Project:Captive Ring Turning

ProjectInfoBox Captive Ring Baby Rattle
Status:	done
Release Date:	March 2019
Initiator:	Lukas
Materials Used:	wood (apple log, self-dried), beeswax
Tools Used:	wood lathe, woodturning tools: roughing gouge skew chisel spindle gouge hook tool
Approx. Cost:	next to nothing

Turning "captive rings" is a tricky technique, but tried by many woodturners at some point.

I taught myself how to do it in order to make a one-piece rattle for some awesome babies!

tl;dr

• hard wood
• patience
• shape & sand as much as you can before "freeing" the ring
• cut the ring at spindle height or it may break at the last moment ^[1]
• expect some burn marks

Choosing the Material

You'll need especially even-grained and dense wood for this project or the rings are prone to breaking.

I was very happy with the apple log I had laid aside for this project all along, but the birch and especially fir that I used as first tests behaved pretty badly.

Making the Hook Tool

First of all, I made the special tool needed to undercut the rings. There are commercial "ring" or "hook" tools available but I had seen DIY versions made from hex keys and obviously just had to try that!

Materials:

• scrap wood (hardwood - here: cherry)
• surplus large hex key

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  square up the woodturning blank
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  the first step of most tool handle woodturning projects is the ferrule - e.g. cut with a pipe cutter
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  a brace is very useful to pre-drill the center hole on a woodturning blank
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  once the handle is turned round, the ferrule can be used to determine the shoulder position
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  make the handle rather long - like all woodturning tools, it should provide good leverage
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  a sturdy tailstock on the wood lathe can help to press the ferrule onto the tool handle
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  the hex key and ferrule should be glued in place with epoxy
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  amazing what you can still make out of a little bit of junk! (rest of the scrap wood for comparison)
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  finally grind a scraping tip onto the (former) hex key

Educative Failures

• first attempt: scrap fir wood
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lessons learned: wood too soft, piece too thin

• next try: birch (poor quality)
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lessons learned: wood still a bit too soft, parting tool much more suitable to define the ring width than spindle gouge, poor bevel on the hook tool, use even less force than usual

The second birch ring turned out a lot better than the first so I decided to get serious!

Baby Rattle

• the final piece :-)
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  the apple log was dried quite nicely and only had two superficial cracks
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  tried to find the center as closely as possible to the log would rotate nicely and not lose too much material
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  first step in pretty much any woodturning project: roughing
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  sketching the dimensions of the first elements: end knob, gap, ring (1/2 gap width), gap
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  after defining its outer curve with a parting tool and then a spindle gouge, the future ring is slowly undercut with the hook tool
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  burn marks are to be expected when using a self-made tool for this job - just make sure you don't generate enough heat to crack the wood!
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  fast forward: two rings are cut! See "educative failures" above for more details on this part of the project
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  this part was a bit scary (not tested beforehand): "planing" the middle section with the skew chisel while the rings are taped to the side
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  give the end knobs some shape until you're happy (don't take too much off the diameter!)
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  sanding the rings' insides is possible by taping some sandpaper to the spinning middle section and holding the rings
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  applying beeswax is easy with the lathe spinning - most of it melts just by friction!
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  even out the beeswax and work it in deeper with a paper towel
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  waxing the rings is not possible with the friction method as they would just stop spinning - use a hot air gun instead
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  after parting the piece off on the lathe, I sanded the ends by hand (although a disc sander would have been much better)
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  one more waxing step with hot air...
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  done!