes Foam Dome.

[Tandum]

After a year or so procrastinating on design, I've got a foam dome obs underway.

Many thanks to Steve (Kinetic) for inspiration and email support as well as Baz at A.S.I.G.N. (http://www.asignobservatory.com/index.php?option=com_content&view=article&id=52&Itemid=48) for a brilliant web site, not to forget Joe Garlitz (http://eoni.com/~garlitzj/geodome.htm) who got the ball rolling.

My pier is in, the foam is now a dome and the rings are under way.

I've plonked photos and a story online (http://starshed.net/obs/index.htm) but here's a few pics anyway.

Yipppeeee :D

[Astroman]

Robin, it looks great! The Pier looks good too, and has held up very well, I am the original maker of that pier, so I hope it serves you well into the future. The construction looks very good, and the foam will serve as a great insulator of heat too, great design. Good luck with it all in the future. Look forward to seeing more as time goes on.

[mswhin63]

That is looking great, i am also interested in this design using foam as well but have to move house first as there is not enough room to assemble it and the remove it if i do move.

I am getting a little fed up moving the scope in and out of the house or garage all the time.

I use the same router, nice strong one.

[Tandum]

Cheers Andrew, Alex said he transported it from S.A. on the cheap, the thing weighs a ton. I got a sheet and a half of foam left and thought I'd line the 1.2 meter wall with it rather than toss it. There was far less waste than I thought there'd be.

It's a little daunting when you've cut all the triangles and see just how many there are Malcolm. I've scalled this one back 30% to fit in the back yard, so the edges on my triangles are about 400mm instead of around 600mm as per the plans. That makes it easier for one person to manage while building but it still took 2 of us to lift it and turn it over :)

[kinetic]

It's like there's a new baby on the way (sniffs) and
I'm buzzing with excitement. Ahhhh they grow up so fast:)

You do realise the aesthetic improvements still continue after
10 years though?

Steve

[mozzie]

looking good robin!!! keep the photos coming.well done

[adman]

looks good robin - I didn't realise when you posted photos in the Ten Chain Hill thread that you had cut all those pieces yourself - that must have taken some doing?!

Are you happy with the strength of the dome now its all glued together?

Adam

[HCR32]

Want to build me one? $$$$

[Tandum]

Yes it is, especially when you can see the end of the tunnel. Now if it would only STOP RAINING !!!!! I could get the circular concrete floor underway.

Here's a couple more photos Pete.

Adam, I knocked up a quick cutting bench (see pic) with a cutter on the end and then cut the bench up for the rings once the foam was done:) Once you get a rhythum going it happens pretty quickly. I cut 2 triangles out of 4mm MDF with a box cutter and a metal straight edge and used them to draw cut lines on the foam. When it was complete and upside down the edges where a bit wobbly but right way up it's surprisingly ridgid, like an egg I suppose. It still needs the bottom ring and associated internal reinforcing to go onto it and a waterproof coating, render or similar will do it and I shouldn't forget the shutter I guess :)



No, once is enough for me thanks, I'm totally foamed out :D

[mozzie]

its looking real good robin.. one question how do you get in or is it light enough to lift off each time ????

[mozzie]

aahhh !!! i see robin its the dome and the walls are coming... youve taken on a task here and your doing a bloody good job...what are the walls going to be made of..????

[Tandum]

Just framing pine with a ring top and bottom to keep it round and probably alsynite around the outside on a concrete floor. If it stays fine I should get the floor done this week-end, well most of it. I had to do the dome first to get an accurate diameter for the rings. It only needs to be 1.2meters tall and I might add a pod sticking into the garden bed. I swapped a TV for an eeep box yesterday so that makes the control PC nice and small :) The pc is that box screwed to the back of the monitor.

[ChrisM]

Robin,

The dome looks very neat - well done on tackling this design. Please keep the pictures coming. Do you happen to know its weight? I enjoyed reading your blog - brought back a few memories. Mine was built from 9 mm plywood (also 105 triangles) and is much heavier of course.

I'll be interested to see what you do to waterproof it; mine is just numerous coats of a thick waterproof paint. The geodesic shape is inherently strong, and once the dome's base ring was fixed in place, the whole thing stiffened up considerably. Of course, cutting the slot weakens it, but adding the frame in that aperture brings it back to a strong shape.

I might add a few dome construction pics to my thread later - just realised that I don't have any there.

Good luck with the rest of the project.

Chris

[Tandum]

If I had to guess Chris, I'd say 15-20Kgs and probably 1/3 of that is glue :) It's hard to estimate as it takes 2 to lift it due to the size. A client of mine is a builder and he suggested coating it in sikaflex pro which is sort of like a hi-end long life silastic, but I think cost will kill that idea, render will be the cheapest way to go.

[Tandum]

Boxing is in for the concrete and I banged in some expansion joints so it doesn't push on the pool or the pier footing or visa versa. I'm going to get concrete taxi (http://www.concretetaxi.com/)to do the concrete, quick, easy, no left overs and no mess, and not much more dollar wise than bagged pre mix to be honest.

