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Thread: Drill Sharpeners
07-30-2007, 11:58 AM #41
I'm looking for a CNC drillpoint grinder to install in my regrind shop. I've shortlisted the Newpoint the Darex XPS 16 & the Avyac NC 240 based on web research alone. I have no actual user reports about these machines.
Has anyone used these machines or used drills ground on these machines? How would they compare to top-line 5-7 axis CNC grinders as far as drillpoints are concerned? Setup and grind speed, versatility, and ability to regrind all the big-brand points is important.
07-31-2007, 10:31 AM #42
I have watched one of these drill grinders work. To be very honest I'm not impressed. Part of the problem was the lack of experience the sales rep had with them.
I wouldn't plan on buying one for regrinding carbide. The sales rep I talked to repeated himself so many times about how important the honing of the cutting edge is I got a bad feeling.
I didn't like the fact that they use one collet set up that only has the ability to do up to 5/8. It isn't very quick either. I didn't check to see how close to center the point was. However I have 4 darex drill grinders and none of them are much better than .003 from center. I should have the factory clean or repair my collets, since I have reground thousands of drills with them. What I'm trying to say is the colleting system is the same basic thing between what I have and the XPS 16.
The only reason I would buy it is if you had to regrind radial swept split points or some type of your own signiture point. With it being slow, you better have a decent customer base that will pay a premium price for your grinding service.
Also the darex rep I delt with said the XPS was the only way to make a 4 facet split point. I personally know old tool grinders that used to do 4 facets all the time in special indexing heads on cincinnati tool grinders(cleveland heads).
I'm not trying to rain on your parade, but be cautious about the $16K you'll spend on one.
07-31-2007, 12:19 PM #43
At one of the shops where I worked at - we had one. It was not worth the money that they spent to buy it, due to the fact that you have to pay a machinist wage to get a machinist to stand in front of it and operate it.
At that time, the Hemley tool truck came to the shop once or twice a month and he paid them by the pound for used drill bits and files.
Sold them regrind drill bits cheaper than they could sharpen them - themselves.
One other shop I worked at - if they gave you a drill bit smaller than 1/2 inch, they told you to keep it after you were done. Not to bring it back to the tool room. Due to the fact that it cost them more money to sharpen it and put it back in the proper bin than what it was worth.
They had buckets of Diamond tipped drill bits, colbalt drill bits by the thousands. Just sitting in buckets - waiting for the Hemley tool truck guy to haul them away.
08-06-2007, 09:49 AM #44
08-06-2007, 12:13 PM #45
I once owned an Avyac C226 drill grinder and was favorably impressed with it. Wish I had kept it actually. I know nothing of their CNC grinders, but the video is compelling
08-06-2007, 12:32 PM #46
I ran an Avyac 3P32 during my years as a tool grinder. I would also recommend one - as long as I did not have to make the payments! I recall it being a pretty expensive piece of equipment.
08-06-2007, 01:12 PM #47drilling is essentially a roughing operation
I have a Darex SP2500 (coincidently they retailed for $2500), does only 135 degree split points. Plus, two SRD's that do all other point angles, but no point splitting (except by hand/eyeball).
08-08-2007, 11:08 AM #48
The CNC Avyac drill sharpener costs more than some 5 axis tool grinders which can grind a blank carbide rod into a drill! Lets see what Newpoint offers..
08-13-2007, 10:09 PM #49
We have an old Darex at the shop. Looks like a bench grinder with a few attachments. Works great as long as folks don't use the wheels for snagging burrs.
I have a Farrel Sellers #1-GA that the shop tossed last year. It is in perfect condition since nobody knew how to use it.
The V-blocks for small drills are missing so I haven't had a chance to fiddle with it. This unit requires repositioning of the drill for each lip. I understand this gives accurate results but it appears to be a PITA. That might be another reason it was not used.
08-14-2007, 01:27 AM #50
Although not avaliable as a new machine any longer i have a Cincinnati "Spiral Point" drill sharpener. Makes great drill points that cut closer to size than any chisel or split point.
Dam complesx machine that generates the drill point by making the grinding stone orbit about the drill. Can produce any angle point you wish to flat bottom drills. Just dress the stone to the angle required. Whole unit is mounted on a cabinet with dust collector....
08-14-2007, 01:42 AM #51
You should see the one in the J&L book. It's a CNC drill sharpener. Just put it in and it detects the size. Just tell it what you want, split point or w/e. There is one draw-back though...it costs $17,000!
