Being semi-new to Mercedes (Mercs...Benzes?), it will be awhile before I have any good advice for all the experienced Mercedes mechanics out there. Instead of just trying to harangue people with my strident agit-prop, perhaps I can share my experience with a tool that some of you may have thought about buying.

The Drill Doctor drill bit sharpener may seem extraneous, I mean bits aren’t that expensive, but if you’ve ever been trying to finish a job either after hardware stores have closed or a long drive from one, and you discover that all of your ¼ inch bits are hopelessly dull, this little item could pay for about half of itself in one day. Whoever coined the phrase “a poor workman blames his tools” never tried to drill through ½ inch of steel with a dull bit. Then again, I think the essence of that saying is that a truly good workman will know how to make or at least maintain his tools. And so, in that spirit…

The makers of Drill Doctor make big, professional bit sharpeners as well, so they know these things. This model doesn’t look too heavy duty but it gets the job done. I could never quite justify the investment (about $150 though the price is going down) until I was installing a horizontal propane tank under my step van and needed to drill a 3/8 hole in the frame with only a few inches to do it in. I’ve got the Sioux close quarter drill (another nice tool) but I needed a bit that protruded from the chuck ½ inch or less. I couldn’t just cut the tip off and use that because I learned years ago that a 3 jaw chuck will not grip the fluted end and drill straight, at least on bigger bits.

I cut the bit so that I had some shank and maybe an inch of flutes. The flutes are shallower toward the shank side so it didn’t sharpen up in the normal way but I did manage to drill the hole in the frame.

I got the version with the ¾ and ½ inch chucks. A lot of the guys I work with have at least a few twist drill bits (as opposed to spade or forstner) between ½ and ¾ inch and they’re a lot more expensive than the smaller bits, so I especially wanted to be able to sharpen those. The 6 and 12 inch long bits are a bit steep as well and it’s a drag to throw those away when they’re dull.

It does split point and regular bits as well as carbide tipped concrete bits. It’s a bit of trick to get the split points right; a magnifying glass comes in handy, is almost essential actually. I can do a ¼ inch split point in maybe 3 to 5 minutes. At 2 to 3 bucks a pop, that’s around $30 an hour in savings – not too bad for part time work but the convenience of never being without sharp bits is the real benefit. Bits smaller than 3/16 are almost not worth doing, at least in split point, the other way works well enough.

The honing wheel is diamond encrusted – the bits don’t even get hot. I bought a spare wheel for around $20 and I haven’t needed it yet.

My Amazon stock is hurting, so give it go, won’t you. The basic unit is pretty weak, I’d go for the flagship model.

http://www.amazon.com/exec/obidos/tg/detail/-/B00004U8PE/qid=1116559786/sr=1-1/ref=sr_1_1_etk-tools/103-5130462-5272615?v=glance&s=hi&n=228013

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Te futueo et caballum tuum

1986 300SDL, 362K
1984 300D, 138K

I purchased that exact same model about six months ago when some guys over on the mbz.org diesel list were raving about them. At the time there was a "Buy It Now" price offered on Ebay for ~$120, so I think about 6 or 7 of us picked them up. Sad to say, I haven't found time to test mine out yet, but I do have a box full of dull bits waiting in my shop.

I'll be damned. And here I thought I was breaking new ground. Mine came with an instruction video. Not hard to learn. I need to get a better magnifying glass, or at least a bigger one. I use the one on my Swiss Army Explorer knife, which I saved from my days in the Swiss Army. It's a great little lens, high quality, but small.

With the glass, you can see the dullness of your old bit and then marvel at the exciting newly honed surface! Yes, you and your friends can have hours of fun!

Whoa, back to reality, the split point thing needs a magnifying glass, cuz you can go too far and then you have to start over. You'll see....

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Te futueo et caballum tuum

1986 300SDL, 362K
1984 300D, 138K

The larger stuff I can do well by hand on a bench grinder, it's the small stuff I can't do and never have a new one when I need it. How does it work on 1/8 or so?

Jorg

You're a better man than I am.

I'll tell you though, I bet it would be damn near impossible to do split points on a bench grinder.

I haven't tried 1/8 bits in a while. I'll give it a shot and get back to you. It'll be a few days. My warehouse/office is about 40 miles away (long story, not the best deal, spaces like that are harrrd to find around here) and I won't be there for a few days.

__________________
Te futueo et caballum tuum

1986 300SDL, 362K
1984 300D, 138K

I'm not sure what a split point is. I was taught how to sharpen them in shops class 3+ decades ago and although I've tried jigs in the past I've always gone back to sharpening them by hand.

I was told stainless was the best compromise bit for re-grinding and that cobalt, etc. wasn't suitable. True?

Jorg

I was taught by my father the way to grind them by hand. The only thing I use to get them right is a L.S. Starrett drill point gage. It tells me if I have the correct angle and also measures the lips (cutting edge) of the drill I'm sharpening. When the angle and the lips are right your drill will have shavings coming out of both flutes. I have seen the Drill Doctor work and I think that they are a neat little tool and time saver.

