Sharpening Drill Bits Smaller than 3mm (1/8")

[RickKrung]

Is possible though the use of a small pin vise (or similar). 


I just put a four-facet point on an 0.92" (2.33mm) drill bit that is the pilot drill for a screw head countersinking tool.  The point really isn't that pretty but it works, whereas if not sharpened it might have been tossed. 




Positioning the flutes was tricky, but this drill bit had an exceptionally wide web so maybe more normal (thinner web) drills will be easier.  I used the DF diamond wheel and the material really came off the drill bit fast, so very slow and gradual feed and a gently touch was necessary.  I may try it with the DE wheel to see what that is like.  I think the grind finish from the DE wheel would better suit such small drills anyway. 

I didn't like the knurling on the barrel of the pin vise I have and it's collets don't allow full length insertion, so I will try a so called "Precision Pin Vise" from MicroMark.  Holds down to 0.039" drills and I don't think I want to be trying anything smaller. 


Rick

[RichColvin]

Rick,

This is brilliant!   Putting this on SharpeningHandbook.info soon.

Kind regards,
Rich

[RickKrung]

Rick,

This is brilliant!   Putting this on SharpeningHandbook.info soon.

Kind regards,
Rich

That would be cool.  Please let me work with you by providing some better/different photos and maybe info on further trials.  I'd like to get it worked out to where the points are "pretty" as I think they'll be more functional. 

Rick

[RichColvin]

Rick,

Sure, np.  You've got my email.

Kind regards
Rich

[Ken S]

Interesting work, Rick.

Ken

[courierdog]

After talking to Rick via email. The use of some means such as a pin vice to simulate a larger drill bit for the DBS-22 drill bit clamp. I have ordered a set of pin vices via Amazon and will continue on with Rick's idea. Rick has a great idea that just must be pursued. I even contacted Mats at Tormek Support and he also agrees there is a need for a simple means to sharpen sub 3mm drill bits

[RickKrung]

After talking to Rick via email. The use of some means such as a pin vice to simulate a larger drill bit for the DBS-22 drill bit clamp. I have ordered a set of pin vices via Amazon and will continue on with Rick's idea. Rick has a great idea that just must be pursued. I even contacted Mats at Tormek Support and he also agrees there is a need for a simple means to sharpen sub 3mm drill bits

Yes, we have been discussing this via PMs.  I do not recall now who came up with the idea of using the Starrett pin vises, but I bought two sets (accidentally).  Having two sets is actually very good, as I think the hexagonal handles present a problem for adjusting the drill bit flutes and I plan on turning them down to round (on one set only).  I am including my explanation from my latest PM for more detail...

I am confident the Starrett pin vises can be set/clamped in the DBS clamp so that the tip of the drill bit can extend only a slight amount beyond the tip of the pin vise.  That should be easy enough to do when securing the drill bit in the first and then securing the pin vise in the DBS clamp.  It is the hexagonal handles on the pin vise that present the problem, however. 

Given that the pin vise handles are hexagonal, they will clamp in the DBS in only one of three to six ways, when it comes to orientation of the drill bit flutes in relation to the grinding wheel.  Loosening the drill in the pin vise AFTER the pin vise is clamped in the DBS and adjusting its rotation so as to align the flutes with the marks on the DBS is where I see the problem.  I think that will be a clumsy/kludgy maneuver.  What will happen is that when you get the flutes aligned and then attempt to tighten the nut on the vise, the drill bit may tend to rotate.  So, it will be very important to check the alignment AFTER you've tightened the drill bit.  If not quite right, do it again.  The problem will come as a result of the split collet that actually clamps the drill bit spinning with the nut as the nut is tightened. 

I think it would be much easier if the handles of the pin vises were totally round, not hex.  That way, the drill bit can be clamped in the pin vise without regard to alignment and then the vise would be rotated within the DBS for a much easier alignment of the drill bit flutes.  Thus, I plan on turning down the hex handles to round on my lathe.  But, as I've said, all of this is low priority for now.   