I also trimmed the bottom of the dome to make it flat. As all edges of every triangle are tapered, the bottom of the dome is also tapered so it's not flat, which makes for a poor glue bond to the turntable. I also found this one was up to 25mm away from true (see pic). However, the foam is pretty easy to work with, I knocked up that cutter in no time at all and ran it from my dew controller. I measured down from the ring, set the string to distance all the way round, drew a line with a marker and cut it. Hint, red hot is tooo hot for the cutter, that just makes holes :D

I also got the eee box cleaned out and setup for Astro Apps and remote control.
It has wireless built in but it's a gutless CPU. For control it should do ok.
I'll keep my eyes open for a cheapish Solid State Hard Drive.

Also Brundah1 has put me onto some quality wood glue. TITEBOND III water proof wood glue from http://www.hardware.net.au/

I also found 10litres of paint in the shed so just finished painting the bottom ring. Back to making more rings tomorrow :(

oh, and thanks to ChrisM for some great ideas via email ...

[Tandum]

The floor is in. Concrete Taxi arrived today but the damn camera went flat so only got one crappy pic of the truck before it died completely. The pour ended up being about 4 square meters in area and cost $210. Best part is that it only took an hour and a half to pour and finish the slab. Magic :D

[mozzie]

starting to take shape now!!!
are you starting the walls soon?

[Tandum]

I want to get the turntable done first so I'm laminating, glueing and screwing the bottom turntable ring tonight seeing the wood has been cut. I already have the bottom ring/plate for the wall done and painted and I picked up a few concrete self tappers today to bolt it down. I'll need to pay more attention to detail on the top two, they need to be right. Won't get much else done this week-end, it's full bottle with social events and they are forecasting rain through Saturday/Sunday anyway.

One tip, new jigsaw blades make cutting plywood a whole lot easier :P

[Tandum]

Bit of action here today. Both turntable rings have been made and matched, the upper ring overhangs the lower ring just enough for the weather proofing to take effect, I hope :) Sand and paint tomorrow on them.

Also bolted down the bottom plate for the wall, got the geometry done and worked out the entry etc etc. I see the end of the tunnel :D

[Astroman]

Lookin good! I should do more on mine, but it's raining :(

I have been looking for a small quantity concrete place here in Adelaide too... I like the idea of them mixing it on site, was the batches the same consistency though? Do they mix the whole lot then pour or is it single bags at a time?

[Tandum]

http://www.concretetaxi.com/ Check out the videos on the site. Basically the truck is full of blend and water, they push that into the mixer bin on the back of the truck and add bagged cement to obtain the requested strenght. The mixer bin has a huge screw in it to mix and dispence. Here's a price list but I dunno if they are in Adelaide, it is a Perth based franshise.. That may be Brisbane prices?

It's not cheap but it's definately easy and quick and from what I calculated, it cost me a lttle more than premix bags, minus draging the trailer out to get the bags, not to mention mixing them in a barrow.. I didn't bother checking costs for mixing it myself with a mixer, it was just too small a quantity to consider it and I'd end up with lots of left overs to deal with. This way you don't even have rubbish to go in the bin :)

[edit]
They made 2 mixer loads for me (6 wheel barrows full) I had one barrow load left over and used it under the wheely bin spot instead of tossing it. There is always somewhere you need concrete :D

[pmrid]

Looking good mate. For a man who claims no woodworking skills, you're making a pretty fine job of this.
Peter

[Tandum]

More arse than class so far pete.
This is where it will start to look like Homer Simpson's bird house :P
The wall is done ...

[ozstronomer]

Robin The observatory is really coming along nicely. You should be rightly proud, excellent effort :thumbsup:

Looking forward to seeing the rest of the build and getting the full "blow by blow" at the next 10CH outing.

So once it is finished the clouds WILL go away...won't they? seems like a never ending parade ATM :sadeyes:

Cheers Geoff

[Hagar]

Looking very good Robin. The whole thing is taking shape and really looks the goods. Almost time to give you gear a work out and sit back and enjoy.

Great effort. Well done.

[Tandum]

Another day with very little work on so I got the dome glued to the top ring, no wheels yet. It's got 2.45meters of head room and 1.85meters internal diameter between the inside ring edges and is looking more like the goods now. Still need to add internal reinforcing to the dome and some extra bracing to the frame but that should only take a day with a saw.

Also tested my wheels idea on an offcut. I'm going to route them into the turntable to reduce the gap between the top and bottom ring. Cut up some 6mm brass rod for axles. Looks like a worker :)

No Geoff it will never clear up now, although the days are clear, got a touch of sunburn today.

Doug, at least I'll have some where to set the stuff up. It's still all packed up since the last trip away in early September :(

[mozzie]

taking shape now.you should be proud of what youve done

a fantastic job!!!!!!!

[h0ughy]

A mushie in the yard - wow it pops up quick looking good.

[Tandum]

Cheers guys, it all seems to be going almost as planned although it's a little taller than I imagined it would be. Seeing its right beside the pool fence, I had to make sure there aren't any hand holds or steps so I made the the wall tall enough to be part of the fence. They are doing random pool compliance checks up here and coming down hard on pools that don't comply.

