Drill Speed On Poly

**Mike Fretto** · 08-23-2005, 10:20 AM

We are interested in some input on the proper drill speed for poly lenses. We are using the Smart Drill System and seem to be having some problems with the bushings on Sillhouette frames fitting a little loose. We changed the bit to a brand new one and just started using a drill seal on the lenses to prevent cracking in the future. We are not sure if the drill seal is affecting the hole size at all I wouldnt think so. There is some doubt on our part as to what the proper speed of the drill should be for poly I feel it should be slower and step drill thicker lenses. Any help would be appreciated.

**Chris Ryser** · 08-23-2005, 02:03 PM

Originally Posted by Mike Fretto

We are not sure if the drill seal is affecting the hole size at all I wouldnt think so. There is some doubt on our part as to what the proper speed of the drill should be for poly I feel it should be slower and step drill thicker lenses. Any help would be appreciated.

"DRILLl SEAL" will not affect the size of the hole, it just seals the minute cracks and rips made by the drill.

See that you drill slow without overheating the poly and as you say use the step drill method.

**mshimp** · 08-23-2005, 02:28 PM

Didos to what Chris said.We also use the smart drill. However the drilling charts that smart drill provides are not always accurate. Check with the frame manufactuer to make sure the bit is not too large.

**misunderstood** · 08-23-2005, 02:30 PM

I use a dremel and drill by hand.....I never have these problems......

**rsandr** · 08-23-2005, 03:13 PM

Originally Posted by Mike Fretto

We are interested in some input on the proper drill speed for poly lenses. We are using the Smart Drill System and seem to be having some problems with the bushings on Sillhouette frames fitting a little loose. We changed the bit to a brand new one and just started using a drill seal on the lenses to prevent cracking in the future. We are not sure if the drill seal is affecting the hole size at all I wouldnt think so. There is some doubt on our part as to what the proper speed of the drill should be for poly I feel it should be slower and step drill thicker lenses. Any help would be appreciated.

We drill these 1.4mm in diameter and have no problems.
If you are doing the cheaper variants some have 1.5mm bushings.
I would buy in some 1.4mm bushings and do these also at 1.4mm if that is the case.
Keeps everything uniform.

Rick

**Clive Noble** · 08-23-2005, 10:47 PM

I have found that the best way is to drill slowly using a 1.2mm 'bit' then opening to 1.4 using a hand tool (fitted with a 1.4 bit) I then Clean the periphery of the holes on both sides very gently with a Dental conical drill piece.

I've also got a selecion of the plastic bushings, hard, soft, long, short, in all thicknesses.... however, I have to say the quality does vary and I've found that the original softer Silhouette type still is the best

**Mike Fretto** · 08-24-2005, 08:32 AM

What seems to be happening is the fit is very tight using the 1.4mm recommended bit straight from the drill you really have to push on the bushing to get them in the hole. After applying the drill seal the whole seems bigger or maybe smoother is a better way to discribe it, the bushing slides right in. Smart drill makes a 3.5mm bit we may try that, but bottom line is this, with a new 1.4 the fit is good after sealing the hole its not as tight.

**chip anderson** · 08-24-2005, 09:27 AM

There is a company in Jackson, Oliver H. VanHorn that I have found has any drill bit diameter and configuration you might desire as well as most machine tools. Note: I don't think you can reach Oliver H. VanHorn on the net. I also suspect any good machine supply store can get whatever you need.

Now has anyone had the stuff to try drill bits in .01 mm larger and smaller diameter diameters, mounting a lens and looked at the stress in a polariscope?

I think you can find the answer this way. Ideally you want the least stress without a lose mount. And as I have said before, drills do different things (smoother holes) if some sort of lubricant or cutting oil is applied at the time of drilling. Note some hand or electric drills have no lubrication and others use cutting oils.

I would do this research myself but I don't do enough in house drilling to justify it.

Chip