So I was thinking today that companies put massive rim weight to yoyos and that it works, they spin long and I like heavy throws so it works for me. So if I wanted a yoyo that was heavy, for me, I would think about making the ball bearings heavier.
But that would make the center of the yoyo heavier…sooo what about hubstacking the darn thing and then making the size a bearings super heavy? Yes, you can put black weight rings or machine extra weight in, but I’m talking, specifically, about hubstack bearings being made heavier.
Is that possible? Would they still spin fine? What are the number of realistic possibilities that could go wrong? You could make the delrin stacks out of metal or something and then viola! More weight.
This is an idea for those, like me unless I’m the only one…yeah right, who likes heavy throws. I mean like 73+ grams heavy
Well, as for making a heavier bearing, that wouldn’t really be an issue until you start learning about materials strengths and costs.
Most bearings are made of Stainless steel, whose density is 7.88 grams per cubic centimeters.
Let’s look at the two most dense (and not radioactive :P) metals, Lead and Osmium. Lead has a density of 11.4 grams/c^3 and osmium has a density of 22.6 grams/c^3. Lead is very ductile(soft) and osmium is very brittle – Not things you would want in a yoyo bearing. On top of all of that, it would be very difficult and expensive to precisely machine out bearing parts from those materials, all for a few grams gain. Stainless steel or ceramic are really the only practical materials for bearings. they have the perfect balance of durability and machinability
Making other parts like the hubstacks out of metal could be a more practical solution.
Also, if you want a more stable and heavy throw, pushing weight out further towards the rim is the way to go. (Warning: Physics ahead) Moment of inertia(Moment of inertia - Wikipedia) is a property of a rotating mass to resist changes in velocity, so the higher the moment of inertia(let’s call it “I”) is, the longer it will spin. "I " Is higher for objects with less mass in the center, and lower for objects with more mass in the center. I is also exponentially higher as you increase radius. Also, read about gyroscopic precession(Precession - Wikipedia), it’s the tendency of a rotating body’s axis of rotation to rotate or change. This effect is lessened by a larger radius.
Point of all of this is to get a heavier yoyo while still retaining stability and long spin time, you want to either increase the radius, increase weight at the rim, or decrease weight at the hub.
Based on what was stated earlier, I think perhaps the application of denser materials to key locations might be the best bet.
If you’re going to coat a bearing with a dense layer of something, well, that’s going to add thickness. Depending where you add thickness, it may no longer fit in the bearing seat. If it gets INSIDE the bearing, it’s going to take away from the room the balls have to spin in.
The other concept would be another thing that has been suggested already and that’s accomplished by buying a One Drop or other side-effects compatible yoyo. The different opions have different weights, so you’re actually making changes in the exact center, not “near center”. Although, the weight is centered, it is to the outside of the yoyo, not dead-center.
Adding weight to bearings isn’t going to do you any good, especially if you add it to the outer diameter of the bearing. When the yo-yo is spinning at the end of the string (and when you are holding hubstacks), the outer diameter of the bearing is not spinning. Therefore, when at the end of the string or when the hubstacks are being held, that extra weight isn’t doing anything useful.
When the hubstacks are released or the yo-yo is popped up (alleviating the string friction) the internal friction of the bearing causes the outer race to accelerate back up to the speed of the rest of the yo-yo. Acceleration requires energy. That energy comes from the energy in the already spinning yo-yo. In other words, the yo-yo will slow down when the bearing, hubstacks, etc. come back up to speed. This will only decrease sleep time.
Your idea adds weight in a detrimental way. If you want extra rim weight, add weight rings. Dif-e-yo has been doing it for years. If you want to be able to change the center weight, use a yo-yo with side effects.
