Hollowing systems questions

[Bernie Kopfer]

I started researching hollowing systems because I can see how they would make bowl turning easier on my back, neck and shoulders. And probably less white knuckles too. Depth need beyond 10 inches is doubtful. And let me state emphatically I am not interested in fabricating a system.
There appear to be several systems out there with Carter @nd Oneway being the name brand manufacturers. My first criteria was to use some sort of a captured system: roller/slider bar style or an articulating arm system.(Major size/storage difference) Are the articulating arm systems strong enough to withstand a major catch without bending something? The Harrison system is relatively inexpensive, but does not appear very robust. Anyone have experience with it or other articulating systems ie Elbo?
The slider systems appear to be made for deep hollowing and weight lifting! But mass does have advantages.
So I value any information that you can share about commercial systems and your experiences.

[Richard Coers]

You should expect considerably more sanding time with scrapers on a hollowing system than when using a bowl gouge. You won't have the shoulder to ride on, so forming a smooth fare curve with a scraper on a rod will be way more difficult. Also the scraper bits will be worse on the end grain. If you use a tilted Hunter Tools insert, you will get a shearing cut. But personally I can't shoot a fare curve easily with that either.

[Bernie Kopfer]

You should expect considerably more sanding time with scrapers on a hollowing system than when using a bowl gouge. You won't have the shoulder to ride on, so forming a smooth fare curve with a scraper on a rod will be way more difficult. Also the scraper bits will be worse on the end grain. If you use a tilted Hunter Tools insert, you will get a shearing cut. But personally I can't shoot a fare curve easily with that either.

you are absolutely correct. That’s a compromise I’ll put into consideration.

[John K Jordan]

Yes, the surface from the hollowing system bit would leave a very rough surface. But it wouldn't make sense to me to go from directly from the hollowing system to sanding without making finish cuts with the bowl gouge. Since the bulk of the wood is gone finishing cuts with the gouge (or perhaps better, a Hunter Hercules) would be much less physically demanding.

After the inside curves are defined with the gouge you can also use one of several larger diameter scrapers in handles (Sorby teardrop, etc), or better, a good NRS to remove tool marks and smooth the inner surface of the bowl before sanding. (Seems to me a lot of people who use these systems to turn hollow forms avoid the whole issue of smoothing the inside by making the opening too small to see or feel inside! Not possible for a bowl, of course.)

As for your question about articulated arms, I don't have experience with the hollowing systems (I hollow by hand) but I have read that some of the articulated systems with multiple joints may have a little more play (slop) which seems undesirable. The torque force would depend on the size and sharpness of the bit, the type of wood, and the aggressiveness of the hollowing! (I think if there are massive catches with any tool something is wrong with the geometry or the technique.) Cutting/scraping across end grain could be more demanding than the things I've hollowed (by hand) with the grain parallel to the lathe bed.

JKJ

[tom lucas]

Have you considered a coring system as an alternative?

I wouldn't use a hollowing system to make a bowl. No need to, really. Now a hollow form is a different matter. Not sure when a bowl becomes a hollow form. But likely when the wall angle is too steep to maintain good bevel contact. If you have a sliding or turnable head stock, moving it to the end of the lathe or, turning it to face you, would be my first remedy for the back issues. In these situations you won't have to bend over nearly as much. Cutting bowls shouldn't take a lot of force. So if you are finding it takes a lot of "work" perhaps your tools need to be sharpened, sharpened differently, or your technique changed. I find hollowing out simple bowls to go really fast with just a bowl gouge, and not at all stressful on the body. Rough inside hollowing takes only about 5 minutes. Final cuts another 5 minutes or so.

Manual cutting of hollow forms - they do wear me out, and not an enjoyable process. So I too have been wanting a hollowing system. I've sorta settled on a Clark system but won't pull the trigger to buy until I get my lathe into a larger space that will let me turn off the end of my lathe. I've never used a hollowing system, but I've studied just about everyone being sold and some home made rigs too. From much reading they all work pretty well. Though some have limited depth, like the Harrison. It seems like an OK hollower as long as you don't go too deep with it. With any of them, just stay within the manufacturer's recommended maximum depth of cut and you should be good.

