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Subject: Drill bit sharpening help

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Beth and Allen    Posted 07-19-2018 at 20:05:29 [URL] [DELETE]        [Reply] [No Email]  
  • Drill bit sharpening help
  • I need advice or help getting some drill bits sharpened. I can sharpen my bits up to 3/4" with my drill doctor. But I have bits from 49/64" up to 1 1/8 that I need to sharpen. I've tried doing them on a grinder and a belt sander with very little luck. I've looked around South Jersey for someone to do them but no luck. Does anyone know of someplace that I can send them to get them sharpened.Thanks and God Bless, Beth and Allen.

    Tony C    Posted 07-21-2018 at 17:12:06 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Drill bit sharpening help
  • Gruchow Grinding
    Branchport NY

    (315) 595-2772

    1 1/4" HSS around eight bucks or so. IIRC 1 1/4" is as big as they can handle. Worth a call.

    TheOldHokie    Posted 07-20-2018 at 18:30:45 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Drill bit sharpening help
  • The key to sharpening drill bits is two pieces of geometry:

    1) The flute angles need to be matched.
    2) The flutes have to have sufficient relief angle to allow the sharpened cutting edge to engage the work ahead of the trailing edge.

    When you run a properly sharpened drill you should get two continuous "curls" from the flutes. If you only get one curl one of the flutes is off and the drill will run oversize, hot, and off center. That is usable but not what you want and an off center sharpening job. If you get none both flutes are off, probably relief angle, and the drill is junk. It is unusable, won't cut worth a dang, and a PITA to deal with.

    Hand sharpening a drill is a real skill and a jig with a cam action guide for generating the relief makes it a lot easier.

    TOH

    Tim Daley(MI)    Posted 07-21-2018 at 07:29:03 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Drill bit sharpening help
  • Yes, that is true, however, if you are using a lathe and your set up isn't absolutely perfect, with tool aligned dead nuts center, square and perpendicular in X, Y, and Z axis, even a new drill will cause it to only cut off one flute. New drills out of the box these days can be poorly sharpened as well. the art of hand sharpening should be taught in every High School, trade school, and college machine tool class in the USA. One problem is that the instructors never were trained properly. Some younger ones these days had always used drill sharpening devices and never learned the hand method. It's like the machine tool industry today whereby some kid on a tube using CAD/CAM software thinks he is a CNC Programmer. If he has never had to learn the actual NC G-Code, write an actual working program out by hand, and has had no hands-on machining experience, he has no clue what feed and speed are all about. Back in the day, a real NC Programmer (like me) had to learn binary coded decimal, how to trig out angles and then add in tool nose radius compensation constants, how to generate arcs and partial arcs with TNRC and then enter the absolute values in the G-CODE punched tape for the machine control/tape reader to operate. CNC machines do not use punched paper or Mylar tape anymore, and CAD'CAM systems will use ATNRC codes too BUT if the "programmer" doesn't know what the true value should be, relies on whatever info he inputs, expect errors. By teaching hands-on with Bridgeports and engine lathes, a student needs to get and understand the 'feel' of feed and speed, what torque is, and what too much or too little of any one will do. One example, by hand drilling a piece of steel on a Bridgeport, one can feel what happens when they try to feed the tool too hard or fast. Also, temperature affects everything too. Workhardening is a term you never hear anymore. Ask any modern CAD/CAM CNC "programmer" what the sine of 30 is or what a G30 command is for. I'd bet he can't answer you.

    Tim Daley(MI)

    TheOldHokie    Posted 07-21-2018 at 17:22:39 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Drill bit sharpening help
  • The evolution of CNC programming has gone the same path as every other form of programming. Higher level software (aka Interactive Development Environments) takes care of the lower level details and it makes for faster and more sophisticated program development. CAM modeling software designs the part and produces the 3D model along with the G-code to machine it all in one fell swoop. Machining speeds and feeds are worked out by the software from the same canned basics old school G-code programmers used. There is simply no need for the average CNC programmer to know those things. Early in my career I spent several years designing and building CAM software of that sort and over time that niche has grown immensely and made the design and manufacturing process vastly more efficient and productive.

