Golf Ball Barrel FAQ

[dongfang]

Hi,

Yeah it seems Im lucky with dimensions of things here. But I can never really know the ID of pipes before I have them in my hands; my supplier doesn´t say on his web site, and his stock is a mix of manufacturers and ratings. I´m only happy that sometimes, I can get thick, fat walled nuclear bomb proof PN16 plumbing for the price of PN10.

Regards
Soren

[Gepard]

Soren, check out Pipestock over here in the UK, they list the dimensions on their site.The pipes are the same size regardless of manufacturer (we also call pipes by their OD).

[MrCrowley]

Hi,

Yeah it seems Im lucky with dimensions of things here. But I can never really know the ID of pipes before I have them in my hands; my supplier doesn´t say on his web site, and his stock is a mix of manufacturers and ratings. I´m only happy that sometimes, I can get thick, fat walled nuclear bomb proof PN16 plumbing for the price of PN10.

Regards
Soren

Here PN10-18 is the same price, only PN21 is more expensive.
I'd hardly call it bomb proof I had PN18 blow on me at 110psi

[rna_duelers]

I've had PN12 burst on me at 120psi or so,from PN10-18 the same price...Dang...I'd love that,when the pressure rating goes up here the price does the same.

PN21 hmmm Didn't know they had that in PVC.

[MrCrowley]

Yeah they do, quite rare, I doubt its worth the extra 45psi though.

[Sam@UoN]

Nominal sizes came about to give you different groups of pipe, the actual values are based around the nominal diameter but vary to keep other aspects of the pipe (throughput/strength etc) either constant within the group or nice round numbers...

That said, what they choose to keep constant mainly depends on the preferences of the manufacturers' main customer so is pretty arbitrary!

[Ranger]

Are there any more suppliers of 1 1/2" SDR-21? I'm trying to find some and I'm having a hard time, I looked online and I dont want to pay $30 for 5 ft of pipe if I can get it elsewhere.

[clemsonguy1125]

Are there any more suppliers of 1 1/2" SDR-21? I'm trying to find some and I'm having a hard time, I looked online and I dont want to pay $30 for 5 ft of pipe if I can get it elsewhere.

Just use the yellow pages for your city or surronding cities I found a supplier within 10 miles of my house, ask at local hardware stores even if you know they wont have it, sometimes they will direct you to a supplier

[spudtyrrant]

most suppliers refer to it as class 200 pipe as well, so if you ask for sdr-21 they may not know what you are talking about.

[Ranger]

most suppliers refer to it as class 200 pipe as well, so if you ask for sdr-21 they may not know what you are talking about.

I figured that out, at home depot they dont have SDR-21 but they do have Class 200 pipe. BUT they dont have 1 1/2"

[shardbearer]

This is the cheapest place on the internets for class 200 pipe, $0.81/ft+shipping. Buy the 4' sections, the 5' has like double the shipping cost cause it's oversize. And it's purple/pink!

[Yamroll]

So here's a question, has anyone experimented with a hop-up system for golf balls?

My concern is that, if the ball is spinning in an unpredictable way coming out of the barrel, it'll slice/hook unpredictably...

Any thoughts?

[jackssmirkingrevenge]

My concern is that, if the ball is spinning in an unpredictable way coming out of the barrel, it'll slice/hook unpredictably...

What would cause it to spin unpredictably?

Inducing upward spin through a "hop up" system would add lift and flatten out the trajectory, but would not cancel out any other irregular spin in any direction.

If you really wanted to stabilise it by spinning, you want the axis of spin to be parallel to the direction of travel - ie, rifling

Hop-up is there to compensate for the poor sectional density and velocity of airsoft projectiles.

For the sake of comparison, here's how airsoft BBs compare with golf balls in terms of sectional density:

0.12 gram BB - 0.42 g/cm²
0.25 gram BB - 0.88 g/cm²
45 gram golf ball - 3.10 g/cm²

This means that the golf ball will lose velocity at a much slower rate (as it is designed to do, compared to BBs which are meant for short range and minimal energy) and therefore if fired at the same velocity will have a flatter trajectory and go further than an airsoft BB

Have a look at this post, might be helpful.

[Yamroll]

Well, my concern is that, if as it releases from the cannon, the ball acquires a horizontal spin, it could easily spin off course much the way a slice or a hook occurs in golfing, or even a bend in soccer.

My thinking was simply that, if I knew I was imparting top spin on it, horizontal spin would be minimized (unless it manages to get a dual axis, gyroscopic spin going), so it would at least reduce the balls propensity to curve off to the left or right.

I know a big part of the purpose of hop up is to counteract gravity somewhat, which I don't REALLY care about for golf balls, I know their inertia and CD will really minimize the need for horizontal uplift, but if I was going to impart spin on it (short of rifling, I don't want to mess with trying to rifle SDR21), topspin seemed the logical choice

Or am I overthinking this? I guess when it's going 500 feet per second it wont really have time to trail off too far...

[mark.f]

A hopup has been done for golfballs. However, even in golf, too much backspin will plant the ball much shorter than intended. When driving, too much backspin will lift the ball very high, only to have it come down very short. (My brother watches a lot of Golf channel... what can I say? )

It doesn't have to be too complex. Take a look at the hopup (on clide's golfball cannon):