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Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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#1
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drill bit sharpening
I have one of those entry level drill doctors. SOmetimes, when I
sharpen large bits, the bit comes out with the point ground down. What am I doing wrong and are these repairable? Is there a better way to sharpen these? |
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Yeah, by hand--really not hard at all--and that's coming from a semi-spas.
Harder for really small drills, but then even these drill docs don't go super-small. And easier iffin you got good eyes. But 1/8 and up should be no problem. Best to let a shop guy show you how. And it's just as quick by hand as w/ these gizmos. bip bip, yer done. Longer if the bit is actually broken. I've been told that you really gotta pay some bux for a Darex or sumpn, and *even then* you can get disappointing results. ---------------------------- Mr. P.V.'d formerly Droll Troll wrote in message oups.com... I have one of those entry level drill doctors. SOmetimes, when I sharpen large bits, the bit comes out with the point ground down. What am I doing wrong and are these repairable? Is there a better way to sharpen these? |
#3
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Major NG sore spot! Drill Doctors are CRAP!!! One of my guys has one and
brought it in and sharpened a bunch of drills that then wouldn't cut. Upon inspection they had a slight negative rake Hmmmm. If you learn to do them by hand, you will learn empathy with the bit and become a better metalworker. wrote in message oups.com... I have one of those entry level drill doctors. SOmetimes, when I sharpen large bits, the bit comes out with the point ground down. What am I doing wrong and are these repairable? Is there a better way to sharpen these? |
#4
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On Thu, 28 Apr 2005 16:17:59 GMT, Tom Gardner wrote:
Major NG sore spot! Drill Doctors are CRAP!!! One of my guys has one and brought it in and sharpened a bunch of drills that then wouldn't cut. My personal experience differs from your observations. Upon inspection they had a slight negative rake Hmmmm. Can't imagine how that could happen unless he was using it very wrong. The camming action of the drill holder is pretty un-screw- uppable. If you learn to do them by hand, you will learn empathy with the bit and become a better metalworker. Sure, but saying that Drill Dr. is crap because it's fundamentally flawed isn't an accurate statement. |
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"Dave Hinz" wrote in message ... On Thu, 28 Apr 2005 16:17:59 GMT, Tom Gardner wrote: Major NG sore spot! Drill Doctors are CRAP!!! One of my guys has one and brought it in and sharpened a bunch of drills that then wouldn't cut. My personal experience differs from your observations. Upon inspection they had a slight negative rake Hmmmm. Can't imagine how that could happen unless he was using it very wrong. The camming action of the drill holder is pretty un-screw- uppable. If you learn to do them by hand, you will learn empathy with the bit and become a better metalworker. Sure, but saying that Drill Dr. is crap because it's fundamentally flawed isn't an accurate statement. I have two of these. A 750 bought about 4 yrs ago, and a 400 bought recently. I never could get the 750 to sharpen correctly. The 400 works great. Discovered that the collet holder that came with the 750 was different than the 400's. 400's holder works in the 750. Found out too late that they redesigned the holder and were replacing the old holders for free......Paul |
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"Tom Gardner" wrote in message . .. Major NG sore spot! Drill Doctors are CRAP!!! One of my guys has one and brought it in and sharpened a bunch of drills that then wouldn't cut. Upon inspection they had a slight negative rake Hmmmm. That has to be some wicked grinder! Rake angle on twist drills is established by the helix of the flute. Therefore, regardless of how the end of the drill is ground, rake angle is not affected. If you're telling us that the drill was higher at the heel than at the cutting edge and wouldn't cut because the lip was lower than the heel, then I would suggest to you that it had negative *relief*, not rake. They are not the same, and should not be confused. Harold |
#7
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If one guy gets really good grinds from a DD and another guy gets unusable
grinds, it does NOT mean that one of those guys is a bozo. It could equally well (and more likely does) mean that the DDs are not manufactured to close tolerances and one machine is bad and the other isn't. There has to be a reason that Darex dropped the DD. I suspect it has manufacturing problems. GWE |
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#9
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On Thu, 28 Apr 2005 12:48:06 -0700, Grant Erwin wrote:
If one guy gets really good grinds from a DD and another guy gets unusable grinds, it does NOT mean that one of those guys is a bozo. Well, they could be using it wrong. If you don't get the depth of the bit as compared to the camming surface correct, all bets are off. That'd be my guess as to where the most likely error would be made. It could equally well (and more likely does) mean that the DDs are not manufactured to close tolerances and one machine is bad and the other isn't. If you were familiar with the mechanism, you'd understand why that statement is nonsensical. There has to be a reason that Darex dropped the DD. I suspect it has manufacturing problems. Yes to the former, I doubt it to the latter. An injection mold isn't going to change randomly from unit to unit, so user error is much more likely than manufacturing problems. A distributor chosing not to sell a particular product can happen for any number of non-quality-related reasons. (shrug?) Mine works great, for what it is. I just don't like seeing one person's bad experience be expanded out to badmouthing an entire product line. |
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.....
