A Milling Course – mistake?

This topic has 7 replies, 5 voices, and was last updated 12 January 2012 at 11:44 by Terryd.

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12 January 2012 at 09:46 #81831
Wolfie
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@wolfie
OK my other question has generated some confusion for me.

The book I’m working from, Harold Hall’s ‘ Milling A Complete Course’ has a little piece about climb milling and direction of travel etc. However he calls it up and down milling.

Thing is there is a diagram of each and a bit of text. the text goes as follows.

“Such terms as up milling (climb milling) and down milling…..”

But looking at the other sites a couple of people posted they don’t agree, their captions indicate that its down milling thats climb milling. Is it wrong in my book?

Diagrams on page 15 and text on page 17, can anyone confirm this?
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12 January 2012 at 09:46 #5857
Wolfie
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@wolfie
12 January 2012 at 10:01 #81832
David Clark 13
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@davidclark13
Hi There

Down milling is climb milling.

regards David
12 January 2012 at 10:11 #81834
Terryd
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@terryd72465
Hi Wolfie,

David is correct, it seems to be a misprint. The diagrams are correct but it is the down milling which is climbing. If you study the diagram on P15 you can see which cutter is tending to ‘climb’ up on to and over the work. As I said in the other thread, that tends to pull the work into the cutter. Up milling is tending to push it away (similar to the difference between a front and rear mounted part off tool on a lathe – now wait for roars of disapproval).

Best regards

Terry
12 January 2012 at 10:41 #81840
Eric Cox
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@ericcox50497
ok you asked for it Terry.

Put a piece of bar in the lathe chuck and a parting tool in the tool post so the tool touches the bar. Now photograph it from the tail stock.

Turn the photo upside down and you have a rear mounted tool.

There is no difference between the two. Can we please put this myth to bed once and for all.
12 January 2012 at 10:47 #81841
Wolfie
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@wolfie
OK cheers thats cleared up the confusion
12 January 2012 at 11:32 #81847
David Littlewood
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@davidlittlewood51847
Eric,

Surely then you have a rear-mounted tool on a lathe with the bed up on top. Hardly the same!

David
12 January 2012 at 11:44 #81849
Terryd
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@terryd72465
Posted by Eric Cox on 12/01/2012 10:41:30:

ok you asked for it Terry.

Put a piece of bar in the lathe chuck and a parting tool in the tool post so the tool touches the bar. Now photograph it from the tail stock.

Turn the photo upside down and you have a rear mounted tool.

There is no difference between the two. Can we please put this myth to bed once and for all.

Hi Eric.

I agree that it looks exactly the same if photographed but there is actually a very great difference, you might as well take a still of a stationary car and try to work out in which direction it was about to move. It’s not simply about the position of the tool, (oh that engineering was that simple the world would be a easier place) but about the rotative forces, geometry and the envelope of space in which the tool has to work while the component parts are flexing, and is the reason why tools break at smaller not larger diameters, but I’ll leave you to work that out.

In order to analyse the tool action you would need high speed, high res. video of both methods not a still photograph. So until that day, for myself at least, I’m keeping an open mind on the matter while awaiting that proof.

However it is put to bed because the thread is not about that subject, I merely used it to illustrate a point.

Best regards

Terry

Edited By Terryd on 12/01/2012 11:47:06
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