However, I'm not looking forward to doing the shutter, at all. How wide should the opening be? The original plans show one triangle which is about 600mm on his plans but that's only 400mm wide on this dome. If you look from inside it's obvious the top pentagon should go and then follow the joins down but that makes for a curved opening, 800mm in the middle and 400mm top and bottom. I'm not keen on making a curved shutter, square is good :D I don't think 400mm is wide enough, 600mm sounds right. What do they use on a bought one?

[leinad]

Nice project. Just out of curiosity of its strength against UV and wind; would covering this in paper mache or something similar be beneficial in improving strength and lifetime?

[Tandum]

I'm going to render the dome in concrete. It will add 45Kgs to the weight and cost about $30. It's definately not water proof as it is nor is the glue I used. It currently looks like this, and it's raining again :( But at least I can work inside :)

[mozzie]

robin before you clad the walls think about putting some power points in the stud work you can never have enough power...
small fan, red light, mozzie zapper these little luxuries in a dome:lol::lol:

[Tandum]

Not a lot of activity this week, weather has been dreadful, constant passing showers, always overcast, yuk. However I got inside the thing and put in the dome reinforcement around the whole dome and got the bracing into the wall.

The wall wasn't stable enough as it was. Give it a bump and it would wiggle, I'm sure I could have pushed it over if I tried hard enough. I have braced it each side of the door way and braced a bay opposite the door way. Thanks to Dave (Brundah1) for the tips. It doesn't wiggle now, it's solid as. Similarly the dome is 300% more secure. You can punch it from the inside and it just feels solid.

Thanks to allan gould for letting me come over and check out his sirrus dome. I now have the shutter plans ready to roll and have started on the rings for the shutter.

Allan, I set up the scopes inside and used the caveman version of lasers around the scopes. Broomsticks and tape :)

[allan gould]

Robin, really looking forward
to your progress with the observatory.
It's looking great at the moment.

[Tandum]

Allan, it's looking like the shutter will have to be 650mm wide minus the shutter framing, 42mm, so about 610mm. It is a small dome, 2100 O/D. I can't make the opening any longer either or the door won't roll round the dome. I note the sirrus domes solve this issue with a flip out door.

Therefore I see a problem with the 10". If it's looking east and then eventually pointing straight up, the dome will have to be rotated before it gets to azimuth or it will not see some of the sky, the slot will not be long enough. I can still move the pier a bit, It's bolted down with concrete bolts, but I'll suck it and see first. If I manage to automate it, I might be able to fix that in software. However I think this is a penalty of having a small dome.

[RickS]

You're sounding like the electrical engineers at work, Robin :)

[Tandum]

http://www.iceinspace.com.au/forum/showthread.php?t=66351

Check out this thing from jaycar and then see the current drivers for it :D

Azimuth sensor is the problem, I think the parts from an old ball mouse might do it.

[RickS]

Very neat! USB is the bane of my existence at present. Good to see that it's useful for something.

[peter andre]

Hi Robin,
Congratulations on your achievements so far!
You're doing a mighty job, and can't wait to see the Observatory completely finished and ready to go.
Are you planning an Observatory warming party??.......just kidding!
Best of luck with your final finishing touches, and hopefully the rain stays away for you.
cheers,
Peter
p.s. i am getting good results with my qhy8pro.

[Tandum]

Hi Pete, exactly when are you getting to use that camera :)
I don't think it's ever going to clear, I've even stopped checking the weather sites :(

More progress photos. Got the dome off the wall to do the shutter, so the wheels are in, the shutter ring is made and I've sealed the foam with paint I found in the shed.

After talking to a few people, I've decided to seal the doam with acrylic paint under the render as the render will most likely crack at some stage. I've given it a couple of coats of the paint I had here and good old bunnings had a litre of stone finish acrylic on the wrong tint pallet for $6. This stone finish paint has a texture like sandpaper which should help the render to stick as well as being the final sealing coat on the doam.

I hope to get the shutter in before the boy child has all his mates over here on Sunday for a BBQ.

Getting close now :)

[RobF]

Looking good Robin. Have you done any calculations on how long you'll be able to image in each direction without going out to tweak the dome? Sounds like you might be planning to automate rotation sometime anyway?

[Tandum]

Hi Rob, finished those exams?

I've been doing everything with a view to automate, that is, I'm trying not to box myself in. I bought and tested that control card, it works, There are already ascom drivers for that card so I don't have to write them, I'm pretty sure I can get a pair of windscreen wiper motors to drive the dome ring, but I'm not sure about the azmith feedback or the shutter control.

Right now it looks like I will have to have a fold out lower section like the sirius dome so I can see low enough to drift align the mount, and hopefully have a curved, wheeled type door for the rest of the opening that 'could' be motorised to open/close that main shutter.

My woodwork skills have been amplified a lot by doing this project, so it may all be possible, I wouldn't have imagined that when I started this, then again we might get a hail storm tonight and the lot could be reduced to dust :rofl:

One thing's for sure, I'm sick of making wooden rings for the stinking thing :tasdevil:

[Tandum]

Took the plunge and cut a hole for the shutter. I haven't fixed it in place as yet, I've run out of time to do any more. Xmas parties start at 4pm today and run the rest of the week-end :cheers:

[bert]

Hi Robin,

Just to provide some inspiration for the dome automation system, here is mine. I went a little crazy and got a pcb board made, I found that I didnt like the way that 12v was fed thruogh the k8055 board, so I bypassed that with the pcb.

