Hi everyone.
It’s been on my mind for a while to share some of my techniques for making wooden yoyos for those who are already experienced in making them.
This eposode is on a technique called ‘shear scraping’.
Have you noticed when you turn your wooden yoyos that sections near the endgrain sometimes look a lighter colour than the side grain? You may also notice that usually no amount of sanding seems to remove these marks and often highlights them even more. You can see what I’m talking about in the picutres below.
Even the best wooden yoyo makers have difficulty with this, but with practice using the right techniques, you can virtually eliminate it.
Why does this happen?
This occurs from turning the shape of the half using scraping instead of slicing the fibres. If you use a skew turned on its side, a flat end scraper or any other kind of tool in a scraping position, you end up flattening the endgrain fibres causing them to feel rough and reflect light differently. This gives them a lighter, and /or streaky appearance.
Now, although scraping damages the fibres, I do think it is the best way to turn a yoyo half because it is far easier to control than, say slicing with a bowl gouge, which often leaves an uneven surface with grooves.
How can I stop this from happening?
If you’re going to scrape yoyo halves, it’s an inevitability. However, you can clean up the flattened fibres using shear scraping at the final stage of turning each half.
How does one ‘shear scrape’?
Firstly, turn your half to the point where you would ordinarily have one pass left with the tool to complete it.
Next, align your scraping tool at a steep angle to the yoyo half (75-80 degree angle to the toolrest). I normally use a square end scraper, but you can use a different tool. Its possible to use the wing of a spindle or bowl gouge or one of those Ezy wood tools. Refer to the picture below.
Next, maintain firm pressure and move with a smooth motion from the inside of the rim to the outer. Make sure you swing your body to do this, not move your arms. Maintain the orientation of the tool the whole way, otherwise you can catch slightly and make it worse. This is something that will take a lot of practise to get a proper feel for it. You know you are doing it right when you have very fine ‘angel hair’ shavings (see pictures below).
After each pass check to see that the grain is cleaning up. If you can feel that areas just next to the end grain are still rough or have obvious light streaks, continue to make another shear scaping pass and inspect. You are taking off hundredths of a millimetre with each pass, so if you need to do 5 or more passes, you will not be taking off large amounts of material.
After you have completed shear scraping and have removed all flattened grain, sand like normal. You will notice that the colour is uniform and streak free all around the half. You can see that there is no streaking in these maple halves.
Some species or individual pieces of wood are more prone to this than others and require more cleanup. Woods like cherry and maple in particular. Generally speaking, the softer the wood, the more easily flattened grain occurs.
I hope someone found this helpful. If you have, I will make further posts on some of my techniques.
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