Woodturning Blanks

From CoMakingSpace Wiki

spindle blanks cut from various softwood scraps - good for practicing (e.g. file handles), but not suited for complex shapes

In any woodturning project, you will start out with a "blank". Those can often be quite small and reclaimed from (free) scrap wood! Some even literally grow on trees, but often you'll need to make some preparations before actually starting to turn.

using a 3D printed "center finder" to estimate the center of a not exactly round apple log
a brace is very useful to pre-drill the center hole so the lathe's center does not split the wood

In general, you should look for an even grain structure and avoid knots for easier turning. Single flawless pieces are optimal, but with some experience you can also try to fill cracks with a suitable resin or turn carefully arranged & glued "segmented" blanks. Whatever you end up doing, make sure to estimate the center of the blank as closely as you can to reduce unwanted forces and unneccessary waste of material!

The more unneeded wood you can remove before turning, the better! Octagonal blanks are relatively easy to make in most cases, and the extra sawing steps are quickly worth it at larger diameters.

Contrary to many other woodworking techniques, a bit how much? of moisture (or even "green" wood) can be helpful when turning. Very dry, hard woods (e.g. beech table leg used for some Tigerente wheels) can be hard to cut and produces small chips rather than nice, smooth shavings.

Wood Species

Very soft wood, like fir/spruce, is actually NOT easy to turn, you'll often get tear-out instead of nicely shaven surfaces (similar to planing these woods). So while it's good to start "soft" to understand catches & tool angles, prepare yourself to acquire some higher-quality wood for your take-home projects.

Lukas made very positive experiences with self-dried apple logs, but (cheap) birch logs do not turn much better than softwoods because they are grown too fast.

Micha has tried plane (Platane) and hated it, but is often seen in the Space happily turning maple.

Spindle Blanks

lots of material can be saved by gluing together different sections - e.g. to have a larger blank thickness only where needed

Spindle blanks (Kanteln), i.e. those you would turn lengthwise (and often between centers), ideally have a straight grain along the spindle.

The diameter of these is often quite small and you'll get away with a square blank.

Tree branches and small logs also make great spindle blanks if they're not too curvy!

Cutting Square Blanks

Glued Spindle Blanks

When your stock is too thin for the work you have planned, you can glue two pieces together - just make sure to have them in the right orientation so the bond won't crack due to the wood "working" later on!

Very schematic grain constellations that should work: [1]

  • )( (might open in the center, but not visibly)
  • ==
  • //
  • NOT ()
  • NOT =/ (or any other mix of different cuts)

Have a look at the somewhat more sophisticated illustrations on HolzWerken.net if this doesn't make sense ;-)


Bowl Blanks

We now have a wood lathe capable of serious bowl turning ! Here we can start to collect information on bowl blanks

starting points:

Sourcing

If you do not want to make your own blanks or, perhaps more likely, don't have the proper kind of wood at hand, you can buy blanks at numerous stores. Just do a quick online search for "Drechselholz", "Drechsel Kantel" or "Drechsel Rohling" and you should find what you need! As usual, please share your experience if you try out a shop :-)