Hollowing with John Jordan tools

This was the week I was supposed to have spent with John learning about hollow forms at the Marc Adams School. Perhaps it will still happen, but I bought a set of his large tools and have been trying to teach myself how to use them in the interim. About the third time (I'm a slow learner) I had a catch that threatened to break my arm I've decided that I really do need instruction going forward. (A piece of 3/4" steel rotating in a big circle at a couple hundred RPMs gets your attention!) I've made a half dozen increasingly nice pieces (thinner, smoother walls, smaller entrance holes, better looking shapes) using primarily Ellsworth style tools I acquired many decades ago after a class with him, but there are places I can't reach with the straight shank tools that the Jordan hooks get to pretty easily.

I've searched the web and Youtube but haven't found a good instructional video on using these tools. Can any of you point me towards a good demo?

 

The usual culprit is that you get the cutting edge above center. Error on the lower side of center, and have the end of the handle just slightly higher than the cutter. If you get it angle up or above center, it wants to self feed and that's a catch. You might want to read some of John's articles. https://www.johnjordanwoodturning.com/fine-woodworking---turned-and-carved-vessels.html


View: https://www.youtube.com/watch?v=ZWlE-6pL7w0

 

Roger, were you using the Jordan arm brace when this happened? I had one of those for awhile and never got comfortable with it. The tool just seemed easier to control without that arm brace. I've watched John do it a lot and, of course, it looks effortless when he does it. I love his tools, but I never got the hang of using the arm brace.

 

Richard. I hope you meant turn at or above ce ter. When the tool tries.to catch and you above center it is pushed into space. When you are.turning below center it tries to pull.the cutter deeper into the wood. One thing that helped me was to put a negative rake on the top.of the cutter. It's a little less grabby that way. Still important to stay at or above center. I still hollow by hand occasionally to keep my skills up but much prefer using captured bar rig. I dont do enough hollowing of larger pieces to be comfortable doing it by hand and it's almost relaxing using my home made Jamieson rig.

 

Yes, I had the arm brace attached, but in the most recent incident I was holding the tool on the round part ahead of the brace -- the divots in my arm from the time before haven't healed yet. I've been trying to keep the tool more or less on center. With the Ellsworth angle tip I'v been finding it works better when I rotate the tool slightly counterclockwise so the tip will be angled a bit downward, ie if 9 o'clock is level then twisting to 8 or 8:30 is less catchy while still cutting well. I haven't had much success in trying to replicate that presentation with the Jordan hooks.

Thanks for the links to the article and video, I will watch them this morning.

 

Roger
I have John’s 1/2” and 3/4” sets. My 5/8” set is a mixture of Simon Hope and Trent Bosch. I use all of them depending, but like the JJ tools. I have used the 1/2” “free” hand. As a learning I did a bowl using the hollowing tools just to be able to see. However my elbow/shoulder cannot take the abuse any more and I have a hollowing system. Anymore when I’m doing small hollow forms I set up the system even with the 1/2” bars. The tools can take the abuse, but my old joints can’t.

 

And... oops! I suppose one of those laser thickness tools wouldn't be the worst thing. I would have sworn I was following the curve, but I was clearly cutting in a straight line.

 

It's "Deja Vu all over again". I thought those tools died out 20 years ago with the advent of torque arresting boring bars.

 

Well, good point and one I've been contemplating. Two kinds of thoughts come to mind;

One is that people who do this for a living use tools of this sort, presumably not because they don't know about or can't afford a "system". There must be a motivation, and perhaps one that involves better expression of what they are trying to accomplish, or perhaps speed, or something else. I haven't discovered that motivation yet, and haven't had the opportunity to ask.

Two gets rather more metaphysical, if not epistemological; at what point does the work become a product of a machine rather than a work of craft? How something is made is probably not important to 98% of buyers or users of the object, but it is important to me as the maker. I haven't quite reached a conclusion on this one yet; on the one hand most of the real craft and "artistic" decision making certainly goes into the shape you create and how you make use of the natural variation in the wood to enhance that shape. On the other it seems like a slippery slope to just programming a CNC machine to cut out whatever shape you've imagined in whatever numbers you can dispose of. Cutting stuff on a lathe with hand-guided tools is pretty archaic after all.

So I thought I'd start out doing it "by hand", just as I learned to cut dovetails and M&T joints with a saw and chisel before contemplating a jig. I'd like to think my machine cut joints are better for having spent the time understanding, carefully tuning and fitting joints (and screwing them up).

And perhaps this is all BS ;-).

 

After counseling a friend who was having trouble hollowing with JJ tools turns out he was sharpening them too blunt. The heel of the bevel was stopping his tool from cutting. I was counseling him on the phone so took a while to solve it.

