Dome from twin wall polycarb
After watching this site grow over the years and making many models I have finally made a grown up one.
Its 4m in dia and constructed from standard 10mm twin wall polycarb thats been glued together.
Thanks for a great site as its enthused me into making rather than just being a watcher.
[ Comments 10 ]
I would like to make dome for an astronomical observatory. The dome have to able to rotate 360 degre and have a slit for observing to the sky. I will use aluminium Carbonate for the dome. Any one can help me for design?
can you upload some photos of how you attached the polycarb?
I did not attach it to anything. Its a stressed skin design. The edges are held in place with H section plastic extrusions. A polymer adhesive is used to hold each edge in place. Its been running a few months now and seems to work well. In places I did not seal the cavity adequately so have some condensation. Otherwise all is good, its really solid for 10mm thick material.
This may help
This was the top section which slotted straight on top.
To my knowledge this method has not been done before and it was not until the day of erection that I knew it would work. I had built many prototypes and spent two winters and summers testing the adhesives. You can see that the segments are held in place with spacers and its all a bit wobbly until the last bit gets put in - then it suddenly locks up solid.
I was on holiday when the big winds came last week. Happy to say that the tree went the right way. Happy that the dome is still here.
question could you make slots inside the triangle pieces then use some sealant on both sides
That looks really good. Luck was on your side with that tree! How is the dome holding up now we're into winter? May I ask what glue you decided was best for outside as I've a polycarbonate Florabest coldframe that needs a bit of glue where the original has perished.
The neighbours shed was trashed in the 60 mph winds we had. The dome stood strong. The adhesive used was Stixall from Tool Station. I have tried many adhesives in prototypes and StixAll has proven to be the best. Silicone did not hold well to thye Polycarb. I cleaned with a Acetone based cleaner - this also etched the surface in prep.