Fire extinguisher as a buffer

[Gabe01]

Do they have a unique thread or is it bsp?

[blazerbotics]

I think the thread on the bottle is M25

[Mouldy]

M25 X 1.5 if I remember correctly for the 2kg bottles.... I had a blanking plug that size and drilled n taped the end of it to 1/2" bsp. Was nice to finally meet you at the weekend btw gabe.

[Gabe01]

Thanks for that just trying to find an adapter from the extinguisher to a QEV. Great to meet you to Bud, I feel inspired to finish off my robot, finally!

[maddox10]

Big fire extinguishers have a M25*2 thread, or a tapered thread around 4/3 BSPT or NPT.

But I suspect, in the vein of the weightklass, Gabe01 means a 1 kg powder extinguisher from a car or so.
Those use a manufactorer own thread, something like a 1" 28 tpi

Those are big and heavy for the job of a low pressure buffer in a feather. You're better of with a 12 oz painball bottle then. Smaller (but big enough for most rams in use), and lighter than a cheap powder extinguisher from a car.

[Max]

What size bottle is it? Different bottles have different threads, its usually stamped on the side of the bottle.