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2011-02-24 by designer_craig
Does any one know when the commercial guys have their carbide PCB drills sharpened do they just dress the tips or do they grind the flutes as well? Just wondering if resharpened drills will drill a smaller hole after sharpening or are they just a little shorter. Was thinking of getting some resharpened drills for the shop. Craig
2011-02-24 by Donald H Locker
They only reshape the tip. The flutes don't actually wear in service. Resharpened bits are a great deal for people like us. They can't be used in the big machines when they get too short, but they are plenty long enough for manual operations. Donald. -- *Plain Text* email -- it's an accessibility issue () no proprietary attachments; no html mail /\ ascii ribbon campaign - <www.asciiribbon.org> ----- Original Message -----
> From: "designer_craig" <cs6061@...> > To: "Homebrew PCBs" <Homebrew_PCBs@yahoogroups.com> > Sent: Thursday, February 24, 2011 5:03:55 AM > Subject: [Homebrew_PCBs] Carbide PCB drill ? > > Does any one know when the commercial guys have their carbide PCB > drills sharpened do they just dress the tips or do they grind the > flutes as well? > > Just wondering if resharpened drills will drill a smaller hole after > sharpening or are they just a little shorter. > > Was thinking of getting some resharpened drills for the shop. > > Craig
2011-02-24 by Leon Heller
On 24/02/2011 10:03, designer_craig wrote: > Does any one know when the commercial guys have their carbide PCB drills sharpened do they just dress the tips or do they grind the flutes as well? > > Just wondering if resharpened drills will drill a smaller hole after sharpening or are they just a little shorter. > > Was thinking of getting some resharpened drills for the shop. I use them all the time, and they work very well. I get mine from Mega Electronics (UK). Leon -- Leon Heller G1HSM
2011-02-24 by twb8899
--- In Homebrew_PCBs@yahoogroups.com, "designer_craig" <cs6061@...> wrote: > > Does any one know when the commercial guys have their carbide PCB drills sharpened do they just dress the tips or do they grind the flutes as well? > > Just wondering if resharpened drills will drill a smaller hole after sharpening or are they just a little shorter. > > Was thinking of getting some resharpened drills for the shop. > > Craig > I was in the printed circuit business for many years and drilled several million holes per month. We used new bits for multilayer boards and replaced them after 2500 or so holes depending on the customer and project. After multilayer drilling the bits were sent out for re-pointing then used again for two layer boards up to approximately 3500 holes and re-pointed again. After the second re-point the bits were used only on single layer boards until they were worn out or broken. I paid around $1.75 USD per bit for middle of the range bits such as .028" to .125" etc. The smaller and larger sizes cost more due to complexity and/or cost of carbide. The cost to re-point any size bit was $0.25 USD each and this included new depth rings. All of this took place over ten years ago so I don't think those prices would be good today. Even though it was inexpensive to re-point I eventually bought a sharpening machine that had diamond wheels, drill bushings and a microscope. From then on I bought new bits and maintained them in house. We actually broke very few bits but I kept all the carbide shanks and now grind them into engraving bits and other small cutters for the CNC machines I use today. The only way to know how many times a bit has been re-pointed is to measure the flute length and compare it to the original specifications. Many sellers of "resharpened" drill bits are actually selling used bits which are fine for hobby projects even though they aren't very sharp. I hope this answers some of the questions concerning pwb drill bits. Tom
2011-02-24 by Cristian
> I eventually bought a sharpening machine that had diamond wheels, > drill bushings and a microscope. Let me know where to buy such tool, Tom, please. Cristian
2011-02-24 by designer_craig
I was going to buy some from Drill Bit City: http://drillcity.stores.yahoo.net/ One thing thought, the carbide bits are vary birttle and I found it was not possible to use them with a hand held tool like a Dremel. Not even sure you can use a low quality drill press. The quill runout needs to be fairly good and the down feed needs to be very sensitive or you will snap them. You also need to turn them very fast, they like speeds around 30,000RPM -- some PC drillers use 100,000 RPM. I have had success at 5000 RPM on my CNC Bridgeport mill. I am sure I will snap a few before I get he feed rate dialed in. I have plans for a high speed spindle but not had time to work on it. Craig I will be drilling with my CNC bridgeport --- In Homebrew_PCBs@yahoogroups.com, Cristian <bip@...> wrote:
> > > > I eventually bought a sharpening machine that had diamond wheels, > > drill bushings and a microscope. > > > > Let me know where to buy such tool, Tom, please. > Cristian >
2011-02-24 by michael tenore
