G'day all. I'm really hoping someone can help me here.

I'm wanting to create 1/2 sphere shaped holes in some softwood & have no idea how I would go about doing it. I don't have any fancy equipment or machinery, just your basic tools that can be used for drilling & sawing etc.

My idea is to have 2 separate blocks of wood, each with different sized 1/2 spheres that correspond to each other, so that when the top piece is laid on the bottom piece, the 1/2 spheres line up to create complete empty hollow spheres in the middle. And of course, the spheres have to be really smooth.

Each of these spheres would be of a size to completely encase say a 10mm, 13mm, 16mm, 20mm ball, & the ball would not be able to move. So basically a nice neat fit. The largest would be no more than 22mm, & the smallest would be the 10mm.

So, any ideas on how to create these half spheres in each piece of wood reasonably easily.

Best bet would be on a lathe.

Without a lathe try this: work out what depth of hole you would need to drill at various diameters from the centre (I imagine some geometry knowledge would be useful here). You will need to take into account the diameter of the drill and the angle of the drill bit point to ensure none of the drill goes further than desired. Use a drill press and drill out the holes (as many as possible) and then carefully use a chisel to remove the rest. You'll need small chisels though.

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The other day I described to my daughter how to find something in the garage by saying "It's right near my big saw". A few minutes later she came back to ask: "Do you mean the black one, the green one, or the blue one?".

Thanks for the reply Peter. Appreciate your suggestions. I can't see what I want being done in a lathe unless I do each sphere in a separate square of wood then glue those together to make one length. I really wanted all the 1/2 spheres in one piece of wood, so I only end up with 2 bits of wood. The top piece & the bottom piece.

I quickly did these up in paint to show what they should look like. Each ball would sit exactly half it's diameter into it's corresponding hole so when the 2nd piece of wood was placed on top, the other half of the balls diameter would sit in the corresponding hole in the top piece & both faces of the 2 bits of wood would be against each other.

Side view. The light colour is the outline of the wood & the dark colour are the spheres.



Looking down from the top.

It would be an expensive way to do it but you could use different sized round nose router bits
814 Round Nose Bits : CARBA-TEC

Best way would be with router cutters of the appropriate size but you are looking at one cutter per hole.

I have seen someone make similar shaped holes using Spade drill bits ground into a half round shap, but you get left with the pilot hole in the middle which would have to be filled afterwards.

There isn't really an easy way to do this apart from individual router cutters

just like making a wooden spoon mount piece in 4jaw chuck gouge each hollow

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Thanks for the suggestions guys. much appreciated.

I asked in a couple of other forums I'm with & using a router was also given as possibly the easiest. I've never had one so didn't know you could get bits to do this. And because I've not had one, I didn't think of that option.

Funny you mention the spade bits ground to a half round shape, cadas. One of the members in my gold prospecting forum suggested the same thing.

Cheers

Hey Nomad,

Jump on the CNC section and post a 'Who could do This" Thread, I bet that you get a few replys, there would be some one close and handy who could do thia job.

HazzaB

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Check out my Website www.harrybutlerdesigns.com.au

So what are you making with this line up of holes? You forming glass or metal or something?

Could be done on a lathe. The hole position is just moved across the face. Screwed on to a backing plate.

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anne-maria.

Tea Lady
(White with none)

ceramics exhibition and blog I am part of.http://www.jacpromotion2011.com/

Like this?

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anne-maria.

Tea Lady
(White with none)

ceramics exhibition and blog I am part of.http://www.jacpromotion2011.com/

Acetabular reamers, but I don't think they're made that small.

And really, really, expensive.
They're used for preparing sockets for joint replacement surgery.

Cheers,
Joe

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Yuuuuuuck!

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anne-maria.

Tea Lady
(White with none)

ceramics exhibition and blog I am part of.http://www.jacpromotion2011.com/

It is easy to make a sphere
1. Go to Hare and Forbes a purchase a lathe cw61160M for about $81000
2. Spend 3 or 4 years learning how to use the thing and to program the computer which drives it
3. Spend a short time writing the CNC code
4. And in no time at all you will have perfect spheres

I hope that helps

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Anyway children you may all pack up your books, push in your chairs and quietly go to bed.

Or you get some really nice person to do it for you!

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anne-maria.

Tea Lady
(White with none)

ceramics exhibition and blog I am part of.http://www.jacpromotion2011.com/

Thank you for your suggestions people, they have all been appreciated.

I have decided to modify the spade bit idea (that cadas mentioned) as being the easiest, as in, don't have to grind the bits down to a half round shape. Also modified the design to suit, & will only need to use one piece of wood,
As usual, I thought of the more complicated way of doing something, first. So what I'm going to do now is, just drill the different holes to a depth that is the same as the diameter. Then I just have to cross drill the 1mm guiding hole these need, exactly in the centre of both the diameter & height of the holes.

I could also do this with straight end cutting router bits in a plunge router, & I see they come in most of the sizes I need. Hmmm, lets see. My local Men's Shed has a nice big sliding table plunge router & bits to go in it. I'll just have to see what sizes they have. Better wait until we finish the project we are doing using this machine, first, though.

See what I meant above by my statement about the complicated thought first. Here I am using this lovely sliding table plunge router, & didn't even give being able to use that a thought.

Oh, yes. Tea Lady wanted to know what I'm doing. I make necklaces, previously using gemstone beads. But after years of using them I was finding them boring, & after discovering Polymer Clay late last year, have switched over to this medium. Polymer clay - Wikipedia, the free encyclopedia

I started off making what are mainly called Pebble & Nugget beads, because they are free form & that's what they look like. Lately, I've branched into round beads also, which you can use special bead rollers to form them into perfectly round beads. You can get close doing it by hand, but not as close as using a roller.

Some of these rollers don't have holes in the sides of them to put the piercing pins through the bead while it is still in the roller, thereby getting the hole exactly through the centre of the bead. I'm finding it very frustrating trying to centre the holes through the beads, & thought of making a contraption so I could make that exercise a lot easier & quicker.