Question by MattN: Engineering coursework help about milling machines :(?
Depth of cut and cutter type for roughing and finishing cuts
Position of workpiece – datum point
Safety cut out
Information and explanations regarding these?
Thank you for your help people 🙂
Answer by WingmanI am guessing your are talking about a CNC mill?
I have no experience with one, although I wish I did.
On a manual mill, for a datum point, I use an edge finder and locate the left hand edge of the
Stationary jaw on the milling vise.
Once located, I zero out the X axis Digital Read Out / DRO.
Then I lower table till the edge finder will clear the top of the vise jaws,
move the table to the left 1/2 of the edge finder diameter.
Then zero out the X axis display again.
This makes the left hand corner on the stationary vise jaw X = 0.000
I do the same thing for the inside edge of the same vise jaw to make Y = 0.000
Most work pieces I work with, fit into the vise.
My DRO map/ drawings are based on the top left hand corner on the work piece.
For round work like bolt circles, I work off of the center point of the work piece.
That work piece is lightly center punched, clamped to the mill table and a pointed
edge finder is used to locate the circle center.
The X and Y axis on the DRO are then zeroed out to make the center point of the
work piece X = 0.000 and Y = 0.000
For depth of cut, a lot depends on the physical size of the mill,
the physical condition of the mill,
the rigidity of the clamping of the work piece,
available mill horse power,
size of the cutter/ diameter,
number of flutes on the cutter,
what I am using for coolant.
what material the work piece is made of/ steel, aluminum, exotic
A good rule of thumb is depth of cut to not to exceed cutter diameter.
This can vary again by all the above mentioned items.
For the traveling speed of the milling cutter, I do the math and try to keep the chip
thickness to 0.010 inches or less.
Safety cut out, the mills I have worked with are all world war two or earlier and do not
have a safety cut out.
Guards are usually just clear PVC plastic. I prefer guards made of clear lexan as
they are less prone to breakage than PVC plastic.
Guards are primarily to keep the coolant and chips from going on the floor.
For depth of cut, here is a Google search that contains much information.
Google search for [milling cutters, depth of cut]
http://www.google.com/webhp?sourceid=navclient&ie=UTF-8#hl=en&source=hp&q=milling cutters, depth of cut&btnG=Google Search&rlz=1R2GZAZ_enUS364&aq=f&aqi=&aql=&oq=milling cutters, depth of cut&gs_rfai=&fp=25bac56246434a91
For milling machine guards
[milling machine guards]
http://www.google.com/webhp?sourceid=navclient&ie=UTF-8#hl=en&source=hp&q=milling machine guards&rlz=1R2GZAZ_enUS364&aq=0&aqi=g5g-m3&aql=&oq=milling machine g&gs_rfai=&fp=25bac56246434a91
[tutorial milling machine workholding]
http://www.google.com/webhp?sourceid=navclient&ie=UTF-8#hl=en&rlz=1R2GZAZ_enUS364&ei=2JG0S_ehE4TINd7HkOwJ&sa=X&oi=spell&resnum=0&ct=result&cd=1&ved=0CA4QBSgA&q=tutorial milling machine workholding&spell=1&fp=25bac56246434a91
[tutorial CNC mill datum point]
http://www.google.com/webhp?sourceid=navclient&ie=UTF-8#hl=en&source=hp&q=tutorial CNC mill datum point&btnG=Google Search&rlz=1R2GZAZ_enUS364&aq=f&aqi=&aql=&oq=tutorial CNC mill datum point&gs_rfai=&fp=25bac56246434a91
[tutorial CNC mill workpiece positioning]
http://www.google.com/webhp?sourceid=navclient&ie=UTF-8#hl=en&rlz=1R2GZAZ_enUS364&q=tutorial CNC mill workpiece positioning&aq=f&aqi=&aql=&oq=tutorial CNC mill workpiece positioning&gs_rfai=&fp=25bac56246434a91
I hope this enough information for you, feel free to email me.
This link will take you to my Profile Page;
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