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2013-03-09 by Boman33
Recently I remember an article about using broken PCB carbide drilling bits to make V tipped router bits. Basically grind the desired angle and then grind off half the bit. There was a careful procedure to allow accurate and good performance. I have googled, hunted in the email lists, and my own computer without success. Any suggestions where I can find it? [Non-text portions of this message have been removed]
2013-03-11 by Les Newell
Just grinding a point then cutting off half the bit won't work as the cutter would have no clearance angle. You would get a really rough cut and quite likely snap the tip off the cutter. Grinding the flat is a pain as you need to remove a relatively large amount of material and you need to be quite accurate. This page gives some great info <http://www.antaresinc.net/FactAnatomy.html>. Note that you need a fairly fine diamond wheel to get a good enough finish. If you don't already have a wheel and a suitable grinder it is far cheaper to buy the cutters than make them. Considering the price of new cutters on eBay it is not really worth the effort to make them in my opinion. If you have a suitable diamond wheel it is worth resharpening cutters as they wear out quite quickly. My grinding fixture is really simple but works well. I have a mount that has a 1/8" hole bored in it. This is bolted to my tool and cutter grinder and supports the cutter. I then clamp a collet to the cutter. The collet has an arm sticking out of it which I use to rotate the cutter. I have a stop that locates on the arm and prevents me from rotating the cutter too far. The position of this stop controls the clearance angle. Once set up it takes about a minute to sharpen a cutter. Les
On 09/03/2013 08:16, Boman33 wrote: > Recently I remember an article about using broken PCB carbide drilling bits > to make V tipped router bits. Basically grind the desired angle and then > grind off half the bit. There was a careful procedure to allow accurate and > good performance. > > > > I have googled, hunted in the email lists, and my own computer without > success. > > Any suggestions where I can find it? > >
2013-03-12 by Boman33
I 100% agree that it is not cost-effective to grind my own bits but I like to know to be able to do it in an emergency while waiting for bits to arrive. Bertho
From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com] On Behalf Of Les Newell Sent: Monday, March 11, 2013 08:19 To: Homebrew_PCBs@yahoogroups.com Subject: Re: [Homebrew_PCBs] PCB Milling bits Just grinding a point then cutting off half the bit won't work as the cutter would have no clearance angle. You would get a really rough cut and quite likely snap the tip off the cutter. Grinding the flat is a pain as you need to remove a relatively large amount of material and you need to be quite accurate. This page gives some great info <http://www.antaresinc.net/FactAnatomy.html>. Note that you need a fairly fine diamond wheel to get a good enough finish. If you don't already have a wheel and a suitable grinder it is far cheaper to buy the cutters than make them. Considering the price of new cutters on eBay it is not really worth the effort to make them in my opinion. If you have a suitable diamond wheel it is worth resharpening cutters as they wear out quite quickly. My grinding fixture is really simple but works well. I have a mount that has a 1/8" hole bored in it. This is bolted to my tool and cutter grinder and supports the cutter. I then clamp a collet to the cutter. The collet has an arm sticking out of it which I use to rotate the cutter. I have a stop that locates on the arm and prevents me from rotating the cutter too far. The position of this stop controls the clearance angle. Once set up it takes about a minute to sharpen a cutter. Les On 09/03/2013 08:16, Boman33 wrote: > Recently I remember an article about using broken PCB carbide drilling bits > to make V tipped router bits. Basically grind the desired angle and then > grind off half the bit. There was a careful procedure to allow accurate and > good performance. > > > > I have googled, hunted in the email lists, and my own computer without > success. > > Any suggestions where I can find it? > > [Non-text portions of this message have been removed]