Best online source for hemispheres?

[novahobbies]

I thought there was a sticky for this, but I haven't been able to find it (and my Google-fu is very weak today apparently!) but can someone direct me to a good inexpensive source for some clear 1" diameter plastic hemispheres? Amazon used to be a good source, but the smallest I can now find is 1.5 inches....and the minimum plastruct order I see is $20, which I'd like to avoid if possible. Any help would be appreciated!

[naoto]

Would something like these be what you're interested in?
http://kitkraft.com/1-_Clear_domes/

Hrm... Gotta pop into the store one of these days -- haven't been there in ages.

[novahobbies]

THAT'S the link I was looking for! Thank you sir. Bussards for the Daedalus....check!

[Joseph C. Brown]

I thought there was a sticky for this,

Fixed.

[zaphod]

These look great!
Truncate them a bit and you have an antenna dish that is "parabolic enough".

[abledog]

Would something like these be what you're interested in?
http://kitkraft.com/1-_Clear_domes/

Hrm... Gotta pop into the store one of these days -- haven't been there in ages.

Oh man.. I need to stop by there myself!

Thanks for the reminder !

[jpolacchi]

What if you want to get really big ones?Who makes acrylic domes at a reasonable price that are in the 2-3 ft. diameter range?

[naoto]

Just curious... has anybody considered other materials, like paper, for larger sizes (assuming that you don't need something transparent) ? You could use something like a large balloon or perhaps an exercise ball as a form, then build up a papier-mâché shell over top of it. The minor sticking point would be the commonly-used material like newspaper isn't as common nowadays.
https://www.wikihow.com/Create-Papier-M%C3%A2ch%C3%A9

[jpolacchi]

Balloons aren't "ROUND".That's a problem if you want to make a "DEATH STAR".

[Zubie]

As one approaches the "Yule" I have noticed that different kind of plastic balls become available in craft and dollar stores for making tree decorations or even specialized packaging. While they aren't normally stocked on shelves at other times of the year, you can still find them online if you search for "plastic craft ornament balls", although they are much smaller than the foot+ sized some here are looking for. Maybe in that case one may need to look for large plastic fishbowls or domed cake covers. Can one still find the plastic acorn toy vending machines? (I think the last time I looked stuff just comes in baggies)

[jpolacchi]

I did discover one online manufacturer...it wasn't too expensive.I think the 24" dia. acrylic domes were somewhere between $100-$200?I don't recall exactly.The 36" domes were closer to $300.00.The domes come with a flange that (in some cases) needs to be removed.I think they provide the domes without the flange,but it costs allot more.

[naoto]

Balloons aren't "ROUND".That's a problem if you want to make a "DEATH STAR".

Balloons are indeed round, though not perfectly spherical (on the other hand, if you're trying to build the egg version of the Death Star...). Another idea is to use something like a beach ball (which may be a bit closer to being a sphere than a balloon) as a form.

How 'bout a 75cm exercise ball? (about 29 1/2 inch diameter)
https://www.walmart.com/ip/Gold-s-Gym-7 ... l/51077980

Speaking of Death Star...
https://www.boredpanda.com/the-death-st ... ikea-lamp/

Death Star Beanbag Chair Cover (no longer available)

[naoto]

https://univfoam.com/props/30-inch-large-eps-foam-balls
https://www.ebay.com/itm/LARGE-Polystyr ... 0621701043

[Zubie]

Just curious... has anybody considered other materials, like paper, for larger sizes (assuming that you don't need something transparent) ? You could use something like a large balloon or perhaps an exercise ball as a form, then build up a papier-mâché shell over top of it. The minor sticking point would be the commonly-used material like newspaper isn't as common nowadays.
https://www.wikihow.com/Create-Papier-M%C3%A2ch%C3%A9

At Arisia (one of the local "'Con"s) my kids used this method in an event called "build your own planet" except instead of papier mache they used a combination of tissue paper strips and Modge Podge. Messy, but effective, and in the end surprisingly sturdy given the thinness of the final shell. With a couple of coats it might stand up to the rigors of a more serious structure. Of course, they weren't looking for perfection, just a rough "planet" shape and not particularly smooth finish, but who knows if anyone wants to try something like a Shmoo ship (Life Apr 21,'61 pg 49) maybe.

