My Field Target Project

[QVTom]

Adding to what Mike said about the need to single point.  The ID of common tubes almost never matches the minor diameter of a standard thread.  It would be nice but life is not that easy.  If you pick a standard thread you will likely have to open up the ID to match the minor diameter of the tread.  Then subtract the depth of the tread from your reduced wall thickness to see what you are left with.  You will probably be shocked how little will be left.  A single point allows you to use the ID of the tube as your minor diameter, leaving the maximum material possible for strength. 

Remember, your tube is only as strong as the weakest section.

Tom

[PatrickB]

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[PatrickB]

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[PatrickB]

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[QVTom]

Probably best not to jack Mike's thread so I'll quickly state my thoughts.  You may want to look in the R&D gate for tube threading specifics, there is a lot there, or start a new one.

1) Using Barlow's formula for pressure vessels, with your tube, I get a SF of only 2.5 @ 3000psi.  Not enough IMO and material fatigue could be an issue.

2) The closest standard internal thread is a  1.313x16.  It has a minor of 1.25 which is good and a thread depth of 0.041 which leaves you a wall thickness of 0.084 which is a SF of 3.4 and is adequate to handle the force of the end plug BUT if the threaded sections sees pressure(o-ring location), this reduces your SF to 1.7 at 3000psi

You need to take a hard look at your pressure requirements and material choices. 

[QVTom]

http://en.wikipedia.org/wiki/Unified_Thread_Standard

[PatrickB]

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[Spike589715]

Hi
I am revisiting my project for an electronically triggered rifle - I am looking to modify an existing gun rather than build from scratch as I really don't have the tools for that
Anyway I would be interested in which solenoid you ended up using ? Just may point me in the right direction

Thanks

Simon

[PatrickB]

Hi
I am revisiting my project for an electronically triggered rifle - I am looking to modify an existing gun rather than build from scratch as I really don't have the tools for that
Anyway I would be interested in which solenoid you ended up using ? Just may point me in the right direction

Thanks

Simon

Simon,
somewhere, on the first or second page you will find a link to the solenoid he used.
Pat

[AZBOBCAT]

I know it's a rather old post but interested in if you are selling parts or guns.

[wayne nicol]

what an awesome build. are you out there Michael,
or does anyone know how to contact him- i too am interested in talking to him about the rifles he might be selling?!
thanks
wayne

[strever]

Gentlemen
his gun has won so many records that he is backlogged almost 6 months
http://www.usairriflebenchrest.com/records/
and very expensive
i have one and it is the most expensive gun i have

here is a pict of Paul Bendix shooting Mikes gun
Paul holds the 750 69X record with this gun :-)

[wayne nicol]

thanks strever- appreciated. would still love to chat to mike- if hes about.
thanks
wayne

[wayne nicol]

is  mike around?