I think the damage on crank shaft was not to bad. #17B sz2

Now the situation is like this:

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But it was as next:

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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

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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).

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And how did i get to the Perkins part serial number? Googling next page

from bearings number:

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And what is the status now:

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On bearing  above you may see horizontal line which is checking from clearance tape thread:

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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:

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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).

Grit size table
ISO/FEPA Grit designation CAMI Grit designation Average particle diameter (µm)
MACROGRITS
Extra Coarse (Very fast removal of material, hardwood flooring initial sanding) P12 1815
P16 1324
P20 1000
P24 764
24 708
P30 642
30 632
36 530
P36 538
Coarse (Rapid removal of material) P40 40 425
50 348
P50 336
Medium (sanding bare wood in preparation for finishing, for gentle removal of varnish, also used for skateboard grip tape) 60 265
P60 269
P80 201
80 190
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
100 140
P120 125
120 115
Very Fine (sanding of bare wood) P150 100
150 92
P180 180 82
P220 220 68
MICROGRITS
Very Fine (sanding finishes between coats) P240 58.5
240 53.0
P280 52.2
P320 46.2
P360 40.5
Extra fine, start polishing of wood 320 36.0
P400 35.0
P500 30.2
360 28.0
P600   25.8
Super fine (final sanding of finishes, final sanding of wood) 400 23.0
P800 21.8
500 20.0
P1000   18.3
600 16.0
P1200 15.3
Ultra fine (final sanding and polishing of thick finishes) P1500 800 12.6
P2000 1000 10.3
P2500 8.4
P3000 6
P6000 4

 

4 comments

  1. Oj čau.
    Škoda da nisi zmeru zračnost pred poliranjem gredi. Zmeri zračnost tudi na glavnih ležajih s starimi ležaji (bronzinami). Glede na slike mi zgledajo še dobri. Glede na meritev zračnosti na ojničnih ležajih ki je 0.075mm in kot praviš izven mej boš mogu dat brusit gred na -0.25mm, kot si že ugotovu. Vendar zna bit, da je dovolj dat brusit samo ležišča ojničnih ležajev in glavne pustiš na miru. Zato zmeri prej zračnost glavnih s plastigauge-om. Praviloma bi mogu po brušenju vse skupaj dat še balansirat ( z vztrajnikom) če ga ima. Ampak glede na to da je mašina od barke in dela verjetno precej na nizkih obratih se jaz nebi preveč sekiral. Tu je brušenje gredi 80€- tako da boš imel en občutek o ceni. Pu beušenju se prepričaj da so ljni kanali na gredi ščiščeni opilkov.

    Bi pa jaz obvezno prekontroliral kako je z oljno pumpu. Jaz sem tudi enkrat mislu da je kriva zračnost na ležajih pa je bla na koncu oljna pumpa. Če je običajna zobniška se da z listični premerit zrečnosti med zobniki in na ohišje če je znotraj toleranc( recimo 0.1mm). Potem še preglej če te zanbit jebe kak ventil od nadtlaka olja če ga ta motor ima.

    Lp iztok

  2. Ola Iztok. Ce klikness na sliko se prikazze, krogec s plusom, za zumiranje.
    Poglej si 6to sliko. “The conclusion my clearance is 0,003 of inch now.”
    Gred je zze brussena na prvo mero pod standardom. Obrabljenost lezzaja pa je priblizzno 1/10 od razlike med dimenzijami (brussenji). Razlaga meritve s plasticcnimi trakom je podana s ccetrto in peto sliko in z linkom med njima.

    Lezzaje sem kupil.

    Pumpa je tudi slaba. Zdaj issccem drugo. Ravnokar sem se vrnil iz glavnega mesta Gutemale in zzal nimajo pumpe. Iz Amerike rabi possiljka 10 do 15 dni. Bom probal dobit eno druge roke.

  3. Aha zdaj vidim po part No. da je že prvo brušenje. Ma ja une 2-3 stote bo po moje lih kolko je obrabljen lezaj. Srečno z popravili. lp

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