Modifying drillbits for drilling-after-shaping

[The Smoking Yeti]

Hey, so I've got my BP bit etc. but when I drill the mortise with my good ol' fashioned 5/16" HSS twist bit... its an adventure to say the least. How can I modify the bit so it doesn't dig into the wood? Cus... yeah.

[The Smoking Yeti]

Anybody?

[Charl]

I am no pro when it comes to shape-first, I am sure somebody else with more experience will pitch in, but here's my 1/2 cent!
When shaping first, for me, you have much more control if you do the drilling on the lathe. Draw out your draughthole, mortise and chamber lines on the shaped stummel. With the drillbits in the headstock, use the tailstock to push the stummel toward the bit. Attach small scrap pieces of briar with CA glue to the stummel so that the point of the live center does not damage the wood.
Hope it makes sense.

[andrew]

Drill on the lathe.

Charl is right about the basic steps.

It is possible to freehand the drilling completely, but you need to slightly dull the center of your drill bit. That way it won't grab as quickly. The catch is that you will have to push a little harder through the material. It's so easy to drill on the lathe that I wouldn't bother with this unless you are really wanting to learn how.

[Tyler]

I use a normal 5/16" for the mortise, no modification necessary. What trouble are you having?

[The Smoking Yeti]

Ha! Everyone but tyler mis-understood me. The issue I have isn't large. I just am having "grabbing" issues with the drill bit. I looked down the mortise and there wasn't a clean cut bevel where the mortise was drilled. It had some "grab" marks in the end which I had to work hard to get out. Is it possible that I need to be backing my bit out a bit before I turn the power off? maybe as the bit slows down it grabs?

[Tyler]

Sounds like you are turning the lathe off with the bit still in the mortise? If so, try not doing that. Just push it on, pull it off, and then turn off the lathe.

[andrew]

Yeah, I missed the part where "you have a lathe already". I've only experienced the "grab" when I'm drilling with a hand drill (not typically plan a).