I installed the encoder (rotary) to the back of the motor itself, to save any hassles.

Instead of a direct link to the shutter motors I have used a radio link to the shutter motor controller. The motor controller I have installed in a few friends roll off rooves observatories, and my own, and works quite well with the lesvedome driver.

I have a dome coming shortly. I may be getting ahead of myself. A bit.:D

Just a word of warning. Do NOT activate both motor on and directions shutters at once in the k8055 utility. It can cause the k8055 to blow up. The dome driver software staggers the relay timing to prevent this from happening.

Brett

[Tandum]

Well you know it's a QLD RSL club when there are grab rails above the urinals :D We had to attend this one ....

Cheers bert, I have not even considered any of this yet, except to say I can still connect to all the surfaces required to drive it all. What you have there looks like a drive for a sirius dome, worm driven cog drive which connects to a toothed gear around the dome.

At this point I'm tying to avoid getting metal bent/shaped etc, I wanna see what I can do with my tools. Jigsaw/router/square/level. Your azimith feedback would fail if the dome slipped in a wheel driven environment.

I thought that domedriver site showed the board driving relays to power everything, I might need to take another look? I would have thought driving relays would avoid any current problems on the board?

My next problem is a curved door ... bugger, wood is supposed to be square and straight ....

[edit]
I should also note that only 5 of the 8 turntable wheels connect with the upper ring. It all turns just fine but it appears that the bottom ring is not level. A number of those wheels never touch the top ring. More on this one later.

[bert]

Yes the dome driver uses relays, what I mentioned before can still happen with relays, it is not a current problem, but a short circuit. Attached is a pic of another system that I made by wiring in relays instead of the pcb.

The drive I am planning to use is a steel reinforced rubber belt, like a timing belt but used in high end sectional garage doors operators, attached to the inside of the dome. I have a drive cog for it already. It will not slip. I have the same setup driving my roll off atm, it would be very easy to use in your setup, it simply could be glued/stapled to a circular inside face in your dome.

Dont be too concerned about the wheels, it is almost impossible to get that many wheels to face upto the dome, afaik most manufacturers use 3 fixed wheels and 3 sprung wheels to keep them toucing the ring.

Brett

[ozstronomer]

Robin

That dome is really coming together nicely... great work:thumbsup:

You really have mastered the woodwork side as the shutter frame seems to fit perfectly in place. Will you fiberglass it to the foam or just use a few tubes of silicon?

Looking forward to seeing how the automation goes...good luck

Geoff

[Tandum]

Cheers Brett, a cogged belt sounds like a winner, I imagine they'd be expensive though. I'll probably contact you when I get closer to that bit of it.

The shutter came out ok in the end Geoff. If you look hard enough you'll see where I glued some foam back, in front of it, chopped too much out, ooops! I haven't tried silastic on foam yet, not sure if it would melt it or not. Liquid nails is waterproof and doesn't melt it :)

I'll have to setup the workshop out back again, now the kids had his BBQ out there and then have a bash at the doors, in between rain storms of course. They've forecast rain all week and though to next week, again :rolleyes:

[allan gould]

Robin
That dome is really looking great. Very interested in seeing how you motorise it. Are you doing it to fully automate it to the scope tracking?
Allan

[Tandum]

Hi Al, I'm wondering how I'll do that too :) I'd imagine maxim would handle tracking sync between the dome and the scope via the obs control panel. I honestly haven't bothered to check it out yet. The dome driver I guess I'd use is only a trial and times out so I'd want something to trial it on first. At the moment it's all stop due to rain, I'm not game to plug any power tools in, everything is damp.

[ChrisM]

Robin, Your dome is coming along well! Regarding only 5/8 wheels making contact, I used a rotating laser level to ensure that the wheels (which in my case are stationary) were level. I had to shim a few of them. Of course, this assumes that the bottom of the dome ring is not warped.

Chris

[Tandum]

We got the dome off this morning before the rain started and I found a high point with my low tech laser, a stringline level :)

Looking at the 4day forecast, it's just more rain through to Sunday night :(

[mozzie]

ahh robin your the blame for all this weather!!!!
theres no need to rush your dome to use it the weather may clear by next christmas!!!

[bert]

The way to sync the dome to your telescope via lesvedome dome driver is to select your ascom telescope as POTH (plain old telescope handset) when you configure POTH you select your normal ascom telescope driver and lesvedome as dome driver and they will sync up.

Brett

[Tandum]

Cheers bert, allan is keen to automate his sirus dome, I told him to talk to you, hope that's ok.

