Member postings for Grindstone Cowboy

Hi Folks

I know there are some campanologists on here, so maybe you could help, along with the metallurgists...

Via a bell-ringing friend, I am about to acquire a few lumps of bell metal - don't worry, it's all legal, they are apparently fitting new crowns(?) and this is part of what's been cut off to do so.

He has been told it is (most likely) 77% copper and 23% tin. My question is, what might it be good for for a home machinist? I believe it was very hard to cut, which is slightly putting me off.

I know the ideal is to buy proper machinable materials, but, hey, it's free!

Thanks, Rob

My tap also arrived this morning, Martin, thanks again

Rob

Sorry, can't help with the question, but congratulations on owning a bit of history - one of my favourte authors, Trustee from the Toolroom being amongst his best work.

Rob

Hi John, it's 3/4" nominal - you've raised a very good point which I hadn't fully considered.

Thanks for the insight.

Rob

Thinking of making a direct screw-on type for my Boxford C, but not sure whether to go for ER32 or ER40. Any suggestions which might be preferable?

Thanks,Rob

Don't know about that particular instance, but a late friend who was apprenticed at Broadbent lathes once tried to explain to me a system for doing this - not sure I got all the details, but it involved a sort of linear cam, or wavy ramp, parallel to the leadscrew. The leadscrew nut (possibly a solid nut rather than half-nuts) was rotated slightly in both directions by this, thus cancelling out pitch deviations in the leadscrew thread. Hope I've explained that clearly, it did make sense when he told me, although I have since wondered how they got the nut follower to bear on the cam, some sort of spring-loading, possibly?

Rob

I've had no end of arguments over this "cotter pin" name with people who should know better - I'm with you 100%

Rob

+1 for leavig it to weather naturally - it's a bit like painting brickwork, once you start, you have to keep on maintaining it.

Rob

Whilst flicking through the channels, I keep coming across a TV programme entitled "Made in Britain" - this seems to show that there are still items being made entirely in this country, although they may not all be things I would need, want or be able to afford.

Rob

Not sure if it's been mentioned yet, but if you put the blade in the frame so it cuts on the pull stroke, most of the rigidity issues go away.

Rob

Thanks Bernard, I'll pick one up at the show in October and give it a try.

Rob

Do the T-shape parting blades fit OK in the holders designed for the tapered type, or is a bit of judicious modification required?

Rob

Well, these might work, or could end in disaster..

Links to https://www.sciencecompany.com/Patina-Formulas-for-Brass-Bronze-and-Copper.aspx

Rob

Don't know what it is or where you'd get it, but I believe there is a chemical used to patinate newly cast bronze statues.

Rob

I've been lucky enough to work out a swaps system with my local guy - although the first load I took in (copper HW cylinder) got me on his books with ID and the usual formalities. So now if I take in, say, a radiator, he'll swap it for some mild steel bar to save writing out a cheque.

Rob

Well, my daughter had collected a few conkers whilst on holiday, and we had them on top of the gas fire in the living room. Didn't see a spider for months. She then moved them out of the room and the very next day, I spotted a spider in there. Coincidence? Maybe, but it convinced me.

Rob

(just realised, now I have my glasses on, that this is not a spider...)

Not having a clue what they are, I'd never thought about it at all

A quick Google gives me the impression they are for diesel engines - I've never had a diesel.

I guess the validity of the theory could be proved fairly easily by doing an emissions test on a car with old, dirty oil, changing it and then repeating the test. Anyone with free access to an MOT-grade emissions tester?

Rob

I don't mind 'proper' spiders, but these virtually invisible, long-legged ones that seem to have become more prevalent over the last ten or fifteen years really get on my wick! They don't even build decent webs, just stringy strands that get all over your face.

</rant over>

Rob

Must be the NASCAR version, for racing on left-hand oval tracks

Rob

Hmm, this was definitely much larger - I may be wrong in saying Corgi, though.

Rob