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  #1  
Old Sat 07 February 2009, 15:27
Barman
Just call me: Bart #36
 
antwerpen
Belgium
Tolerace of the hold-down shaft (M1 30 224T) ?

Finally I found someone who will make for me parts : M1 30 224 T and M1 20 220 .
First thing he asked me , was the tolerance of the shaft M1 30 224T?
I don’t know ?
After some search on internet I came to the following conclusion :

. http://www.skf.com/skf/productcatalo...on=Tolerances1

The following issues did I selected :

Bearing : 6304 2Z
Bearing tolerance class : Normal

Recommended fits : -> Radial bearings with cylindrical bore ->

Stationary inner ring load -> Easy axial displacement of inner ring on shaft unnecessary

h 6

If you fill this in , the following result appear .

0 - 0,013

So, I think the tolerace of the shaft is between 20 mm and 19,987 mm for “ press fit a bearing “ .

Can someone confirm this result?
Thank You
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  #2  
Old Sat 07 February 2009, 20:43
Gerald D
Just call me: Gerald (retired)
 
Cape Town
South Africa
Bart, your research is indeed 100% and your answer is perfectly correct.

However, most DIY builders do not have the tools to measure that accurately, so they cannot check it when it comes back from the machinist. That is why I move the responsibility to the machinist and give him a sample bearing. All machinists have experience in getting the bearings to fit nice and tight, but sometimes even they have a slightly loose fit and then Loctite does the rest.
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  #3  
Old Sun 08 February 2009, 15:04
Barman
Just call me: Bart #36
 
antwerpen
Belgium
Thank you for your reply.
Now I am sure.

Today I found a shaft with a diameter of 28 mm on my work .

I suppose that the first piece (=15 mm) of the shaft may also have a diameter of 28 mm instead of the given 21mm .The dimension of the inside ring of the bearing is about 30 mm.
So , I think as long as it remains below 30 mm it is ok..( = > less turning )

And indeed , in the case of a loose-fitting “Loctite 641” will fix the problem.
( I had not thought of it )
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  #4  
Old Wed 19 January 2011, 19:31
Red_boards
Just call me: Red #91
 
Melbourne
Australia
Tight fit can be solved, too.

Put shaft in freezer and pinion (in my case) in the oven. They metal expansion and contraction will do a good job of loosening the fit and then grow again for a tight fit. This was the way of fitting starter motor gear rings to older minis when I was young.

I wouldn't heat bearings too much.
I wouldn't do this if the fit isn't close to start with.
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  #5  
Old Wed 19 January 2011, 20:08
domino11
Just call me: Heath
 
Cornwall, Ontario
Canada
Red,
This time of year I just leave the stuff outside overnight. -29C this weekend again.
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  #6  
Old Thu 20 January 2011, 18:54
Red_boards
Just call me: Red #91
 
Melbourne
Australia
I can leave one part in the sun and it will get to 50C pretty quick!
Condolences
If I lived where you live I'd have to cross a border and three or four states just to go surfing - not to mention the Brrr factor
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