cardiffrob
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Lycoming or Continental aircraft engines? IO360 pin is about 6.5 inches, IIRC
- Thread starter Pete.
- Start date
graffian
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I can't find any spare pins at all except some small motorbike ones.
I have a 6inch piston in front of me, I though the pin was pretty small, it's actually 2.4" diameter!
Now you have mentioned them I need[yes I do] a cylindrical square rather than relying on my 246 blocks;
maybe I need a myford grinder.
I have a 6inch piston in front of me, I though the pin was pretty small, it's actually 2.4" diameter!
Now you have mentioned them I need[yes I do] a cylindrical square rather than relying on my 246 blocks;
maybe I need a myford grinder.
Pete.
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There's a cylindrical square on homeworkshop for £40. I'd buy it myself but I need other stuff more.
I'm getting on a bit
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I'm puzzled why you can't make one
To those who may be interested in the inheritant differences between a lathe and a grinder regarding accuracy.
The diameter of the crossslide handwheel is much larger, the distance the slide moves is much less. There is also a great weight pulling on the crossslide so that the pressure on the feedscrew is constant.
Lathes are for thou's grinders are for tenth's
Using my lathe (Colchester Master 2500 (Bed reground 2001, saddle Turcited and scraped) I am happy to work regularly to thous, and for tenths I would lap. It is used fairly regularly.
Using my cylindrical grinder (Jones & Shipman 1300 EUIR late 1960's vintage and never rebuilt), even though it is used only once or twice a year, will work to tenths without really trying, and so long as it's up to working temperature can hold fractions of tenths to the limit of my measuring capacity. Same is true of my J&S 540 surface grinder, but that gets a bit more use.
I believe that the difference is not so much the positioning of the tooling as the method of material removal. The lathe tool will only take off material down to a certain size, until the chip is too small and the tool rubs (*) and doesn't cut. Whereas a grinding stone, properly dressed and 'open' will remove material down to incredibly small sizes - effectively as small as is normally needed.
And this despite the fact that if you look at the action of a grinding stone under a microscope, it's as though every little grain is it's own lathe tool, making curly swarf !
(* this can be used to your advantage burnishing work to a finish)
Using my cylindrical grinder (Jones & Shipman 1300 EUIR late 1960's vintage and never rebuilt), even though it is used only once or twice a year, will work to tenths without really trying, and so long as it's up to working temperature can hold fractions of tenths to the limit of my measuring capacity. Same is true of my J&S 540 surface grinder, but that gets a bit more use.
I believe that the difference is not so much the positioning of the tooling as the method of material removal. The lathe tool will only take off material down to a certain size, until the chip is too small and the tool rubs (*) and doesn't cut. Whereas a grinding stone, properly dressed and 'open' will remove material down to incredibly small sizes - effectively as small as is normally needed.
And this despite the fact that if you look at the action of a grinding stone under a microscope, it's as though every little grain is it's own lathe tool, making curly swarf !
(* this can be used to your advantage burnishing work to a finish)
graffian
Seer unto the end of his beard
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So I don't need to get a myford just find a way to the deepest recesses of sussex;-)
I watched some videos by suburban tool[?] one was on OD grinding. He was touch the dogs[something like that] to
roughly align the work and then he started stuffing paper under the tailstock!
Wallace
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Just pressed one out of a rod & piston, measured with a digital caliper: 1.0935" OD, 0.7495" ID and 3.5665" L. Circa 1965 manufacture, should have 8 but there is some rust pitting where they have been sat around. Yours for postage.
Wallace
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No worries, could you use a section of fork leg or perhaps a Mini radius arm pin?
Section of a hydraulic cylinder rod? Loads of cylinder repair places out there to chat up - it's not even very expensive to buy new
http://www.ebay.co.uk/itm/Hard-Chro...hash=item1a0b185ed4:m:m4DTKnmqR_5lVrojFzjVvpA
http://www.ebay.co.uk/itm/Hard-Chro...hash=item1a0b185ed4:m:m4DTKnmqR_5lVrojFzjVvpA
Pete.
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Actually I was given some EN8 ground cylinder rod today Andrew. I particularly wanted the ID and OD ready-made but in a pinch I can bore the rod I have. My lathe has been out of action this week with a snapped belt but I have just today fitted a new one so it looks like my best bet so far.
Eddy: Thanks but 54mm is too big for this. They'd be handy to have if you do have any spare but don't put yourself out please.
I've never really needed to work to tolerances that I cant even see may be a thou or so but getting below that and then debating the divisions thereof in a welding forum, well I agree with jobs being made as accurate as you can in high tech manufacturing but where does it stop.