    The same is true for almost every form of programming - nobody writes "low level" code anymore and many younger programmers don't "know" the underlying machine architecture, the networking or communications protocols being used, the details of memory management, file organizations, or how it actually gets done. I cut my teeth on assembly language programming - something most younger programmers have never seen outside of a class. At one point that was a basic skill requirement for a good programmer. Now the need for people with that knowledge is limited to the people designing chips and building operating systems. Heck - in a modern operating system only a tiny portion of teh code is wriiten in assembly language and most of it is written in a higher level compiled language.

    The explosion of the world wide web is another perfect example of how this has benefited the world. A modern IDE lets a web programmer build complex graphical users interfaces in a 1/10th the time it would take coding it by hand. Doing it the old way would stall the development process immensely. In fact having the old skills but not the new ones makes you a less desirable candidate for employment. Despite having vastly more knowledge of the "old school" nuts and bolts I cannot compete with my son who is extremely accomplished in modern IDE's.

    This is the nature of digital computing and has been for the last 50 years. Machine coding has replaced human coding at every generational cycle of software development and that process will continue for the foreseeable future. It doesn't make modern programmers any less accomplished than their predecessors - they simply work on a whole new level of issues many of which would confound the older generation.

    TOH

    Tim Daley(MI)    Posted 07-23-2018 at 16:19:24 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Drill bit sharpening help
  • Yes I agree 100% Dan. In todays' business, I wouldn't think about writing out a CNC Milling program by hand as most workpieces are extremely complex, 3-D, multi-axis parts and most are made of exotic materials like titanium. One cannot afford a machining error due to an incorrect G-CODE value. The use of Master Cam and such is blessing in these cases. But a basic, simple program should be handled in MDI otherwise. Mill a surface, spot a hole pattern drill the pattern, tap the pattern =-basic stuff. the other issue with some of the younger and some older as well, "programmers" is they have no basic machine tool training and rely on the CAD programs to choose speeds, feeds, and tooling for the job. Most CNC lathes deal with 2-axis, X and Z. Some CNC Lathes offer live tooling fo some limited milling work. A little simpler to program but setting up and running a lathe is much more difficult than a mill. In the last 15 years of my working days I was in charge of processing/programming work at Valenite. They had purchased a new OKUMA MAC-TURN 50, a new technology machine tool that combined a lathe and mill. It had 7 axis. At the time of purchase there were only two machines in the world. The US Navy had the first one, and ours was being built so had to wait 6 months for delivery in September, 1998. I did ALL the G-CODE programming for that written out longhand, but with DNC uploading and downloading to and from the machine was easier via interface -no more clumsy tape readers and Mylar tape. MAZAKs followed with their INTEGREX series, but I had dealt with MAZAKS sinvetet70's and condemn any MAZAK operator because they were not true programmers. MAZAK invented their own method of programming called MAZATROL so an operator could set up the job at the machine then 'program' it with a series of key commands. the ironic thing was that the MAZATROL language used the G_CODE format, only it was just buried in the system. All you saw o the CRT was a series of part absolute values and some funny Mazak icons. I had a sign in my office that said "MAZAKS ARE FOR PUXXIES"

    Tim Daley(MI)

    Farmer Dan    Posted 07-20-2018 at 18:10:22 [URL] [DELETE]        [Reply] [Email]  
  • Re: Drill bit sharpening help
  • I have a drill doctor I use on bits up to half inch. Any larger or if I'm in a hurry I usa my bench grinder. I would recommend learning to use the bench grinder. More satisfaction and a lot handier than sending them out. I don't worry about all that fancy lingo or angles just eyeball them. Long as they cut a round hole thats all I need,

    Rustyal    Posted 07-20-2018 at 09:47:30 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Drill bit sharpening help
  • The correct way to sharpen them is the bench grinder. The larger drills are easier to sharpen on a larger grinder. A belt sander will not work.

    steveVa    Posted 07-20-2018 at 20:14:01 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Drill bit sharpening help
  • Come to think of it I have a drill guide for my bench grinder. I have also used a sharpening stone. I lay it on the drill bit with the drill in a vice and running.

    steveVa    Posted 07-20-2018 at 09:14:14 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Drill bit sharpening help
  • I saw a you tube video on simple inventions not long ago and someone made a simple angled jig that attached to a grinder. They used that to sharpen bits of all sizes. I will send you a link if I can find it.

