Soda Bottle to 1/2 UNF adapter STL file for 3d printing

[OldSpook]

Mentioned in another thread someone was using soda bottles with a machined adapter to act as a moderator on his air rifle. That's great but overkill for a project like that one. Here is the STL file I made this afternoon which will print a standard soda bottle cap to 1/2 UNF adapter. You'll need a 1/2 UNF TAP to finish cutting the threads on this thing. I deliberately print those a few thousandths too small and then run a tap through to clean them up. Any good hardware store will have a 1/2 x 20 UNF tap. I've already printed one and it came out just fine. I use PETG but I'd think PLA would work as well. PM me for any questions or ask here.

Here is an image from OpenSCAD and the STL (zipped) file.

View attachment adapter.zip
^^^ The zip file ^^^

 

[OldSpook]

Works surprisingly well with a half liter coke bottle.
This is my "Talondor" .22 cal at about 60 foot pounds.

 

[Daygo619]

Can’t PM just yet but interested in one of your .30 cal moderators.

 

[Lobi]

Mentioned in another thread someone was using soda bottles with a machined adapter to act as a moderator on his air rifle. That's great but overkill for a project like that one. Here is the STL file I made this afternoon which will print a standard soda bottle cap to 1/2 UNF adapter. You'll need a 1/2 UNF TAP to finish cutting the threads on this thing. I deliberately print those a few thousandths too small and then run a tap through to clean them up. Any good hardware store will have a 1/2 x 20 UNF tap. I've already printed one and it came out just fine. I use PETG but I'd think PLA would work as well. PM me for any questions or ask here.

Here is an image from OpenSCAD and the STL (zipped) file.

View attachment 330944

View attachment 330946
^^^ The zip file ^^^

View attachment 331275

OldSpook,
How hard is it to write the code?
I want to try this with a Umarex Hammer. I believe it's M18x1 threads on the bbl (source: Umarex Hammer moderator adaptor). Get code or print and sell me one (is that even legal here?). Sure would like to zero in my scope at home rather than at the range.

 

[MikeVV]

Ha...just finished off a 2 liter (same size cap) Pepsi. Will a Pepsi bottle work instead of Coke ?
Maybe I should wash it, and buy one of OldSpooks adapters.

OldSpook - How much do you get for a copy ?

MIke

 

[OldSpook]

OldSpook,
How hard is it to write the code?
I want to try this with a Umarex Hammer. I believe it's M18x1 threads on the bbl (source: Umarex Hammer moderator adaptor). Get code or print and sell me one (is that even legal here?). Sure would like to zero in my scope at home rather than at the range.

I just drew one up for a M18x1 thread but I think that might not work on a standard bottle cap because the M18 thread is so large in diameter. There may not be enough clearance. Put a bottle cap on the threads and give me an idea how much clearance you have between the threads and the cap. I'll spend a little time thinking about it today or tomorrow. There are bottles with larger mouths though, like some of the green tea bottles.

Ha...just finished off a 2 liter (same size cap) Pepsi. Will a Pepsi bottle work instead of Coke ?
Maybe I should wash it, and buy one of OldSpooks adapters.

OldSpook - How much do you get for a copy ?

MIke

I'm not selling them. YET. But you can take that file and have it printed on line at a number of different places, or maybe you have a friend who can print it for you? I need to spend a bit of time thinking about that before I make a decision on it. I am sorry.

 

[badger5th]

That is cool Does it work better if you put a small amount of water in first and carefully level it to shoot? If the air discharge energy disrupts the water rather than slapping the side of the bottle it seems it would dissipate energy more effectively.

 

[OldSpook]

That is cool Does it work better if you put a small amount of water in first and carefully level it to shoot? If the air discharge energy disrupts the water rather than slapping the side of the bottle it seems it would dissipate energy more effectively.

It works pretty well actually. I was surprised. I've been kicking ideas around about what you could do to make it work better. The best one I've had so far is to spray some of that foam insulation inside the bottle and let it harden up. You wouldn't want to fill the bottle with it, just coat the inside.

 

[iAMzehTOASTY1]

That's awesome!

 

[OldSpook]

Made a new file for an Arizona green tea bottle. I just like the bottle better. Also it's a larger cap.l'll attach that file to this thread later on this evening when I go in the house. The first shot went wild and then the next three printed right where the rifle is zeroed in a group about the size of my little fingernail.