The hollower isn't all that you need, though. You also may need a steady rest.

[John Keeton]

If you are using 1/4” HSS square cutter stock it is easy to grind a NRS tip that works well.

[Steve Nix]

I started out with aMonster system but have now upgraded to Trent Bosch setup . It’s a good solid setup and the 3/4 bars you can hollow ten inches safely. I used the 1/4” HSS cutter when I got Trent’s hollower but have converted all my bars to the 6mm cup cutters. You will need a scrapper that Trent’s offers that works on his system. I converted the HSS scraper to AZ carbide teardrop scrapper. I have both the laser and a homemade camera system. I fine the laser works best for me because it takes less setup time . My two cents

[Jeffrey J Smith]

While you're researching, look at Lyle Jamieson's system - its reasonably priced, can go deep, and can use hunter carbide cutters. Its a captured bar system that takes most of the strain out of hollowing. Also has adapters for laser or camera. I made mine from Lyles measurements years ago and it still is the best solution I've found to hollowing with a minimum of fuss.

[William C Rogers]

I have the Hope system that is an articulating arm. It can withstand a catch. I’m not sure it is still available in the US. My choices would be the Jamison or Bosch systems. As far as a smooth surface I only worry about how far you can feel with your finger. in a hollow form. It’s a hollow form and just needs to be somewhat smooth, not super smooth like an exterior surface.

I would not use a hollowing system to turn bowls. A bowl gouge and a bottom of bowl gouge is all I use. Like others have said you just can’t get the right finish non a bowl with a hollowing system IMO. Best choice would be to find someone to give you some instructions. I had a club member show me and the white knuckle syndrome went away.

[Peter Blair]

I have multiple systems both hand held and captured. The captured really work well for me and I have fitted a carbide cupped cutter to all my captured bars. I see no reason not to use it to produce a bowl though I don't personally because I like to use my gouges. Fitted with a camera system it would allow you to do hollow forms and bowls easily with way less stress to your body.

[Greg McClurg]

I had a monster system and converted to the Trent Bosch system. I think it is a great system, and if you contact Trent he will help answer any questions you might have.

[Kyle Iwamoto]

You want to use a hollowing system to turn bowls?
If you're getting white knuckles, my $0.02 is RELAX. You should not be getting white knuckles IMO. I like to use a bowl gouge and turn bowls. It's fun. I do get tired if I turn all day, but no white knuckles. Sharp tools?
A hollowing system is a hefty investment. I have a Monster system that I put a Rolly Munro shielded cutter. Works great.

[Allen Mattsen]

I started out with aMonster system but have now upgraded to Trent Bosch setup . It’s a good solid setup and the 3/4 bars you can hollow ten inches safely. I used the 1/4” HSS cutter when I got Trent’s hollower but have converted all my bars to the 6mm cup cutters. You will need a scrapper that Trent’s offers that works on his system. I converted the HSS scraper to AZ carbide teardrop scrapper. I have both the laser and a homemade camera system. I fine the laser works best for me because it takes less setup time . My two cents

I recently received my Bosch system, and bought the hook teardrop scraper. Went with John Jordan 3/4" tools other than scraper. Camera came today and I'm waiting on a coupler to connect to my monitor. Excited to get that figured out for a test drive.

How did you mount your camera to the laser bars?

[Bernie Kopfer]

Does anyone have or used Tim Yoder’s Elbo hollowing system? Appears to be significantly more robust than the Simple Hollowing System.

[Peter Blair]

I had one a long time before it became a Tim Yoder Elbow. It was the first hollowing system I had. I didn't like it, as I recall it moved too freely and I didn't like attaching it to my tail stock. If you are on a budget, for my money the best system would be to would a Jamieson system.