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Steel ball bearing as Duo 250 trackball
- Thread starter Bama
- Start date
It will work just fine though the feel of the movement will be different.
Fabulous idea, I hope it works out. Is 19mm the trackball spec or did you use a caliper on the original?
I don't have a Duo open ATM so I couldn't check. I don't think the ball would touch the brass, check if the rollerball is supported by the mechanism's rollers? If the copper/brass ring is the bottoming out support it's a no go. If so the weight of the ball bearing may stress the support structure? Dunno, I've got one colored ball so I haven't looked for them, but if marbles are available in 19mm they'd make some crazy trackballs.
Smoothness might be a concern in terms of frictional interface differential with the roller material?
On a side note, the mass of a bearing would have made tweaking Bezier control points a lot more accurate given the inertial upgrade when I was doing that in the field.
I don't have a Duo open ATM so I couldn't check. I don't think the ball would touch the brass, check if the rollerball is supported by the mechanism's rollers? If the copper/brass ring is the bottoming out support it's a no go. If so the weight of the ball bearing may stress the support structure? Dunno, I've got one colored ball so I haven't looked for them, but if marbles are available in 19mm they'd make some crazy trackballs.
Smoothness might be a concern in terms of frictional interface differential with the roller material?
On a side note, the mass of a bearing would have made tweaking Bezier control points a lot more accurate given the inertial upgrade when I was doing that in the field.
I have a couple chrome and gold platted ones that look amazing in the Duo and 1x0 series. I always liked the colored plastic balls that were once popular.
Failing that, there's a fairly reasonably priced complete NOS trackball assembly.
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F142744323329
https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F142744323329
Just checked marbles out, a 3/4 inch "Shooter" is 19.05mm! [
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edit: Just checked the PB100 trackball is about .9885" and Outside the North America, 1-inch marbles are sometimes used as shooters.
One wonders what was used in trackball protyping? 100 series Powerbooks are an oddball size at 1 3/16 in. so they're 3/16" short of the 1 3/8" marble standard.
] edit: Just checked the PB100 trackball is about .9885" and Outside the North America, 1-inch marbles are sometimes used as shooters.
One wonders what was used in trackball protyping? 100 series Powerbooks are an oddball size at 1 3/16 in. so they're 3/16" short of the 1 3/8" marble standard.
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Very nice, where'd you get the ball bearing? Gotta get a few marbles as well to test the mass differentials for feel.
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