In the last few hours I tried to make the 30 degree draft wall, but couldn't ...

[ovisopa]

Hello guys, 

I didn't made any new post in the last few months as I didn't had any problems with the models I needed to mill, but today was not my day, I also got a cold, so nothing helps today, not the mood, not the model .. nothing...

I first tried to make the blade at 30 degree angle from the original DXF, but I got some weird geometry errors where the petals are joined, I than tried to smooth the original dxf using CamBam, it did not work either.

Next step was to redraw the shape using Fusion, I used splines tool.. but I couldn't make the wall at a 30 degree angle.

I tried once more, using a 3 point arc, I rebuilded the flower, even if there was a small difference between the original dxf and the resulted drawing, it's not an issue. This time I had more luck, I could make the draft but only at 29 degree, if I tried to extend it to 30 degree the draft wall was not created at all.

One more issue with my last drawing is the it created an error in 3D model only between 2 petals, all the other are perfect, but 2 petals generated an error , as you can see bellow :

Any idea what is wrong, how can I fix the resulted 3D model , to have the wall at 30 degree, and also have it joined between all the petals ? 

[g-andresen]

Hi,

is it this, what you are fighting for?

günther

*You´ll find some values in the parameterlist.

[ovisopa]

Yes, but how did you did it ? 😄 

I'm opening the file right now to check it, but the screenshot looks good.

[TrippyLighting · Accepted solution]

This is all about technique.

First I moved the shape in the imported sketch o the center using the move tool.

Then I only sketch 1/2 of one petal, so with 6 petals, I only sketch 1/12th of the entire shape.

I use 2 3-point splines for the curved parts.

Then I extrude, mirror, combine, pattern and combine all this into a single flower shape.

With that geometry drafting to 30 degrees is no problem. Model attached.

[g-andresen]

Hi,

have a look at browser, timeline and paramterlist!

günther

[ovisopa]

I think I know the workflow you have, I will try to make again the flower at the correct scale and with the petals intersection a few mm moved to the interior  of the flower, to make it as similar as the client original dxf

Thank you.

Will let you know how it works

[chrisplyler · Accepted solution]

Are you TRYING to make this thing asymmetrical? I added some construction lines to your sketch and dimensioned/measured some things. No two opposing petal intersection points have the same distance between them. There is no common center point. The outside curves of the petals are made of various spline and arc segments that are all different. No two petals are the same. It's a mess. Is that what you WANT?

Assuming that you want something that is symmetrical, why would you try tracing over a DXF by eyeballing it? Maybe try it kinda like this:

[TrippyLighting]

@chrisplyler The flower shape I used in my screencast is symmetrical. It just suffers form the DXF consisting of small line segments instead of smooth curves. A 2D tessellation problem.

[chrisplyler]

Oh, I just realized you want it hollowed out. So then this:

[chrisplyler]

I know yours is symmetrical @TrippyLighting. Still, your top edge thickness is not constant. Mine CAN be "assymetrical" in a way, although it is still regular:

[TrippyLighting]

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@chrisplyler wrote:

I know yours is symmetrical @TrippyLighting. Still, your top edge thickness is not constant. 

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I don't see how that's relevant to the posted issue.

[chrisplyler]

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@TrippyLighting wrote:

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I don't see how that's relevant to the posted issue.

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It isn't. It's just something that I would want if I were going to mill this part. Yours is probably close enough that nobody would ever notice anyway, but if it was worse, it makes a part look sloppy instead of professional, especially if the part is symmetrical. My eyeball would just think, "That's weird. I wonder if there was some CAM error, or if the mill was just old and had some unexpected backlash in it." Not a big deal, but that's how I think.

Also maybe a weaker part without consistent wall thickness. Don't know if that's a concern here or not, but something to think about. Maybe one WANTS to design in a predictable failure mode, and so creates a thinner area in a specific location or something.

[ovisopa]

I haven't replied yet as I slept for a little more than 12 hours, this is my way of getting better when I feel sick.

When I tried to redraw the sketch in fusion, I always tried to make a perfect copy of the client's dxf, and this is why I ended up using splines or arcs with many nodes, the secret is to use less nodes, I made the smaller flower just now, using @TrippyLighting and @chrisplyler technique, it didn't took more than 5 minutes to have a full flower ... so easy..

bellow is my progress with the big flower, all the roughing operations are done. now I start the sharpening of the blade, the tricky part is between the blades, on the exterior side.

[TrippyLighting]

Very nice!

[chrisplyler]

@TrippyLighting, together, we are making the world a better place.

[ovisopa]

Between the blades, on the exterior side, it's still not sharp, but the client needs the internal leather part that is cut using this cutting die. I will cut a test and will let you guys know if I still need to struggle more with sharpening of that area only (on the CAM forum) 🙂

So far I'm very happy with how this utting die came out, I really like it 😄

[ovisopa]

all good. Thank you again for fixing my problems!!! (and showing the solution with those awesome screncasts)