09-17-2007, 11:37 PM #52
I think you are being unfair to Drill Doctor .
of course its not as good as a G&L, Winslomatic, black diamond, or a dozen others . What do you expect for $118 ? I used my original DD blu box for 3 years until I messed up the diamond wheel location by hammering it on . Called the factory and asked if they could fix it .. no problem , sent it back , 4 days later a brand new unit . Totally unexpected considering the warantee was long past . Yes it did have its sniglets , and took a small bit of skill to get the smaller drills right . Now I got the new plastic box , the 750 unit . I love it , my CNC's love it , I sharpen & split new drills right out of the pack . All my dull center drills are now sharp , because of the variable drill clearence feature .
The 40 year old Sterling still does the 3/4" on up , but until I get my dream sharpener , for a bargain price at auction I will gladly continue to use and replace these handy grinders . The new factory in town has the big Darex , the
$ 5,000 unit and it is just a grownup version of my unit . Can't wait till they get the $900 attachment to do the 1 flute countersinks
09-18-2007, 01:16 AM #53
We have a darex M2 POS hasnt been right since the day we got it
09-18-2007, 11:44 AM #54
Expanding on my previous post--I have a Darex M3 and a truly ancient Black Diamond in my home shop. Sounds excessive and likely is, but both came my way fairly cheap, and I see why.
As far as accuracy goes, neither one has any title claim there. The Darex is not rigid enough in its fixturing. Plus, the drill holding chucks are always suspect with respect to concentricity, in my view. It is mostly the chuck holding fixturing that causes off center grinds. If the operator is careful about maintaining even pressure on the chuck and fixture during sharpening, you can do a credible job for non-critical use. I doubt it holds 0.003 inch concentricity or anything like that, and certainly not with any degree of consistency. Regrinding anything smaller than about 3/16 diameter gets difficult, and a 1/8 inch drill is a challenge (yea, who in a production shop even bothers, right?).
But with care it gets the job done better than any freehand regrind I have ever done or seen. Have reground a lot of previously freehand sharpened drill bits and it is always educaional to see the errors.
The Black Diamond is a more rigid machine with respect to the drill collet holding fixturing. The collets are certainly an improvement in precision with respect to drill holding. Problem is (unlike the Darex) it is susceptible to wear in the fixturing causing off center points. Again, an operator with a delicate, consistent, touch can resharpen ok for non-critical use. Smaller drill sizes (than the Darex) can be done more easily or consistently, but given the wear of my machine, accuracy is still a challenge.
Otherwise comparing the two, the old Black Diamond is inflexible with respect to changing relief angle (don't know about their modern machines, as mine dates from before WWII). The Darex is nice in that regard as it allows easy change of relief angle.
Both require an operator to have a sensitive feel, consistent technique, and ability to think about what he is doing, not just twist the chuck holder around without thinking.
While they have certainly been useful to me, am still looking for a better (and cheap) drill sharpener--not a likely combination.
09-18-2007, 01:41 PM #55
FlatBeltBob, Quote, "I love it , my CNC's love it , I sharpen & split new drills right out of the pack." Finally, another DD owner that has bothered to develope the simple skill to properly use the tool as intended! [img]smile.gif[/img] I'm betting that there is less variation in the quality of the DD than there is variation in the skill of the various operators. Too easy to give a half-assed attempt and write it off, "cheap piece of crap." You'd try harder if you gave thousands of $ for it.
Bet few of these guys stick NEW bits in their expensive Rube Goldberg grinders hoping for improvement. Too much trouble to remove collets, wipe tapers and new collet and you'd damn well better wipe if you want centered points. Jeez, why collets for tools with such a variation in diameters?
The DD and the simple but very capable Sterling for up to 3" diameter and you've got the lot covered!
Seriously, it is understandable that a full featured CNC drill bit grinder would be a good thing in a sharpening shop or a very high production shop, specializing in drilling. One that had the need to sharpen hundreds of bits a day.
Just dump a barrel full of various style, material, flute count, multi facet point thinning and diameter, dull bits into the hopper, push the button and go back to the production machines or for another barrel full of dull bits, while the 5 figures$ wunderkinder kicks out perfect bits unattended. Hell, for what they want for them, they ought to sort, stick the bits in indexes and put them on a shelf in the toolroom. Those activities take longer than it takes to touch up a bit on the DD or Sterling.
In the normal shop where less than a score of bits will need touch up a day, (unless you have a real learning dissability), it would be hard to justify the all bells and whistles equipment. Something about cost to value received in your lifetime.....
Oh, did you catch FlatBeltBobs, "my CNC's love it?" Not just a lowly hobby shop.
FlatBeltBob, do you run your CNCs with line shafting and flatbelts????
Just stirrin' the pot Bob