Its better to use high speed steel or cobalt bits.. they can be found cheap from Victor machine or travers or on the web! The carbide bits break too easy even with a dremel drill press. regard mike.. --- On Thu, 2/24/11, designer_craig <cs6061@...> wrote:
> From: designer_craig <cs6061@comcast.net> > Subject: [Homebrew_PCBs] Re: Carbide PCB drill ? > To: Homebrew_PCBs@yahoogroups.com > Date: Thursday, February 24, 2011, 2:26 PM > > > > > > > > > > > > > > > > > > > > > > > > > > I was going to buy some from Drill Bit City: > > http://drillcity.stores.yahoo.net/ > > > > One thing thought, the carbide bits are vary birttle and I > found it was not possible to use them with a hand held tool > like a Dremel. Not even sure you can use a low quality > drill press. The quill runout needs to be fairly good and > the down feed needs to be very sensitive or you will snap > them. You also need to turn them very fast, they like > speeds around 30,000RPM -- some PC drillers use 100,000 RPM. > I have had success at 5000 RPM on my CNC Bridgeport mill. I > am sure I will snap a few before I get he feed rate dialed > in. I have plans for a high speed spindle but not had time > to work on it. > > > > Craig > > > > I will be drilling with my CNC bridgeport > > > > --- In Homebrew_PCBs@yahoogroups.com, > Cristian <bip@...> wrote: > > > > > > > > > > I eventually bought a sharpening machine that > had diamond wheels, > > > > drill bushings and a microscope. > > > > > > > > > > > > Let me know where to buy such tool, Tom, please. > > > Cristian > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
2011-02-24 by Donald H Locker
Thank you for the information, Tom. Real intelligence from someone in the business is invaluable. I haven't purchased resharpened bits in a very long time, but when I used to do it, microscopic examination of the points convinced me they were actually re-pointed (I did return a batch of unsharpened bits once; kind of funny at the time). Things have probably changed since then, so it's good to get that pointer (pun intended :). Donald. -- *Plain Text* email -- it's an accessibility issue () no proprietary attachments; no html mail /\ ascii ribbon campaign - <www.asciiribbon.org> ----- Original Message -----
> From: "twb8899" <twb8899@...> > To: "Homebrew PCBs" <Homebrew_PCBs@yahoogroups.com> > Sent: Thursday, February 24, 2011 12:45:09 PM > Subject: [Homebrew_PCBs] Re: Carbide PCB drill ? > > --- In Homebrew_PCBs@yahoogroups.com, "designer_craig" <cs6061@...> > wrote: > > > > Does any one know when the commercial guys have their carbide PCB > > drills sharpened do they just dress the tips or do they grind the > > flutes as well? > > > > Just wondering if resharpened drills will drill a smaller hole after > > sharpening or are they just a little shorter. > > > > Was thinking of getting some resharpened drills for the shop. > > > > Craig > > > > I was in the printed circuit business for many years and drilled > several million holes per month. We used new bits for multilayer > boards and replaced them after 2500 or so holes depending on the > customer and project. After multilayer drilling the bits were sent out > for re-pointing then used again for two layer boards up to > approximately 3500 holes and re-pointed again. After the second > re-point the bits were used only on single layer boards until they > were worn out or broken. > > I paid around $1.75 USD per bit for middle of the range bits such as > .028" to .125" etc. The smaller and larger sizes cost more due to > complexity and/or cost of carbide. The cost to re-point any size bit > was $0.25 USD each and this included new depth rings. All of this took > place over ten years ago so I don't think those prices would be good > today. Even though it was inexpensive to re-point I eventually bought > a sharpening machine that had diamond wheels, drill bushings and a > microscope. From then on I bought new bits and maintained them in > house. > > We actually broke very few bits but I kept all the carbide shanks and > now grind them into engraving bits and other small cutters for the CNC > machines I use today. The only way to know how many times a bit has > been re-pointed is to measure the flute length and compare it to the > original specifications. Many sellers of "resharpened" drill bits are > actually selling used bits which are fine for hobby projects even > though they aren't very sharp. I hope this answers some of the > questions concerning pwb drill bits. > > Tom >
2011-02-24 by Donald H Locker
A decent drilling machine will make your carbide bits last a long time. HSS or cobalt bits may not break from bending forces, but they will dull very quickly and then break from torsional overload. If you only drill a few hundred holes in your life, HSS or Co may be sufficient. Donald. -- *Plain Text* email -- it's an accessibility issue () no proprietary attachments; no html mail /\ ascii ribbon campaign - <www.asciiribbon.org> ----- Original Message -----