Rick

I realize that turning these hex handles down to round is not something most Tormek users can do, but it is something I can do.  My recommendation to anyone who wants to try this is to be sure to buy any pin vises with round handles.  Most have knurling or grooves to provide grip as the primary use of these are as hand held tools.  Those knurls or grooves present a potential source of misalignment in the DBS holder - at least in my OCD/precision oriented brain.  It may not be that much of a problem as the pin vises probably align just fine for most drill bits.  Any misalignment will become more significant as the size of the drill bits gets smaller. 

I look forward to reading about anyone's efforts and progress along these lines. 

Rick. 

[courierdog]

Rick:
You are correct in regard to the shape of the Pin Vice and the issue of the drill bit slipping when mounted in the pinnace. As You said I intend to turn down the handle of the pinnace so it is totally round and allows sufficient clearance for the bit to sharpened. I will have a better idea when the Pin Vice set arrives tomorrow as to the amount of modification required to the Set Up. Regardless, your concept of using a Pin Vice for the Sub 3mm drill bits i believe is the correct approach. The Starette pin vice also uses a very precision clamping process and should result in the more accurate of the ones I have been looking at. The Harold Hall process of using a collet while extremely accurate, his jig is far more complicated than the Tormek DBS-22 set up. Plust Harold Hills set up was geared more to ward the model building which due to the scale of work requires a higher degree of accuracy than that of the Tormek approach.

[RickKrung]

I must have missed it, perhaps in one of your PMs, but is there a link to this Harold Hall procedure that you can share?  I'd at least like to see it.  May be some useful insights.

Thanks,

Rick

[courierdog]

Starting from the beginning
Drill Sharpening, the basics  Harold Hall
http://www.homews.co.uk/page354.html
Small drill bits, <<1mm
https://www.model-engineer.co.uk/forums/postings.asp?th=166364&p=1
Four Facet Sharpening of Small Twist Drills
http://www.modelenginenews.org/meng/smalldrilljig.html
Drill Sharpening Etc.
https://www.gadgetbuilder.com/DrillSharp.html
I received the set of 4 Starrett Pin Vices I found the one that fits the 1/8 in (3mm) drill bit
I used the DBS-22 Depth Guage to adjust the drill bit protrusion so that the Pin Vice clamp is ahead of the DBS-22 Drill Bit Clamp.
Placed the assembly on the DBS-22 slide for a trial fit for clearance of the drill bit and the Pin Vice vs the grinding wheel.
Low and behold we may have a viable solution for sub 3mm drills.
The Pin Vice appears to clear the grinding wheel and the Adjustment clamp of the Pin Vice does sit in front of the DBS-22 drill bit clamp.
Tomorrow I will attempt to sharpen the 1/8 inch drill bit using this assembly.
Thanks for Listening

[RickKrung]

I'm encouraged by your progress.  I haven't seen those articles on sharpening.  Looks like some good stuff. 

The video by Alan Holtham and the article DRILL POINT GEOMETRY by JOSEPH MAZOFF are the references I've used.  Always good to have more good information.

Looking forward to your report on how it worked.

Rick

[courierdog]

Rick:
As I feared, while the Pin Vice clamps and allows sufficient clearance at the grind wheel face. The back end of the Drill bit is not supported sufficiently to provide the required centricity for sharpening.
Essentially the drill bit requires total support in the same way the DBS-22 supports bits larger then 3mm.
So this means a clamp similar in nature to the DBS-22 drill bit clamp perhaps a simplified slip in sub assembly which will cradle the drill bit in its full length from 3t5 mm of the grinding wheel to the fullest length of the bit shank.
A Pin Vice or a collet only provides clamping and support at the forward end of the drill bit which becomes very apparent when you begin the sharpening process of the sub 3mm drill bits.
This is a bit disappointing however perhaps someone else will step forward with another suggestion to aid us all in the pursuit of Sub 3mm drill bit sharpening
Thanks for Listening