# drill doctor



## porthos (Oct 12, 2017)

thinking about getting a drill doctor 750. anyone have one or had one ? and if so; were there any issues that you may have  had that might stop me from getting one. i do a really bad job of sharpening my bits by hand.


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## Buffalo20 (Oct 12, 2017)

I have one and have worn out another, have done thousands of drill bits, with no issues. I wouldn’t be without one.


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## David S (Oct 12, 2017)

Do you have a size range that you wish to sharpen?

David


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## Doubleeboy (Oct 12, 2017)

My two cents.....  If your eyes are any good you can learn to sharpen bits larger than 3/16" pretty easy, its the smaller ones that using a machine is helpful for.  Drilling is a roughing procedure, if you need accurate dimension hole you follow that up with boring and then maybe a reamer.  I have a 15 year old DD, its okay but I only use it on the bits under a quarter inch in size.  Personally I find the DD to be a bit gimmicky, made of plastic, takes some fiddling to get it to do a 118 degree bit accurately and takes for ever to do a bit that has a lot of damage, IMO its basically a touch up tool.  The really small bits that won't fit correctly in DD collet I do by hand with a stone, or just chuck em and grab a new one.


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## NCjeeper (Oct 12, 2017)

I use the DD 500 with decent success. Bits bigger than 1/2 I sharpen by hand.


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## menace (Oct 12, 2017)

I have a DD 750 and hundreds of drill bits which I sharpen every few years so the diamond wheel needs replacement! With a fresh wheel I can split point nicely with great results. Great little machine!


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## kd4gij (Oct 12, 2017)

I have an original dd 750 and been happy with it.


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## randyjaco (Oct 12, 2017)

I have both the 750 and the 500. They do a great job.

Randy


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## porthos (Oct 12, 2017)

thanks guys. i'm going to put that on my "buy" list. i will be using it for touch up. i can probably get close by hand ; and use the drill dr. for finish


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## Wreck™Wreck (Oct 12, 2017)

Doubleeboy said:


> Drilling is a roughing procedure, if you need accurate dimension hole you follow that up with boring and then maybe a reamer.


Just a question, if you set up a machine for a boring operation why would you use a reamer afterwards? Would not drill and ream be more expedient.


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## T Bredehoft (Oct 12, 2017)

Drill  bore, ream will give a more accurate hole. not perhaps rounder, but more in the correct place. Ream for exact size, easier than boring to that size.


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## woodchucker (Oct 12, 2017)

T Bredehoft said:


> Drill  bore, ream will give a more accurate hole. not perhaps rounder, but more in the correct place. Ream for exact size, easier than boring to that size.



I have had both good and bad luck with reamers. Sometimes they come out oversized, using a correct size, not an over, or under reamer. If I am worried and don't want to bore, I'll ream under and lap to size. As far as it being concentric, I think boring is the best choice.
My opinion, yours may differ.. that's ok too.


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## tweinke (Oct 12, 2017)

I have a 750 and it works well for many bits but there are some bits that just defy sharpening in the thing. I think it is due to the flutes not being a standard twist.


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## Doubleeboy (Oct 12, 2017)

Wreck™Wreck said:


> Just a question, if you set up a machine for a boring operation why would you use a reamer afterwards? Would not drill and ream be more expedient.



I could be wrong, but when I was in school we were taught drill, bore, ream if you want accurate hole.  If your drill takes a turn east or west while drilling, the reamer will follow it.  A sharp boring tool will more likely straighten the hole out, then ream to final size.


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## royesses (Oct 12, 2017)

I have a tradesman 500, the older tall green one. I've had it too long to remember. It does a great job on drills up to 1/2". Above that I sharpen by hand on a bench grinder. As with any machine you need to develop a feel for it and this takes a little bit of time. Follow the instructions provided with it and then practice with a few drills. It is worth the price if you are old and have problems with your eyes and maybe not a steady hand. It is a good idea to get one or two extra diamond wheels. Also it is a good idea to get a drill angle gauge to check for equal length on the cutting lips. I also have the left hand chuck for it. Just don't have the 3/4" chuck and it is no longer made.

Roy


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## Bob Korves (Oct 13, 2017)

Drill grinding machines and aids, all of them, work but are not foolproof.  Same with doing it by hand and eye.  You have to know what you are looking for in the finish grind, and know how to get there.  At a bare minimum, read the instructions, beyond that some study of drill geometry and how drills work is necessary.  Then you have to understand how to adjust the geometry to get the desired results.  All quite doable, but just being in the dark and making sparks will not get good and consistent results -- with any method.  I have a DD750, an old Craftsman swing jig that mounts next to a bench grinder, and my eyes and a grinder rest.  I get excellent results using any of those methods.  The DD is the least fussy of them.


