|Michael Gilligan||05/08/2020 07:53:14|
16190 forum posts
Recommended viewing for your next ‘tea break’
|576 forum posts|
Thanks for that Michael,
the biggest beating I ever fitted was 3meters in diameter.....All hand assembled in Switzerland......
If u can remember the Mont-Blanc tunnel fire years ago....we had a number of bearing in a container stuck in the fire.....saw pictures of the container when opened.....al the plastic bearing spacers had melted and made a right mess....
we had no work for a few months.....
the firm operated a timed supply system with no spares....
I told them that was crazy, especially as they had already had most of the money for the machines....
..That’s accountants for u.....penny wise pound foolish.....me in suit"s....hahaha...
|Brian Wood||05/08/2020 09:19:16|
|2243 forum posts|
Well found Michael, absolutely fascinating
|Douglas Johnston||05/08/2020 11:58:21|
699 forum posts
No wonder quality bearings are so expensive. So many corners to cut with cheaper bearings. The balls from quality bearings make excellent references for checking micrometers etc.
|1167 forum posts|
Most inconsiderate of the supplier Clogs. JIT (Just in time) delivery means someone has to manufacture and store at their own expense, components just in case a tunnel has a fire. Unbelievable the amount of "Dead" money is stored in overproduced stock, "Just in case".
4768 forum posts
We often found JIT turned out to be NQIT. Not quite in time.
|961 forum posts|
Now do that for a roller. Just compare the cost of roller and ball bearings with the same dimensions.
I used to buy bearings for myself and others at local bearing stockists. If you wanted more than one you would be offered a discount of over 50%. They kept large stocks because most customers had to make an urgent emergency purchase.
|norm norton||06/08/2020 13:51:15|
|127 forum posts|
Yes that was a good little video to see, thank you.
It appears that rolling the balls repeatedly up a series of spiral channels eventually forces them to self wear and become spherical. I wondered if any grinding paste/suspension was included or if their own grit did the job? I think they mentioned lapping paste for the final polish.
I thought I read many years ago that early ball bearing manufacture involved dripping molten steel from the top of a tower, with the molten steel forming a ball before it cooled and hit the sand at the bottom? or have I muddled this with another process?
I think that Britain has never (?) had its own ball bearing manufacture, which is why we were in trouble for the two world wars. Industry was using imported metric bearings in the 1930s because you find them in otherwise fully imperial motorcycle parts.
|1167 forum posts|
Yep, DH Mosquitos on the bearing run, Sweden (SKF) to UK. Bomb Bay Loaded.
|Stuart Bridger||06/08/2020 14:51:14|
|464 forum posts|
Norm, you are thinking of lead shot manufacturing which was traditionally done in a shot tower
6181 forum posts
Not quite, Ransome and Marles, still going, started in 1900 and I'm sure others must have had a go. Not easy to make steel balls all exactly the same size, perfectly round and suitably hard and tough. Slight shortcomings cause wear and reduce bearing life.
Ball bearings were in short supply despite the efforts of British makers and anyway the best bearings during WW2 were made by SKF in Sweden. Back then there were still trade secrets. This website says SKF supplied 31% of British ball bearings during WW2 and 58% of German.
|Stephen Spindler||06/08/2020 17:42:33|
|7 forum posts|
Hoffmans in Chelmsford was a bearing manufacturer, looking at old maps a "bearing manufactory". I think attempts to bomb it were made in WW2 and I believe it closed sometime in the early nineties. Almost the entire site is now cleared and occupied by Anglia Ruskin Uni but one building along with a nearby Marconi building retained.
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