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Bama

Steel ball bearing as Duo 250 trackball

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Hello All,

 

I need a replacement 19mm trackball. I have a 19mm steel ball bearing.  Is this safe to use the metal ball bearing as a replacement?  My reason for asking is that I can see what looks like copper at the base of the trackball assembly.  I attached a picture.

 

Thanks,

Bama

95334837-C05B-4A94-B40E-363F87C9C3CD.jpeg

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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.

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Just checked marbles out, a 3/4 inch "Shooter" is 19.05mm!  [:D]

 

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.

Edited by Trash80toHP_Mini

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19mm steel ball bearing works terrific!   Now I only need a retaining ring. (I don’t want a loose ball bearing bouncing against my glass screen when the lid is closed.)

 

Any ideas for this part in the United States?

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