No action here today, I actually had some real work to do ... income does it for me :)

[Tandum]

I'm pretty sure volume of rain equates to the number of dollars spent on astro gear. This thing has cost less than a set of filters so far, I'd be looking closely at all these ebay C11's coming into the country and where they are landing :) Not to mention the AP mounts getting off aircraft. It's not me, I didn't do it :D

[Tandum]

Just how wet has it been this week :( To day the sun came out for a couple of hours so I router cut the template for the door. I use these templates to draw the cut lines for the pieces that go into the next part. I need another 8 of these parts to laminate a piece to make the door.

Just after I sanded the template, the rain blew in and soaked all the wood :(

[Tandum]

What the !!! It stopped raining for a couple of days so I picked up where I left off.

The shutter had been under the tarp for a week, in the rain and unpainted so it was moldy and some of the laminates where pulling apart. Reglued and clamped the crappy bits, sanded it off and undercoated. Got it leveled in the dome and glued it in at last. I had already glued in a few triangular reinforcement blocks inside and screwed the shutter to them as well as glueing it to the foam. The inside of the window is about 650mm wide.

Made up a half ring for the window. Didn't pay enough attention to detail here so I ended up with joins in the top and bottom layer right on top of each other. After I routed it and picked it up I found this out when it snapped. Bugger .. Had to join 2 bits to get the lenght for one side of the window. Not to worry, it works, patched the bits together with glue and a metal tie.

Made up a quick lower window out of offcuts to get the measurements for the main window. The lower window will be hinged so it can swing open for when I need to drift align.

The sliding window works, unbelieveable, this was my biggest worry. I'll be installing some guide wheels that I have, under the curved bits, so it doesn't rub on the track and eventually I'll cut those cross bars out as they will definately hit the back of the dome once it's rendered. Wood cross bracing will go in instead.

Next is the render on the dome. Looks like lots more rain coming so I have just put a final coat of arcylic on the wood and the tarp goes back on for who knows how long :(

[edit]
I also painted the dome with the rock texture paint so the render will key to it. The dome feels like course sand paper now.

[Tandum]

What do ya do when it's raining ?

Skin curved doors of course :)

[edit]
Looked like it had enough rain by midnight. Clamp and leave to dry :D

[Tandum]

Nightmare .....

I have installed the shutter and made the fold out window and the sliding door. Both work a treat and overlap each over perfectly. Today we put the dome back on the wall. I have recently levelled the wheels on the wall.

What the!!! The dome ring now has a bow in it around the shutter. I gently clamped the dome ring to the base ring so all wheels are touching and eventually triangle joints around the shutter came apart. (see image)

What's happenened is I fixed reinforcing inside the dome after cutting the hole and screwed the shutter to that for strenght about a week later after the rain. But holy smoke, the dome is so strong it pulled the ring out of shape when I screwed the shutter in.

I've released the tension on the shutter reinforcements and the ring is flat again but now the shutter is spreading apart and my beautiful door and window won't fit :(

I hope to resolve this without having to rebuild them.

[jenchris]

Arrgh!! what a shame!

[Tandum]

The cracks aren't a problem Jen, it's the time it will take to fix. Glue takes days to dry when it's wet. This could take up to 2 weeks to fix just waiting for glue to dry :(

[jenchris]

use epoxy.
or even Polyester!!
I've got some if you want it I only live a short distance away!!

[Tandum]

Thanks for the offer Jen but I have loads of stuff here.

[marki]

Epoxy works really well with polystyrene Robin, much better than PVA. It does not eat the foam and will set in the time prescribed on the tube. The best thing is that it really strengthens the foam along the joint. I used to use it all the time when building foam wing RC planes.

Mark

[Tandum]

It would be too expensive to use to any extent Mark.
I've poured 10 litres of PVA glue into the wood alone and used so many tubes of no more nails I've lost count :)

[marki]

Hi Robin

I was thinking more along the lines of using it in your high load areas (e.g. ring to foam and around your doors etc). I used to buy 2 litre cans of the stuff from a construction supplier here in Perth at quite reasonable prices as you skipped the middle man. It came in part A and Part B 2 litre cans so you ended up with 4 litres of glue which spreads for ages on styrene. You just mix up what you need and put the lid back on the cans. Sticks like you know what to a blanket and forms a really strong bond.

Mark

[jenchris]

ATL Composites a local firm make a product called Techniglue which is filled with fibre (rayon I think) and is a sort of thixotropic glue with a pot life of about an hour. Somewhere in the region of 35-40 dollars a kilo. But it goes a long way and I've used it for boat building. So it is weather proof and VERY strong - but remains slightly flexible so it won't crack or shatter

[Tandum]

Thanks for the suggestions but the glue phase is almost over. Jen polyester resin (Bog) is no good, it melts the foam, I tried that this arvo. Mark, the dome is reinforced to the ring using wood triangles, see inside the dome in the image, and it works too well. I used nomorenails to glue the dome down and a combo of pva and nomorenails to glue/screw the wood. It's not going anywhere and that has been proven this week with the wild storms that have swept the city. But honestly, it needs a glue with a gap filling ability comensurate with my abilty to build stuff :)

I have filled the gaps around the shutter with canned foam and will reattach my wooden triangles between the shutter and the dome internally for strenght. I have pulled the shutter into shape with hooks and string but fully expect to have to make a new door and window, when these storms stop of course.