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1983 300-D turbo
1985 300-D turbo
1959 Harley Panhead chopper
1929 Ford coupe restored
I hang out with Boneheaddoctor at Schuman Automotive OBK#5
All liberals are mattoids but not all mattoids are liberal.

Howdy All,
We have one at work that works quite nicely, very handy item to have around.

__________________
Frank X. Morris
17 Kia Niro
08 Jeep Wrangler 4 door unlimited

The easiest way to see what a split point is would be to look at a semi-big one, say 3/8 to 1/2, with a magnifying glass and compare it with a regular one. It will say on the label if it is or not. I don't know how well I can explain it, but here goes.

First, the benefit of a split point bit is that it is a lot less likely to skate across a metal surface before it finally finds a purchase. Of course, you can just use a punch to start a little dimple to avoid that but the split point (SP) saves time.

The angle is different between standard and SP, not sure why, I believe it is 135 degrees for SP and 118 for standard, 118 looks sharper. The drill doctor has a little gauge built in to the front -- you hold the bit up to it to determine the angle, though it can be a little hard to see. It has a grinding setting for each angle. You chuck the bit into the 6 jaw chuck, there is a centering device to get the flutes in the proper relation to the cams on the front side of the chuck. For both standard and SP, the initial procedure is the same -- you rotate the chuck in one of the openings, the cams give the proper angle on the flutes.

The standard bits are done at this point. The SPs go into another opening and the back side of each flute, the non-cutting side, is ground at a steeper angle, fairly steep actually, on each side, so that when you look at the bit straight towards the head you see a sort of cross effect, and the normal little wide spot between the flutes, about 1/16 or so wide on a 3/8 bit (I'm guessing), has been reduced to almost a point. The point prevents the skating. You have to be careful on the SP part -- the first stage is pretty easy -- the SP part requires a delicate touch and frequent examination with the magnifying glass.

I wish I was a better metalurgist, but I don't believe I've had trouble with any of the different type bits, cobalt or otherwise. I recall from a tool maker friend of mine years ago, that you don't want to get the metal too hot when you sharpen tools. Of course, most guys know this -- you keep a water plunge nearby. I don't know how many times though, when grinding a pitted wood chisel down, I've gotten impatient, didn't quench it soon enough, and produced a discolored part which usually means you've reduced the quality of the temper somehow.

Even after numerous passes in the Amazing New Drill Doctor (pat pending -- I ought'a be selling the damn things at state fairs), the bits never seem to get hot. Must be the diamond wheel. Perhaps the grinding wheel method is what limits the type of metal that works well, that is, certain metals might get too hot or be too hard for a standard grinder to adequately handle, again, I'm guessing.

I might have to check one of those out. Might be easier than the gauge on the D.D. Does that measure the cutting angle of the flutes or the angle of the overall point to the shaft? The latter is what I need.

And now, ONWARD....into further discoveries!!

__________________
Te futueo et caballum tuum

1986 300SDL, 362K
1984 300D, 138K

Well I wouldn't know what to believe coming from El MIRAGE, Cahl - ee -FOR - nya.


ps: You would not believe the crap I get onna account of living in the People's Republic of Bezerkeley, CACA.

__________________
Te futueo et caballum tuum

1986 300SDL, 362K
1984 300D, 138K

Go to http://catalog.starrett.com/offices and look for Drill Point Gage #22C EDP #50151 and you will find the full particulars on it.

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1983 300-D turbo
1985 300-D turbo
1959 Harley Panhead chopper
1929 Ford coupe restored
I hang out with Boneheaddoctor at Schuman Automotive OBK#5
All liberals are mattoids but not all mattoids are liberal.

Howdy CMAC,
Ah!¡ Berkeley and El Mirage at opposite ends of the political spectrum. That's the variety called California.

__________________
Frank X. Morris
17 Kia Niro
08 Jeep Wrangler 4 door unlimited

Not another drink like it!

__________________
Te futueo et caballum tuum

1986 300SDL, 362K
1984 300D, 138K

I have one that I have used about 50 times with great success. I drill a lot of steel and it's a real time saver to keep bits sharp. My 9/16 and 5/8 I still do by hand, but for everything 1/2 to 1/8 it works great. It is very useful on unique bits, like the ones inside wood screw countersinks that have a flat side (and thus can't be replaced by regular bits when they break). I've never had a problem with them wandering, but I center punch and go up in ~1/4" increments when I drill, hand or press, and I use cutting fluid on the heavy/hard stuff. The drill doc is well worth it.

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1982 Mercedes-Benz 300CD
1982 Mercedes-Benz 240D - stick

Any of you guys ever owned a ' chain drill "?
This is a portable hand operated drill which has an adjustable length chain which goes around the object to be drilled....and forces the drill forward with threads...
Some things like frames are made from very hard steel... I watched a guy use a hydralic floor jack to press his electric drill into my Ford pickup chassis to install a receiver hitch... I was sure glad I had not tried to install it myself...
The chain drill has been praised in at least one of " The Machinist's Bedside Reader" by Lautard... particularly interesting books... ( series of 3 ).