Piston Block Broke My Pipe!

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.

Have you ever fixed yours with a coupler?

yes
1
100%
no
0
No votes
 
Total votes: 1
User avatar
jrrdw
Moderator
Moderator
United States of America
Posts: 6572
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Has thanked: 39 times
Been thanked: 22 times
Contact:

Donating Members

Fri Oct 20, 2006 4:59 pm

Just like it says. I have 3, 1 1/2" X 10/32 screws holding my piston stop, (made of wood), my piston, (also wood) has hit it hard enough to hammer it back breaking the pipe it's screwed to, (5 shots). The pipe cracked long ways. I think i all ready came up with a quick fix, (long lasting i hope). I'm going to cut the pipe in half at the screws and glue it back together with a coupler, then rescrew the stop block in place.
User avatar
joannaardway
Corporal 5
Corporal 5
Posts: 949
Joined: Mon Oct 09, 2006 4:57 pm
Location: SW Hertfordshire, England, UK.

Sat Oct 21, 2006 1:20 pm

I've never had this problem. A spring or rubber bumper in the system saves situations like this.
User avatar
SpudStuff
Sergeant 5
Sergeant 5
Posts: 1410
Joined: Sat Dec 10, 2005 3:55 pm
Location: Cupertino, California
Contact:

Sat Oct 21, 2006 2:50 pm

I have heard of people breaking cleanouts. You should order a SCH 80 plug from McMaster.com that should solve your problem. I also fould that small 1/4" long pieces of air hose work great as a bumper.
User avatar
Velocity
Sergeant
Sergeant
Posts: 1039
Joined: Tue Feb 07, 2006 5:42 pm

Sat Oct 21, 2006 3:36 pm

You said you used three screws? That is definitely not enough. Look at the supah valve, considered by many to be one of the best valves out there. The piston stop has 27 screws on it.

The more screws you have, the less chance it has of breaking, for the force is being distributed more evenly.

I'd use 10+ at least
User avatar
POS
Specialist 3
Specialist 3
Posts: 395
Joined: Thu Sep 14, 2006 4:19 pm

Sat Oct 21, 2006 4:13 pm

I had the same problem, but I calculated a safty in the gun. The block was not the end of the pipe. The pipe was made a bit longer, the block is zitting in the middel. I filled the pipe up with a metal thin pipe (5 mm) tapen al around so it fits in the bigger pipe, due to reduce the pilot volume.

I used a spring as a block, the spring was smashed into the copper block, and I mean IN, not inside. The block got destroyed, the spring also, and the piston dammaged. At 130 psi.
User avatar
jrrdw
Moderator
Moderator
United States of America
Posts: 6572
Joined: Wed Nov 16, 2005 5:11 pm
Location: Maryland
Has thanked: 39 times
Been thanked: 22 times
Contact:

Donating Members

Sat Oct 21, 2006 5:39 pm

The strongest shot was about 40psi according to the gauge, i cut it in half this morning, and fished out all of the busted piston block pieces. After pondering the damage i relized that the block didn't fit snuggly inside the pipe. Allowing it to get hammered sideways and that is how the pipe got cracked. I allready had a spring in it, but it's not very strong. Now that i can access the back of the piston, i'm gonna get a longer stronger spring for the piston. It's a world of difference when venting the pilot chamber with the modded sprinkler valve! As for the screws, i did away with them by glueing in some left over pvc pipe for a piston block, i didn't think about useing a rubber bumper along with the stop. I wish i would have! You see, i didn't do my homework and now i pay the price!!

Let this be a lesson to all the noobs, do your homework!

broke piston stop

patched with coupler
Post Reply