Hollow form question?

[Toney Robertson]

Does the grain orientation matter on HFs? Are most side grain like bowls or end grain like goblets?

Does anyone know of any online videos about how to use the McNaughton hollowing rig?

I notice on the McNaughton site that the turner was actually standing on the opposite side of the lathe. My lathe is now sitting too close to a wall to do that. Is that a problem? I do have a Nova so could I rotate the headstock?

How large does a HF need to be before using a steady? Or should you use one all the time?

I don't have a compressor in the shop. That is how I have seen the chips removed from inside the HF - Is there another way?

Do you treat green wood the same for HFs as you do bowls - i.e. the 10% rule?

I have not done one yet but I am obviously thinking about it!

TIA. Sorry for the length of this post.

Toney

[Richard Madison]

Toney,
Lots of good questions. Have only a couple answers. The shop vac is useful for removing debris from HF turnings, and has the added advantage that it does not blow said debris everywhere. You may need to tape a slightly smaller tube to end of standard vac hose. Most HF's I have seen and all I have done are end grain turnings. That's not to say that it can not be done the other way.

[Jim Becker]

99% of the time, I prefer end-grain orientation for hollowforms, but it's not a 'rule'. Most of the hollowing systems are scraper oriented and perform "best" and "cleanest" on end grain, too.

If you don't have compressed air available to help clear chips from a hollowform, you can just use a piece of soft wire bent into an "L" with a short base. This is the technique that David Ellsworth teaches. In fact, even with compressed air, you sometimes need to mechanically remove chips if the become "impacted". By soft wire, I mean someting like the thick soilid aluminum wire sometimes sold as guy wire for TV antennas.

[Steve Schlumpf]

Does the grain orientation matter on HFs? Are most side grain like bowls or end grain like goblets?

Toney, the grain has more to do with the form you wish to turn. Examples would be a vase style of HF would be done end grain, a HF where the width is greater than the height would most likely be done face grain. In the end – that decision is up to you. I have turned birdseye maple endgrain so that the birdseye can be seen. Turn it face grain and it will disappear.

Does anyone know of any online videos about how to use the McNaughton hollowing rig?

No experience with the McNaughton but I know there is a instructional DVD out there for it.

How large does a HF need to be before using a steady? Or should you use one all the time?

When you are turning a HF and the tail stock is removed – the only thing supporting the piece is the chuck. When hollowing there can be some severe forces that occur should you ever get a catch and the steady rest is just an additional means of supporting the work.

I don't have a compressor in the shop. That is how I have seen the chips removed from inside the HF - Is there another way?

Depending on how large the opening to your hollow form is you can use your fingers, a bent coat hanger or even your shop vac (my personal favorite).

Do you treat green wood the same for HFs as you do bowls - i.e. the 10% rule?

I stick with the 10% rule for bowls and hollow forms but have found the one critical factor is to keep the walls an even thickness. Leave the bottom to thick and you can almost guarantee something is going to crack!

Hope that helps answer some of your questions - if not, let us know!

[Reed Gray]

For chip removal, there are a couple of ways. One, you can take the form off the lathe, hold it up side down and shake it out, but take the form and the chuck off as a unit, don't take the form off the chuck and then try to remount it back into the chuck. It never goes back on the same way. I have one friend who took a ice tea spoon (one with a long handle), and bent it like a goose neck hollowing tool with the spoon at a 45 degree angle, and with the form slowly spinning would use the spoon to guide the chips out the mouth. I also used to use a 1/2 inch inside diameter piece of flex pipe, and stick it in the form and blow it out. I do have large wind capacity (yes, I know!), and do remember to inhale BEFORE you put your lips on the pipe. Turning wet wood, you will get more shavings, and turning dry wood, you will get more chips.

I prefer the McNaughton hollowing blades. You can free hand them, which will wear you out fairly fast, you can put them in a captured system, which I do for larger hollow forms, or for the smaller ones (up to 8 inches deep) I put them in my Monster articulated hollowing tool. I prefer them to the cutters that come with the Monster. The articualted systems do make hollowing a LOT easier, especially with a laser pointer. A bit more of an investment than you may want to make at this time, but really worth it to me. One can never have too many toys.

I prefer end grain orientation for my hollow forms. You can get cleaner cuts on the inside of your form if it is one that will be more open. With the flat grain forms, all of your hollowing tools cut as scrapers, and if you get the Hunter or Eliminator tools, they have carbide discs that cut at a shear angle. They will do better with flat grain than the scrapers. Of course, you can leave the top of your form more open, and then cap it, so you don't have to worry about what the inside looks like. I have found the Eliminator (carbide disc at a 45 degree angle)superior in removing the cone you get in the center of your hollow form if you don't drill it out first.

I haven't used a steady rest yet. I have gone 12 inches deep, but a steady would have helped. When I get around to going deeper, and I will, I now have a steady rest. Rounder forms, especially if you have a wide jaw chuck on a big tenon will hold most hfs. Small jaws on a small tenon need a steady rest. When they get longer and thinner, then you need a steady because they will vibrate and whip. Perhaps more so for a beginner turner, 3 to 6 inches, fairly safe (note, I did not say totally safe), over 6 inches, probably a good idea, and over 10 inches, a necessity.

I turn everything green to final thickness, and then let them dry and warp. A bit easyier to dry, and I like the warped shapes. Getting big pieces dry enough so they won't move is almost impossible. This way I never have to worry about the 10% rule. Some one could do a whole book on the subject of drying turnings and wood.

robo hippy

robo hippy

[Bernie Weishapl]

For chip removal I use a piece of copper pipe. I cut it almost into about a inch back then split that part in half. I open it up, bend it down to make like a hoe. Solder it for strength and you can then shovel out the chips. You can bend the ears back for a smaller opening. Hard to explain but works great.