- Thread starter Gritineye
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Gritineye
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That way of working is described in old shaper books, so quite acceptable back then in the right hands.
I have a book somewhere I'll have a look when I get a mo.
pressbrake1
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I think he’s roughing out anyway
Slow speed high clearance gears can work just rough cast
Working to a line should give him 5-10thou
Windmills worked with wooden gears carved by hand, but at relatively slow speeds. It's horses for courses, you'd not make gears that way for for instance for the output gear chain from a gas turbine, but perhaps to keep a rolling mill working it would be OK.
Many a lathes back gear has been welded up and hand filed, and for the duty it serves it's fine.
Many a lathes back gear has been welded up and hand filed, and for the duty it serves it's fine.
Kram
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Im going to assume the bigger the gear is, the less important it becomes particually if oversized for the task and given enough clearance. Perhaps if it were a precision gear train then it could be half the size.
That was one slow pour, not ideal, I dont know if slag and oxides easily float to the top as Ive heard that steel casting is like syrup.
That was one slow pour, not ideal, I dont know if slag and oxides easily float to the top as Ive heard that steel casting is like syrup.
pressbrake1
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I was told steel is really liquid and leaks everywhere
redlig
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If we repatriate all our old machinery we could recycle all our own scrap and save sending it to the East and then bringing it back again. Win win situation. There has to be a flaw in that idea somewhere but I can't spot it.I love watching these videos.
Most of the old British machinery has gone over there. I reckon it won't be long before we start bringing it back
Probably the same stuff goes into it as with any other scrap metal place in the world. The cooking is what counts not the ingredients
pressbrake1
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Looks like sg iron
Munkul
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I for one really enjoyed watching that video.
You can poke holes in their process as much as you want, but nothing is fundamentally wrong with it. The pour, itself, looked pretty decent, at least the casting that came out was all in one piece and looked like it machined ok.
And they are making great whopping slow moving gears that would cost tens of thousands to make over here. If you could even get them made at all.
You can poke holes in their process as much as you want, but nothing is fundamentally wrong with it. The pour, itself, looked pretty decent, at least the casting that came out was all in one piece and looked like it machined ok.
And they are making great whopping slow moving gears that would cost tens of thousands to make over here. If you could even get them made at all.
Scalarocco
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Yes...
Kram
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Most of the scrap going in looked to be mild steel sheet, tubes etc.. motorcycle spockets show at 59 seconds.
Best case, the slag has floated to top and been machined off, worst case there are oxides throughout the gear making it weaker.
There are ways to avoid it, pour fast into a proper basin and sprue to accept the melt, designed to minimise velocity and air entrapment.
Id disagree. Hot metal oxidises instantly and a slow pour like that has a huge surface area exposed to air. Would you mig weld plain wire without gas?
Best case, the slag has floated to top and been machined off, worst case there are oxides throughout the gear making it weaker.
There are ways to avoid it, pour fast into a proper basin and sprue to accept the melt, designed to minimise velocity and air entrapment.
Munkul
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you may be right, I have zero foundry experience.
But remember, whatever oxygen is in that mould is quickly used up, inside that mould within a few seconds will be a reducing atmosphere. How do you think they get away with pouring high grade cast steel?
Any foundry work has a few variables like that which are hard to control, but controlled as best they can. Clive is probably as good an authority on this stuff as anyone on here.
However, if it's cast iron/low grade steel, it doesn't really matter anyway.
pressbrake1
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When making up a mix they use steel scrap and add hematite
