Bearing Sizes for Trackballs

[IntruderAlert]

I want to experiment with some different types of bearings on my 3" Imperial Track Ball but I don't know the size for them

The bearing web sites that I have looked at are asking for Dimension in Decimal Values Only (Ex. 1.5000)
I need the measurements for Inner, Outer and Width but I don't have a micrometer or anything to get a good measurement with

I also have an old 3" WICO and I know that they use the same size rollers and bearings too.

[Flinkly]

not like you shouldn't, but i fail to see the logic.  if it ain't broke, don't fix it.

also, i can't really help, so just consider this the maiden post of this new thread.

[IntruderAlert]

well.. this one is about due for some new bearings anyway so i want to see if there might be a longer lasting, better performing bearing at a reasonable price

for example these ceramics and ceramic hybrids

[Bones]

Ceramic bearing are designed for extremely high speed applications and cost an absolute fortune due to the fact that they are usually classified as high precision. I have seen catalogues where these things are rated to 100,000 RPM for smaller sizes!! Most ceramic bearings will cost you hundreds of dollars each and upwards....

If you send me your approximate sizes I will advise you of standard options. (14 years bearing salesman here

[IntruderAlert]

I'm sure there are some high tech applications where the prices are that high
But you can get 16 ceramic bearings from this guy for 20 bucks
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=47346&item=7153016308&rd=1




..and 8 ceramic / stainless bearings here for $25
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=36624&item=7151427202&rd=1






I've just got to make sure that I order the correct size

[Captain_Dingo]

I can tell you that the inside diameter of my bearings is 5mm, from comparing them to a router bit bearing.  I forget what the outside diameter is.

I'd email Bob Roberts and see if he knows the exact specs.  I don't have any calipers here that I can use to get you an exact measurement, unfortunately.

[Avery]

I just ordered some bearings from McMaster Carr (www.mcmaster.com).  They stock 1 each, everything in the world of hardware.

I'll have to remeasure them though.  If I haven't posted numbers by tomorrow, pm me to remind me.