|1197 forum posts|
Nul Points Francis IoM, for lateral thinking, too subtle. Are you sure the pad linings aren't sintered? Had a clutch plate and brake pads on my Guzzi, wore a bit more quickly than the normal but stuck like the proverbial.
Wonder how many slices to turn from a sash weight? Doh.
Nick Clark 3, how about another couple of numbers? We know the diameter but not the length or quantity, every little helps.
|Paul Lousick||29/09/2020 13:54:22|
|1542 forum posts|
Sash weights may be a cheap source of CI but they are normally made from cheap material and contain lots of cavities and impurities. The outer surface is often very hard and difficult to machine.
|Brian G||29/09/2020 15:56:34|
|715 forum posts|
I wonder if "glass hard" silver steel might break under the bending load?
|Jeff Dayman||29/09/2020 16:12:10|
|1896 forum posts|
Depending on how many rods are needed, it might be worth talking to a foundry that makes large iron castings. When they vent large sand castings with vent wires to allow trapped air steam and gases to escape, the iron often fills the vent cavities in the sand to make "wires" of cast iron projecting off the castings. Usually not such large dia as 3/16 but if you ask they may be able to oblige and make you some "wires".
Not sure how machinable such wire would be, could be chilled, could have a lot of sand inclusions picked up from the vent openings in the sand. Just food for thought.
Some time ago I saw a TV program showing such a foundry in I think Cornwall UK making Royal Mail post boxes and parts for Aga cookers among other things. This may help track a foundry down, I hope.
5479 forum posts
Not really enough detail from the OP but it seems to be a requirement for a school demonstration, which may need to be conducted more than once. Does it really need to be round as 'bar' can aslo be square.
If you and other schools need this more regularly CES might be persuaded to do the honours and add to their product list.
|not done it yet||29/09/2020 17:04:03|
|5024 forum posts|
Here you are Bazyle.
That is how it is done/what it is for. Simple expansion experiment. for Physics or Science lessons.
edit: Fig 2 experiment
Edited By not done it yet on 29/09/2020 17:05:13
|Speedy Builder5||29/09/2020 17:30:35|
|2107 forum posts|
I wonder if 'hard' brass would shear easily enough, otherwise graphite carbon Eg thick pencil leads. or how about some of these - wouldn't break the bank
|Speedy Builder5||29/09/2020 17:39:00|
|2107 forum posts|
getting more expensive:-
This is getting silly
and just to be really silly, how about using some Cerobend - quite brittle but melts at just under 100 deg C, so would have to be kept away from the hot end of the bar - perhaps not !
|Rod Renshaw||29/09/2020 17:40:01|
|174 forum posts|
I wonder if the sash windows in dolls' houses have cast iron sash weights?
6331 forum posts
Though I hate the mess cast iron makes I might have a go at a few to see if it can be done. One of the pictures in NDIY's link shows the pins are perhaps 2" long, length not critical.
I have a block of ex-night storage heater cast-iron full of awkward pockets. The plan is to hack a lump off with an angle grinder about 50mmx25x25" then slice it into 5x5x50mm square sections with a slitting saw, and finish off by turning them. Probably take 90 minutes each at £8.72 an hour to make 16 assuming no breakages! Bound to be a way of doing it faster, but what?
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