It is late, I am tired and I am not even going to proof or spell check this, 'night all teenut " MY PERSONAL FAVORITE TEENUT POST! Everyone should read it twice. Karl |
#11
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It is possible that the bad grinds could have come from user error and
not manufacturing tolerances. You are being a bit sensitive when you say that what I wrote was nonsensical. More accurately, it is logical, but you assert is is unlikely. OK. It's just another point of view. Have I looked closely at the Drill Doctor? No. I have a better drill grinder. GWE Dave Hinz wrote: On Thu, 28 Apr 2005 12:48:06 -0700, Grant Erwin wrote: If one guy gets really good grinds from a DD and another guy gets unusable grinds, it does NOT mean that one of those guys is a bozo. Well, they could be using it wrong. If you don't get the depth of the bit as compared to the camming surface correct, all bets are off. That'd be my guess as to where the most likely error would be made. It could equally well (and more likely does) mean that the DDs are not manufactured to close tolerances and one machine is bad and the other isn't. If you were familiar with the mechanism, you'd understand why that statement is nonsensical. There has to be a reason that Darex dropped the DD. I suspect it has manufacturing problems. Yes to the former, I doubt it to the latter. An injection mold isn't going to change randomly from unit to unit, so user error is much more likely than manufacturing problems. A distributor chosing not to sell a particular product can happen for any number of non-quality-related reasons. (shrug?) Mine works great, for what it is. I just don't like seeing one person's bad experience be expanded out to badmouthing an entire product line. |
#12
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"Grant Erwin" wrote in message ... It is possible that the bad grinds could have come from user error and not manufacturing tolerances. You are being a bit sensitive when you say that what I wrote was nonsensical. More accurately, it is logical, but you assert is is unlikely. OK. It's just another point of view. Have I looked closely at the Drill Doctor? No. I have a better drill grinder. GWE I've managed to come up with good grinds as well as bad grinds using my DD. Not orienting the drill properly will absolutely cause the trailing-edge-higher-than-the-cutting-edge problem mentioned earlier. I've found that when I pay attention to getting the drill positioned properly, that the DD does a very nice job. It can be a little persnickety, but ninety five percent of the time I get a good result on the first try. Peter |
#13
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"Harold and Susan Vordos" wrote in message ... "Tom Gardner" wrote in message . .. Major NG sore spot! Drill Doctors are CRAP!!! One of my guys has one and brought it in and sharpened a bunch of drills that then wouldn't cut. Upon inspection they had a slight negative rake Hmmmm. That has to be some wicked grinder! Rake angle on twist drills is established by the helix of the flute. Therefore, regardless of how the end of the drill is ground, rake angle is not affected. If you're telling us that the drill was higher at the heel than at the cutting edge and wouldn't cut because the lip was lower than the heel, then I would suggest to you that it had negative *relief*, not rake. They are not the same, and should not be confused. Harold I'm truly embarassed! |
#14
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"Dave Hinz" wrote in message ... On Thu, 28 Apr 2005 16:17:59 GMT, Tom Gardner wrote: Major NG sore spot! Drill Doctors are CRAP!!! One of my guys has one and brought it in and sharpened a bunch of drills that then wouldn't cut. My personal experience differs from your observations. Upon inspection they had a slight negative rake Hmmmm. Can't imagine how that could happen unless he was using it very wrong. The camming action of the drill holder is pretty un-screw- uppable. If you learn to do them by hand, you will learn empathy with the bit and become a better metalworker. Sure, but saying that Drill Dr. is crap because it's fundamentally flawed isn't an accurate statement. Don't forget I'm biased and cheap! |
#15
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I have one of those entry level drill doctors. SOmetimes, when I
