Equal sides to yo-yo.

Thinking that unbalanced sides of yoyo would really mess up the action, is there a way to make the two side of a yoyo exactly the same [thinking of wood trickery here since cannot seem to conjure up a reasonable way to do it] . Could turn one side, make a pattern of that shape, then use to turn the opposite side.

But with the tricks I see folks invent here, assumed there might be one for the equal yoyo. Had been planning for a long while to make them for my grandsons [8&13] and expect it's time to do before time gets by and their future wife(s) might think it silly :D.

So any magic means out there in yoyo land? If not, suspect I will make quite a few halves before I judge two relatively the same....(since it's for the grandsons, bet the wife would be more amenable to CNC...but not the banker :o). Thanks...

I've not made a yoyo, so take this for what it's worth(less than nothing).

If you end with pieces of equal thickness and turn them to equal diameter(could be checked with a caliper), I don't think you'll find much difference in the two halves. The only other variable would be for the radius on the edges of the two pieces. You might try a search for Ed Davidson's videos(aka yoyospin)... He's done some neat videos on pens, stoppers, and yoyos.

What I've done in the past was to turn the disc to full width of both sides plus 3/32". After you make it round and all the fun stuff, measure the EXACT middle and part with a 3/32" pating tool. This usually works...give it a whirl!!

Hi Chris, I am working on something that although is not a yo-yo still has 2 sides that need to match, this is what I did. I glued glue blocks on one side of each piece, mounted each one 1 at a time and turned a small hollow in the inside face of each...so if you set them down facing each other on a table you have the 2 hollowed areas facing each other, and glue blocks on the outside ends of each piece. Now I tool a piece of scrap and turned it to fit inside each hollow with only "1/16 seperation between them for a jam chuck. I mounted each piece onto this jam chuck and mounted on the lathe, now both pieces are "1/16 apart yet mounted as one piece with a glue block on eacvh outside piece. I turned them both to size and am ready to do the detailing on them this afternoon. This way I can make them identical as they are mounted together at the same time...this is probably confusing, if you want pics let me know and I will take some this evening for you....

I think I would make a template and use it to determine if the two sides are the same.

I've turned some yo-yos and David is on the right track. Start with identical thickness wood (I ran mine through a thickness planer till I got the desired thickness. I then roughed them out on a bandsaw and drilled holes in the center.

Using that center hole, I mounted both pieces on the lathe at once and turned a slight bead centered on the joint. As long as you make a half decent symmetrical bead, the two halves will have the same mass and moment. You can then turn a slight V centered on the joint and sand to round off the inner edges.

Cut your blanks from a board and glue them together with wax or other paper, then turn, then separate and finish. Penn state sells a cutter for yo-yo's if you're going production mode, and they have kits with ball bearing ctr post. Haven't done one yet cuz I have a cool plastic one with lights.
Good luck,
Michael

Yoyospin makes his yoyo out of one piece of stock, i.e., they are solid, not two pieces of wood. He uses a profile gauge to make sure the shape is the same on both sides. His DVD is pretty good.

I've turned a couple dozen of them from some 4x4 maple. I used a vernier calipers to set out the thicknesses and size of the grove for the axle. I never had a problem with them spinning out of balance. I believe if you just come close it will work fine. Sanding the sides can be accomplished by reversing the yoyo in either a jam chuck or 4 jaw chuck. If something were out of balance, you really have lost much but some wood. I have made the conventional kind and the butterfly models. I prefer the butterfly for doing tricks. A good waxed string helps a lot. Also sand the grove for the string. Less friction means a longer spin.

Starting with the same thickness of wood and then turning to a profile card will get you in the ball park. I then use a gram scale and do some light sanding to have exactly weighted halves.

Regards, Steve

Really good info and thanks so much. Have a really small postal scale from HF so that will do for measuring in grams, but think I will also try the single block. If I can get it close on turning, sanding can bring it to exact if I make a contour gauge...or buy one...it was on my list of stuff I needed for another project anyway and they are inexpensive...a rarity. And it's time to make the thin parting tool...saved a sawzall blade for just that purpose...although I'm not sure it is sufficiently stiff or hard to not flex or keep a hard point. Again, thanks for the comments.

You can get close with jigs and templates. If you want them perfect, then you need a scale that will measure down to at least 1/10 of a gram. The weight on both sides needs to be perfect.

robo hippy

I wrote an article a while back on making a ball bearing yo-yo. You can find it here:

http://www.woodturningonline.com/Tur...ring_yo-yo.pdf

I don't know if the mods will remove this since it links to a different woodturning site. Usually, the species of the wood has more to do with balance than how identical the halves are. They still need to be really close, but if you have wood that is more dense in some locations than others, than you are fighting a losing battle. Acrylic is wonderful due to it's homogeneous nature. Good luck!