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  #41  
Old 15-05-2022, 04:43 PM
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Bassnut (Fred)
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this might be a bit boring, unless your into DIY domes I guess .
A bit of a milestone today, finally got the slot door and its wheels sorted, along with making it rainproof, its been a bit of a challenge.

Turns out bending PVC angle with a heat gun is easier than al, it turns to putty, difficult to handle melted, but you can do anything with it.

So I used angle al for strength (wheel guides)and angle PVC to rainproof. Including U section (Yeah, bending U section, who would've thunk that was a thing )
The pic is pretty rough, but will all will pan out in post. Ill use Topaz magic

I lost 2 days of stuffing around with adhesives thinking that would look cleaner than screws and pop rivets. What a disaster, slippery, al moved all over the place and what a mess, my hands will be black for weeks. Liters of turps to remove and back to trusty screws and pop rivets.

Round everything continues to be a painful headspin in every way possible (All structural materials are supplied flat, nothing is usable out of the shop).
But I must say, im OK with it, occupies the grey matter
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Last edited by Bassnut; 15-05-2022 at 05:12 PM.
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  #42  
Old 16-05-2022, 11:07 AM
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strongmanmike (Michael)
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Looks professional in that close up, nice

Mike
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  #43  
Old 16-05-2022, 11:23 AM
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sheeny (Al)
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Well done Fred.


As an engineer I appreciate the challenges of your design, and I'm following with interest. Nice job on the bending.


Al.
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  #44  
Old 16-05-2022, 04:47 PM
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Bassnut (Fred)
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Quote:
Originally Posted by strongmanmike View Post
Looks professional in that close up, nice

Mike
Thanks Mike .Professional . I wont show a pic of the outside yet, its too embarrising, much adjusting was done, so many extra holes .

Quote:
Originally Posted by sheeny View Post
Well done Fred.


As an engineer I appreciate the challenges of your design, and I'm following with interest. Nice job on the bending.


Al.
Thanks Al. As an engineer, you must groan at what hackers like me do . Everything is from bunnings and hand tools, its sooo time-consuming. I bet theres a 1000 better ways to do this but I DONT CARE. Im dodgy and proud

Today, guide rollers.
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  #45  
Old 18-05-2022, 06:28 PM
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Today, drive for the slot door.
Rack and pinion is easy for a ROR, straight rack cut to length and a gear to match.
Curved rack for a dome is a bit of a problem, Id hate to think what a custom diameter curved rack would cost. I see flexible rack for sale but for huge money, and it seems to me the spec would change the more it was curved.
Anyways, i thought id post this update as its as it solved a problem unique to domes. And I havent seen this solution on the net.
ABS 3d printing is not suited to small engineering mechanical parts, so I made the rack and gear big and chunky. The gear goes onto a 6mm gearbox shaft with a flat. That would last 5 seconds before stripping the ABS and spinning. So I alradited a metal knob with a grub screw in it into the gear, so strong.
Ill use the same rack but a different diameter for the dome drive. The rack was printed in sections (size the printer can take)that can be easily be bolted together. Those segments BTW can be printed by many 3D shops in OZ in 5 days for about $10ea. I will use about $50 in ABS stock on rack and pinions for the whole project. The $20 motor/gearbox from ebay in the pic also has an encoder attached, so if something goes wrong whilst opening /closing the controller will know immediately and alarm.
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  #46  
Old 18-05-2022, 10:51 PM
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Joshua Bunn (Joshua)
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This is very cool, Fred. wonderful ingenuity and it looks great.
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  #47  
Old 03-06-2022, 05:23 PM
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Thanks Joshua .
Small update.
I taped the segment joints up with Byute Flash. Got a bit worried with the wrinkly look, but with 2 coats of flat primer it's looking ok, ill use many flat white metal paint top coats. Flat paint hides imperfections.
The inside is painted with flat black Dulux Metal shield epoxy enamel. This is SERIOUS paint. The pic shows just one coat of this flat black enamel over white primer. Never before have i seen such coverage of black top coat over white!. One coat to my surprise will do!.
Ive always liked Dulux for pigment density, but this is nuts. It was very thick, possibly due to the temp being 10 deg and twice as much paint used over coverage stated on the can. Lesson learned, paint metal when its cold, half the work!.
The 3D printed rack fitted to the slot door worked a treat on test .
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  #48  
Old 04-06-2022, 06:34 AM
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Wow looking good Fred, you're having fun, huh?

