golf ball bb's

[Pointman PUG]

I was just wondering why bb's aren't indented like a golf ball...the aerodynamic properties are proven but is it a case of too much air leakage around the bb or does it create too much "hop up".....I must stop smoking too much!!!

[joec1]

Cost to manufacture would be more. Making it a more expensive sport.

[Zak Da Mack]

Then why isn't there a small market for them? I bet people would buy them. My guess is that the dimples would cause the air to escape and help prevent an airtight seal. This would decrease the FPS and probably make the gun worse.

[Airsoft-Ed]

I've thought about this before, I remember watching an episode of the Gadget Show, or it might've been Mythbusters that explained the improved aerodynamic properties related to the dimples and I immediately wondered why no one had ever made any, 'cos I'm certain they'd prove a massive hit and show a big improvement in range.

 

The reason no one's done it is because it would cost an untold amount of money to research and develop them, how deep do the dimples need to be? If they need to be quite deep then it'll be hard to keep the same number of BB weights available, as well as making them hard to manufacture.

Not to mention they'd be hard to manufacture anyway, cost a bomb as the tolerances would have to be immensely high for it to be worth doing and there's also the fact that the ridges of the dimples might well be prone to chipping off and easily penetrating mesh goggles.

However, if anyone ever did try to produce them, I'd buy them. No doubt.

[Pointman PUG]

Thanks guys!!

[M_P]

This always cones up a couple of times a year, would be nice if possible.

Having previously done a long ass assignment on dimples effect on balls, yes it would be beneficial, but realistically it won't happen for the reasons Ed has stated. They'd have to be minute, and minute would be very expensive. A golf ball's dents are pretty small as it is, and a bb Is just a small fraction of a golf balls size.

 

Ed, pretty sure it was mythbusters, they dimpled a car I believe? (Unless I'm thinking of something else) Had a quick look whilst researching it.

[Ian_Gere]

I don't know that the cost would be prohibitive. Consider this for a mo... if, purely for the sake of argument, it was proven that spheres of exactly 9.63mm flew much further than other spheres, because of some bizarre interaction between sound and air pressure, how expensive would it be to make BB's that size from scratch? Come to think of it, who decided on 6mm, why, and how expensive was it to make the first machine? How about golf balls?

 

All it takes is the R&D to prove that dimpled BB's are sufficiently better than smooth ones to be a probable sales success and investment capital. How would they do it? I suppose that, since good quality BB's are polished to achieve their uniformity, the 'blank' would be injection moulded with dimples and the surface polished to remove any defects, just as now. Does it matter if the interior of the dimples is as highly polished as the outer surface?

 

From Titleist

Since it is the reduction in drag created by a turbulent layer of air sticking to the dimpled surface in flight which is responsible for the effect, it's likely that the interior of the dimples need not be as smooth as the polished surrounding surface. The crucial piece of information we need is whether the effect is scalable and, if so, in what way? Would miniscule dimples, the same relative size to a BB that those on a golf ball are to it, produce a similar percentage drag reduction? If so, I'd bet a bollock that, if any loss of FPS was noticeable at all, it would be more than offset by the better drag coefficient.

I have to say I'm confident that it would work. Maybe the effect will not scale so the drag drops in the same way, but for the sake of retooling an injection mould, even if it only gains us 10m I'd say it was worth it. If it does the same for BB's as it does for golfballs then double the range would revolutionise the sport! What makes me confident is that fighter jets have a surface applied to their bodywork which is like synthetic shark skin and has a microscopic grooved profile - if microscopic grooves are worthwhile, microscopic dimples should too, right?

Personally I don't have a jeweller's loupe or a drill bit tiny enough (which is always going to be the hard part), but if there's anyone here who is, or knows, an engineering student, a university workshop is what we need...

[M_P]

ALso worth mentioning is the fact that we strive to get the highest quality polished rounds available. Which contrasts the fact that before dimples were implemented on golf balls, golfists used to use heavily worn balls covered in dents, scratches and the like.

 

Yes iain on the microscopic groves point , I believe you're correct. Everything I tested pointed to a higher amount of smaller dimples being superior to A lower amount of large ones. Also the 'pattern' in which they are put in will have an effect too.

 

I don't think drilling into a bb will be precise enough and would lead to too many uncertainties. I think that's the issue, yes it is technically possible but having to do it on such a large scale would most likely be too expensive and would prohibit them being sold to most people.

 

I would also like to stress that I certainly do not like golf.

[Ian_Gere]

Mate, I'm not, nor did I, suggest/ing that they be manufactured by drilling into plain polished BB's!

