Hollowform Troubles

[Frank Kobilsek]

Guys, How do you drill the pilot hole down the middle of taller hollow forms? I use a long 3/8 drill bit in a homemade handle. Saturday I was roughing a cherry HF about 11" tall. My pilot hole wander so far that it made hollowing a pain. The hole was maybe 1/2 off center about half way down the form so I had a stalagmite sticking up in the middle which was very difficult to cut. I had other troubles with this piece but I have noticed as I get taller or use less stable wood the pilot hole is not always my friend.
Frank

[Mark Cothren]

I haven't done anything over about 9"-10"... but I haven't experienced the problem you describe. I drill with a Forstner bit (using an extension in a Jacob's chuck w/ morse taper) in the tailstock. I just drill as deep as I can go, then just hollow out the rest of it. If I get a "stalagmite" in the center bottom that means my cutter tip isn't on center and I can adjust and then fix it. But I've never had a drill/Forstner bit leave one in the bottom...:confused:

[Jim Becker]

I don't drill pilot holes...'haven't since the first few. When hollowing, you can use your straight boring bar to handle that task integral with the hollowing.

[Bernie Weishapl]

Frank I bore down in with my big Ellsworth bowl gouge. Haven't had any trouble so far.

[Keith Burns]

Jacobs Chuck in the Tailstock with a forstner bit the basic size I want to make the opening. Drill in as far as I can and hollow the rest.

[Frank Kobilsek]

Thanks Guys, Sounds like bigger hole is my option because I've tried Bernie's method and just can't seem to figure that out.

Can't wait till these pieces are dry. They are cherry burls from Bill at Penns.

Frank

[Curt Fuller]

Sometimes it's just wierd grain in the wood that tends to send the bit off on it's own direction. You could try just drilling an inch or two, then hollow, then drill, then hollow...........

[Joe Tonich]

I use an IRWIN Speedbore extension that I bought at Home Depot or Loews, can't remember which. (Like this one... http://www.mysimon.com/9015-11020_8-31882778.html but mine fits 7/16 hex shank). It's a little large for my forstener bits but if you go to their specialty screws, etc.... aisle, they have brass sleeves that fit in the extension and hold the bit snug. All you have to do is drill out the sleeve for the set screws to fit thru. The extension and sleeve cost about $16 total and it is a solid setup when using the tailstock to drill..

[Frank Kobilsek]

Joe, I have one of those, I'll try it next time, and Curt your are right on. I working thru a bunch of cherry burl I ordered from Bill at Penns wood. Nice stuff, lots of inclusions. Punky voids mis-directed the pilot drill. On shorter stuff I handled it. This tall one got off -center a couple times do to 'operator error' which compounded my problem.

THanks Guys

Frank