Chamfers In PartDesign - Anyone working on a fancy stopped cut ?

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LHC
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Chamfers In PartDesign - Anyone working on a fancy stopped cut ?

Post by LHC »

Good Morning Folks -

My quest to learn Freecad continues and a friend of mine asking me to model him something has accelerated my learning a bit (and generated some swearing as well, but we won't talk about that....)

Here's a little model that I drew up in Part Design and try as I might, I could not get the chamfers to work properly. It seems the ability for the chamfer to automatically "die out" when transitioning to another surface does not exist. It's sort of like a stopped cut when you are using a wood router to carve a chamfer on an edge of a piece of wood. When you stop before you exit off the end of the wood, you're left with a smooth transition back to the edge based on the rotational movement of the cutter.

If I use the chamfer tool on the edge shown it just throws an error. By drawing a little sketch and sweeping a 45 degree chamfer sketch around the necessary edges it sorta works but you end up with discontinuities at the ends.

I vaguely remember this fancy feature existed in Fusion 360, but it's been a couple months since I used Fusion and my memory is getting fuzzy (that's a good thing - less chances for me to confuse the way things were done there with the way things are done here :D )

Anyway, I'm just wondering if this sort of thing can be done in FC, or maybe someone is working on it? If not, might it be a feature to consider tossing on the list ?

Thanks and Cheers from sunny Canada.....

Lewis

OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22670 (Git)
Build type: Release
Branch: master
Hash: 12155f4aab09047c5697db0c1b3cf93b02edda03
Python version: 3.8.6
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.4.0
Locale: English/United States (en_US)
Attachments
Chamfer Idea 1.jpg
Chamfer Idea 1.jpg (59.95 KiB) Viewed 891 times
Chamfer Idea 2.jpg
Chamfer Idea 2.jpg (57.73 KiB) Viewed 891 times
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papyblaise
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Re: Chamfers In PartDesign - Anyone working on a fancy stopped cut ?

Post by papyblaise »

Hi
unfortunely you can't do that in PartDesign , but in Part Wb
Do a partial one : half cylinder and half radius (green in my picture ) then select the angle and whith the tool "Filet" select "variable radius" , choise 0.01 to start and 5mm for the end > OK
Miror , new cylinder (at left ) , cone and filet the base and the top
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exercice.PNG
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exercice.FCStd
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LHC
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Re: Chamfers In PartDesign - Anyone working on a fancy stopped cut ?

Post by LHC »

I'd not ventured out of the part design workbench yet, so I went to part workbench and tinkered a bit. I was successful in filleting the edge of a cube with variable radius fillets, but it seems the chamfer tool does not have this ability - only a 2 distance setting. However this is good to know and might suit my purposes. Thanks for the feedback !
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Roy_043
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Re: Chamfers In PartDesign - Anyone working on a fancy stopped cut ?

Post by Roy_043 »

Alternative solution: create a a fully chamfered base and then stick a cone on top.
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Chamfer_Example.png
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LHC
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Re: Chamfers In PartDesign - Anyone working on a fancy stopped cut ?

Post by LHC »

That approach is a bit more to my liking actually. Just need to think about the order of creation. One question that I was wondering - is there a way to take the object created in part design and then work with the more versatile fillet in part workbench or are the objects inherently not compatible between the two workbenches ?

Thanks
chrisb
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Re: Chamfers In PartDesign - Anyone working on a fancy stopped cut ?

Post by chrisb »

You can well use Part operations on Bodies, but you shouldn't apply them to the features inside. This is easy done for Booleans, but for fillets you have to set "DisplayModeBody" from "Through" to "Tip".

Please note that you cannot continue directly editing the body. You have to create a new one using the Part object as a BaseFeature. I don't like such to and fro so I try to apply functions from outside of PartDesign when I'm done with the bodies.
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LHC
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Re: Chamfers In PartDesign - Anyone working on a fancy stopped cut ?

Post by LHC »

Thanks Chris
I understand the concepts of tip and basefeatute but not the "through". Guess I need to keep reading the wiki...
Regardless, I agree it certainly sounds like a convoluted process and most certainly not parametric which I've come to grow quite fond of thanks to Fusion 360. This is not a showstopper for me though. Thanks for the input.
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papyblaise
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Re: Chamfers In PartDesign - Anyone working on a fancy stopped cut ?

Post by papyblaise »

Sorry, I didn't see you asking for a chamfer
then draw a triangle on the side and use the edge of the fillet as a path to make a sweep, boolean subtraction
and the rest of the work is the same
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exercice2.FCStd
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exercice2.PNG
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LHC
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Re: Chamfers In PartDesign - Anyone working on a fancy stopped cut ?

Post by LHC »

papyblaise wrote: Sat Nov 14, 2020 7:20 am Sorry, I didn't see you asking for a chamfer
then draw a triangle on the side and use the edge of the fillet as a path to make a sweep, boolean subtraction
and the rest of the work is the same
Ok - thanks - I need to start thinking outside the box - your solution to getting a variable chamfer is a nice trick to remember. There is so much for me to learn but it's made easier with access to masters like yourself!
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papyblaise
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Re: Chamfers In PartDesign - Anyone working on a fancy stopped cut ?

Post by papyblaise »

.....with access to masters like yourself!
if only everyone who laughs at me could read you :lol: :lol:
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