troubles with sleeving barrel

[wblteen]

I took two pieces of sch 40 scrap 2 inch that I had laying around and quickly sleeved them together to make sure I could do it correctly before I did it for the actual barrel of my gun. I am glad now that I did. the barrel seems to be too small for the golf ball. I can force it through, but i really don't think this would be very practical for a barrel. The fit is way too tight. Do I need to wedge in a spacer in the gap of the inner pipe??

[iPaintball]

Correct me if I'm wrong, but the inner barrel is not 1.5" SDR 21. SDR 21 is a thin walled pipe that fits golf balls perfectly. If this is not SDR 21, buy some from pimpmann.

[willarddaniels]

Correct me if I'm wrong, but the inner barrel is not 1.5" SDR 21

Right. He said it is 2" sch40.
Either use the 1.5" SDR 21 or make the OD of the 2" smaller by way of lathe or lots of sanding.
Of course, the gap you have on your sleave is the unallowed kerf of the saw blade you used. (Kerf is the width - amount of material - lost when using a saw.) If you used a table saw, and you wanted to remove .25", you should cut two passes the same width as the blade, typical .125" instead of drawing two lines .25" apart and cutting on the same side (left or right) of the line. You should draw your lines .25" apart and cut only between the lines. This accounts for the kerf.
After all that, I may have created more questions or problems than there already were...

[wblteen]

From other posts I have read, this is a plausible way to make a golfball barrel. I was just wondering if anyone else has run into this problem. In the second picture it looks as though the golfball would fit just fine on the vertical plane, but not on the horizontal. Does anyone know if this is caused by the gap i left in the inner pipe?? It seemed to me that cutting the strip out a little bigger than it needed to be would help make it easier to insert it into the other pipe.

[willarddaniels]

easier to fit, yes, but it makes an eliptical shap, not a circular, as you have noticed and pointed out. So, yes; this was caused by the gap you left. That gap also allows air to pass by your projectile instaed of pushing it.

[MrCrowley]

Yeah go for the SDR 21 this is really a waste of...

a)air
b)pipe
c)power
d)time

[aturner]

wblteen, I have not had that problem.

I'm sure you've looked at this by now...
http://www.spudfiles.com/forums/viewtopic.php?t=300&

You can see that I also had a gap when I sleeved 2"PVC to make golf ball barrels. It might not show up in the photos, but I think the gap on my barrels was about half as much as the gap on yours. So I recommend trying it again, but remove a thinner strip of PVC from the inner pipe. With such a large gap, your inner barrel might not be able to lay evenly against the outer barrel.

Also, in the photos of your barrel, only one end is shown. What's happening on the other end? If the inner barrel sticks out from the end of the outer barrel, it can tend to pull apart. With your short test barrel, the effects of any distortion at one end of the barrel could have a big impact on the other end of the barrel.

Finally, is it possible you have an odd size GB? Or maybe a GB that is swollen or distorted from sitting in a golf course pond for too long? I dunno. May want to try a couple of different brands of GB's?

Random idea.......lately I've been thinking of filling the gap on my sleeved barrel with hot glue. To do this, I may try to preheat the barrel with a heat gun, then use a heavy duty glue gun with a high rate of flow. The primary benefit would be a tighter seal, meaning less energy would be wasted in blow-by. In addition, I think the hot glue would grip the ball and could serve as a hop up, giving the GB backspin and thus longer flight times. Mine is already a very good barrel, but I think it could be superior with a tighter seal and hop up. If this works, I'll post to the existing how-to topic.

Good luck!

[wblteen]

I will try this again and make the gap smaller. I have tried other golf balls that I have, five gallon bucket full, none that I tried fit. The inner pipe is fully incased in the outer. This time I will try a little bigger piece of pipe as well.

[aturner]

I also wanted to mention that I did the same thing as you, where I first tried to make a short GB barrel in order to test the construction process before bothering with a longer length. From what I can recall, it didn't work out very well. It was harder to work with the short section, and I don't think the finished product was very good. But when I went to 4 foot and 6 foot lengths it just seemed to work out.

Another thing to keep in mind is that a tight fit could improve performance up to a point, and assuming you fill the gap in the inner pipe. If the static friction is high, but the kinetic friction is "reasonable", then it could work very well. Think along the lines of a burst disk....as long as the ammo doesn't jam in the barrel!

[Legendpilot]

I thought I would share my experience again with 2" s40 pvc golf ball barrel sleeving. I used the plans by Foxx and had a devil of a time.

I made my cuts on a table saw which I had to cut and re-cut again until I was happy with the fit. I utilized hose clamps (2) to hold the cut pipe tightly together, then I started beating, and hammering, and pushing, and jumping, trying to defeat the seemingly impossible task. I noticed my hose clamps s-l-o-w-l-y micro metering their way down, I knew then that this was at least working.

I spent the next 40+ minutes working towards my goal and at one point broke about 1/3 of the pipe off. I used this to my advantage when I realized I was just going to have a shorter barrel, and my job was that much closer to being done!

All in all, I'm happy with the final results. The proverbial 'gap' is non-existent for most of the length of the barrel. The gap that was left closest to the breech I used to wedge in a small piece of neoprene to hold the ball when loaded, it doesn't roll out. I also sanded down a few of the broken pieces of pvc and utilized them as a ball stop. At the muzzle end, I notched out a small area and JB welded (best stuff on earth) a small piece of neoprene in for a hop up. The balls fly straighter than ever, and far mind you.

Anyway, here are some pics. The handcrafted orange flames give it an overall kick-ass look when mounted on The Harley.

[schmanman]

maby your golf ball is not quite standard size.
try another brand, and a couple balls.

[aturner]

LegendPilot, that is really nice, with no gap at one end! It's good to see someone else has been successful with this approach.

Sounds like your barrel required more effort than mine. I wonder if the lack of any gap created somewhat of a bind, and made it more difficult to complete the sleeve. This could explain why some of the pipe broke off!

[Legendpilot]

Thanks aturner! My original thoughs while making this barrel were of throwing it into a blast furnace, but patience payed off in the end.

I thinking that it did bind ever so slightly, but it was the sharp blow from the 10lb mull that sent pieces a-flying! -Lp

[DR]

Why even bother with the hassle of cutting a near-perfect slot out of a piece of pipe and then wrestling into another for 45 minutes, when you can just buy a custom-sleeved barrel?






The useable portion of this barrel is only a mere 22-3/4" long, but when attached to a 1" Pneumatic-modified Orbit WaterMaster Valve, it'll launch a golfball over 350 yards.

The tolerance between the golfball and sleeving is so small, that the only gap you see is the recess in the dimples of the golfball!

Also, the inside of the sleeving is extremely smooth, as compared to the wavy-texture of PVC pipe:

[aturner]

DR, your barrels are very nice. Can I purchase one of those fancy barrels at my local hardware store?

No?

Well then, you have the answer to your question.

People sleeve a GB barrel for the same reasons they build their own spudguns instead of ordering them from any number of websites. I think the "fun" is to take basic materials and make something new.