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Posted: Thu Nov 15, 2012 5:07 pm
by garybdavis
What's WIP? :?

I replaced my welded up pipe with a 4" galvanized nipple, cap and reducer bushing. I get 100' to 125' shots at 200psi with it. That's about the range I need. I got over 20 shots with it at 1800psi in the HPA tank (my scuba tank is getting low...). That's enough efficiency for me. I realize you guys are mostly about how far you can make if fly, but I need to keep it in the stands and not have to fill up after each shot. 8)

I've removed the elbow connecting the tank to the Palmer reg and it's a lot more balanced and still compact. I lubed the o-rings on the slide valve lightly with Magic Lube and that helped (at first I put too much lube and it leaked pretty bad).

If I want to weld up my own pressure tank, I'll rig up my hand hydraulic pump to it and test it up to 500psi. That is below the 1 1/4 pipe rating and well above what I'll be using it for. Unless you guys think otherwise?

Posted: Thu Nov 15, 2012 5:35 pm
by jrrdw
WIP = Work In Progress :wink:

Posted: Tue Nov 27, 2012 4:03 pm
by garybdavis
Update:

1. The slide valve worked very well, but newbies had trouble with it. So, I modified a blow gun for the pilot and added a push button for the pressure chamber fill.

2. Standard plumbing replaced with a custom machined manifold on the pilot side of the QEV. It integrates the blow gun pilot, gauge, fill valve and pistol grip mount into one piece of steel. I turned it down, bored a .335 hole and drilled tapped 1/4 & 1/8 pipe thread holes for the various components. I cut 3/4 pipe threads on one end and machined flat spots on the other end to get a wrench on it.

3. Standard 1" scope rings work pretty good for mounting the Palmer female stabilizer. The ring was welded onto the bottom of my custom made pistol grip. Really, there's no better way to mount the reg as the 1/8 pipe threads aren't substantial enough.

4. Custom pistol grip. Made from 1 1/4 EMT, flattened to an oval in a press and welded to a split 1" pipe half. It's bolted to the custom manifold. A 1/4" 800psi plastic hose from Palmer makes the connection from the reg to the manifold.

5. I added an adjustable pressure relief valve from Palmer to the FS reg. I also added a push button bleed valve to the elbow of the pressure chamber. So, the launcher can be discharged safely if you don't want to fire it.

6. Added a pressure snubber to the pressure gauge to protect it from the sudden pressure drop when fired.

7. Custom pressure chamber. I welded this from 1 1/4" galvanized pipe and a 3/4" nipple. After blending the welds, I hydro tested it with my hydraulic press to 700psi. I even stamped the end cap with the pressure rating and date.

8. I covered the welds up on my barrels with bondo and sanded them down while spinning them on the lathe. Made for a nice look.

Overall the gun is nicely balanced and the ergonomics are comfortable. It is heavy at 11.5 lb (including the 48ci HPA tank which weighs 3lb). Just about anyone can shoot it with minimal instructions. You can fill the pressure chamber at whatever pressure you want for each individual launch which is nice. The reg is set for 250psi so it keeps anyone from filling it to some crazy pressure. At 200psi, I'm shooting 120' with a nice arc. That's probably about right for most t-shirt launching in medium size football fields. Some more testing and then some final paint... And perhaps, a custom foam case layout using my hot wire foam cutting table...we'll see. :)

Posted: Thu Nov 29, 2012 8:48 am
by garybdavis
I did a test last night. Filled the 48ci bottle to 3kpsi and shot t-shirts at 200psi. Average range was just over 100' with a nice, high arc. Care to guess how many shots I got off before the bottle went below 200?


Survey says.........48 I was hoping for 40 so I was pleased.

Time for final breakdown and paint. :D

Posted: Thu Nov 29, 2012 5:28 pm
by jackssmirkingrevenge
Looking fantastic, congratulations on an extremely respectable first build!

In the spirit of spudfiles, might I suggest a smaller calibre and longer barrel so you can do some proper damage ;)

Posted: Fri Nov 30, 2012 11:41 am
by garybdavis
I thought I might build a barrel for golf balls next - just for fun. :D

The 3" barrel will shoot a plastic (vinyl) football (american football that is) 100'. Funny thing is I have to just stuff it in the end of a 14" barrel to get it to really fly. If I place it all the way inside the barrel (next to the QEV), it doesn't fly worth a darn. I made an extra 3" barrel and cut it down to 7" long, but it didn't quite have the same pop as the longer barrel.

With the 2.5" EMT barrel (actually closer to 2.75" as measured), I can shoot a tennis ball straight up in the air and get over 6 seconds of hang time (at 200psi).

I'm looking at some of those foam stress balls to shoot for an upcoming public event. Hopefully, they will be dense enough to fly well and soft enough not to knock anyone out. :) :) I want to fly them way up and still be safe for folks when they come down. We have a sponsor that is going to pay for this ammo and they are cheaper than shirts.

Posted: Tue Jan 15, 2013 3:35 am
by jakethebeast
This build looks very nice! Did you make a golf ball barrel? Eager to know what it did with it if you made it :D

Posted: Tue Jan 15, 2013 9:43 am
by garybdavis
Thanks for the compliment. I haven't built a golf ball barrel yet. Seeing how far the foam stress ball goes, I'm afraid of what I might do with a golf ball!

I did get side tracked doing the custom foam layout for it's case. I built a hot wire foam cutting table for that. Oh, and I did add a needle valve in front of the charging button/valve. I took of the "T" handle and pressed a nut on it to make it more compact overall. It allows me to charge it very slowly so I can pick the exact pressure I want the next shot to be at.

Regarding the stress ball. It's right at 2.75" in diameter which works perfectly in the 2.5" EMT barrel. At 275psi, I can shoot it well over 300 ft and the hang time for a straight up shot is over 7 seconds. I can a similar hang time for a tennis ball at over 6 seconds.

I'm going to shoot the foam stress balls at a July 4th fireworks show to entertain the crowd before it gets dark enough for the fireworks. We have a sponsor who is paying for it by having his company printed on the back side. At $1.26 per ball, it's cheaper than t-shirts and probably safer.

Posted: Tue Jan 15, 2013 9:56 am
by garybdavis
Here is a pic of the hot wire foam cutting table I built to create the foam layout. Every custom cannon deserves it's own custom case!

Posted: Tue Jan 15, 2013 12:28 pm
by jackssmirkingrevenge
Wow, kudos for the professional setup! Also, if you haven't done it already you could probably load more than one stress ball for a wider area coverage :)
I'm afraid of what I might do with a golf ball!
That's not a typical spudfiles attitude :roll: MOAR DAMAGE!!!

Posted: Wed Jan 16, 2013 12:58 am
by c11man
The purple paint really gets me. Amazing work on the launcher, even is designed for non destructive purposes :shock:

and with that carrying case, it has the looks of a commercially available product( I just wouldn't try to go though the airport with it)