sharpen large bits, the bit comes out with the point ground down. What am I doing wrong and are these repairable? I believe the inconsistency on the Drill Doctors is due to the method it uses to rotate the drill to the correct angle so that the cam mechanism will put the right relief angle on the drill. If the drill is rotated incorrectly you will not get the right angle on the point. The mechanism used to set this angle is a pair of sheet metal edges that come out and are supposed to squeeze the drill inbetween the flutes and rotate it to the correct angle.. I'm not convinced that even if it was consistent that this method will work correctly for all drill sizes, but even aside from that I'm having problems getting the drill rotated to the correct angle to get ground properly. I would prefer if they just showed you which angle the drill is supposed to be oriented in the collet so you could do it by eye, but I guess I'll have to play with the thing to figure that out. On some drill sizes my Drill Doctor is working ok, but on the size I actually needed it for I'm also getting the wrong relief angle. Paul T. |
#16
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In article t,
Peter Grey wrote: "Grant Erwin" wrote in message ... It is possible that the bad grinds could have come from user error and not manufacturing tolerances. You are being a bit sensitive when you say that what I wrote was nonsensical. More accurately, it is logical, but you assert is is unlikely. OK. It's just another point of view. Have I looked closely at the Drill Doctor? No. I have a better drill grinder. GWE I've managed to come up with good grinds as well as bad grinds using my DD. Not orienting the drill properly will absolutely cause the trailing-edge-higher-than-the-cutting-edge problem mentioned earlier. I've found that when I pay attention to getting the drill positioned properly, that the DD does a very nice job. It can be a little persnickety, but ninety five percent of the time I get a good result on the first try. Except that it does not seem to do a good job with the split-point drill sharpening with the smaller sizes. One thing to watch for, however, is that it is sensitive to the helix angle. The common jobbers' style bits work fine in it, if it is used as it should be. Those with either lower or higher helix angles wind up mis-positioning the flutes, and can wind up with excessive or negative relief as a result. (What is needed is a couple of more index marks for those differing helix angles, and matching detents. Enjoy, DoN. -- Email: | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
#17
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"DoN. Nichols" wrote in message ... In article t, Peter Grey wrote: "Grant Erwin" wrote in message ... It is possible that the bad grinds could have come from user error and not manufacturing tolerances. You are being a bit sensitive when you say that what I wrote was nonsensical. More accurately, it is logical, but you assert is is unlikely. OK. It's just another point of view. Have I looked closely at the Drill Doctor? No. I have a better drill grinder. GWE I've managed to come up with good grinds as well as bad grinds using my DD. Not orienting the drill properly will absolutely cause the trailing-edge-higher-than-the-cutting-edge problem mentioned earlier. I've found that when I pay attention to getting the drill positioned properly, that the DD does a very nice job. It can be a little persnickety, but ninety five percent of the time I get a good result on the first try. Except that it does not seem to do a good job with the split-point drill sharpening with the smaller sizes. One thing to watch for, however, is that it is sensitive to the helix angle. The common jobbers' style bits work fine in it, if it is used as it should be. Those with either lower or higher helix angles wind up mis-positioning the flutes, and can wind up with excessive or negative relief as a result. (What is needed is a couple of more index marks for those differing helix angles, and matching detents. It should be said that I'm using my DD on standard run-of-the-mill drill bits, so your observations are undoubtedly correct. Peter |
#18