I'm still tossing up if I will spring for fibreglass or just do render for the skin. It's $20 compared to about $400. Weight is the main difference I guess, 6 kilos compared to 40Kgs, and as it is, 2 of us can still lift it on and off.

[marki]

If your wallet can stand it go for the fibre glass as it is far less likely to crack then the render.

Mark

[Tandum]

I've got hold of some armawall (http://www.taubmans.com.au/public/professional/texture/product-guide.aspx)cheap off ebay. It is a 3 part render system and is a thin base primer, a premixed acrylic roll on render, which is foam safe, plus a membrane top coat which looks a lot like really thick paint. One day the rain will stop long enough to apply it :rolleyes:

[allan gould]

Today looks like your day -clear and dry. Have to get it done before Xmas

[Tandum]

Ha .. today was unexpectedly clear but I planned for Tuesday, it was looking like the go, but equally unexpected, it seems every one of my clients with a pending BAS form is trying to empty their bank accounts before xmas. Being busy with work is good for a change too :)

[Tandum]

Finally, it has stopped raining. I jumped in yesterday as soon as the sun came out and rendered the dome. This armawall stuff is quite odd, it's like super thick paint with fine gravel in it but it sticks like crazy. I got some on the wood and it's very difficult to get it off once it's gone off.

I started running out so it's a bit thin bottom right of the shutter but all the joints are sealed and I don't want to fork out for more of the stuff, off the shelf it's not cheap. Strangely enough, it's fexible when set. You can knock on it and it's solid as, but if you push a triangle, you can feel it flex. Obviously it's not as smooth as I wanted so I won't be doing this for a living but he top shield coat seems to fill all the pits and smooths it out a lot.

I sanded off the shutter wood as best I could and painted some of it and it's joint with the dome render and it's obvious the top shield works best on the render. Tomorrow I'll paint the lot, if it keeps clear and I don't have a roaring hang over :D

Happy New Year :cool:

[Astroman]

looks very nice, good job

[Tandum]

Naaa, it's not that good close up, there's lumps and bumps all over the place, we are calling it rustic :)

Forgot to put the tarp back over it Saturday, we were out, and it rained all day. That softened the thick bits and turned em into putty. Sun came out today and it looked hard enough to paint by 5pm so I did. It's now 2am and the paint is still wet. It better not rain tonight or tomorrow or the back yard is going to have 2 liters worth of white grass :( I've had enough of the rain now thanks.

Quick picy, no rain overnight so the first flat coat dried and I put a texture coat on. Looks a lot better with a texture coat on it :)

[peter andre]

Robin,
Happy New Year to you and your family.
Considering the horrible weather we are having, I think you are doing a great job! It must be frustrating with all this moisture in the air.
hopefully soon you will be laughing and all that hard work came to frutation.
Now we need clear skies for at least one year, I think you and everyone deserve it!
cheers,
Peter

[Tandum]

Same to you pete. Last images on my pc are dated September, it has to stop soon, surely.
In the mean time I've gone bedouin to try and get the window finished in the rain :lol:

[RobF]

The next thing that'll happen is every tree and bush in the vicinity will grow 5m with all the wet.....:whistle:

(Hope not though! :))

[Tandum]

The council got proactive a few months back and cut the trees back. They where the trees blocking the street lights :rolleyes: I only have one neighbour, to the left, the council cut the trees behind the house. I'm hoping they'll grow back a lot ;) But the jasmine on the fence flowered early this year and needs to be cut now, it restricts my view north if not kept in check, but I'm not game to order the skip with all this rain about, I need to use power tools to cut the hedge :sadeyes:

Anyway, got the window plus the pulley to open it and the lower flipout door sorted tonight. Painted inside the dome and got some flat black in the obvious places, more of that paint is needed. I'll upload some pics tomorrow. Oh, and the tent is water proof, that's a bonus :D

[Tandum]

Quick update.

Dome is back on the wall, curved door is finished, although I need a thicker cord to open/close it and some minor adjustments are required to keep the cord in the pulley. Flip out window is finished and has internal locks and chains fitted. The entry door has been built and needs to be skinned. I have ordered some stratco maxirib (http://www.stratco.com.au/Products/Roofing_Walling/Types/Maxirib/Maxirib.asp)to skin the wall/door with an expected Friday arrival. Almost there :D

Sorry for the crap photo, I'll replace it tomorrow. It's hammering down out there tonight.

[h0ughy]

LOL looks like a lot of sunshine dripping off the dome ;)

looking good Robin

[Tandum]

Tell me about it dave, with something like 40 days straight with rain, the build has crawled to a near standstill :( So much stuff to paint/render adjust, when will the rain stop? Although, once the steel arrives, I should be able to skin it with battery tools in the rain :)

I believe that is lockup stage and calls for lots of drinks :D

[pmrid]

Don't forget the old builder's superstition - when the roof is finished you have to put up a broom or something before you get on the pistol. Otherwise you risk incurring the wrath of the gods of something-or-other. Any builders out there who can explain?

Peter

[Tandum]

Got the steel this morning and bolted it straight on. I'll have to redo the entry door, it's just not right. I figured I'd build a door jam to suit, mount the door in it and then mount the jam. The framing just isn't square enough for a close fitting door.

