Project:Captive Ring Turning
(Redirected from Captive Rings)
| ProjectInfoBox Captive Ring Baby Rattle | |
|---|---|
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| Status: | done |
| Release Date: | March 2019 |
| Initiator: | Lukas |
| Materials Used: | wood (apple log, self-dried), beeswax |
| Tools Used: | wood lathe, woodturning tools: |
| 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
square up the woodturning blank
the first step of most tool handle woodturning projects is the ferrule - e.g. cut with a pipe cutter
a brace is very useful to pre-drill the center hole on a woodturning blank
once the handle is turned round, the ferrule can be used to determine the shoulder position
make the handle rather long - like all woodturning tools, it should provide good leverage
a sturdy tailstock on the wood lathe can help to press the ferrule onto the tool handle
the hex key and ferrule should be glued in place with epoxy
amazing what you can still make out of a little bit of junk! (rest of the scrap wood for comparison)
finally grind a scraping tip onto the (former) hex key
Educative Failures
- first attempt: scrap fir wood
- next try: birch (poor quality)
The second birch ring turned out a lot better than the first so I decided to get serious!
Baby Rattle
- the final piece :-)
the apple log was dried quite nicely and only had two superficial cracks
tried to find the center as closely as possible to the log would rotate nicely and not lose too much material
first step in pretty much any woodturning project: roughing
sketching the dimensions of the first elements: end knob, gap, ring (1/2 gap width), gap
after defining its outer curve with a parting tool and then a spindle gouge, the future ring is slowly undercut with the hook tool
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!
fast forward: two rings are cut! See "educative failures" above for more details on this part of the project
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
give the end knobs some shape until you're happy (don't take too much off the diameter!)
applying beeswax is easy with the lathe spinning - most of it melts just by friction!
even out the beeswax and work it in deeper with a paper towel
waxing the rings is not possible with the friction method as they would just stop spinning - use a hot air gun instead
after parting the piece off on the lathe, I sanded the ends by hand (although a disc sander would have been much better)
one more waxing step with hot air...
done!
