Bearing scraping film

[Stuart Giles]

I'm amazed that there are people on here talking about BUYING bearing scrapers. Where's that A7 owner high degree of parsimony that's usually apparent 

During my apprenticeship I spent some time working with the bench fitters, one of the older blokes there encouraged me to make my own scrapers using knackered files as the basis and the shape of each is exactly as per those of my mentor. here they are:



Heated up and allowed a slow cool, the three square and half round files were completely soft and were filed and bent to shape before being heated to red heat, quenched, and tempered to light straw before stoning them to get a decent edge. George, the elderly fitter who gave me the idea was only half impressed with the result as you can still see the ghost of the files' serrations in my finished scrapers. I do have a couple of "shop bought" scrapers now too, but these ones seem nicer to use somehow.

[Bob Culver]

I have heard that same voice on other US Govt films. Like how to land a Liberator with only one set of wheels down....

[A G Wood]

Stuart, I think George is being a bit harsh, they look like a nice bit of work and a time-honoured use for knackered files. I think the reason they feel nicer to use is because they're basically bespoke, and you have most likely unconsciously subtly  adapted them to your own hand. I have read of the outer races of large ball bearings being repurposed as scrapers too, the advantage was given was they are already on their way to being hollow ground due to the ball groove

[Chris KC]

Interesting film Simon, thanks for sharing.

Sorry if this is a dumb question, but is there a reason reamers can't be used to finish white metal bearings?
Or is it just a question of cost?

[Bob Culver]

Without checking out old posts I forget who knows what. So for whoever...
A fixed reamer provides only one size and normally only readily available in set intervals; often a crank finished or worn below the original exact size. With all reamers alignment is tricky and easy to introduce chatter marks, esp with the adj type which require patient clean assembly to get all blade heights equal. As with mostcutting tools, reamers do not always handle very fine cuts well.
The guy in the film in the second part was dealing with long small dia solid bearings probably of standard size and his audience would have often had access to full workshop eqpt so mention of reamer option would have been appropriate.

[Chris KC]

Thanks Bob.

My Googling did eventually find some instances of not only reaming but also broaching and, on larger bearings, even hammering being used to size white metal bearings, generally as a short cut to reduce costs. As you suggest, the consensus seemed to be that it's not a preferred method; but viable at a pinch.