Drill Doctor 750X - Sharpening Large Bits............

[tlmartin84]

For starters, I have to say this thing was worth every penny and has paid for itself.

However, I have a set of M7 "large" drill bits, that range from 9/16-1" , and I cannot put an edge on them to cut with. Anything over 7/16" starts getting sketchy with the edge quality. I set them to 135 degrees, and then do a split point on them.

They feel sharp, stick them in the press and they won't do anything. Any suggestions?

 

[Bretny]

1/2in+ just hand sharpen. Once you get the feeling and look of the angles needed it's very easy. I can hand sharpen down to about 1/4in but below that gets iffy.

You really dont need the sweeping angle on the bit like the drill doctors grind to. Just two angles, the cutting edge and clearance out the back a bit.

 

[Bannik254]

Drill doctor doesn't put enough relief behind the cutting edge. I use the drill doctor for trueing up the drill geometry then add more relief by hand afterward.

 

[tlmartin84]

1/2in+ just hand sharpen. Once you get the feeling and look of the angles needed it's very easy. I can hand sharpen down to about 1/4in but below that gets iffy.

You really dont need the sweeping angle on the bit like the drill doctors grind to. Just two angles, the cutting edge and clearance out the back a bit.

I can sharpen by hand, the doctor just makes it quick and easy. I'd just like to figure out what the issue is.

 

[tlmartin84]

Drill doctor doesn't put enough relief behind the cutting edge. I use the drill doctor for trueing up the drill geometry then add more relief by hand afterward.

Is that problem just for the larger bits that the relief becomes a problem though? I would think it would be the same on the small bits as well.

The smaller bits sharpen so well, its like cutting butter.

 

[Slednut]

It's always ready to do it's job.

 

[Sumboodie]

Drill doctor doesn't put enough relief behind the cutting edge. I use the drill doctor for trueing up the drill geometry then add more relief by hand afterward.

Same

 

[Sumboodie]

It's always ready to do it's job.

That's an old one. They re-did them about 15 years ago.

 

[Slednut]

That's an old one. They re-did them about 15 years ago.

Yes, it came with a VHS tape as an instructional aid.

 

[seber]

It took me forever and a call to figure it out. It will do the job but the manual is worthless. Call the company help line and they will talk you through it. I guarantee no one can do it as well manually. I don't care what they claim.

 

[kenc184]

The drill doctor 750 only goes up to 3/4" I think, not sure how you'd fit in a 1" drill bit?
I have two of the old fashioned ones, one with a coarse diamond and one with a fine. Great tool.

 

[Sumboodie]

Yes, it came with a VHS tape as an instructional aid.

Yup. I had that one too. Recently upgraded.

Works decent enough. I have to sometimes touch up by hand, but it gets it 95% there.

 

[tlmartin84]

The drill doctor 750 only goes up to 3/4" I think, not sure how you'd fit in a 1" drill bit?
I have two of the old fashioned ones, one with a coarse diamond and one with a fine. Great tool.

Yeah good catch, my bit set goes to one inch. Largest I have sharpened (or attempted to) is 3/4".