So almost lockup.

I've poisoned the grass around the concrete base so I can get a clean seal with the sikaflex once it's clear of flora. Might even setup in there tonight if I can find a usb->serial thingo that works. Had to sell mine to get a client going before xmas and the replacements aren't here from the US yet :(

[Astroman]

Nice work, looks terrific! good to see you got a bit of clear to get some photo's.

[Tandum]

Nice blue skies here today for the first time in a long time. Just trying to get the mount aligned tonight. Re-leveled the pier and have spent hours trying to remember how to align it :P

[RickS]

A labour of love, Robin. Looks great!

[astroron]

Nice work Robin :D
Looks great :thumbsup:
Cheers

[Tandum]

Cheers guys, it's taken a while to get here and it's not done yet. There is a lot more to it than I initially thought, but we're getting there. The entry door is not in a good position when the scope is shooting east but I'm hoping to run it all remotely so it won't be as much of a hassle as it has been tonight trying to get the mount aligned. In out / In out constantly tweeking it.

I had to google PHD polar align, I had forgotten how to do it :(
But here's a phd graph from the em-200 with guiding turned off.
FL is 860mm into the qhy5. Well worth the effort :D

[Tandum]

Thought I'd try for first light tonight. Jammed the newt into the shed late in the afternoon and quickly found out that most of the usb plugs are rusty and the laptop can't run the qhy5 and sx wheel at the same time.

Well I guess it has been four and a half months, 18 weeks or 126 days since it was last all connected ....... :rolleyes:

Got it all to go but visitors arrived before dark and left after it clouded over :mad2:

Thought I'd give it a couple of crownies to see if it clears.

The newt in the dome is a really tight fit, but it does fit :) Last pic is the entry door. Look out :eyepop:

[peter_4059]

Looking good Robin. What are you doing in the way of coma correction with the Newt?

[Tandum]

There's baader corrector in there but I'll have to have another look at distances now I have the starlight wheel going although it should be pretty close to right. And the rings also need an update, I'm sure that's where the flex was coming from last time I used it.

[Tandum]

Still plugging away at it here and here's a few more snaps.

Got the Entry door done so we have lockup :) Screwed a hasp and staple onto it to stop it blowing open in the wind. I'm trying to find a rod type lock that pushes a rod up and down, through the door and into the frame. Bought some rubber flooring and got the first 4 bits in.

Spent a fair bit of time trying to get the dome to rotate beter than it is. Looking at the wheels, there is already signs of wear on them and about 75% of the tapered wheels contact the dome so the dome is squashing the wheels somewhat. Also they don't have bearings just bushes and they are prone to slide on their axles and bind. All this tends to make the dome slide at times and bind up on the guide wheels.

I've been round to the metal benders and they can bend me a 30x30x3mm alum L for about $150 and I found some ball bearing U wheels to suit so I might upgrade the ring. I did do a first light with the 10" newt on M42 and found I had to move the dome every 15minutes or so or the guide star would be lost so automation is really a must have.

I've added the M42 image, which is just 5x5minute subs, Ha binned x1 with O3,S2 binned X2. Spent 2 minutes combining and curving this one but have some shorter shots to overlay one day. No calibration files used at all and I think I have these 36mm baader NB filters in the wheel back to front. I'm guessing the mirrored side should point to the scope?

[edit]
I forgot to mention that I used up all the left over foam by lining the lions share of the wall cavities including the door. Three remain unlined, they face the garden and fence so won't receive sunlight and will be used for mounting power supplies etc. I put a digital thermometer in there this arvo and it was 1 degree cooler than the ground floor of the house, however the obs is still vented through the slot between the dome and the wall.

[allan gould]

Robin
It's looking good. The dome automation is also a must but if you are going down that route also need remote desktop (another must-do).

[Tandum]

I prefer VNC allan. Remote desktop requires the user account on the remote pc to have a password, VNC requires a password to connect to the remote pc. I got the little eeepc all setup and ready to bolt to the wall.

I got the floor in and a ton of little jobs including moving the pool fence.
I guess we'll see where the leaks are later this week :rolleyes:

[adman]

looks great Robin - is that blood I see spattered on the concrete floor in post #94?? talk about blood sweat and tears....:lol:

Adam

[Tandum]

Ya got me adam, I dunno what it is, my blood isn't that thick and it has froth on top :) It's gotta be glue. I must have spent well over $300 in bloody glue. I'll work it out one day, I have a bag full of recipts to add up :help:

[edit]
Needed a holesaw to get power into the shed and I've never owned one. Got a 13 piece set off ebay for $22 courier delivered. I'm sure it's junk but I only need to make one round hole and I ordered them Monday morning and they where here Tuesday morning with a bonus 1" wood bit :D There's another receipt that won't make it into the bag.

[Tandum]

Got the PC, Monitor and Power Supplies installed. Turned the monitor wall mount sideways to get it to point up. There is no keyboard/mouse attached, I run it all from outside the dome but will use the monitor to focus the newt, (I have a robofocus for the tak) then turn the monitor off. I might need a mouse in there to do sub frames for NB focusing. I'll use that Pine board for a power supply shelf but I'll wait for the new USB hubs and cables to arrive so I can make it all neat.

