Variable Depth cut in HSMworks

Hello

I am just starting out using HSMworks within Solidworks and have a machining problem as per the attached screen shot , the part has an angled bottom and i only want to machine the outside profile .
The part is 20mm thick and needs to have the outer profile that is maximum 18mm.and help in a jig .

i want the cutter to to offset the bottom of the part by 1mm all the way around , as the longest cutter i can get is 45mm

If i try 2d contour as per the screenshot 1 it cuts the full depth all around

if i use the same cutter path using Contour in the 3D menu it try's to cut a weird path around the top of the part screenshot 2

Im sure i am missing something ??

Quote:

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Originally Posted by sean69_uk

Hello

I am just starting out using HSMworks within Solidworks and have a machining problem as per the attached screen shot , the part has an angled bottom and i only want to machine the outside profile .
The part is 20mm thick and needs to have the outer profile that is maximum 18mm.and help in a jig .

i want the cutter to to offset the bottom of the part by 1mm all the way around , as the longest cutter i can get is 45mm

If i try 2d contour as per the screenshot 1 it cuts the full depth all around

if i use the same cutter path using Contour in the 3D menu it try's to cut a weird path around the top of the part screenshot 2

Im sure i am missing something ??

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https://www.youtube.com/watch?v=ZdGElizxfFs


3D will always choose every hole or contour if that is within the set depth of the selected area. Unless either the tool don't fit or the selected area is shallower.

Thank you for the video , didn't really help much I'm afraid .

i am trying to machine the outside not the top face

sean

Quote:

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Originally Posted by sean69_uk

Thank you for the video , didn't really help much I'm afraid .

i am trying to machine the outside not the top face

sean

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The setting of all the heights doesn't just correspond to a face cut. It applies to ALL types of cut.
You must be setting it up as 'bottom of stock' in the box or something and not putting any values in.

The dark blue lower line position denotes the depth of the cut.
Even when you contour around the outside of a part, the cutter should only go as deep as the seetting of the blue line.

I work in mm so for instance:
For a 2D contour I usually put in:
Top height (light blue) as 'stock top' in the box with a value of +1.
Cutting then starts the cutting process at +1 above the stock and I helix in. This avoids the cutter hitting any imperfections in the material at the start.

Bottom height (dark blue) The limit of depth my cutter will go.
If say I have a 25mm thick piece in and I want to do a contour 2d around the outside ciut to only 20mm deep.
I would set the box as 'stock top' and a value of -20 (negative 20).
The blue line will now stop short of the stock bottom and the cutter will not pass this depth.

Then on the next tab I would do my cut around the outside of the part. Then run 2 finishing passes.

Now I have a nice smooth cut all the way around the outside of my part at 20mm depth.

Hi

Thank you

that is how i did it, i managed to do it in 2 cuts top part first , down the taper 35mm depth and then the bottom half all the way down to the model bottom , leaving the tapered part but did have to use higher retract height

i had hoped that you could select offset from contour say -0.5 mm and it would follow the contour rather than taking the mean height as your bottom depth

regards

Sean

Quote:

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Originally Posted by sean69_uk

Hi

Thank you
that is how i did it, i managed to do it in 2 cuts top part first , down the taper 35mm depth and then the bottom half all the way down to the model bottom , leaving the tapered part but did have to use higher retract height
i had hoped that you could select offset from contour say -0.5 mm and it would follow the contour rather than taking the mean height as your bottom depth
regards

Sean

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Watch out for the 'stock to leave' setting in the next tab page for roughing.
If say I put in 0.5mm it will not only leave the 0.5 stock on all the way round the sides but it will also leave it on the bottom.
So my previous neg20mm depth will actually be neg19.5.

I don't like leaving any on the bottom though because it can cause issues when it sometimes retracts and then plunges for a finish cut.
If I wanted to cut to 20 depth with a rough + finish I would set rough to neg20.5 with stock to leave at 0.5 (this then only cuts to 20 depth). Now there is nothing for the cutter to hit when it plunges for a finish at neg20 to remove the 0.5mm from the sides.

If you put in a neg value of say -0.5mm stock to leave it will cut inside the 'model' boundary and go deeper by 0.5 all round.


I think this is the kind of thing you are suggesting yes?.

Quote:

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Originally Posted by sean69_uk

Hi


i had hoped that you could select offset from contour say -0.5 mm and it would follow the contour rather than taking the mean height as your bottom depth

regards

Sean

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Are you looking for something like in the images below, first image is with bottom edge selected as the contour, second image is with an offset of +3mm applied and the third image is how it would be cut.
If I was doing that cut then I would cut away the stock above the shape first so that using this strategy does not need a really long tool, as long as it is a little longer than the 20mm height of the shape.
Then the answer would be yes you can assuming that you have the "Trace" 2D Toolpath available in your toolbox :D :D :D

Regards
Rob

Just for anyone who trips on this later, the Trace 2D is included in HSMXpress as well as HSMWorks, so anyone using HSMWhatever can use that approach.

You would have to use a Trace 2D to do this part in HSMXpress, unless you fixtured it for the angled cuts which... is way worse than a few extra sketches.