Modeling Tank/ASA Threads?

[goofyman23]

I'm pretty damn new to Fusion 360 and am trying to create a thread protector for my tank. I thought the threads were 1/2' NPT-14 but no dice (those are also tapered?). I've seen NGO tossed around, but I dont think that's a recognized/actual thread.

Any insights welcome on how I can get these done in F360 would be mucho appreciated!

[DocsMachine]

It's nominally 1/2" NPS, or National Pipe Straight. Try that if it's an option.

Doc.

[Jackson]

Astm f 1750

[goofyman23]

Slick! I'll see if I create a custom thread XML file now

[Spider!]

Astm f 1750

Nice reference. The CGA320 spec reference there is for the threads.

There are a few bottle protectors on thingiverse, but they are fun to make on your own.

My threads kept coming out "grabby". I eventually used a set of spaced nubs that seems to work well. I like tapered pipe threads on prints otherwise. Hard to screw those up.

[goofyman23]

Nice reference. The CGA320 spec reference there is for the threads.

There are a few bottle protectors on thingiverse, but they are fun to make on your own.

My threads kept coming out "grabby". I eventually used a set of spaced nubs that seems to work well. I like tapered pipe threads on prints otherwise. Hard to screw those up.

Yea, I thought about remixing someone else's, but assumed (lol) this would be a item to try and model for my first Fusion 360 go.

[Spider!]

It's nominally 1/2" NPS, or National Pipe Straight. Try that if it's an option.

Doc.

I do believe that was the start of the standards trail. I used to know the story, maybe from haveblue's old site?

The nps spec had some different fit tolerances for different uses. The cga spec is tighter and designated for co2 use. It's not much more than threads. Then you have the actual pin valve ANSI spec.

No one should feel bad that their printed threads don't match a bottle top. For many years and off and on later, manufacturers couldn't get things consistent in brass and aluminum.

[DocsMachine]

Well, as I recall, Tippmann basically invented it, but outside of them, it was basically "just make it fit", until a proper standard was formed and adopted.

'Cocker threads were the same way, as Simon from Inception found out. I did kind of the same thing back when I was developing my Automag barrel adapter- I measured every 'Cocker barrel I had, and found a surprisingly wide range.

And I'm not talking homebrew stuff- some of the old DAC barrels had comparatively huge threads, I ran across more than a few guns they simply wouldn't fit into. I had an early LAPCO aluminum that was sloppy loose- if you didn't have an O-ring on the base of the threads, it'd rattle loose after just a couple shots.

If you're just making a thread cap, don't even worry about the O-ring sealing surface, just make a short section of 1/2"-14 NPS thread.

Doc.