DBS 22

[CleanCut]

I have used the DBS22 on about 10 bits from 4 to 10 mm. Took me a few hours but getting the hang of it. Now for the but! I can shape the four facets BUT I can't get the primary facets to meet at a point. I can increase the secondary facets so that the primary facets become a narrow strip but a chisel point remains. If I go beyond this then I grind out the primary facets. Where am I going wrong?

[Stickan]

I think you need to take two steps back ;-) Your missing something, cant figure it out but you should check out the video if you dont have done that

http://tormek.com/international/en/grinding-jigs/dbs-22-drill-bit-sharpening-attachment/

and then follow the instruction again. Every step is neccesery to follow.

Stickan

[CleanCut]

Thanks Stickan, I was beginning to think there were no users of the drill bit jig in the Forum. I have rechecked the videos and the instructions and think I am following the advice. Are you able to get the 4 facets to make a point?

[Stickan]

I do, but the first time I tried it I forgot to use both the primary and secondary depth adjustment screw and then the drillbit was no fun!
I moved the holder to the secondary screw but adjusted the secondary depht with the primary screw. And that made it hard to get it right.

[Herman Trivilino]

There are a few users of the DBS-22 on the forum, it's just that they haven't been around the last few days.  They'll be back soon.

[Ken S]

I have a DBX-22 and have used it successfully.  It takes some practice and "fiddling".  It does a very nice job, but I haven't gotten to the skill level where I can "set it and forget it". 

I recommend sneaking up on grinding to match the edges.  Once you get the edges right, it makes  very impressive edges.

Good luck, and keep us posted.

Ken

ps I find the bits closer to 10mm easier to learn with.

[CleanCut]

OK, I think I have it! Favourite tipple in hand and another (more) careful read of the instructions and I find on page 10, diagram 6 from the top: "Grind alternatively both the primary facets until they reach over the centre of the drill." This is counterintuitive for me and hence ignored! I did not grind over the centre of the drill. I will follow the instruction and let you know the result. Thanks for your suggestions.

[Stickan]

Thats going to solve your problem! When you then are doing the secondery facett you need to use the magnifier to see that the tip will be perfect!

[CleanCut]

I failed again. Working on a 8 mm drill bit, I was unable to get the primary facets to extend past the centre of the bit. Symmetry prevailed, the two primary facets refused to cross the centre. The leading (cutting) edges of the primaries lined-up across the centre of the bit no matter how much HSS I removed. When I grind the secondaries, I continue to get a chisel point of about 1.5 mm. I used a setup of 11 and 118 degrees. Help!

[Ken S]

Cleancut, I am winging this answer, as I have not used my DBS-22 in a while.  That stated, I believe you may have removed too much with the primary facet grind.  Try removing enough with the secondary grind setting to completely remove the primary facets.  Then set up to primary and proceed very slowly.  Check frequently.  Sneak up on matching the facet lines.  Start with barely removing any primary facet metal.  Note where the lines are.  Then set the adjustment to do just a little more.  Your lines should be approaching each other.  Go slowly.

This may seem tedious, however, once you get the hang of it, it will go faster.  And, you will like those crisp four facet edges.

Keep posting.

Ken

[CleanCut]

Thanks Ken, I like your alternative approach! If I follow you, after I have got near to establishing the four facets, I remove the primaries by over grinding the secondaries and then reestablish the primaries. I like this idea as there would be much less grinding with the primaries as the four facet end point is approached.

I should add that as I look at my last effort on an 8 mm bit in good light (I must do something about that) I have got the cutting edges of the primaries to be just past the centre line - with a lot of grinding. I stopped there because any further advance on the secondaries would have removed the primaries after all my hard work. I will now try Ken's innovative method on this bit!

Thanks to Strachan for the offer of FaceTime help.

[Ken S]

I have found Alan Holtham's DBS-22 video useful.  My one suggestion would be more concentration on aligning the primary facet leading edges would be useful.  I realize that no company wants to leave an impression that a product is difficult to use.  The DBS-22 is not difficult to use, however, it does take some practice.  The results are worth the effort.

Ken

[CleanCut]

I am pleased to report that I have succeeded in grinding four facets as per instructions and videos! My difficulty was a lack of belief that the narrow width I was leaving for the primary facets would not survive drilling through tough material (jarrah, HSS). The width of the primaries on a 8 mm bit are less than a mm. Having never seen a four facet grind and only familiar with the amount of steel of the primaries on the usual 2 facet grind I had a disbelief problem. On reflection, it is only the leading edge of the primaries that do the cutting, the secondaries are to get unnecessary steel out of the way. So, why not reduce the bearing surfaces of the primaries to a minimum.

Thanks to the Forum and to Stickan for your help.

I would be interested to know the history of the 4 facet grind for drill bits. None of my references mentions it. Any help among the Forum?

[Ken S]

Thinking about the DBS-22:

I have an old Belsaw key cutting machine.  The depth of cut is controlled by a micrometer head. The threads on the depth of cut adjusting screw on the DBS are .5 millimeter, or roughly .020.  The standard threads on most micrometers are 40 TPI, or .025.

With that in mind, using a bit large enough to easily see, we should be able to get a rough idea of how much of the primary facet is removed from adding just a partial turn beyond the initial contact.  I'm sure there is some trig to support this more exactly, but a good eyeball would put is in the ball park.

I will do some experimenting with this the next time I sharpen drill bits.  In the meantime, I thought I would throw out the idea to the forum.

Ken