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## chips&more (Oct 13, 2017)

Well, I guess I’m alone on this one. I have used a DD and was not impressed. Cheap construction for one. Hard to control equal land grinds on the bit for two. I can keep going… I sharpen by hand even small ones like #80 using a loupe and abrasive disc. I have a Darex, does OK, a little better construction but not totally the best. I have it set-up for 135° split point…Dave


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## yendor (Oct 13, 2017)

I have a DD 750 as well and have found it very useful in keeping bits sharp.
If I have a bit that is really bad I either hand grind to close (as I am not a great free hander) or toss it.


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## Sleddog (Oct 13, 2017)

Wouldn't an affordable DD type of end mill sharpening tool be nice


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## Alan H. (Oct 13, 2017)

Have both, good results.  I like sharp bits.

A very economical solution.


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## BGHansen (Oct 13, 2017)

I have a DD 400 (older model) and have had very good success.  Like others do larger bit by hand using a General gauge for angles/depth.

Bruce


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## jim18655 (Oct 13, 2017)

I have one and it's OK after the learning curve. I found out the relief isn't correct and you need to set it a little more otherwise it makes a sharp bit that won't cut. Also, you need to reset the bit in the holder if you need to remove a lot of material or else the center setting changes too much.


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## maker of things (Oct 13, 2017)

I have the 500 and like it so much I bought one at work too.  Many of the guys could never get a good bit out of it.  Turns out it's a machine, like many others, that there is a technique required in order for it to work correctly.  I think the idea of it being a "drill bit sharpener" throws some people off.  A "pencil sharpener" more or less sharpens the pencil when you just stick it in there, while the DD is really a bench grinder with alignment fixture.  If you don't set it up per the instructions, the bit will not get sharp in any way that is useful to you.  I had to reread the instructions several times I sharpened bits before the order of operations and proper alignment stuck in my brain. 

It probably doesn't help that most of the time we are trying to sharpen bits we are just trying to real quick get something done.


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## Bob Korves (Oct 13, 2017)

jim18655 said:


> I have one and it's OK after the learning curve. I found out the relief isn't correct and you need to set it a little more otherwise it makes a sharp bit that won't cut. Also, you need to reset the bit in the holder if you need to remove a lot of material or else the center setting changes too much.


Yes, the "tooth rest" contact point makes a difference in all these jigs.  Drill extension beyond the tooth rest changes the geometry of the grind.  Different helix angle drills also require different amounts of stickout beyond the tooth rest.  It also matters how aggressive of a grind you are trying to achieve.


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## Groundhog (Oct 13, 2017)

I have a DD 750 but also sharpen by hand. I think the success with drill sharpening comes more with knowledge than the apparatus. I've seen people who can't sharpen a simple drill with the DD because the do not use it properly (like not getting both flutes even),  just as I've seen people who can't sharpen a drill by hand because they haven't learned how - free hand or with a jig.
Either one works for me and is easy once I learned how, but before I learned the finer details of either method did not produce very satisfactory drill bits.


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## 4GSR (Oct 13, 2017)

I had a DD 400 or 450, I don't remember now.  It did okay on sharpening bits.  Upgraded to a 750.  What a POS!  Could not get one single bit sharpen where it would cut!  My hand ground sharpen one cut much better!  I also have a older Dartex M-2 I use now.  So much easier to sharpen using it over the 750 in my opinion.


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## Wreck™Wreck (Oct 13, 2017)

Doubleeboy said:


> I could be wrong, but when I was in school we were taught drill, bore, ream if you want accurate hole.  If your drill takes a turn east or west while drilling, the reamer will follow it.  A sharp boring tool will more likely straighten the hole out, then ream to final size.


Boring is a precision method of making holes itself, if you set up for boring why not just bore to size and skip the ream?


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## Doubleeboy (Oct 13, 2017)

Wreck™Wreck said:


> Boring is a precision method of making holes itself, if you set up for boring why not just bore to size and skip the ream?


Beats the tinkle out of me, maybe because a fresh reamer gives a better surface finish.


