Hollow form....hole diameter?

Rob Bourgeois

Member
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24
Location
Baton Rouge, LA
OK I am set up for hollowing.

Is there a rule of thumb for how big of a hole you should have in the HF for the boring bar? 1/4 larger, 1/2inch? Or is it simply..how brave you are with the hollowing.

I know that it may depend on the HF shape depending on your ability to reach. But My question is more of..what size do you start with.
 
Rob I have did these with openings of 1" to 2". I like to put a collar on mine so then I will do the 2". Most times it is 1" and I will collar those also if I feel it needs it.
 
What Bernie said. Depending on the shape of the piece, anything between 1" and 2" is doing pretty good with a 3/4" shaft. My average is probably around 1-1/4" for a piece with a relatively flat top and wide shoulder. Using a Don Pencil Stinger the smallest hole I've done so far was 7/8".
 
Rob, I don't do a huge number of hollow forms, but I do enough. Back in the 90s it seemed like it was the thing to see who could go through the smallest hole possible. There were plenty of hollow forms out there that were huge, with tiny little entry holes. Then collars came into fashion, disdained by some and looked upon as salvation by others, because now the small hole could be retrofitted to the form, making the whole process (or is that the hole process?) :rolleyes: easier.

My own personal philosophy of turning hollow forms, collar or no, is to make the hole in the form proportional to the form itself. Some forms get large holes, some get small, and some get collars. I'm not really interested in the "smallest hole possible" thing, although there is nothing wrong with that as long as the finished piece looks good. The only caveat with larger holes is that you need to spend more time on the inside, not necessarily for customers, but for those other turners who are going to judge your work by how smooth it is on the inside. :dunno: For some pieces with large holes, this can be a valid component, but most of the time these things just sit around on a shelf and look pretty, so as long as it is not too rough, I don't worry about it.

Good luck with it!

Bill
 
I appreciate the replies.

This weekend were my first attempts at a non-ornament/non mini that I turned with the d handle. With the minis I was able to go less than 1/2 inch since the tools were so small and it was always capped or collared.

Hopefully this one makes it through the hollowing...1 in DNA, 2 in smoker.
 
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Hey Rob...I was just thinking this weekend that we hadn't seen you here in a while. :wave: Late to the thread, but my philosophy is about like Bill's. Some are small, some are big, and some are somewhere in the middle. With my 3/4" bars, I tend to start with a 1 1/8" or 1 1/4" Forstner bit, then enlarge the hole if I think it's necessary.
 
Hey Rob...I was just thinking this weekend that we hadn't seen you here in a while. :wave: Late to the thread, but my philosophy is about like Bill's. Some are small, some are big, and some are somewhere in the middle. With my 3/4" bars, I tend to start with a 1 1/8" or 1 1/4" Forstner bit, then enlarge the hole if I think it's necessary.

After Christmas, I got sick, almost got tonsils yanked. Good times...and loss about 10 pounds to boot. One more tonsil problem, and they may get removed. Adults having their tonsils removed is supposed to be painful...I am not looking forward to it..(based on past luck)

I used a 1 1/8 inch hole today and it work better with the 5/8 bar than my prior attempts. Either that or I am getting a bit more comfortable with it.
 
Don't wait until you such an infection you have no choice.

BTDT! No picnic when done when you're an adult,

Painful - Yes. No two way about it.

Had trouble getting the bleeding under control. Was back in the hospital a week later to stop the bleeding. The stomach will tolerate only so much raw blood and then it ejects it! Forcefully! Ripped the stitches out. Bad news.

Forget ice cream. I didn't even want to swallow spit!

My condolences, Rob. It will be better if it is done without them also being inflected. Don't wait. Get it taken care of!
 
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