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Posts by TranquilTempest

Volume, not yield. Yield refers to the proportion of good dies on each wafer of silicon. You'd only switch for better yields if there was a major problem the current fab was unable/unwilling to fix.
Meh, I think I'll just stick to Kerbal Space Program.
the overshoot would be the ball against the pad more than the ball against the rollers.
I guess I need to read the spec more thoroughly.
All of mine had 1 extra roller, with a spring on it that held the ball against the encoder rollers.You misunderstand. USB mouse standard uses a signed char(8 bits, 7 bits for magnitude, one for positive/negative) to send mouse position updates. That means you can move the cursor 127 counts per poll interval in each axis(sign indicates direction), and at 1khz that's 127k counts per second. To get more than that you'd have to write mouse drivers for the PC that allow a...
A typical mouse ball masses what, 20 grams? At 40g acceleration thats 8 newtons across a contact area of say 1mm. So that's a pressure of 8MPa, which is less than 1/8 the yield strength of plain old cheap ABS. Okay, so what happens if you drop the mouse and it's subjected to 350g acceleration? Well your ball is covered in rubber, so the contact area increases. As I said before, top speed is only an issue of how fast you want to count pulses out of the encoder, at 127khz...
Ever play with lego bricks? There are tolerances there at .0004 inches (10 ┬Ám), and that's injection molded ABS. There's only one truly critical dimension on an encoder wheel, and that's the diameter of the roller, the encoder isn't going to care if there's a couple thou of runout on the code wheel. Small parts are relatively easy for injection molding, when you have a large part it's a lot harder to deal with varying cooling rates.Oh, and plastics and metals both have...
The speed is easy, it's not like you're going to melt the encoder wheels moving the mouse too fast by hand. Extreme acceleration would be a bigger issue, the tradeoff there would be the force required to move the mouse vs the force required to overcome the tensioner and lose contact between the ball and the encoder.
Or count it in hardware.
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