[Tesral]

I did discover one online manufacturer...it wasn't too expensive.I think the 24" dia. acrylic domes were somewhere between $100-$200?I don't recall exactly.The 36" domes were closer to $300.00.The domes come with a flange that (in some cases) needs to be removed.I think they provide the domes without the flange,but it costs allot more.

Those are good prices. Acrylic is pricy. Very pricy.

Kids bouncy balls? Use them as a form as per the balloon idea.

[jpolacchi]

Give these guys a look: www.eztopsworldwide.com/cameradomes.htm

[naoto]

I did discover one online manufacturer...it wasn't too expensive.I think the 24" dia. acrylic domes were somewhere between $100-$200?I don't recall exactly.The 36" domes were closer to $300.00.The domes come with a flange that (in some cases) needs to be removed.I think they provide the domes without the flange,but it costs allot more.

Those are good prices. Acrylic is pricy. Very pricy.

Kids bouncy balls? Use them as a form as per the balloon idea.

How 'bout exercise balls?
https://www.google.com/search?q=exercis ... 74&bih=608

Hrm... I wonder how many S/F geeks could you get to buy an exercise ball if it was decorated like a Death Star?

speaking of balloons... who knew that weather balloons could be made to be scary?
https://www.youtube.com/watch?v=I6Ffr1U7KMY

just in case you're in the market for weather balloons...
https://www.scientificsales.com/Meteoro ... n-s/25.htm

[zaphod]

I'm sorry to see Kit Kraft closed their doors. I hope they're okay, wherever they are...

[Andrew Gorman]

These are solid, but inexpensive:
https://www.tapplastics.com/product/pla ... ochons/139

[Mr. E Man]

Have you looked at Ebay?

Disregard. I just noticed how old this thread is.


E

[Kylwell]

https://www.amazon.com/AOMGD-Christmas- ... to_dp&th=1

[mike robel]

While an old thread, I am surprise noone mentioned plastruct.com

They have 357 different kinds of domes, some are like skylight, some are flattish and others are 1/2 hemisphere in various sized up to 6 inches or so.

I used them extensively for fuel tank bulkhead and antennae's.

https://plastruct.com/search?page=1&q=Domes

[jpolacchi]

Plastistruct is under new ownership(over a year now to my knowledge) and "ALLOT" of items they had are unavailable.

[naoto]

And if you don't mind doing some cutting, ping-pong balls are around 40mm diameter (about 1.57")
and perhaps another thing that might be worth looking into -- fishing float/bobber/buoy -- I believe there are some that can be snapped apart.

[Andrew Gorman]

A lot of fishing bobbers are styrene. Ping Pong balls are some un-glueable plastic, unfortunately.

[naoto]

A lot of fishing bobbers are styrene. Ping Pong balls are some un-glueable plastic, unfortunately.

from what I'd read, ping pong balls are made of ABS, so you'll need to use something other than the usual model plastic glue (for polystyrene)

[Andrew Gorman]

I tried acrylic cement with methylene chloride on them a long time ago, without success. Materials change- I should try again!

[jpolacchi]

Not to my knowledge. Your "standard" ping pong ball is made of styrene, but you can use MEK to melt both styrene and ABS plastics.

[seam-filler]

Official ping pong balls are made of ABS since 2013 - so MEK would work fine. Cheaper (toy) ones may be made of styrene. Before 2013, they were made of cellulose (which is why acrylic cement with methylene chloride wouldn't have worked back then).

As an aside, the size of ping pong balls was increased from 38mm dia to 40mm in 2000

[Andrew Gorman]

I picked up some ChiCom dollar store ping pong balls today- still unglueable with methylene chloride laced acrylic cement... I'll have to try the official variety.