Easier O-Rings: The hacksaw method

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bugwubber
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Easier O-Rings: The hacksaw method

Post by bugwubber »

Ok first off, I drew my inspiration from both US Water Rockets and Air Command's website tutorials and I've combined them with a smattering of my own desire to avoid difficult steps in construction. Thanks for putting those tutorials out there guys!

This process will create a stepped launch tube with an O-Ring seal.

The parts are the same:
1/2" CPVC pipe
1/2" PVC pipe
1 #94 O-ring
PVC/CPVC cement

Tools needed:
Hacksaw

Now 1/2" CPVC ALMOST fits inside 1/2" PVC. Using previous methods, the piece of PVC I had needed to be bored out slighty to get the CPVC to slide in. That was not exactly easy, especially if you don't have exactly the right size drill bit. Then it hit me, after building 6 launch tubes, how to make this easier.

Here's my hacksaw method to get that CPVC easily installed in PVC:

1. Cut a 3/4" ring off the PVC
2. Cut a 2" slit down the middle of one end of the CPVC.
3. Put a small amount of glue on the CPVC towards the end of the slit
4. Push the 3/4" PVC keeper ring on the CPVC until it covers the end of the slit.
5. Push the O-ring on up to the keeper ring
6. Add small amount of cement to the end of the CPVC
7. Push the PVC pipe on to the CPVC until it presses up against the O-ring.
8. Cut the CPVC and PVC to desired length and install in your launcher.

Thanks,

Bugwubber

Pictures:
parts
parts
launch tube- parts.jpg (120.08 KiB) Viewed 115 times
cpvc ct
cpvc ct
launch tube- cpvc cut.jpg (118.51 KiB) Viewed 115 times
assembly order
assembly order
launch tube- assembly order.jpg (125.3 KiB) Viewed 115 times
keeper ring
keeper ring
launch tube- keeper ring.jpg (119.15 KiB) Viewed 115 times
o-ring
o-ring
launch tube- o-ring.jpg (107.75 KiB) Viewed 115 times
complete
complete
launch tube complete.jpg (103.97 KiB) Viewed 115 times
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U.S. Water Rockets1
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Re: Easier O-Rings: The hacksaw method

Post by U.S. Water Rockets1 »

That's odd.

The Inside Diameter of your 1/2" PVC pipe must be slightly different than ours because we can slide the CPVC inside without boring anything out. Sometimes it is snug, but it does slide over. If you put PVC cement on both surfaces, the glue gets really slippery and they slide easily.

Must be different brands of pipe or something.
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bugwubber
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Re: Easier O-Rings: The hacksaw method

Post by bugwubber »

U.S. Water Rockets1 wrote:That's odd.

The Inside Diameter of your 1/2" PVC pipe must be slightly different than ours because we can slide the CPVC inside without boring anything out. Sometimes it is snug, but it does slide over. If you put PVC cement on both surfaces, the glue gets really slippery and they slide easily.

Must be different brands of pipe or something.
I am sooo jealous of your PVC supply :-)

My PVC inside diameter: 19/32
My CPVC outside diameter: 20/32 (5/8)
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Re: Easier O-Rings: The hacksaw method

Post by peeg2819 »

What is the equivalent AS568A Dash Number for a #94 O-ring. I can't find #94 anywhere
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Re: Easier O-Rings: The hacksaw method

Post by bugwubber »

peeg2819 wrote:What is the equivalent AS568A Dash Number for a #94 O-ring. I can't find #94 anywhere
-208
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Re: Easier O-Rings: The hacksaw method

Post by bugwubber »

Oh and make sure you get the #70 hardness. The #90 will be too hard to get the rocket on.
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