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  1. point is if you want part flat in relaxed...

    point is if you want part flat in relaxed "unclamped" on its airy points or minimize sag from its own weight. thick sheet metal supported on its ends sagging. if done on a horizontal mill on a angle...
  2. . i usually get jig or fixture plate usually its...

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    i usually get jig or fixture plate usually its 6061 T0 or annealed and its usually fairly flat as is. but its strength or tensile strength is much less. 7075 usually for higher strength...
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    maybe get coolant bacteria dont like. often...

    maybe get coolant bacteria dont like. often coolant ph is 9 or 10 and a device like aquarium air pump bubbles air through it all day long. maybe change coolant once a year cause it gets oil mixed in...
  4. 1) every day medium size castings like that are...

    1) every day medium size castings like that are milled to .0004" per 40" flatness. usually indicate or probe before removing from table. waviness of <.0003" TIR is commonly expected
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    2) normally...
  5. . unless annealed rather than T6 you have like...

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    unless annealed rather than T6 you have like 99.9999% chance it will easily be not flat over .001" and .050 to .100" warpage after machining not unheard of. and of course machined plate will often...
  6. Thread: Recession?

    by DMF_TomB
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    23,344

    . ironic Fuji doing much better than Kodak cause...

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    ironic Fuji doing much better than Kodak cause they invested in making many things becoming a bigger company not selling parts of the company.
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    Steve Jobs wasnt perfect much obviously Apple...
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    . sandpaper even when trying to remove .0001"...

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    sandpaper even when trying to remove .0001" takes a lot of effort. obviously I have had to remove .0001" from surfaces before over the decades.
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    if rough surface needed for adhesive bonding...
  8. Thread: Recession?

    by DMF_TomB
    Replies
    272
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    23,344

    technology change from internal combustion...

    technology change from internal combustion engines and pollution control devices on automobiles to electric vehicles using electronics rather than complex transmissions will have a Massive effect in...
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    . . typically when rougher finish wanted for...

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    typically when rougher finish wanted for applying epoxy you machine at much higher feed rate. rather than .0030" ipt or less you got .010" to .030 ipt feed. or use a corncob or serrated type...
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    . some places sell end mills with 90 degree...

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    some places sell end mills with 90 degree point or ends for drill, chamfer and milling. obviously it depends on length to diameter ratio
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    typically when over 3x or over 3x dia in length tool...
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    advantage with a different work offset for each...

    advantage with a different work offset for each part is when each part is probed and different work offset used for each part. the probing can get exact location on specific features like a bore or...
  12. . i find when i engrave a part i use a sharpie...

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    i find when i engrave a part i use a sharpie marker tool holder 1st. nothing worse than engraving parts with spelling errors. by looking at sharpie marking 1st i often catch spelling errors before...
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    caustic ultrasonic cleaning, rinse than...

    caustic ultrasonic cleaning, rinse than passivating treatment is common on stainless steel parts. it actually makes then more resistant to rusting
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    hot caustic breaks down organic carbon based...
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    excel

    Excel does math and the math can include many factors
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    sudden tool failure often can have a random factor. that is for every 100 parts you can have 99 parts with no tooling problems. BUT the 1...
  15. as anybody with a copy of the Shiyong Wujin...

    as anybody with a copy of the Shiyong Wujin Shouce (standard hardware handbook) knows most items are made to Chinese government GB standards
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    advantage being if made to government standard than in...
  16. a simple (usually free) excel spread sheet works...

    a simple (usually free) excel spread sheet works better. operator records machining times and reason for delays. then after months to years you can easily see delays and reasons why. for example...
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    . 1) some machines have more trouble at certain...

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    1) some machines have more trouble at certain rpm, for example max rpm in low gear. if machine goes into high gear at 700 rpm you might have more trouble tapping at 600 to 700 rpm
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    2) same with...
  18. drill depth to dia ratio has a big effect. ....

    drill depth to dia ratio has a big effect.
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    can drill a million shallow holes with no problems and can easily have massive sudden tool failure with deeper drill depths. you should try drilling...
  19. . 1) obviously some aluminum is more abrasive...

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    1) obviously some aluminum is more abrasive (dulls drill faster) and sticks to cutting edges more easily especially if coolant not reaching drill tip. different material can easily effect things....
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    cast iron

    kind of basic apprentice learning of part stability
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    cast iron castings are often annealed after casting at a extra charge. if not annealed they can vary more in metal properties that is the metal...
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    . depends on many things including 1) what...

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    depends on many things including
    1) what material you are milling
    2) what is cutter made of hss or carbide
    3) length of cutter stickout of holder
    4) length of tool holder
    5) hp of machine and...
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    they have had surface grinders, milling machines...

    they have had surface grinders, milling machines and planers for 150 to 200 years now. hand scraping and lapping might be used for final finishing
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    1hp is equal to about 746 watts . if you doing...

    1hp is equal to about 746 watts
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    if you doing heavy cutting using 10hp thats 7460 watts thats means heat (like having 5 electric room heaters on making about 25,000 btu of heat)). a lot of heat....
  24. 99% of time rough threads with certain metals is...

    99% of time rough threads with certain metals is just need tapping fluid instead of coolant.
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    and obviously going slow rpm has nothing to do with problem as hand tapping is always done slow....
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    . i use a 36" granite square and 6 foot straight...

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    i use a 36" granite square and 6 foot straight edge occasionally. i use a crane. obviously too heavy to pick up. normally stored in a felt clothe lined wood box on wheels. not something you leave...
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