How do you create a pocket with angled sides

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sheeraza
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How do you create a pocket with angled sides

Post by sheeraza »

Hi,

I am trying to create a pocket that has an angled side and the corners need to be sharp corners i.e. not rounded.

See here which is what I am trying to achieve https://drive.google.com/file/d/1iXn9ab ... sp=sharing

I have a V-angle tool and have tried a simple pocket i.e. straight cut down and create the pocket sides, but obviously this will always cause an internal rounded corner because of the rotation of the tool, see here https://drive.google.com/file/d/16CkbCz ... sp=sharing

Can anyone help?

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scottp55
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Re: How do you create a pocket with angled sides

Post by scottp55 »

Try VCarve toolpath with flat depth set appropriately.
Sorry for the down and dirty file, but got stuff going.
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Re: How do you create a pocket with angled sides

Post by 4DThinker »

If the bit you used has a pointed tip, then a single vector from the top of the sharp corner to over the bottom of the taper and the fluting toolpath will sharpen the corner. Essentially the same as using the vCarve toolpath. Tip of the bit sliding from the outside corner down to the sharp inside bottom of the corner.
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gio14
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Re: How do you create a pocket with angled sides

Post by gio14 »

you simply can't, obviously the internal radius of the corner will be the same as the tool radius

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dealguy11
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Re: How do you create a pocket with angled sides

Post by dealguy11 »

You absolutely can. There are several ways to do it. The most straightforward are:

1. V-carve toolpath using a v-bit, with clearance tools for the center
2. Pocket toolpath followed by a profile toolpath with a v-bit, using the "Sharp Internal Corners" option. You'll need to offset the pocket vector out by an allowance for this - easiest way to figure out the allowance is to create the profile toolpath using the pocket toolpath vector and note the allowance that it automatically calculates.
3. Fluting toolpath as mentioned above.
4. Moulding toolpath with a small ballnose bit

I'd probably go with the v-carve path to keep it simple.
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adze_cnc
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Re: How do you create a pocket with angled sides

Post by adze_cnc »

gio14 wrote:
Wed Jul 07, 2021 12:49 am
you simply can't, obviously the internal radius of the corner will be the same as the tool radius
One of the problems of the Twitter age is "sentences" that are ambiguous and incomplete. at best.

Recast the above as: "You can't using a pocket toolpath only. Obviously...."

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gio14
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Re: How do you create a pocket with angled sides

Post by gio14 »

@ adze_cnc
Sorry I don't work with wood but I make steel molds and probably looking at it from my point of view I have misinterpreted it (I make the pocket with a straight cutter and the corner of the pocket cannot be less than the radius of the cutter)
Forgive me for the ramshackle language but unfortunately I go to google translator

sheeraza
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Re: How do you create a pocket with angled sides

Post by sheeraza »

Hi everyone,

Thanks for your answers. checking the internal sharp corner option worked a treat.

I have another question:

is it possible to create a square pocket with 90 degrees edges and 90 degree angle corners?

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dealguy11
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Re: How do you create a pocket with angled sides

Post by dealguy11 »

I'm not aware of any way to get a sharp 90 degree corner with 90 degree sides on a 3 axis machine with standard tooling. Many MDF door manufacturers will put a 1/16" radius in the corner with a 1/8" end mill or, less frequently, a 1/32" radius with a 1/16" endmill. In practice, once the door is painted that little radius is not very noticeable.

If you really need the sharp corner for some reason, you might try a steeper v-bit (45 degrees or even 30 degrees). The corner will still be slanted, but less noticeably.

If you really, really need a sharp corner with 90 degree sides, then a sharp chisel is your friend.
Last edited by dealguy11 on Tue Jul 20, 2021 5:53 pm, edited 1 time in total.
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FixitMike
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Re: How do you create a pocket with angled sides

Post by FixitMike »

To get a 90 degree corner with 90 degree walls, cut a conventional pocket with rounded corners, then use a corner chisel to square up the corners.
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dealguy11
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Re: How do you create a pocket with angled sides

Post by dealguy11 »

I know of a door manufacturer in the NYC area that sharpens the corners with chisels. Sometimes hand tools are the best option.
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sharkcutup
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Re: How do you create a pocket with angled sides

Post by sharkcutup »

Depending on the project depth of pocket --- (and it is also determined by the angle needed for the pocket walls.)

I would probably approach this with multiple toolpaths

Pocket Clearance - Major removal of material
Pocket Clearance - minor material removal to undersized dimension from the final dimension with wall angle
Pocket Profile using V-bit (closest to the angle required) - final pass around the outer edge for corners and wall sides to final pocket dimension.

The above should work in theory of course that depends on the actual depth of the pocket and tooling used for proper wall angle.

Just my approach, theory, thought, and opinion!!!

Interesting Feature -- Angled Pocket Walls HHHHMMMMMM!! :|

Of course if all else fails hand tools come in handy!!!!

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adze_cnc
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Re: How do you create a pocket with angled sides

Post by adze_cnc »

sheeraza wrote:
Tue Jul 20, 2021 5:14 pm
is it possible to create a square pocket with 90 degrees edges and 90 degree angle corners?
Take a straight-walled drinking glass and try to fit it square into the corner of a room.

I’ve seen many articles (such as this one http://mathtourist.blogspot.com/2009/0 ... .html?m=1 ) that claim you can drill a square hole using a drill/bit in the form of a Reulaux triangle (basically a rounded equilateral triangle) and you do get square sides but with rounded corners.

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dealguy11
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Re: How do you create a pocket with angled sides

Post by dealguy11 »

I once saw a video, don't remember where, of a CNC aggregate head that claimed to operate as a Reulaux triangle to make square holes. Of course you need a large commercial CNC machine capable of using aggregate heads, and I'm not sure it's possible to program the cycle in the Vectric products. Also aggregate heads usually cost thousands of dollars. Was pretty interesting, though.
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