<div dir="ltr">We have an older Darex sharpener. It looks nothing like anything on their web site, but my sense is that it was on the medium end of their spectrum when it was new, and perhaps a $2000-ish machine. Not counting myself, we have one guy who's pretty good, but that machine boggles everyone else's mind. It's critical to get the drill properly aligned rotationally in the collet, and that alignment itself requires two adjustments to the alignment fixture. One is for drill diameter, and that one is odd because the scale on the fixture is somewhat non-linear, which throws some people. The other is for back-rake angle. That "flat" surface behind the cutting edge has to slope away slightly or it drags on the bottom of the hole creating heat. That adjustment is also difficult because it uses the drill point angle as a variable. 118 and 135 are common but we have some drills that are 130 and BOY does that make a big difference getting those adjustments right. Our guy who I describe as pretty good always assumes those 130's are 135, or he believes that 135 is "close enough". Wrong. <div><br></div><div>Of course, the mechanism that supports the collet against the grinding wheel must have the correct point angle too. This adjustment is the only one that makes intuitive sense to anybody, but the difficulties I'm talking about above are in the pre-work to get the drill aligned in the collet in the first place. Get it right and you can make an edge nearly as good as the factory. Get it even a little bit wrong and you're out in left field. <div><br></div><div>We have one specialty job that uses a drill resharpened to a 90-degree point. I am the only person in the shop that can do that drill.</div><div><br></div><div>SO</div><div><br></div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Oct 25, 2019 at 10:58 PM Spencer Yost <<a href="mailto:spencer@rdfarms.com">spencer@rdfarms.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="auto"><div>Hey Cecil,</div><div><br></div><div>When I first got the drill doctor I could not get results I expected. It was close but still not what I expected. I kept thinking it was the machine but after several friends continue to swear by them I finally decided it was the operator :-)</div><div><br></div><div>I went to their web site and viewed several of their videos and realized there was a small trick I was missing. I wish I could remember what it was. I think it’s the orientation of the bit during that initial set up when you set the depth in the chuck. Whatever it was I remember being pretty easy on myself because the manual was not clear on it.</div><div><br></div><div>Anyways maybe go back through some of their videos and some of the other folks‘ YouTube stuff and make sure you’re doing everything. I wasn’t and am much happier now.</div><div><br></div><div>Spencer </div><div><br><div dir="ltr">Sent from my iPhone</div><div dir="ltr"><br><blockquote type="cite">On Oct 25, 2019, at 3:20 PM, Cecil Bearden <<a href="mailto:crbearden@copper.net" target="_blank">crbearden@copper.net</a>> wrote:<br><br></blockquote></div><blockquote type="cite"><div dir="ltr">
<p><...snip...> I have had a couple of the Drill Doctors, but
gave up on trying to get them to sharpen a bit correctly. I just
use my eyeball... After 50 years, it is not too hard. I do have
a drill grinder for bits 3/4 and larger. <br>
Cecil</p></div></blockquote></div></div>_______________________________________________<br>
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