JT Hollowing “Gizmo”

[Tom Sell]

After reading all the Forum comments about the best hollowing systems, I was all set to buy a JT Gizmo for my 1960’s version of a Rockwell/Delta midi lathe (6” throw x 42” long). Now it appears the Gizmo is no longer available, at least that I could find on an internet search. I’m looking for suggestions from Members: what’s the best system currently for hollowing vessels up to about 10” diameter by about 8” deep on a midi lathe?

[John K Jordan]

After reading all the Forum comments about the best hollowing systems, I was all set to buy a JT Gizmo for my 1960’s version of a Rockwell/Delta midi lathe (6” throw x 42” long). Now it appears the Gizmo is no longer available, at least that I could find on an internet search. I’m looking for suggestions from Members: what’s the best system currently for hollowing vessels up to about 10” diameter by about 8” deep on a midi lathe?

If you were looking a something from JT Turning they closed down after Tom Steyer's passing. I haven't heard if someone else has or plans to reopen the business.

There are varied opinions on "best". Do you want to use a laser, a camera, or do it the old way with calipers? Are you partial to articulated or a rigid captive hollower like the Jamieson?

Do you have a budget limitation in mind? If budget is an issue, using an arm brace such as the other John Jordan sells can be quite effective, especially on the smaller pieces that your lathe will handle. (https://www.johnjordanwoodturning.com/hollowing-tools1.html) I have one of those. The captive systems I've seen in use were on larger lathes.

I have one of Jamieson's with a camera that will fit a 16 or 20" lathe but I don't use it. I may try to sell it but it's heavy and bulky and I'm afraid the shipping would be high so I'll probably offer it to local club members. If looking for a used one, you might check with local turning clubs.

JKJ

[Peter Blair]

When I started I had that lathe and bought a really early ELBO. Pretty inexpensive and uses the tailstock to mount to so the bed height doesn't matter.

[Mike Nathal]

Your size requirement is modest, so many different rigs will work fine. The Elbo, Hollow Fast, and Simple Hollowing rigs are articulated rigs on the inexpensive side and will do the job.. If you were looking at the Gizmo, that is a hefty rig with much more capacity. The closest rig to that is the Trent Bosch, but you must stand at the end of the lathe to use it. Do not ignore hand-held hollowers, they do a good job in this size range. D-way and Don Derry both have good hand-held units. The most difficult shape to hollow is a "flying saucer" shape, where the diameter is much larger than the height. Hand held units have trouble with this shape.

[Mike Nathal]

A correction: the Elbo is more expensive than I remembered, and it looks to be heavier duty, comparable in price and capacity to the Bosch. It also looks like it is used primarily at the end of the lathe.

[Paul Williams]

I have an early Elbo tool on a Delta 12 1/2 inch Midi lathe. It works fine. I think I paid about half of what they are asking for the Elbo 2. I don't think it is necessary for most of the hollow forms that I do, but the added control and the laser are nice to have. I have collected all of the parts to convert to the camera system. No reason other than I like the idea, and want to experiment.

[Dave Fritz]

Another consideration is your physical health. It can be hard on the body to hand hold a tool while either a Jamison or articulated system takes much of the pressure. I sold my Stewart brace and now have a Monster which is a breeze to set up and use. I'm due for a shoulder replacement and still can manage in the shop with the Monster.

[Mike Nathal]

The hand held tools from D-way and Derry are designed to have low stress on the body. They are sort of half way between the hand held tools of Ellsworth or Jordan and the articulated/captured systems.

[Tom Sell]

Thanks to all for your suggestions; really appreciate it. I’ve been using the simple D-Way hollower for a couple of years and it’s been pretty effective (despite some scary incidents when turning in reverse overpowered the set screw on my chuck and drove the vessel being turned into the tool rest). Always thought the laser thickness monitor would make hollowing easier and more fun and I’ve got some earnings from a recent craft show burning a hole in my pocket that gives me the excuse to finally buy a system with a laser. Think I’ve settled on Trent Bosch’s version. His 5/8” system looks to be about right for my midi-lathe, the price isn’t out of line and I know from experience with his carving vice, his tools are ruggedly made. Thanks, again, for your suggestions.

[Peter Blair]

I have nothing against any system but for my money a video system that can easily and cheaply be built beats my laser system by a mile. Since I built it I have never used the laser again.

[Tom Sell]

Pete, I’m sure you’re correct; it’s more accurate and looks easier to use, but (from Bosch anyway) it’s an option that’s a good deal more expensive. Are you aware of any on-line instructions that would allow me to replace the laser with the camera set-up?

Tom

[John K Jordan]

Pete, I’m sure you’re correct; it’s more accurate and looks easier to use, but (from Bosch anyway) it’s an option that’s a good deal more expensive. Are you aware of any on-line instructions that would allow me to replace the laser with the camera set-up?
Tom

The setup is easy.

- Acquire a small, lightweight video camera. One with a lens that is not too wide and a lens with a focusing adjustment is helpful. The output should be a type that can be displayed on a monitor.
- Devise a way to support the monitor just above and behind the lathe where you can watch it easily while hollowing.
- Mount the camera where the laser pointer would normally go, so it is positioned above and looks straight down towards the tool bit.
- Tape a piece of clear acetate/plastic overlay on the monitor
- With a marker (a fine dry erase marker will work) trace the outline the tool and tip on the clear overlay.
- It is helpful to draw the desired thickness around the cutter on the overlay using a different color.
- With the outside of the form shaped to suit, turn on the camera and start hollowing. The camera will display the outside profile of the piece.
- The tracings on the overlay will indicate exactly where the tool is at the moment, allowing you to "see" the wall thickness as you turn.

- Retrace the cutter if you change it.

Google will give you lots of information. You can search for something similar to use a camera with a lathe hollowing system
You can find write-ups, threads on forums, videos. types of cameras, etc.
The camera on mine is perfect - I don't remember the type but I could see if it has markings if you want. Mine has a mount so I can use either camera or laser if desired.

JKJ

[Dave Fritz]

Since I know nothing about electrical stuff I traded a club member an old canoe I was no longer using and he told me the camera and back up monitor to get and he put it together for me. Works like a charm and didn't cost much at all. All under $100.

[Tom Sell]

Thanks, Pete, for providing all these details; I’ll give it a try! I’m pretty certain that I can order the Bosch support linkage, which looks pretty rigid, without either a laser or a camera, so I’ll follow your lead and let you know how it all turns out (which may take a while). Many thanks, again, for your help.

Tom

[Tom Sell]

Thanks, Dave. You’ve helped convince me I oughta give the camera/monitor it a try. Now, I’ve just got to find an old canoe!

Tom

[Peter Blair]

I am certain you will be pleased with the results. I'm lucky where my lathe is located I mounted an old monitor to a fan I have at the end of the lathe and I just leave it there takes me about 1 minute to have it working. A good tip I believe is that I found a monitor to which a magnet will stick. I then draw the shape of the cutter on a sheet of mylar which is held on the screen with a couple of magnets and I use a magnet washer over the cutter to give me the thickness I want.