JaHo Onamental turning Device

[Bob Roehrig]

In the process of gathering some information on making a JaHo ornamental turner. Acquired the Rotary table, Cross slide, and Boring head. Attaching this to a Oneway 12" swing lathe so still am in thought to attachment methods. Biggest issue in the works right now is how I'm going to attach the chuck to the Rotary table. No longer have my metal lathe so coming up with something solid and workable is going to be a puzzeler. Any suggestions would be greatly appreciated. The original JaHo used High Density plastic, but obtaining scraps that are 3" x 3' has proven difficult. Very expensive and no one has small pieces. Would love to hear from those that have made one to learn issues they had and how they solved them. Thanks

 

[Kirk Yarina]

Bit late, but have you looked on eBay for drops or round stock? I found several sellers offering HDPE and delrin cutoffs by searching for "delrin drops".

 

[colinsp]

One way would be to get a chuck adapter with the correct thread for your chuck and cut off the female part and mount that on the rotary table. An alternative would be a 3D printed chuck wall mount and mount that on the rotary table. With the Jaho setup you aren't putting much load on the chuck as it isn't rotating so either will work, I have used both of these solutions.

 

[Pete Boa]

Since there's a variety of chuck mounting to chuck back plate methods, and back plate to multiple different types of spindle mount, or even rotary table Morse Taper sizes and 3 or 4 tee slots used on rotary tables Bob. The best solution can't really be answered. What's known as a front mounting chuck that might use for example 4 Allen head cap screws through the face of the chuck and then into a rotary table with 4 tee slots and tee slot nuts would be quite easy. Anything else and I'm guessing your planning on using a threaded wood turning chuck. Without a metal turning lathe its going to be much tougher. And if you don't already have them? Even with the correct chuck to rotary table adapter, your also going to need at least a magnetic base and .001" reading dial indicator to get the adapter and chuck correctly true to the center of rotation the rotary table has.

Plastic may have adequate strength for adapting a threaded chuck back plate to a rotary table and cutting light incisions into wood as the original JaHo used. Frankly it wouldn't ever be my choice. Even aluminum for the adapter wouldn't be what I'd use instead of cast iron or steel. The actual threads on any threaded spindle or adapter are rather unimportant. What is important is what would be called the spindle or adapters register location face the chuck or back plate is threaded up to and then fully seats onto and against. It's those surfaces that ensures the chuck is threaded into a repeatable spindle center line position for the chucks radial and axial alignment. All threads have to have a certain amount of clearance or the two parts can't be threaded together. And it's that same clearance for why there never used to accurately align any parts. It's that spindle register that does the alignment. So any chuck adapter has to be machined as parallel and square as possible to the face of your rotary table. All the spindle threads really do is prevent the chuck from loosening and falling off. Metal lathes and there chuck mounting designs all work much the same even if there a cam lock type. There's still a spindle register they centralize on and seat against. There's also a fine taper that helps with alignment on the D series cam lock design, but the basics all work the same no matter what attachment design the spindle or adapter uses.