oval flange
- Thread starter tiros0
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Have a look at a real oval and see just how many arcs there really are.
Should be easy to do with CNC, but manually a long and painful job to machine.
When I do them (especially if there are many to do) I file up a thin ali blank to the shape that is required and use that to scribe around and mark the metal which has previously been 'blued'.
If you have already drilled and made your blanks, you can put them on a mandrel, stuck together with superglue then horror of horrors, file them to shape by hand en mass. Yes it really can be done, and I promise you, your arms won't fall off at the end.
It really is very easy to do and would take much less time than it would take if manually machining them. You would most probably have to resort to a file at the end anyway, to blend things together.
John
Should be easy to do with CNC, but manually a long and painful job to machine.
When I do them (especially if there are many to do) I file up a thin ali blank to the shape that is required and use that to scribe around and mark the metal which has previously been 'blued'.
If you have already drilled and made your blanks, you can put them on a mandrel, stuck together with superglue then horror of horrors, file them to shape by hand en mass. Yes it really can be done, and I promise you, your arms won't fall off at the end.
It really is very easy to do and would take much less time than it would take if manually machining them. You would most probably have to resort to a file at the end anyway, to blend things together.
John
goldstar31
Well-Known Member
An eccentric chuck as in ornamental turning? Epicyclical gearing- if you must.
Holzapffel is free to download. I've got his three books or is it 4?
Again, Tubal Cain( Tom Walshaw) designer of many engines, wrote his Ornamental Turning book.
No good this playing about with silly QCTP and whatever. Back to First principles- Maudsley and slide rests on face plates.
Not me really now but it isn't that far removed from throws on crankshafts or doing chanters for Northumbrian bagpipes.
You don't go to a shop, you make your own tooling.
Far more enjoyable than going to a tool shop with a wallet spanner. My opinion, of course.
Regards
Norman
Holzapffel is free to download. I've got his three books or is it 4?
Again, Tubal Cain( Tom Walshaw) designer of many engines, wrote his Ornamental Turning book.
No good this playing about with silly QCTP and whatever. Back to First principles- Maudsley and slide rests on face plates.
Not me really now but it isn't that far removed from throws on crankshafts or doing chanters for Northumbrian bagpipes.
You don't go to a shop, you make your own tooling.
Far more enjoyable than going to a tool shop with a wallet spanner. My opinion, of course.
Regards
Norman
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Norman thinks like I do. If I ever had to make more that an occasional one
or two I would make a fixture. A pattern follower if you will like a cam grinder
or Eureka cutter reliever.
Put a stack in the lathe and go for it. Shouldn't be too hard to come up with
a simple something.
Pete
or two I would make a fixture. A pattern follower if you will like a cam grinder
or Eureka cutter reliever.
Put a stack in the lathe and go for it. Shouldn't be too hard to come up with
a simple something.
Pete
Cut a piece of round stock under an angle, this gives a quite good oval depending at the angle and doesn't waste much material.
The edges can then be ground/filed square with a template as suggested, this should save a lot of time.
The edges can then be ground/filed square with a template as suggested, this should save a lot of time.
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That gives an ellipse. Whether that's OP's definition of an oval I can't say.
I use the boring head set to cut externally to do the two main arcs
Then filing buttons to do the ends and blend into the main arcs Should look like thios when done. You can use the lathe to do the same sort of thing but I don't have a pic of that.
Then filing buttons to do the ends and blend into the main arcs Should look like thios when done. You can use the lathe to do the same sort of thing but I don't have a pic of that.
mcostello
Member
I started My apprenticeship in a glass house, they had an oval chuck to turn molds and formers. It positively blows Your mind to see a tool cutting an equal cut them seeing the material doing severe qyrations on the outside diameter. It was not settable as to different ratios as to length vs. width. The ratio was something like 1 to 1/2. How the engineer figured it out is beyond Me. This was around 1950ish so the Internet was not around. Information was not as freely available like now.
goldstar31
Well-Known Member
All that is needed is to Google 'Elliptical Chuck' and out comes dear old Holzapffel.
Holzapffel, in case your history is shaky, made ornamental turning lathes at the turn of the last- not the 21st Century. One , would you believe, went to the Tsar of Russia.
Sorry and all that but that is fact.
Norman
Holzapffel, in case your history is shaky, made ornamental turning lathes at the turn of the last- not the 21st Century. One , would you believe, went to the Tsar of Russia.
Sorry and all that but that is fact.
Norman
Oval flanges are not usually elliptical. They are mostly designed with two pairs of circular arcs, with or without connecting tangential flats. Either way, small ones are a b*?#&% to make accurately. Last ones I made, I rough machined then finished by hand using hardened filing buttons. Tedious, and rough on the files, but the results were not bad.