> From: "michael tenore" <wb2lcw@...> > To: "Homebrew PCBs" <Homebrew_PCBs@yahoogroups.com> > Sent: Thursday, February 24, 2011 3:06:40 PM > Subject: Re: [Homebrew_PCBs] Re: Carbide PCB drill ? > > Its better to use high speed steel or cobalt bits.. > they can be found cheap from Victor machine or travers or on the web! > The carbide bits break too easy even with a dremel drill press. > regard > mike.. > > --- On Thu, 2/24/11, designer_craig <cs6061@...> wrote: > > > From: designer_craig <cs6061@...> > > Subject: [Homebrew_PCBs] Re: Carbide PCB drill ? > > To: Homebrew_PCBs@yahoogroups.com > > Date: Thursday, February 24, 2011, 2:26 PM > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > I was going to buy some from Drill Bit City: > > > > http://drillcity.stores.yahoo.net/ > > > > > > > > One thing thought, the carbide bits are vary birttle and I > > found it was not possible to use them with a hand held tool > > like a Dremel. Not even sure you can use a low quality > > drill press. The quill runout needs to be fairly good and > > the down feed needs to be very sensitive or you will snap > > them. You also need to turn them very fast, they like > > speeds around 30,000RPM -- some PC drillers use 100,000 RPM. > > I have had success at 5000 RPM on my CNC Bridgeport mill. I > > am sure I will snap a few before I get he feed rate dialed > > in. I have plans for a high speed spindle but not had time > > to work on it. > > > > > > > > Craig > > > > > > > > I will be drilling with my CNC bridgeport > > > > > > > > --- In Homebrew_PCBs@yahoogroups.com, > > Cristian <bip@...> wrote: > > > > > > > > > > > > > > > > I eventually bought a sharpening machine that > > had diamond wheels, > > > > > > drill bushings and a microscope. > > > > > > > > > > > > > > > > > > > > Let me know where to buy such tool, Tom, please. > > > > > Cristian > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > ------------------------------------ > > Be sure to visit the group home and check for new Links, Files, and > Photos: > http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links > > >
2011-02-25 by DJ Delorie
michael tenore <wb2lcw@...> writes: > The carbide bits break too easy even with a dremel drill press. I made my own drill press. The only time I usually break bits now, is if I drop them on the floor... and I use 13 mil bits the most! http://www.delorie.com/pcb/dremel-stand/
2011-02-25 by designer_craig
I do use HHS when hand drilling but the bits dull very fast and and start to leave blow out on the back side of the board. I keep a small wet stone handy to touch up the points, which helps. My drill is a little 1.5" dia x 2" long Globe dc motor afixed with a pin chuck and a foot switch. Its served me well, drilled thousands of holes. But its time to move up to CNC drilling. For years I have done wet processed boards using photo resist and film masks but now I would like to set up and do double sided engraved boards. Craig --- In Homebrew_PCBs@yahoogroups.com, michael tenore <wb2lcw@...> wrote:
> > Its better to use high speed steel or cobalt bits.. > they can be found cheap from Victor machine or travers or on the web! > The carbide bits break too easy even with a dremel drill press. > regard > mike.. > > --- On Thu, 2/24/11, designer_craig <cs6061@...> wrote: > > > From: designer_craig <cs6061@...> > > Subject: [Homebrew_PCBs] Re: Carbide PCB drill ? > > To: Homebrew_PCBs@yahoogroups.com > > Date: Thursday, February 24, 2011, 2:26 PM > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Â > > > > > > > > > > > > > > > > > > > > I was going to buy some from Drill Bit City: > > > > http://drillcity.stores.yahoo.net/ > > > > > > > > One thing thought, the carbide bits are vary birttle and I > > found it was not possible to use them with a hand held tool > > like a Dremel. Not even sure you can use a low quality > > drill press. The quill runout needs to be fairly good and > > the down feed needs to be very sensitive or you will snap > > them. You also need to turn them very fast, they like > > speeds around 30,000RPM -- some PC drillers use 100,000 RPM. > > I have had success at 5000 RPM on my CNC Bridgeport mill. I > > am sure I will snap a few before I get he feed rate dialed > > in. I have plans for a high speed spindle but not had time > > to work on it. > > > > > > > > Craig > > > > > > > > I will be drilling with my CNC bridgeport > > > > > > > > --- In Homebrew_PCBs@yahoogroups.com, > > Cristian <bip@> wrote: > > > > > > > > > > > > > > > > I eventually bought a sharpening machine that > > had diamond wheels, > > > > > > drill bushings and a microscope. > > > > > > > > > > > > > > > > > > > > Let me know where to buy such tool, Tom, please. > > > > > Cristian > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
2011-02-26 by Ben L
> Its better to use high speed steel or cobalt bits.. > they can be found cheap from Victor machine or travers or on the web! > The carbide bits break too easy even with a dremel drill press. I use Carbibe bits in a Dremel drill press all the time, drill many 1000's of holes in a sitting and hardly ever break a bit. When I do it is because I got in a hurry and moved the board too quick before the bit exited the board. Ben
2011-02-26 by Leon Heller
I use a Minicraft drill and stand, it's similar to the Dremel. Although the quality isn't very good I very rarely break carbide drills. Using FEC-1 paper composite helps a lot as it's much easier to drill than FR4. I find a break more drills if I use FR4. Leon -- Leon Heller G1HSM