Help with DBS-22 Drill Bit Sharpener Issue

[chrisrosenb]

I searched for this problem & did not find anything.

I recently got a Tormek DBS-22 Drill Bit Sharpener.
Yesterday afternoon I set it up & started sharpening a bit.
I watched the online video several times.
I set the jig up as to the manuals directions.
I used the angle of the old bit  120 degrees.
I set the clearance angle at 11 degrees.

For some reason the clearance side of the face is coming out taller than the cutting edge. The opposite of what it should be.
I cannot figure out what I am doing wrong?












 

[ionut]

Hi Chris,

I do not have much experience with the drill bit jig yet, but based on the instruction manual I believe there is a problem with the setting of the angles. In my opinion the clearance angle should be set in relation to the point angle and not necessarily with the size of the bit. Lets say, if you set the clearance angle to a value, and that value stays set and you start varying the setting of the point angle, after a value of the point angle going lower after one point you will always end with a negative clearance angle in relation with the cutting edge, like I believe it already happened to you based on your last picture. Did you try to set the clearance angle to 14 degrees for the 120 setting of the point angle?

Ionut

[Ken S]

Hi, Chris.

I'm in the same boat as you: new DBS-22 owner.  I haven't had a chance to try it out yet.  You mention watching "the video".  Which one.  I have found a couple, both of which seem good.  Here are links:

http://www.youtube.com/watch?v=fSUa1iFUzkM

http://www.howcast.com/videos/418394-Episode-66-Tormek-DBS22

Ken

[ionut]

Hi Chris,

After reviewing the process and your pictures, the last one shows the primary facet which in my opinion you ground too much for it, but if you look close to the cutting edge the clearance angle looks right, if you look towards the end of the ground area yes that seems to be higher than the end of the cutting edge, but that will be ground down when you will take care of the secondary facets as the drill holder will have to slide to the second stop (S) and that would make the secondtary facet clearance angle more acute.
I will try today to put the jig to work and will let you know how it works for me.

Ionut

[chrisrosenb]

Thank you for the replies Ionut & Ken.

The biggest problem I find with the manual is that the used drawings instead of real pictures.
In the drawings they show that the heal is much shorter than the cutting edge.
In the videos they show grinding the entire face but the cannot show a clear closeup of the clearance angle.
When they grind the secondary face they do not grind the heal, they only grind the cutting edge.

The only way I can get the heal to come out shorter than the cutting edge is to align the cutting edges with the angled line on the face of the jig.
But I cannot grind the secondary face without changing angles.

There has to be something simple that I am missing, I am just very disappointed that Tormek has been of zero help on this.   

[ionut]

Hi Chris,

I have just sharpened a bit three times just to play with. I think by following the manual you will obtain the result they show. There is nothing wrong with the steps you followed when you first posted.
The primary bevel is the one that deals with the cutting edge. The secondary bevel starts from the heel of the primary bevel and closes up to the cutting edge but it is not supposed to touch it. That is also why when the S nut is adjusted for the depth of the cut the manual suggests 1-1/2 turns for start because actually the grinding for the secondary facet takes more material,
My bit I've tried was a 3/8" HSS bit with a 135 point angle and they don't say anything about the clearance angle. The bits in that set are a very good quality, anyways, I started with replicating the 135 angle but setting up for an 11 degrees clearance angle which is common. After I ground one of the primary facets the bit looked kind of yours in the last picture, but when I looked with the magnifier glass the clearance angle at the point when the cutting edge meets the spiral edge was actually correct. At the heel of the grinding it was looking like it was at the same level with the cutting edge which I agree is confusing. When I started with the secondary facet the heel was properly ground, after 1 1/2 base turn of the S knob, I started creeping towards the cutting edge but the wheel will not catch it if the depth of the cut is correctly set in small enough increments. With the secondary bevel you have to stop when the chisel end at the tip is being reduced to a point by grinding the secondary bevel.
The second sharpening was to change the point angle to a 118 and the I reground at this angle only to check for the consistency and it all worked great.
I suggest you to try regrinding the bit following the steps in the manual but before that mark the previous ground surfaces with a marker, that will allow you to see where the grinding takes place.

Ionut

[Jeff Farris]

Thank you for the replies Ionut & Ken.

...
When they grind the secondary face they do not grind the heal, they only grind the cutting edge.

...

This is backwards. When grinding the secondary angle, you are not cutting at the cutting edge at all, but behind it.

[chrisrosenb]

Thank you Ionut. I understand now. I reversed the p & s faces on the bit. I got those reversed from the first video I watched & never caught that I had it wrong.
As I said I was missing something simple.

This is where real pictures of each step of the process would be helpful instead of a drawing of the finished product with lines trying to show each step.

Below is a bit I just sharpened. It is not perfect, but it is a start & I understand it now.
Thank you again.

Chris

[ionut]

You're welcome Chris, I am glad the things turned out OK.
Pictures are always better but I believe the drawings in the manual are OK too, I think the manual explains well the process but that is my opinion.
Your bit looks almost perfect, the essential part is to have the facets properly ground and to have them create a point tip instead of a chisel. But don't worry, I got the same results first times. If it is about using one full turn of the P knob for the primary bevel depth of cut I always get to something like in your picture, instead if I am using half turn of P knob or one turn combined with positioning the bit a hair anti clockwise in relation with the horizontal lines I get the proper result.
If your primary bevels are properly defined and your secondary bevel does not reach the cutting edge towards the extremity of the bit and you end with a point tip that would be OK even if the primary bevels are not looking like in the instruction manual with parallel edges.
Based on your last picture your bit would require just a bit of secondary bevel grinding to reach to the point tip but that would probably touch the cutting edge.
As soon as you start grinding the primary facet the cutting edge moves clockwise as the steel is being removed in direct relation with the depth of the cut so for deeper cuts you would have to take in account this aspect. For a normal worn bit without too much material to be removed I don't see a need to set for a larger depths of cut than 1/2 turns for P and more than 1 turn for S.

All the best,
Ionut
PS thanks for the pictures they look great.