Archimedes drill

**Coco** · 28-10-2009, 11:36 AM

'kay so I have one of those hand drill thingies that you bounce the top up of and down, I made a little dent with a centre punch so the drill bit wouldn't go sliding around. It made a slightly bigger dent in the metal but no hole so I changed the drill bit. It's taking ages and there's still no hole! What am I doing wrong??? !?

**bustagasket** · 28-10-2009, 11:42 AM

i have only used the little archemedes drill on pmc at nics, if i am drilling silver i use the old fashioned hand drill, so sorry huni, i cant actually offer any advice on theis one

(not that i am ever actually any good at advice)

**Coco** · 28-10-2009, 12:02 PM

But we appreciate the effort

**AlexandraBuckle** · 28-10-2009, 12:03 PM

i've used a bow drill - is that the same thing...?

**Boo** · 28-10-2009, 12:27 PM

I have two little Archimedes drills, one for sub 1mm sizes and a slightly larger one and find them superb for pilot holes and general use (for example, I wanted a tiny pilot hole in a timber mirror frame yesterday) where you need something slow and delicate and what I bought them for was drilling holes in polymer clay - for which they're absolutely ideal.

But I suspect that you don't get enough pressure for metal drilling to progress through the hole. I've done holes in copper with them, but find a small powered rotary tool better for silver. Drilling is a complex combination of drill shape (to remove swarf etc.), sharpness, pressure, speed and torque and I don't understand it anything like as well as I'd like to.

I bookmarked this site and it was the one where the penny dropped with some things for me: UK DIY FAQ

**Petal** · 28-10-2009, 12:32 PM

Originally Posted by Boo

I have two little Archimedes drills, one for sub 1mm sizes and a slightly larger one and find them superb for pilot holes and general use (for example, I wanted a tiny pilot hole in a timber mirror frame yesterday) where you need something slow and delicate and what I bought them for was drilling holes in polymer clay - for which they're absolutely ideal.

But I suspect that you don't get enough pressure for metal drilling to progress through the hole. I've done holes in copper with them, but find a small powered rotary tool better for silver. Drilling is a complex combination of drill shape (to remove swarf etc.), sharpness, pressure, speed and torque and I don't understand it anything like as well as I'd like to.

I bookmarked this site and it was the one where the penny dropped with some things for me: UK DIY FAQ

Excellent link Boo - thanks for that

xx

**Di Sandland** · 28-10-2009, 12:36 PM

Brilliant link, Boo, which I've duly bookmarked

**Solunar Silver Studio** · 28-10-2009, 12:53 PM

Hi Coco, Have you used the bit in your drill for anything else before this? I was just wondering if it is possible that the bit could have become blunt. I have had the situation before where my bits seem to just polish the inside of the dent rather than actually bite into the surface of the metal...particularly if I have already centre punched it. A new bit has sorted it!

I also have 2 Archimedes drills 1 with a 1mm bit and the other with a 2mm. I use them mainly on dry pmc without problems but occasionally I have to use them on metal too, which tends to be a bit harder on them!!

**EmmaRose** · 28-10-2009, 12:56 PM

I only use hand drills for fragile or very thin things (ie when no other recourse). Bow drills are a pain unless you have the knack (needless to say I don't). Ergo I bought a pillar drill from B&Q, about £30 their own brand. Not as many speed settings or control as a jewellers one but fraction of the price. It is still my only pillar drill. You can also drill with a pendant drill or rotary tool, but as I am useless at straight lines under the best of circumstances I prefer the pillar drill) If you do get one get a flat clamp vice thing to hold pieces like rings....
Em

**Boo** · 28-10-2009, 01:04 PM

I'm curious - is a pendant drill basically the same thing as a 'flex shaft'? Is it just largely terminology - as I see 'pendant drill' used a lot here, but I've always called mine a flex shaft.

I suspect a pendant drill is the sort with a large square motor that hangs with the flexible drill bit beneath, where my 'flex shaft' is basically a rotary tool, hanging from a hook, with a flexible extension.