Page 35 of 101
Posted: Fri May 11, 2012 12:23 pm
by Goats spudz
i need the exact thread dimensions as its critical it seals and it will be used at high pressure, i know its a non commercial tap size so ill set the lathe for internal threading,
Posted: Fri May 11, 2012 12:24 pm
by Petitlu
1/2 BSP !
I have already used!
Posted: Fri May 11, 2012 12:52 pm
by jackssmirkingrevenge
Posted: Fri May 11, 2012 5:14 pm
by Gun Freak
First result
But as said above, it fits 1/2" BSP.
Posted: Fri May 11, 2012 5:54 pm
by Goats spudz
Gun Freak wrote:First result
But as said above, it fits 1/2" BSP.
I want the reg output, not the tank
threads which are 5/8" UNF and actually its 3/8" BSP that fits, JSR kindly gave me that link which has a 1/2" NPS tap but i found one at work, and will be machining them soon, i didn't want to use "similar" threads because it will be used at 800-1500 psi.
Posted: Mon May 14, 2012 3:31 pm
by Gun Freak
It's 1/4"-14, make sure your tap matches in TPI.
Posted: Mon May 14, 2012 3:49 pm
by Goats spudz
Im getting a Machinist to make it on the Hurco cnc, will post pictures in this thread tomorrow.
Posted: Wed May 16, 2012 11:48 pm
by MrCrowley
Since my piston hybrid requires a dozen hits from a mini-sledge hammer to seat the piston, I was thinking about buying a small (30mm diameter piston) pneumatic cylinder that will push the piston in to place and then be disconnected when the cannon is fired.
Thoughts?
Posted: Thu May 17, 2012 1:08 am
by Crna Legija
MrCrowley wrote:Since my piston hybrid requires a dozen hits from a mini-sledge hammer to seat the piston, I was thinking about buying a small (30mm diameter piston) pneumatic cylinder that will push the piston in to place and then be disconnected when the cannon is fired.
Thoughts?
why is it so tight? i'm guessing its the only way you could make it air tight.
Posted: Thu May 17, 2012 1:14 am
by MrCrowley
I epoxied the o-rings in to the grooves as I couldn't get washers that were the perfect diameter for the piston housing so it was possible for the o-rings to get ripped out of their grooves. Performance is probably better than before so I don't mind it too much.
Posted: Thu May 17, 2012 3:29 am
by jackssmirkingrevenge
MrCrowley wrote:I epoxied the o-rings in to the grooves as I couldn't get washers that were the perfect diameter for the piston housing so it was possible for the o-rings to get ripped out of their grooves. Performance is probably better than before so I don't mind it too much.
Get someone to machine you a proper piston and get o-rings to fit?
Posted: Thu May 17, 2012 5:09 am
by MrCrowley
The o-rings fit perfectly, the problem is the washer is probably 1.5mm smaller in diameter than it should be so the o-rings only have a small 'wall' on either side to hold them in place.
Been tempted to get one made but don't want to sink the money and effort and trying to explain to some Kiwi bloke why I need this metal stock to be cut in to a piston with two o-ring groves allowing it to seal and slide within this iron pipe with the seam removed.
Posted: Thu May 17, 2012 7:26 am
by DYI
Gee, here I am machining pistons to within 0.001" of the bore diameter to prevent extrusion of the o-rings when I could have just used washers and gratuitous amounts of epoxy...
I have no sympathy for you at all
Posted: Thu May 17, 2012 7:49 am
by mark.f
MrCrowley wrote:Been tempted to get one made but don't want to sink the money and effort and trying to explain to some Kiwi bloke why I need this metal stock to be cut in to a piston with two o-ring groves allowing it to seal and slide within this iron pipe with the seam removed.
Just give him a drawing with "Piston" at the top.
Posted: Thu May 17, 2012 10:26 am
by warhead052
MrCrowley wrote:Been tempted to get one made but don't want to sink the money and effort and trying to explain to some Kiwi bloke why I need this metal stock to be cut in to a piston with two o-ring groves allowing it to seal and slide within this iron pipe with the seam removed.
Easy, just say its for a homemade water hammer, you've been having problems with the hammer effect, and that the others you have looked for online cost too much with shipping. And if that doesn't cut it, well go with Mark's plan.