 

I guess it is how you look at it. All the pro that do this for a living are capable of hollowing by hand. However Trent Bosch and Lyle Jamison have developed systems and John Jordan sell the Elbo system (he only sells tools he uses). I don’t classify a hollowing system as a “machine”. I still by hand need to move the cutter by hand. I see it more as a jig. It is not like I set it up and flip a switch and it hollows the vessel. I have a camera system, but I still capable of going through the wall. I did this when I bumped the camera and didn’t realize it.

 

Why “pros” hollow by hand? Don't know definitively as I haven't discussed with them. Perhaps faster, but I suspect it has more to do with the aura around holding the tool in the hands.

Ive done my share of hollowing with HH. While I can do it, and the more you do the better you get, the concentration required, especially after 5-6” depth, and the concern over a catch and losing yet another piece, took the fun out of it for me. I still hollow ornaments and small items HH, but the Jamieson system I have made it a lot more fun to hollow larger items by removing the anxiety of another blow up or an injury. One injury is worth the price of a system.

To Emiliano’s point about HH being able to reach places a system can’t - yes, flatter top shapes closer to the boring hole can require a lot of fettling to get a system to get the right area. I use HH to start all vessels, its easy and not prone to injury, and can blow out chips frequently faster than with the system. The system is used to hollow the top, then I use HH to clean up those hard to reach areas, but they don’t require much tool overhang.

 

Al, just curious as what are the limitations using the Hope or Bosch systems. I have the Hope and also Trent’s extreme bent bar. Maybe I’m “most people” and since I don’t have the Jamison don’t know what I'm missing.

 

I have a slightly different perspective on the topic of hand-held vs. hollowing rigs. I've done some hollow form turning, but not a lot, and it's not something I want to put a whole lot more effort into. There are other things that call to me. But I've been around John Jordan some and I've watched him work, and I own one of his pieces. When I hold it in my hands and look at it, I recall the memory of watching him work. For me personally, my enjoyment of that piece is enhanced by knowing - and remembering - the level of skill that went into making it.

 

interesting discussion, thank you. I've been having fun (mostly) while doing hollowing. It's not a form I've ever explored before, for reasons I don't understand myself-- intimidation perhaps. I'm sorely tempted by something that will give me more control-- or at least less chance of injury. I'm not so worried about having to return firewood to the firewood pile, but as described above I have had catches that threaten serious injury.

That of course begs the question of which one-- there appear to be a bewildering array of choices, each seemingly more gigantic than the next. My shop is big, but I really don't want it to get crowded, so I'm certainly not going to buy three. Each appears to have staunch advocates, which suggests that most do their job at least adequately. Off to do some reading! A shame that Totally Turning and the Symposium didn't happen, it would have been a good chance to put hands on the major varieties.

 

The Jamieson system has a versatile boring bar with two different pivoting heads and two different angles to insert them into the bar. To make hollow forms that are much wider than they are tall, (like flying saucer shapes) you put the straight shafted pivoting head in the 45 degree hole in the boring bar. I wonder if the Jamieson bar can be used with the Trent Bosch system to achieve the same shape?

 

As far as I know any boring bar can be used in any system. I can achieve the same angles with my Hope boring bar or use my “bent” bars to do the flyings saucer shape.

 

The best system is dependent on the application, ie the shape and size of the HF’s the user intends to make, as well as storage concerns. Ive noticed many choose an articulating type because they take less room to store, and they dont intend to make a wide range of shape or size.

I wanted a system that could do a wide range of depth and dia, up to 18”-20” depth and 12-14” dia, and of course smaller. After researching all the systems and the boring bars/heads/cutters that would be needed, the jamieson system came out on top - it was either the best price or right at it, and seemed to provide the greatest flexibility. I store the d handle and backstop hanging from the ceiling. Again, your desired size/depth needs to be decided before hand so you price all needed components. FYI depth determines boring bar dia. There are not “hard” rules, you will find variation in recommendations. It depends on the particular piece of wood.

If you get a system I highly recommend a camera system, not a purchased system but one you piece together. Mine cost me $65 since I had an old computer monitor, so its pretty cheap to do. The lasers work but a camera is far superior.

 

Have you published a description of how you built your system? I looked at some demos online and they were fascinating.

 

No. The particular camera I have is not available, but I saw one very similar in a thread here somewhere. It's a flat square 1-1/2 or 2" with the lens coming out of the flat face. I used a signal converter/power supply (~$25) for BNC from the camera to VGA for the old flat screen monitor. My camera was ~$40, the one I saw in the thread was ~$25. I made a simple camera mount - turned a dowel to fit the jamieson laser rig in place of the pen laser, screwed/glued a small square piece about the size of the camera, and mounted the camera to it with good double stick tape.