Had everything up and running on the little eeepc tonight and with that little ssd drive I installed in it, it handles everything and responds well. Only got 1gig of ram in that win7 box. It's shooting long darks overnight right now :)

The ebay holesaw was crap as expected, the steel wall got scratched and sent the saw blunt, but the saw did cut the wood. I need a 25mm steel cutting hole saw to get the power in. Anyone got one? I'm looking for a BFWE (Bunnings Free Week-End) :D

[RobF]

I dunno where you get the time to do all this Robin! Hats off to you though. The sanctuary is really coming together for you.... :thumbsup:

[mswhin63]

Use a wireless keyboard and mouse, great flexibility and no wires.

[Tandum]

Rob, work has completely collapsed now. I've gone from 6 jobs a day a year ago to 6 jobs a week now. I've lost 3 primary clients to the GFC, they've either closed or sold up and 2 PC shops I was subbing too have closed doors. Time for a forced change I guess before the cash runs out :(


Malcolm, Logitech are making a neat cheap wireless set, I've bought a few of them for others, might get one for me :)



Found water on the floor of the obs on Monday after that heavy rain, under the slot. Everything was dry everywhere on the dome, just water on the floor. Tonight I opened the lower window to align the mount and there is water under that window. There it is :) It's getting in under the flip out window, easy fix.

[Tandum]

Finally got the bits and the time to install a track on the dome. I had a piece of 65mm X 3mm mild steel flat bar bent to fit inside the dome ring. I got some bearinged U-Groove wheels and hacked up a bracket and have bolted it all in.

I have 3 wheels installed so far and we'll see how that goes but I do need to join the ends of the flatbar somehow. I don't have a welder, so is there any other way to join them so they don't flex apart? I can't put a bolt through as I'm yet to install guide wheels which will run on the back of the track.

Previously it was a pain to rotate the dome, now it's a one finger job. It works !!!! :D

[RobF]

Sounds like it just gets better and better Robin. Great work.

[Tandum]

My kingdom for a welder at the moment Rob. I have to tack the ends of the track together.

I did get the guide wheels in between rain showers and tinnies :P

[marki]

If you post it over to Perth I will weld it for you Robin, you even have the choice of mig, tig or arc but will have to supply the box to send it back :P:D. Looking the goods though, well done.


Mark

[Tandum]

Cheers Mark, I decided to avoid getting personal with the fire department so I glued it together. So far so good :)

[Tandum]

We're in the final stages now.
Motor driven Cog drive, Toothed Belt to suit, PC-USB interface board and DC relay board.
If I can get all this stuff to fit and to go it will be a xmas miracle :)

[Tandum]

I had a bash at getting the dome motor mounted this week. I got some metal plate and cut some holes and slots in it to suit. Got the motor to fit it reasonably well so added a spring for tension. Then I cut a chunk out of the lower ring to recess the motor assembly and bolted the plate to the bottom ring.

Looks almost like a bought one :D If I can get the toothed belt stuck to the track, we'll have a motor driven dome :thumbsup:

[edit]
Raining today but not in the dome so I got the belt stuck to the track. The dome is now non slip and motor driven ;)
Encoders and electronics are next to get it under software control.

[Tandum]

It's ALIVE :thumbsup:

I stuck a couple of tiny magnets under the cog so they pass over a reed switch to form a simple encoder. I got the electronics into a box, put a switch on the front for manual control and ran some wires to the home sensor, encoder, PC, power and the motor.

The dome slot follows the scope during a slew so it's definately a goer :thumbsup:

Now, some stars would be nice so I can tune up the numbers in the lesve dome driver software to get it as accurate as I can.

It's an easter miracle :D

[RobF]

Much noise to worry about in the middle of the night Robin?

[Tandum]

Nope, can hardly hear the motor running from the outside at all and the steel track is close to silent. It does give a noticable click as the cog passes over the join in the belt. Also the motor sometimes bucks when it starts up and that gives a click, although adjusting the bolts on the motor plate fixes that one a lot. I could do with some spacers in there so I can screw the bolts down hard.

Got the flashing attached and added an external antenna for the wireless, just needs a lick more paint I think.

Does anyone know if the Dome home sensor azimuth should be set in software as magnetic or true ?

[steve000]

Hey mate,
Where did you get the motor drive and belt from?

steve

[Tandum]

Bert the Automation nut got them for me :)
I guess better gate and door centers could also supply them.

[Tandum]

Just an update. I've found that everything is settling and the internal dome metal drive ring started rubbing against the lower wooden ring and worse still, against the plate the motor is mounted on.

To fix this I simply put some washers under the L brackets mounting the support wheels. This in turn lifted the drive track in relation to the drive cog and in places stressed the glue enough to force it to come loose.

I simply went around the track and epoxied the track back down where it had come loose. I originally used contact adhesive to secure the track

Right now it is running better than ever, pointing out of the dome is quite accurate across the whole sky, so long as I don't use a SBS setup.

Time to consider a motorized shutter :)