How to cut a nice pocket ?

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kak
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How to cut a nice pocket ?

Post by kak »

Hello

I want to cut a nice looking round pocket in aluminium.
It's for my friends volume knob in a front panel of his HiFi equipment.... i'm not sure this is a good idea.
I think there is a little play in my Kress ball bearings, maybe because the upper part is made of plastic and it's not that stiff, but the spot, where the endmill is plunging into the material, is cutting a bigger hole then the diameter of the bit. It's like cutting a small "dog bone".

The pocket must be 32mm in diameter and 7mm deep.
I would like to cut first 31,8mm pocket and then remove the last 0,2mm at full depth.
But I don't want the endmill to plunge at 32mm.

Ramp is a vertical move, but I'm looking for something like " horizontal spiral ramp", cutting from inside and out, at full depth, as the last step.
Can VCP do that?

I was also thinking of using a fish tail bit. Maybe it's not dancing around so much when plunging, as an endmill which can not drill does.

I attach a picture. You can clearly see at which of the four corners of the rectangle the start point is.
Normaly the holes I'm cutting are not visible, but the volume knob pocket will be, because it's 2mm bigger than the knob.
Attachments
DSC_0300-001.JPG

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Adrian
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Re: How to cut a nice pocket ?

Post by Adrian »

You could try creating a profile cut around the outside. The profile toolpath supports lead-in and lead-outs as well as spiral ramping all of which will help that situation. You could then use a pocket within the profile cut to clear the rest.

kak
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Re: How to cut a nice pocket ?

Post by kak »

Thanks Adrian. I will try that and make some test cuts first.

kak
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Re: How to cut a nice pocket ?

Post by kak »

It turned out nice. First profiling with spiral ramping, then pocket, 0.2mm smaller then profiling.
Thanks :)
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Volume knob pocket.JPG

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Adrian
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Re: How to cut a nice pocket ?

Post by Adrian »

Thanks for posting that it worked out. So many people don't and it leaves the threads a bit open ended for people who might have the same issues in the future.

That turned out really nice.

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mtylerfl
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Re: How to cut a nice pocket ?

Post by mtylerfl »

kak, that DID turn out nice!

Adrian, you are a treasure of information and useful tips. Thank you for helping ALL of us!
Michael Tyler

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dhellew2
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Re: How to cut a nice pocket ?

Post by dhellew2 »

Well said Michael, if I could only be half as smart as Adrian [and Michael] :wink:
Dale
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