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"Tom Gardner" wrote in message ... "Harold and Susan Vordos" wrote in message ... "Tom Gardner" wrote in message . .. Major NG sore spot! Drill Doctors are CRAP!!! One of my guys has one and brought it in and sharpened a bunch of drills that then wouldn't cut. Upon inspection they had a slight negative rake Hmmmm. That has to be some wicked grinder! Rake angle on twist drills is established by the helix of the flute. Therefore, regardless of how the end of the drill is ground, rake angle is not affected. If you're telling us that the drill was higher at the heel than at the cutting edge and wouldn't cut because the lip was lower than the heel, then I would suggest to you that it had negative *relief*, not rake. They are not the same, and should not be confused. Harold I'm truly embarassed! Chuckle! Harold |
#19
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When you put the drill in the alignment clam you have to look down on the
sheet metal clamp jaws and besure they are still aligned. If the drill is canted or not correctly inserted the jaws will be offset. I get really good results with mine and I learned to sharpen drill bits by hand a long time ago. I just can't see well enough to do the itty bitty ones anymore. Glenn "Paul T." wrote in message ... I have one of those entry level drill doctors. SOmetimes, when I sharpen large bits, the bit comes out with the point ground down. What am I doing wrong and are these repairable? I believe the inconsistency on the Drill Doctors is due to the method it uses to rotate the drill to the correct angle so that the cam mechanism will put the right relief angle on the drill. If the drill is rotated incorrectly you will not get the right angle on the point. The mechanism used to set this angle is a pair of sheet metal edges that come out and are supposed to squeeze the drill inbetween the flutes and rotate it to the correct angle.. I'm not convinced that even if it was consistent that this method will work correctly for all drill sizes, but even aside from that I'm having problems getting the drill rotated to the correct angle to get ground properly. I would prefer if they just showed you which angle the drill is supposed to be oriented in the collet so you could do it by eye, but I guess I'll have to play with the thing to figure that out. On some drill sizes my Drill Doctor is working ok, but on the size I actually needed it for I'm also getting the wrong relief angle. Paul T. |
#20
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Ahma haveta read it 15 times! Man, what a cupla pictures--or a
video--wouldn't do!! But, perhaps Teenut's bottom line is: Real men sharpen bits by hand.... ---------------------------- Mr. P.V.'d formerly Droll Troll "Karl Townsend" remove .NOT to reply wrote in message k.net... .... It is late, I am tired and I am not even going to proof or spell check this, 'night all teenut " MY PERSONAL FAVORITE TEENUT POST! Everyone should read it twice. Karl |
#21
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#22
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Ok I have to many drill bit sharpeners, Darex, Black Diamond, listie. THe
darex is nice for its size range and is easy to change bit size, and angles. The black diamond is the best within its size ranges it will sharpen as good as new every time. It you want your drills as good as they get this machine is nice, but you need a collet for each size drill, that takes time. the Listie is great for bigger bits but is slow in changing sizes. They all give better results than hand grinding, even from a person who has done thounsands of drills. The black diamond often is better than new finsh. "Proctologically Violated©®" wrote in message news Yeah, by hand--really not hard at all--and that's coming from a semi-spas. Harder for really small drills, but then even these drill docs don't go super-small. And easier iffin you got good eyes. But 1/8 and up should be no problem. Best to let a shop guy show you how. And it's just as quick by hand as w/ these gizmos. bip bip, yer done. Longer if the bit is actually broken. I've been told that you really gotta pay some bux for a Darex or sumpn, and *even then* you can get disappointing results. ---------------------------- Mr. P.V.'d formerly Droll Troll wrote in message oups.com... I have one of those entry level drill doctors. SOmetimes, when I sharpen large bits, the bit comes out with the point ground down. What am I doing wrong and are these repairable? Is there a better way to sharpen these? |
#23
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