Most people use a transparency to draw the tool tip on and then a line or 2 for wall thickness. I made a "target" template, with a circle in the center the correct size for the #1 cutter, then concentric circles in the correct position for actual wall thickness. I just reuse the same transparency, no drawing. The lens and the lens height above CL determine the scale seen on the screen. Using 2 rulers, one placed at the CL in view on the screen, use the other ruler to measure actual length of a value on the screen - 3" at CL measured a little over 9" on my screen, so I have ~3.1 scaling factor. The template actual size is 3.1x the value, so a 1/4" wall is actually ~0.775" from the tool edge on the screen. Pic of the template below.

 

I typically use my left hand placed on the boring bar bar just to the rear of the tool rest, and my right hand on the "D" bracket of the jamieson system. A hand needs to be up close to the tool rest for good control as the final thickness is approached and to smooth the surface. The articulating type might make that approach a little more difficult.

 

OK, the hardware side of this seems reasonably straightforward in any event, but it must require a fairly sophisticated bit of software to do the image analysis and infer the hidden interior position of the cutter from relatively small movements of the visible handle (and some hefty compute power to do it in real time). I've used systems that do similar tasks, eg for automated injection of cell nuclei, but those systems sell for $100K's, albeit for an accuracy of nanometers. Is there an open source software project that enables this? Most sites I've looked at seemed only concerned with the hardware.

 

What I was asking is if you can put the Jamieson bar into Bosch Stabilizer. The bar is the same 0.75 inch diameter, so it seems it could work. This would allow you to do the flying saucer shapes with the Stabilizer.

 

No, no, no......you misunderstand. The template is printed on a transparency and taped on the screen, with the bullseye located on the cutter. No computer, no software. The camera signal is sent to the screen. The pics below show the screen with bullseye on the cutter, and with the cutter inside a HF.

 

Doh! (what more can I say). What an elegant answer.

It does require a method to rigidly attach the camera to the tool so that the geometry remains constant. I had been imagining a system that would work from a fixed overhead camera not tied to the tool. Perhaps still some room for invention there!

 

Michael, yes you can use the Jamison bar in the Stabilizer. However there are many ways to do the shape you are referencing. I can set my Simon Hope bar similar to the Jamison bar or use my Trent Bosch extreme bent to get that shape. I even made some homemade bars. I use all of the bars in the picture can be used with my system.

 

Here is how my camera is mounted. Note that the screen is a small screen that came with the system. I did convert a large 21” monitor to use, but it changed the ratio and was a PIA to drag it out. I went back to my small screen. My ratio with the small screen is close to 1:1, so I don’t even draw the thickness lines.

 

I'm getting ready to start doing a little bit of hollowing and after a bit of YouTube research, I set this system up a couple of months ago.

If you actually watch it on Youtube, I have links, to Amazon, for all the parts used in the Description.

Now I've just got to bite the bullet and buy the Lyle Jamieson setup.

 

I do have a bent tool similar to the ones you are showing. Note that one end of the Jamieson bar looks the same as the Simon Hope tool you show: a straight shaft with the hole for the pivoting head parallel to the shaft. But the other end has the hole drilled at 45 degrees thus allowing a farther reach. I am looking at one of my pieces, 12 inch diameter, 3.5 inch high: with a 2 inch entry hole, both the bent bar and the Jamieson can reach the 12 inch diameter. But the Jamieson bar can reach the same diameter through a much smaller hole, about 1 inch. (Correct me if I am wrong.)

What I am curious about is that the Jamieson bar with the pivoting head in the 45 degree position will have the potential for a lot of torque placed on it, compared to a bent bar. In the Jamieson system, the D-shaped handle seems to counteract the torque nicely. But if you use the same Jamieson/45 degree bar in the Bosch system, it seems you are relying on a single set screw to resist the torque.

 

Cant comment on the Hope setup, but with the 3/4” jamieson bar I use a 1” to 1–1/8” hole to get out to the dia you describe.

As for torque arresting your assessment is correct, and comparison is easy. Measure from the bar CL to the cutting edge, perpendicular to the bar CL, for the 2 setups. The ratio of the 2 #’s is the applied torque difference. If the jamieson is 2” and the other is 1”, the jamieson will create 2x the torque for the same cutting load.

The jamieson D handle uses a set screw to transfer torque from the bar to the D handle. If the other set up has the same size and design of the set screw (cup point) it will hold the same amount of torque.

FYI. I have had the set screw come loose when getting into a chatter situation.

 

Michael, The hope system has a cutter where you can put it on the Hope straight tool and rotate it to any angle, not just 45 degrees. It will function the same as the Jamison with the cutter at 45 degrees in a straight bar. As far as counter acting torque, articulate arm systems are different. The Hope system uses an I” (may be larger) post the arm fits over to counter act the torque where the Jamison is captured. Would be hard to say which is “better”, but both work well.