Now the situation is like this:
But it was as next:
I was using as first 600 water sanding paper and to finish 1000 (check the table on the bottom for bold text). Data for 600: 25,8µm= 0.00002580000 m and for 1000 0.0000183 m
As a reference to get feeling how much the scratches damage in material was i am making next calculations. Under the red elipse (picture below) mark is next standard dimension. And the difference between dimension is 0,01 of inch what is equal to 0,25 of milimeter = 0,00025 metre. And i was grinding down as first with average particle diameter of 0.0000258 m. What is 1/10 of difference. I did use amount of paper which i am holding on picture above. I hope i did not grind to much to compromise clearance which i will have with new bearings. (Exactly How much did i grind i will know when i will put new bearings and compare this one with others).
And how did i get to the Perkins part serial number? Googling next page
from bearings number:
And what is the status now:
On bearing above you may see horizontal line which is checking from clearance tape thread:
The conclusion my clearance is 0,003 of inch now. What is to much. Acceptable tolerance is 0,002. And also there are deep scratches in bearings. I have to get me new one. I did took a risk and because Steve was coming from USA 2 weeks ago and got him to bring me the standard bearings. I did lost 70$, because i need -0,01 bearings (the first size after standard check picture above). I am looking to get them in Rio dulce now.
To ilustrirate where am i working:
Grit size table
The following table, compiled from the references at the bottom, compares the CAMI and “P” designations with the average grit size in micrometres (µm).
|ISO/FEPA Grit designation||CAMI Grit designation||Average particle diameter (µm)|
|Extra Coarse (Very fast removal of material, hardwood flooring initial sanding)||P12||1815|
|Coarse (Rapid removal of material)||P40||40||425|
|Medium (sanding bare wood in preparation for finishing, for gentle removal of varnish, also used for skateboard grip tape)||60||265|
|Fine (sanding bare wood in preparation for finishing, not suitable for removing varnish or paint from wood, use for cleaning plaster and water stain from wood)||P100||162|
|Very Fine (sanding of bare wood)||P150||100|
|Very Fine (sanding finishes between coats)||P240||58.5|
|Extra fine, start polishing of wood||320||36.0|
|Super fine (final sanding of finishes, final sanding of wood)||400||23.0|
|Ultra fine (final sanding and polishing of thick finishes)||P1500||800||12.6|