hollowing w small opening questions

[thomas prusak]

I have been turning for less than one year. (vague statement meaning= I don't know what i am doing). I have a Lyle J hollowing rig with a 3/4" bar that was part of a pkg. deal with a 3520b I recently purchased. What do you guys use to hollow with to maintain the smallest openings? And what techniques and or adjustments do you make in the process? ie. Is it necessary to make numerous adjustments to the cutter in order to hollow different areas inside the form? (I'm referring to the cutter attached with a bolt at the end of the bar) Are the smallest openings hollowed using handheld tools rather than captured or articulating rigs? Thank you in advance for any help

[Steve Schlumpf]

Thomas - small openings in hollow forms can be done but are not something you normally do when first learning how to hollow. A lot of folks start the process with using a forstner bit to drill a hole to depth... then use the cutters to hollow an area by working from the center out towards the outside edge. Because the angle of the wood is constantly changing within the form - you will need to adjust the cutter many times! Depending on the shape of the hollow form you plan to create - you may need a swan neck boring bar to reach into the far corner.

Let us know if you have any questions when you start hollowing!

Here is an old thread that may help explain the cutter angles used. Scroll down until you see my second post... there are some photos that should help illustrate some of the cutter angles used. Cutter Angles (http://www.sawmillcreek.org/showthread.php?116958-Captured-Hollowing-jig-with-Laser)

[Thomas Canfield]

A 3/4" bar and the attachments on the end will limit the size of hole you can work in and I would guess that to be about 1 1/2" or so. YOu will need some smaller tools to go in a smaller opening and some of the smallest openings are done with only bent shaft hollow tools that do not have a cutter attached to end to pass throughh the smallest possible hole. The 3/4" needs to be necked down with some additional tools to work smaller ID. I have a Don Pencil Stinger that is 1/2" bar and with the curved bar find that I still need a 1" hole and use a very short 3/16" cutter to get in the hole.

[Curt Fuller]

You've already gotten good advice. But also, a small opening is relative to the size of the vessel and to the size of tools you need to hollow it. As Thomas pointed out, with a 3/4" bar you'll need about 1 1/2" of opening or slightly smaller if you're really careful. But on a vessel that's 8" diameter, that's a pretty small opening and looks pretty good. On a smaller vessel you can actually use a smaller hand held tool and go through a smaller opening but the relationship to the opening and the vessel stays about the same. I have several hand held tools made from various sizes of allen wrenches that work great for getting under the shoulder on smaller vessels. Then once you get that upper part hollowed you can use a straighter tool, something captured in your jamison setup, for going the depth and not need such a large opening. But it's really a trial and error process until you figure out what works best for you.

[thomas prusak]

STEVE,CURT AND THOMAS,

Thank you guys very much for the valuable info and insight. Very much appreciated.

[David DeCristoforo]

The smaller the opening, the smaller the bar must be. I have hollowed some pieces through a 5/8" opening and a 3/8" bar is about the largest that can be used. It gets pretty hairy with anything over three or four inches deep.