DIY golfball dimples?

[AlpineAce]

Hi guys, first time posting, hope this is the appropriate section.
So Im working on a project and plan on adding the golfball dimples.
Im trying to find a simple way to add these to a slightly compound curved surface. I figured approx 600, 4mm dimples.

thanks!

I'm working on it!

 

[KirbyWan]

4mm punch with the end rounded and a hammer? What are you putting these dimples in? What material?

Kirby Wilkerson

Remember, first define the problem, then solve it.

 

[AlpineAce]

good point, actually I could add the dimples at a couple different stages.
I will first make the basic shape of the part, and the take a mold of it But im not sure If I would add the dimples now or wait till I get the negative of it.
The base shape/mock up will probably be wood/bondo, possibly covered with fiber glass. (alternatively I might just use this automotive modeling clay)

But its not so much how to put a single dimple in, but how do I make 600 of them look uniform, both in spacing and in depth.

But I will probably use a larger then 4mm tool/ball, since Im not going for a full radius depth.

I'm working on it!

 

[KirbyWan]

Hmmm. I see where you're going with this. O.K. if size permits with a clay model, put it in a box and fill said box with spherical ball bearings of a diameter that would leave a reasonable sized indentation, say 8mm. Put a lid on the box and vibrate it so the balls become as closely packed as possible then increase the pressure perhaps by adding more balls. It might take some trial runs to figure out the right size ball, right amount of pressure, right amount of moisture remaining in the clay etc. to get the result you're looking for.

No guarantee this will work, I'm just spit balling.

-Kirby

Kirby Wilkerson

Remember, first define the problem, then solve it.

 

[GregLocock]

I'd get a bag of split peas and stick them to the female mould.



Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[berkshire]

I do not know how much time you want to spend on this. You could grind an aircraft countersink to a halfround shape,then reinstall it into a micro countersink holder, this would give you a uniform dimple. Then all you would have to worry about was the spacing.
B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor

 

[kontiki99]

CNC a set of dies and use the dies to stamp the material your going to using for skin?

In theory, there is no difference between theory and practice; experience suggests that in practice, there is.

 

[verymadmac]

You could use dimple tape

http://www.theaerodyne.com/index.php?main_page=index&cPath=93_160&language=en

 

[ornerynorsk]

Berkshire, how about a ball end mill?

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[berkshire]

ornerynorsk,
It would work if you could fit a means of controlling the depth.
Based on the OP comments I am presuming he is doing this by hand on a plaster/fiberglass plug for a mold, which is why I suggested modifying a cutter to fit a microstop countersink.
B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor

 

[AlpineAce]

yes, well its not just the depth but the spacing, so it all looks uniform.
I did have one thought that I could have the "centers" printed on a vinyl sheet, but still doing it by hand will make for some inperfection.

I'm working on it!

 

[Compositepro]

I've done this before for a project. Use BB's on a sheet of adhesive tape. It is not difficult to arrange them in a closest-packed configuration. This makes a conformable textured sheet that can emboss a pattern into other surfaces like an epoxy putty. You can also vacuum form a poly film over this BB sheet to act as a release liner for molding.

 

[moon161]

Mythbusters used a cutout tool when they dimpled a (plastecine coated) taurus for a fuel economy test (they helped significantly). Push an arc of wire in, twist 1/2 turn, pull out the plug.

 

[Tmoose]

http://media.neccostore.com/Galleries/Large/candy-house-candy-buttons__1.jpg

 

[btrueblood]

...that'd work until Hansel and Gretel came along.

 

[berkshire]

How about this method, a bit high tech, but interesting.

http://www.theengineer.co.uk/sector...e-fuel-efficiency-on-aircraft/1010967.article

B.E.

The good engineer does not need to memorize every formula; he just needs to know where he can find them when he needs them. Old professor

 

[CasaCEO]

bb's in clay... proly the best way to get a negative uniform surface to mold. or you could put a cast onto a golf ball and get a positive impression...

 

[vortexman]

Hi AlpineAce,

You can probably get away with a simpler process than producing a large number of discrete dimples, especially if you know the predominant flow direction. You could introduce some raised ridges, roughly perpendicular to the airflow. The benefit of dimples is due to the fact that they trip the flow from laminar to turbulent, and this can be accomplished using a number of different kinds of surface features. Dimples are used on golf balls because the flow direction on a golf ball is arbitrary. On the body you are working on, I suspect that the flow direction is pretty well known, so even something as simple as some strips of tape might do the trick. Something like this also has the advantage that it can be easily modified, allowing you to experimentally determine the best placement and height of the ridges.

vortexman