Drilling A Wa Handle

MTBob

Well-Known Member
I thought I'd post a few pictures of a fixture I made to drill holes in Wa handles, for use in the dowel assembly method. This is about the third one I've made and each time I've had trouble holding the handle in place and getting a clean straight hole. This fixture seems to solve that problem.
The large angle iron section is 4" x 5/16" and the only piece that I found that, surprisingly, had a 90 degree angle. It's amazing how far off 90 degrees most angle iron is. So after tramming the adjustable drill press table, I aligned a smaller angle iron piece and welded it square. The large angle iron section is heavy and provides mass for stabilization, a big help in minimizing wobble and chatter.
1674339563947.png
Clamping everything together virtually eliminated and wobble or chatter. The wood is Cocobolo, 1/2" drill.
1674339641767.png
I've found using a conventional metalworking twist drill for this task just doesn't work well, even if I've used multiple drill sizes to get to the final 1/2" hole size.
So, I reground a twist drill incorporating a point, similar to what's used for drilling sheet metal. Here's the re-ground bit end. That pointed tip is what keeps the drill from wandering. The tip was ground on a 2x72 belt, roughing with 120, finishing with 400. It helps to use an offset belt to gently shape the pointed tip.
1674339983914.png
Here's the key to minimizing run out, getting the point centered.
1674340178568.png
Grinding the bit for this purpose is simple, just flatten the end, leaving material in the center for a point. Then tilt the bit and grind the flat back to give it a cutting edge, grinding gently & dipping to prevent overheating. Like conventional twist drill bit grinding, having an adequate relief angle to the cutting edge is important. Then carefully shape the tip with a fine belt. Some folks might find using a Dremel offers similar results. I find using the belt grinder provides a better result.
1674340686567.png
1674341215230.png
 
I use a spade drill bit and a pen vise for drilling wa handles. Dont use the screw tipped spade bit; they will pull the blank into the drill bit and you will drill deeper than you want really quickly.

I got this one a long time ago and there are much simpler ones too:
 
That is one excellent job of shaping the drill bit point - I'll bet you do all your drill bit sharpening by hand - no Drill Doctor for you:)
 
I use a spade drill bit and a pen vise for drilling wa handles. Dont use the screw tipped spade bit; they will pull the blank into the drill bit and you will drill deeper than you want really quickly.

I got this one a long time ago and there are much simpler ones too:
You're right a spade bit will do the job too. I'm not fond of those for long holes, to me they seem to cut too aggressively and with a small shaft may tend to wander more than a twist drill.
That pen vice is pretty slick, first time I've seen one of those.
 
That is one excellent job of shaping the drill bit point - I'll bet you do all your drill bit sharpening by hand - no Drill Doctor for you:)
I learned how to sharpen drills when I was a teenager, that was just part of working in a machine shop. I have a Drill Doctor but it mostly collects dust, except for small drills under 1/8". It's harder to get a uniform grind on small drills with my aging eyes.
I touch up my dull drills in 30 seconds on the belt grinder. Once you understand the angles it's really easy to do.
FWIW - Here's an example from a set of sheetmetal drills that my Dad ground. The grind is designed to first contact the center point to capture the drill in the metal and then the very outer end of the drill flute contacts the sheet metal and cuts on the diameter of the hole. It is very hard to grind, but works amazingly well. He ground these on a bench grinder with a bonded wheel. This is truly old-school stuff. Sheetmetal holes are now mostly cut with a hole saw or one piece step cone drill bit. I haven't found a place to buy drills with this grind shape.
1674402518917.png
 
These are what I use to drill any precision holes in my handles. I always called them a Brad point bit.




I’ve never considered sharpening these types of bits, let alone making one from a regular bit. Great job!!
 
Gene: For me this is a case of getting locked into one way of thinking, seeing everything from a metalworking viewpoint. Of course your correct, brad point drills are used all the time in woodworking and many are ground similar to the sheetmetal drills I mentioned. What's kinda interesting though is that bradpoint drill references it don't seem show them being used for cutting sheet metal. But woodworking bradpoint drills have a reverse angle outer cutting edge and should be able to cut sheetmetal if the drill material is hard enough and the cutting edge angle is not to acute. For metal, the center tip (brad point) may need to be shortened and/or sharpened).
Thanks for the clarification, I see Amazon has a bunch of the bradpoint drills with various tip grinds.
 
Its a Japanese style stick tang handle. They are often oval, D shaped or octagon shaped with a ferrule wnd main handle body.KIMG1626.JPG
 
Just a thought... you may be over thinking things a bit. From a wood turners perspective, I made a dead center that I clamp in the vise, mark center of the "handle" top and bottom, the vise usually floats on the table pretty much making it self-centering. you could of course clamp everything down, and align the drill bit center over the dead center, but I find it works well if things feel centered. Just my 2 cents.
floating vise
1.jpg
dead center, quick metal lathe project, turn a shoulder, turn a cone, add a point, fit a washer
2.jpg3.jpg

find center top and bottom
4.jpg 5.jpg
chuck it up and drill,
6.jpg
 
Back
Top