Hmmm ... might this be a challenge ... ? Still hope some of you have experience with this
Jesper
Hi All,
I am having a bit of a challenge that I hope one of you here may be able to help with - I'd appreciate your assistance
As it is I need to make a copper plate with a thickness of 1.5 mm COMPLETELY flat/level, i.e that the difference in thickness across the copper plate (~100mm x 100mm size) is no more than 1/100mm. Additionally, the copper plate is to be entirely level/flat - again differences of no more than 1/100mm from one end to the other. BTW although I'm aiming at 1/100 mm precision I'd actually prefer if it can be done even better ...
I've tried milling a 2mm copper plate on my CNC (which does ~5/1000 mm in an area of this size) down to 1.5 mm - fastening it with double adhesive tape and some "steering bolts" to prevent it from moving on the tape - but the copper "curves" or bends ever so slightly so that it is no longer flat.
I am now considering other solutions like e.g. a vacuum board but I reckon that even if the copper plate may be kept entirely flat during the milling process then the internal tensions inside the copper plate will make it go back to a non-level/flat condition as soon as the vacuum hold-down is released.
I am also considering sanding the copper plate with different grit size sand papers and a light weight so as to not bend the copper plate during the sanding process.
However, I was thinking that maybe one of you have already had a similar challenge - and might know how this is best done ... if this is so I'd appreciate your feedback.
Cheers & thanks for any inputs here
Jesper
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Hmmm ... might this be a challenge ... ? Still hope some of you have experience with this
Jesper
Hi mactec54,
Thanks a lot for your feedback! As it is it has made me check out some options this morning and it seems to be the best solution for my purposes. One question, though: In this video - approximately 1 minute into the video, but it also shows on the video picture here - there's a "conditioning ring" which has a plastic like substance at the bottom of the ring.
I suppose this is a "wear & tear" layer so that the metal part higher up is not worn in the lapping process ... (right?) . Anyway, my question is if you may know which plastic this may be (teflon?) - or maybe have a suggestion for a more suitable material?
Cheers & thanks,
Jesper
Mactec54
Thanks again mactec54 ...
... I sort of guessed this while looking at the video. Actually, quite fascinating that a relatively simple setup like this can produce such a result ...it all must be floating and not retained in any way
Cheers,
Jesper