Help With Dimensions

[PopRocket123]

I've got a SCAR H project that needs some 3d printed parts but I have no way of measuring them. The first is a replacement gas plug which was missing when I got it and the second is the threads from an M4 lower receiver for a buffer tube adapter if you know the dimensions for Fusion 360 or where to find them that would be a big help thanks. 

[Adolf Hamster]

that gas plug looks very similar in profile to the one on the f2000, but then i'm not sure if it's just the same proportions scaled up.

[qyuubi786]

I'd get myself some callipers if I was you. Comes in very handy for all kinds of things. 

[Ropeyshep]

Just now, qyuubi786 said:

I'd get myself some callipers if I was you. Comes in very handy for all kinds of things. 

And a thread pitch gauge. They are cheap and amazingly handy. 

[PopRocket123]

16 minutes ago, qyuubi786 said:

I'd get myself some callipers if I was you. Comes in very handy for all kinds of things. 

Already got a very nice set. I just can't get in to measure the threads an I don't have the part to measure for the gas plug

[Adolf Hamster]

1 minute ago, PopRocket123 said:

Already got a very nice set. I just can't get in to measure the threads an I don't have the part to measure for the gas plug

 

i'll measure up the one on the f2000 for you tomorrow, hopefully you can measure it's socket see if it's the right size.

[PopRocket123]

9 minutes ago, Adolf Hamster said:

 

i'll measure up the one on the f2000 for you tomorrow, hopefully you can measure it's socket see if it's the right size.

Great thanks. If I need to I can just scale it up

30 minutes ago, Ropeyshep said:

And a thread pitch gauge. They are cheap and amazingly handy. 

Will that work with buffer tube threads? They're very deep and different to standard sizes of threads

[Ropeyshep]

1 hour ago, PopRocket123 said:

Great thanks. If I need to I can just scale it up

Will that work with buffer tube threads? They're very deep and different to standard sizes of threads

How are they different? Pitch gauges give you number of teeth per mm and various Whitworth, AF and suchlike old timey pitches. Threads are threads, nothing uses a completely unique version of them. 
 

These threads (🧐 sorry ) seem to suggest a 1 3/16” 16tpi threadform for that stock tube  thread on an AR15 which would seem to be the same fitting as a SCAR. 

 

http://chaski.org/homemachinist/viewtopic.php?t=76344

 

https://www.ar15.com/forums/ar-15/What_is_the_thread_pitch_on_a_buffer_tube_/118-263144/

 

Pick up a dirt cheap TPI and metric versions for your future use:

 

https://www.amazon.co.uk/sourcing-map-Thread-Cutting-Measuring/dp/B07TXZTC6B/

 

https://www.amazon.co.uk/gp/aw/d/B07PDG5ZML

[PopRocket123]

7 hours ago, Ropeyshep said:

How are they different? Pitch gauges give you number of teeth per mm and various Whitworth, AF and suchlike old timey pitches. Threads are threads, nothing uses a completely unique version of them. 
 

These threads (🧐 sorry ) seem to suggest a 1 3/16” 16tpi threadform for that stock tube  thread on an AR15 which would seem to be the same fitting as a SCAR. 

 

http://chaski.org/homemachinist/viewtopic.php?t=76344

 

https://www.ar15.com/forums/ar-15/What_is_the_thread_pitch_on_a_buffer_tube_/118-263144/

 

Pick up a dirt cheap TPI and metric versions for your future use:

 

https://www.amazon.co.uk/sourcing-map-Thread-Cutting-Measuring/dp/B07TXZTC6B/

 

https://www.amazon.co.uk/gp/aw/d/B07PDG5ZML

Ok thanks. They just looked deeper than normal

[Adolf Hamster]

ok so i had a look at the f2000 gas plug.

 

the dimensions to check for the hole are 10.5mm diameter by 12mm deep:

 

solid edge has a nasty habit of exporting .stl files with the units in inches, so some re-scaling may be necessary.F2000 gas plug.stl

 

F2000_gas_plug.stl

[PopRocket123]

That's perfect thanks. I'll let you know how I get on with that this evening. This'll really complete the front end

[PopRocket123]

8 hours ago, Adolf Hamster said:

ok so i had a look at the f2000 gas plug.

 

the dimensions to check for the hole are 10.5mm diameter by 12mm deep:

 

solid edge has a nasty habit of exporting .stl files with the units in inches, so some re-scaling may be necessary.F2000 gas plug.stl

 

F2000_gas_plug.stl 3.97 MB · 0 downloads

Just checked this out and it's a perfect size. I guess FN reuse parts between guns

[Adolf Hamster]

27 minutes ago, PopRocket123 said:

Just checked this out and it's a perfect size. I guess FN reuse parts between guns

 

guess it would make sense given it's just a gas plug.

 

that stl file work ok?

[PopRocket123]

36 minutes ago, Adolf Hamster said:

 

guess it would make sense given it's just a gas plug.

 

that stl file work ok?

Yep loaded no problem. I've send it off to get printed out with the rail extension

[Wo1f]

I was just about to break out the scar’s gas plug to measure! Saved me a job 😂