    Vince/PA    Posted 07-20-2018 at 06:16:08 [URL] [DELETE]        [Reply] [Email]  
  • Re: Drill bit sharpening help
  • Fastenal offers a reasonably priced sharpening service if you can't do it yourself.

    Depends on how close you are to a store.

    Beth and Allen    Posted 07-21-2018 at 08:44:28 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Drill bit sharpening help Reply to Vince Pa
  • Thanks Vince, I called fastenal and was told to bring them in. I'll give them a try and let everyone know how it works out. I have at least 40 bits that need sharpening ,some worse than others. Some of these bits are 50+ years old and are really good bits. I just bought a few bits the other day to fill in some gaps in the sizes that I don't have (can you say sticker shock?). God Bless, Beth and Allen.

    Tim Daley(MI)    Posted 07-20-2018 at 05:28:42 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Drill bit sharpening help
  • Drill sharpening by hand is an art, almost a lost form nowadays what with devices like drill doctors and such. There are drill guide scales, or use to be, a 6 steel rule that had the 59 angled edge on one end with a scale and separate protractor so you could measure each side when sharpening by hand. Standard drill points are 118 included angle for most applications. For a more precise hole, and longer lasting drill, we used Parabolic Drills, at 140 included angle. Carbide is best, but more expensive that HSS. If you ever wondered what that V was for on your bench or pedestal grinder rest, it was a guide for sharpening drills. It cradled the bit at the correct 59 angle. Back in my machinist apprentice training days in 1975, I ran NATCOS (multi-spindle drill press machines), single spindle drill presses, and GANG DRILLS, and had to learn how to sharpen our own drills by hand. Ditto when I moved up to NC Turret Lathes. The hardest machining operation to perform is drilling a hole on a lathe. It will teach you how to correctly sharpen a drill and how to correctly set up the tool and machine. If the tool and the workholding device isnt solid and rigid, you will have problems with oversize holes, tool breakage, and drill walk. Carbide tools will chip or break easier than HSS and never should be used with a hand operated drill motor. The tool/drill must be aligned centered and square to the workpiece. On a precision NC (CNC now) lathe, the tool must be indicated in when set up. Total TIR should not exceed .001. Once you find center, it also must be aligned perpendicular, horizontally and up and down (vertically) so when it drills, it isnt cutting on an angle and cause a misaligned and/or oversize hole. Always use a center drill or better yet,a spotter drill. Using a spotter will give not only a center spot, but will leave a chamfer at the top of hole on the finished workpiece when set to correct depth. As stated, it is an art. Getting the web right, the lands right, and correct angle is so important. If you get stumped on sharpening larger drills, check out your local machine job shops and ask if they could sharpen them for you. Here is a LINK to some very good info on drills.

    DRILL GUIDE FOR HAND SHARPENING:

    Tim Daley(MI)

    K.LaRue-VA    Posted 07-19-2018 at 22:05:11 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Drill bit sharpening help
  • Sharpening by hand is much better than carrying them somewhere.
    Placing two large hex bolt heads together like this:
    _
    / \
    \_/
    / \
    \_/

    Will give you the correct angle between the two cutting edges. Check the bit tip frequently in the angle between the bolt heads as each side is sharpened. The taper away from that leading edge just needs to be the same angle for both sides. Too steep makes a weak edge that won't last as long.

    duey    Posted 07-19-2018 at 20:45:48 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Drill bit sharpening help
  • I also have a drill doctor.. and for the medium size bits, say 3/32 to 1/2, it works OK but it is not 'speedy'. I do wish it would deal with bits from #40 down to #60...but it doesn't... any larger bits, I sharpen by hand...

    When pointing the bit straight up, BE SURE the Right side (or the Cutting edge) is HIGHER than the Left Side. If it is not, it Won't Cut. Practice and Try, Practice and Try. It isn't magic and sending bits out for sharpening is PAIN...

    Good Luck.

    chris eby    Posted 07-20-2018 at 15:17:40 [URL] [DELETE]        [Reply] [Email]  
  • Re: Drill bit sharpening help
  • martins sharpening in Ephrata pa.(Lancaster county) they ship.email me for more info

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