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## Artie (Oct 13, 2017)

I have two of the original 750's that I purchased cheap (nos). Supposedly the motor on the originals were more robust. It was frustrating establishing a repeatable technique with satisfying results.
The DD is great for touchup sharpening once the learning curve is achieved. For really dull or damaged bits I first rough with the bench grinder and finish up with the DD.
I have an inexpensive Northern Tool Klutch stand/mount that converts a 4 1/2" angle grinder into a mini chop saw. It's perfect for sizing old jobber drills into stub/screw machine bits. After hand grinding/roughing with the grinder I finish up those too with the DD.


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## Wreck™Wreck (Oct 13, 2017)

Doubleeboy said:


> Beats the tinkle out of me, maybe because a fresh reamer gives a better surface finish.


Have never seen this in practice though in some instances it may be. Having to reverse the tool out of the hole often leaves visible artifacts on the surface.


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## mikey (Oct 13, 2017)

Doubleeboy said:


> Beats the tinkle out of me, maybe because a fresh reamer gives a better surface finish.



On the occasions when I use a reamer, I am looking for a straight hole with a decent finish. A sharp reamer will produce a really nice finish but it won't produce a consistent size or finish if the hole is not straight first. When it matters, like with a boring bar holder, I will drill to rough, bore to size and straighten and then ream to finish. Works for me.


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## coherent (Oct 13, 2017)

I had the basic 350 model used it lots and worked great but it was only for 118 deg bits.  Just finished building metal building and while building it was going dulling my good metal bits fairly rapidly (prob drilled over 1000 starter holes). Bought the better model that sharpen 135 degree bits and convex and split point bits and it worked great. Sharpened to like new.  I do a lot of metal work and drilling, so well worth it to me.


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## Doubleeboy (Oct 13, 2017)

Wreck™Wreck said:


> Have never seen this in practice though in some instances it may be. Having to reverse the tool out of the hole often leaves visible artifacts on the surface.


 
I was taught to never reverse the direction of rotation of a reamer.  In my experience,  the fastest way to screw up a nicely bored hole is to use a dull  or dinged up reamer or to make the mistake of reversing spindle when removing.


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## Wreck™Wreck (Oct 13, 2017)

Doubleeboy said:


> I was taught to never reverse the direction of rotation of a reamer.  In my experience,  the fastest way to screw up a nicely bored hole is to use a dull  or dinged up reamer or to make the mistake of reversing spindle when removing.


Reversing the tool feed direction not rotational direction.
It is possible in certain applications to pass a reduced shank reamer through a hole in the cutting direction only thus eliminating the need to pull it back through in the opposite direction, this is much like using a nut tap.


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## KMoffett (Oct 14, 2017)

Craig's List Drill Doctor 1400
Ken


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## gi_984 (Oct 18, 2017)

Got a DD750 at an estate sale years ago.  Brand new in the packaging.  It worked okay on light resharpening duties.  Too light for any major regrinds.  There is a lot of flex in the plastic parts.  Having used a Black Diamond and Darex sharpeners in a working shop sure spoils you.  Then I found a deal on a mint condition SRD for home.  That thing is worth every penny of the $400 I paid for it.  I was going to toss the DD750 until I remember it was supposed to split points.  Tried it out after sharpening on the SRD first.  It did better than I could by hand on the sub 3/4 drills.  So the DD 750 currently resides next to the SRD just to split points.


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## woodchucker (Oct 19, 2017)

gi_984 said:


> Then I found a deal on a mint condition SRD for home.


What's an SRD?


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## KMoffett (Oct 19, 2017)

https://www.google.com/search?q=SRD...B24MKHWdQDZcQsxgIJw&biw=1501&bih=694&dpr=1.25

Ken


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## gi_984 (Oct 19, 2017)

Yep,  Ken is correct.  They have been in business a long time.  Still make new ones. But if you find one in good shape at a reasonable price grab it.  Mine was in new condition with extra wheels. Bought it from a retiring machinist who bought one for his home shop.  He barely used it.  Company is still in business and parts are available if you find a fixer upper.  Strongly suggest you test in person versus buying from e-bay unless the seller accepts returns.


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## GarageGuy (Oct 24, 2017)

I have a Drill Doctor 500 that I bought for $40 on Craigslist.  It works great.  If I'm sharpening 10 or more drill bits, I use the Drill Doctor.  Fewer than 10 and I just do it by hand because it's quicker than setting up the machine.  The DD 500 will only sharpen bits up to 1/2", so anything larger I do by hand as well.  One of the car club guys has a shop, and every drill bit he owned was shot.  I sharpened 75 drill bits for him on the DD.

GG


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## unioncreek (Oct 25, 2017)

I have a DD 550 I only use it on drill bits smaller than about 3/16".  Much faster to sharpen by hand once you get the hang of it.

Bob


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