Mike
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  #49  
Old 04-06-2022, 08:23 AM
LonelySpoon (Neville)
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That sealant is a good way to go, Fred.

It's all coming along nicely.

N
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  #50  
Old 04-06-2022, 09:00 AM
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Thanks Mike and Neville.
More challenging than fun id say .
Yes, the flashing appears to be a good guess, I couldn't think of any other way that wouldn't look worse, given my skill set .
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  #51  
Old 04-07-2022, 05:28 PM
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Progress. Dome base built using mini ripple gal. Very light, flexible and stiff once screwed on. The rail for the dome concave rollers was easier than expected to fit. Rather than bent angle, flat 3mm al bar was much easier to bend
and fit with angle brackets, stiff as. Its true within a 1mm or so.
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  #52  
Old 04-07-2022, 08:48 PM
Startrek (Martin)
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Fred,
Brilliant design and clever use of ripple gal , really strong and easy to wrap and screw
Looks great !!
My only observation , being an Obs I’d be using stainless 302 or 316 fasteners and alum small angles etc… like I used in my NexDome. Plated and even gal screws and small brackets rust out after a couple of years , even quicker when your Obs is 200m from the beach like mine is. Salt air is a killer on cheap plated and gal fasteners etc… from China.

Cheers
Martin
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  #53  
Old 05-07-2022, 09:37 AM
LonelySpoon (Neville)
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Nice base, Fred!
Two observations:
1. Instead of brackets and the associated electrical differential causing breakdown /rust, I routed a groove in the base and dropped the ring into that.

2. A year later i ripped that out and replaced it with a hoop of rolled tube, with skateboard bearings. Almost no friction, can turn it with one hand.

Getting tube rolled for my 3m diameter dome cost only $158.

Neville
LSO
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  #54  
Old 05-07-2022, 11:33 AM
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Thanks Martin and Neville

I hadn't thought of the corrosion or rust damn it, although im aware of electrical differential causing breakdown. It was hovering in the back of my mind for a little while but I barged on regardless.

Im not doing this all again, but i will bury everything in metal paint now. This should last until i leave this mortal coil.

I had thought of rolled tube, done by a local shop, but it sounded expensive, i didnt realise it would be that cheap!. I dont have a router or be able to make a slot accurate enough for the ring either.
Ive tested a concave roller on this rail, very smooth and friction free, better than i thought, so I bought a bunch, adjustable.
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  #55  
Old 05-07-2022, 05:14 PM
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Put the dome on the base for the 1st time today (no wheels yet, or rain cover between the dome and base). Its looking a bit janky still, no top coat paint yet. Suddenly realised access might be a pain with the base door, so ill fit a hatch to the other side of the slot (not shown) to allow just stepping in
To give scale, its 1900mm high
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Last edited by Bassnut; 05-07-2022 at 05:27 PM.
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  #56  
Old 05-07-2022, 09:50 PM
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That is brilliant Fred great effort.
Alex
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  #57  
Old 10-07-2022, 12:12 PM
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marc4darkskies (Marcus)
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Looking good Fred!!

Use a hose to simulate a rain storm to make sure you haven't overlooked any sneaky water ingress points!
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  #58  
Old 10-07-2022, 03:43 PM
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Thanks Alex and Marcus.
Absolutely ill be rain testing, was always the plan. Why would you mention this?, no faith?, doubting my vast building skills?

Today I fitted the adjustable wheels (for sliding doors, from bunnings). Was totally surprised how well that went, the dome rolls very smoothly with a finger push.

The quick-release hatch allows very easy step-in access. I was concerned given the small size of the dome that access/standing inside would be a problem. its not.
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  #59  
Old 10-07-2022, 05:31 PM
hrcoleman66 (Hugh)
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Wow, That's progress!

Looks like the conversations standing around at ASOG have born fruit.

BTW, we missed you last week. I was all ready to offer you a seat as soon as you walked through the door.

Seriously though, Careful of those rollers. Exposed to UV, they get brittle and crack.

Cheers,

Hugh
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  #60  
Old 11-07-2022, 03:41 PM
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Bassnut (Fred)
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Thanks Hugh, yes progress.
A rain skirt will go round the dome base. The wheels won't be exposed.
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