 

I mean that somebody needs to do the R&D - find out by educated guesswork and trial and error what size of dimple, what depth, and what pattern works best/at all. That could be done by CNC from a block of plastic, but I believe it would be easier to work from existing polished BB's - admittedly an extremely tedious process by hand, which is why I also suggested that the best place to do it would be a university workshop - where they would have the kind of precision CNC lathe needed to precisely drill a pattern of tiny dimples onto a BB.

 

Prove the concept with working prototypes and seek investment. Dragon's fcuking Den if necessary...

[Pointman PUG]

Awesome discussion guys.......if only we could try it in a real world application!!!

my personal opinion is that it would work,but yes the correct r and d would have to be done....here's hoping one of the bb manufacturers are trying something new rather than just churning out old ideas!

[Pointman PUG]

Awesome discussion guys.......if only we could try it in a real world application!!!

my personal opinion is that it would work,but yes the correct r and d would have to be done....here's hoping one of the bb manufacturers are trying something new rather than just churning out old ideas!

[Airsoft-Ed]

I've posted on Airsoft International's wall about it, might see if Blaster have a Facebook page and repost it there.

 

The only issue with them that I foresee, is that since the BBs would have an uneven surface as a result of the dimples, on each shot the hop would effect a different sized area of BB, depending on whether it caught a ridge or a dimple, so the hopping of them and as a result, the accuracy, could end up being quite inconsistent.

 

Some new hop designs might be required to make it work effectively. Or the dimples be patterned in such a way that the same amount of BB meets the hop every time, consistently.

[Airsoft-Ed]

AI have replied. Turns out it was done before with 8mm BBs.

 

http://www.facebook.com/airsoftint/posts/10151366380022469?comment_id=26199539&notif_t=feed_comment

[Tariq]

Its all about scale. The smaller something is, the less it is affected by drag.

 

Its also why putting spoilers on small cars is pointless in regards to "getting down force" as the boy racers think.

 

Unless you're doing 70MPH most spoilers are doing sweet FA, and at that speed its very minimal. Should be helping fuel economy during motorway runs but you won't be seeing any real increase in rear grip. Hence F1 commentators keep mentioning Mechanical grip. Even with the cars taking the "slow" corners at 60MPH the cars can't rely on downforce to keep them going round properly.

 

I'll ask if i can get my friend to run some simulations for you lot. He's currently working on a thermo-fluid project involving BB's and barrels atm.

[Pointman PUG]

Ahhh...so size does make difference.

Time to get bigger balls!

seriously though thanks everyone for tickling my curiosity...expand the mind and all that!!!

[Ian_Gere]

I think some of the problem we are having in this discussion is caused by incomplete imagination, so I investigated...

 

 

golf ball diameter 42.672mm / golf ball circumference 134.05792848mm

 

dimple diameter 3.556-4.318mm average = 3.937mm / average dimple depth 0.254mm

 

so approx 34 dimples around a golf ball & 168 through it

 

BB circumference 18.84954mm

 

BB dimple circumference 0.5543982352941176mm / BB dimple depth 0.0357142857142857mm

 

(Obviously this does not include the spaces between dimples, but since there are between 300-500 on a golf ball and they vary so much, it'll do as an average figure to work with.)

 

So we need to imagine what width of hop rubber comes into contact with a BB and how squashy the surface is.

 

Off the top of my head I don't know how much that is, or exactly what it looks like, so I've improvised:

 

Uploaded with ImageShack.us

 

So yeah, if imageshack or whatever problem is currently stopping my graphic from appearing sorts its sh!t out, you'll be able to see that, although I've just guessed at what the rubber might be doing, the size of dimples is about right. I believe that a single dimple of this size on a BB would be imperceptible to the unaided eye and that a miniature golf ball like BB would still work in an unmodified AEG.

 

Doing this has changed my opinion on something however: I think there would be a slight drop in FPS - it's beyond simple enough to follow maths to work out by how much the cross sectional area of a dimpled BB would differ from a smooth one, but what we can see easily is that, considering a dimple depth of 0.025mm, if the entire BB were reduced in diameter by twice that amount , it would equal the difference between a standard 6.08mm barrel and a 6.03mm TBB - noticeable, but not needing a radical redesign of gun, however the actual difference would not be anything like as much.

 

After reading the post you linked, Ed, and the links that sprang from it, I have to say that I'm depressed. Clearly BBBMax 0.27g BB's were considered good enough to be worth manufacturing. Where is the data? That bloke who tried drilling his own - completely missed the scale, but "no consistent data?" What was the fcuking data, consistent or not? So they shattered glass and the first thing people do is whinge about safety? Why not clamour for info on how good the blasted things were in flight and, if they were good, for them to be made from a less hard/more frangible mixture?

 

I still think it's something which needs further investigation...

[Airsoft-Ed]

I agree, I'd like to see it researched further.