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My mini 1.73in 'Golf Ball' launcher

Posted: Thu Dec 31, 2009 7:43 am
by Joshatdot
I was talking to a co-worker of mine about my spud canon, talking about this site & what all canons have been made. He asked me if anyone designed one for launching Golf Balls, I said "Yep! there's this really awesome chrome or stainless steel one I've seen at spudfiles.com" Sorry I don't remember who made it.

Anywho, he asked me if it were possible to make one. I told him that 1.5in SCH40 PVC is atad small for a golf ball, but a 40mm ping-pong ball fits just right. He said what's the point of launching a ping-pong ball! But then I remembered that we have thinwall PVC (160PSI rating) and it has a slightly larger inner diameter. Sure enuff a golf ball fits in it (a tiny bit loose though, about 1mm, so use some wading)

Anywho again...here is my mini Golf Ball Launcher:

- 3x3x1.5in Sanitary 'T'
- 3in clean-out adapter
- 3in plug
- 3in to 1.5in reducer bushing
- 1.5in female thread adapter
- 1.5in terminal adapter (the gray one, it's electrical PVC, it has a deeper female smooth area for better glue hold on barrel)
- 1.5x21.75in thinwall PVC pipe (160psi rating)
- 1.5 pipe about 1.5in long to connect the 'T' to a male thread adapter
- 1.5in threaded cap w/BBQ ignitor
- Gorilla Duct Tape to cover the 'T' hole

Chamber is about 6.5~7.25in deep, depending on if you measure from the 3" plugs square hole or not. So I averaged it to be 7in long. Using burnt latke calcs, I guessed it's about 834 ml in volume, so I would need a 21.75in length of 1.5in 'thinwall' pipe, for a 1:1 ratio.

I use the Weber Ignitors, drill a 19/32 hole in a PVC threaded cap and glue it in place with PVC glue and some hot glue for extra help.

I then drill (7/64in) & tap (#6-32) two holes in my chamber, and find correct length of #6-32 stainless steel screws for the gap. Use a #6-32 locking washer & wing nut to secure the BBQ wires to the screws inside the chamber. I finish it up with screw covers.

Posted: Thu Dec 31, 2009 11:04 am
by qwerty
Looks nice! yoo could make the spark gap a little wider though.
there's this really awesome chrome or stainless steel one I've seen at spudfiles.com" Sorry I don't remember who made it.
Is this it?
http://www.spudfiles.com/forums/cannon- ... 19146.html

Posted: Thu Dec 31, 2009 9:05 pm
by Joshatdot
Yeah that's it!

spark gap wider eh? it's prolly now about, 3~4mm wide

Posted: Mon Jan 04, 2010 11:58 pm
by Joshatdot
Had some ignition issues, so I put some PTFE tape on the very top of the screws where they are in contact with the PVC, and widened the gap about 1mm on each side. So far the dry firing is working 100%.

edit: the extra PTFE tape didn't fix my issues. I seem to be getting sparks up behind the Gorilla Tape.

Posted: Tue Jan 05, 2010 2:40 am
by starman
qwerty wrote:Looks nice! yoo could make the spark gap a little wider though.
Why??????? You never need wider spark gaps...never....especially if you are building a multi gap ignition. The more gaps you have the narrower they need to be.

Posted: Wed Jan 06, 2010 12:17 am
by Joshatdot
I widened the gap just slightly, about 4~5mm gap now. I think I've solved my spark issues.

I got some fiber washers on the inside of the chamber, then the ring terminal, then lock washer & wing nut. Before the ring terminal was in contact with the chamber wall.

I've done 40+ dry fires, and they all sparked between the screws.


I am going to look around to find some 1.5" SDR 21 pipe for a tad better fit for a golf ball, and lengthen it to 0.7:1 ratio, about 32in in length. If I cannot find SDR21, I have 7ft of SDR26 leftover from this build, in which a 0.7:1 would be 30.75in in length.