drill doctor first impression

I grabbed a drill doctor 750X to play with. It sounds great in concept.
Here's my first thoughts from playing with it for an hour last night.
- construction is rather cheap, the quality of the plastic parts do seem
ok though, there' just too many of them. The thing wobbles around on the
table in the instruction video. The markings are crude and vague.
Everything it just a white dot. The parts are too complex for no reason.
I don't get it at all. The amount of knurles and holes and other crap on
the "dust cap" is mind blowing.
- the goofy looking cone device that holds the bit is just a chuck with
six sheet metal fingers for the jaws. It actually seems fine for the task.
- precision of the cam mechanism that lifts and rolls the drill bit across
the diamond drum is sloppy at best. It's just a bunch of plastic that
feels loose yet tight at the same time. It feels like there's plastic
springs in there, somewhere. The internal mechanism is some sort of cheap
die cast metal, but there's just too must plastic crap in the way for it
to be stable.
- the plastic door for cheaning out drill bit dust is a joke. It's like a
crappy remote control battery door that's too hard to operate and will
just snap off. It doesn't have to be made that way either. Cheap and fake
best describe that part.
Tried a 3/32" HSS bit at first. The thing leff jagged burrs all over the
cutting edge, had to stone those off after prying them up with my
fingernail. The bit works fine on wood, sort of struggles with aluminum.
The tried a bit around 1/16". Worked fine, no problems.
5/64th bit seemed ok, the cut surfaces still seemed too rough though, even
when cut with very gentle pressure.
Tried a cobalt bit that was also around 3/32" but had that weird high
speed spiral twist. Not sure what they're called. Tried to grind that to
132 degrees but the thing ended up completely flat like and endmill.
Something with the aggressive twist is messing up the "timing" of the
machine when you align the bit in the chuck. The video and PDF manual
mention nothing about how to deal with this sort of drill bit.
Next I tried the split point feature where you jam the bit into the side
of the machine and the side of the cutting drum cut into the bit at about
90 degrees. Since the fit of the plastic chuck and metal casting is tight
you have basically no control and it's all trial and error to even out the
flutes. What they show in the video is complete and utter nonsense.
The little machine really does cut bits rather quickly, but the cutting
drum is rather aggressive and the finish is really rough, even with a very
light touch. The cut surfaces are not smooth and really need to be stoned.
So far, it's a thumbs down. there's nothing the drill doctor can do other
than make a split point that I can't do by hand with my Tormek grinding
wheel. The Tormek can leave a mirror smooth finish if you want, and since
you can see and feel the cutting action you can control it quite
accurately, even by hand. Even if the angle you use is a little wrong and
both flutes match, you're golden.
I'll play with the thing some more to see what it does to larger bits and
to see if the thing runs better once the plastic starts to wear in some
more and the high points on the cutting drum get knocked off.
They seem to be a love or hate type of machine. Any other first hand
stories here with a drill doctor?
Reply to
Cydrome Leader
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I use one to save a drill. One that was broken or chipped.
It puts a cone nose on the drill, not two flats. The back edge needs relief.
I use cross point and never go small on drills - I do them by hand. I use the 3/4" holder and standard holder - about 1/4 or 3/8 is the smallest I'll go. Precision alignment must be done when setting up.
The cutting wheel is a diamond Ring. Do light cuts and don't get it hot and burn the diamonds up.
Martin
Reply to
Martin Eastburn
The stuff I do (all hobby and vehicle/tractor maintenance related) has me drilling holes in a wide range of ferrous and non-ferrous alloys. I seldom need to drill holes smaller than 3/16 - most holes are in the #6-5/8" range
I'm satisfied enough that I keep using my 750X; but I only sharpen regular HSS/cobalt twist drills - nothing with exotic twists, or tips.
One feature I seldom, if ever, use is the ability to grind split points. I find that I can't make them reliably on my 750X. I think that's because the fit of the chuck in the port is just too sloppy for precise positioning.
I concur with all your points about the device's borderline construction-but I think it's on par with its "economy" price point.
As to the finish left on my drills, I haven't had any severe issues with the grind finish you reported; I get reltively smooth "satin-like", no burs finish. I wonder if someone could have the coarse wheel in yours?
Bill
Reply to
Bill
Gee, I've been using a little gadget I bought at Sears in the 70s with great results. Has the same adjustable degrees of freedom as an industrial version I used in a Michelin millwright/machine shop mounted on a big pedestal grinder. The Michelin one handled over 2" dia. while mine only does less than 3/4". Dunno what it's called or who made it, unpromising pot metal construction but no problems in 40 years. Keep it mounted on its own little wheeled stand with a cheapo spindle, old pump motor and the right side-grind wheel.
Reply to
Mike Spencer
I bought a DD about 15 years ago and my first impression was it was a POS and I'd wasted my money but after playing with it for a bit and learning to use it and its quirks I quite like it and it gets used often enough to have more than paid for itself. I like the split point feature and often add that to drills which didn't have that before. Mine is the older style and if you have a newer one I thought they were supposed to be an improvement. Give it a bit more time before you write it off.
Reply to
David Billington
When Curt Anderson of DD was posting here he mentioned turning the chuck backwards after tightening it, until the blades were straight opposite each other instead of slightly spiral. When I do that it works pretty well most of the time. When it doesn't the angle in the center web is wrong compared to a new bit.
-jsw
Reply to
Jim Wilkins
No wonder there are so many bad reviews of DD, if the instructions don't tell you how to properly position the bit in the holder.
Reply to
Larry Jaques
The chuck doesn't have to be tightened that far to properly hold the bit, but it's easy to do if you are used to judging appropriate torque by size.
-jsw
Reply to
Jim Wilkins
General make one version which I will someday set up with a surplus angle driver for rough sharpening. Until then I will use my shop teachers "rock and roll" method as described by "Teenut". this leaves my DD750X to do the final grind which is satisfactory to my requirements. t
Reply to
geraldrmiller
When I first borrowed the B&D unit, I fell in love with it but when I saw the price I gave up. Then I saw what a chap with no idea of drill geometry accomplished, I gave up again. I bought the DD 750X for half the price and have been quite happy with it. Juniors FiL was impressed with the five pounds of "dead drills" I returned to him in usable condition, including the half inch concrete drill minus the carbide insert, dueley sharpened and labelled with a tag wired through a cross driiled hole reading "DRILL SHAPED OBJECT, USE ONLE TO MAKE HOLES IN ROOM TEMPERATURE BUTTER" - FiL totally lost it, but has availled himself of the service of my DD a couple times since. I am not impressed with the split point feature since it goes much too far, but the outcome does work. Broken bits and previous split points get a rough manual grind to extend the life of the wheel.
Reply to
geraldrmiller
Good info. Thanks.
Reply to
Bill

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