STAR 067-30 bushing, how can i see if it is worn out ?

[vroemm]

Hi.

I found a bunch of blocks with two STAR 067-30 bushings in it.
I bought one for 10 euro to see if it is useable for me..
The other blocks might be available for a few more days, but it might not.
I am a newbie walking in the almost dark :-)
I could use your advise.

How can i see if it is worn out ?
Or damaged in a other way.

It is for a +/- 30 mm thick slider bar.
Should i use exactly 30 mm bars, or what ?
I do not want more play then nessecary.

I have no idea how strong a 30 mm slider bar would be to build a CNC router with.
Can someone give me a impression of how strong this is ?

I was thinking about 45 mm, but now i found these bushings i wonder if 30 mm would be enough.
My goal is to build a CNC router with 1/25 mm accuracy. (or am i dreaming ?)


Here are more pictures: http://home.wanadoo.nl/vroemm/cnc/sl...67-30-bushing/

Thanks.