Sketcher -- How to sketch a Lozenge shape (or rounded rectangle)

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rek
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Joined: Thu Sep 09, 2021 6:56 pm

Sketcher -- How to sketch a Lozenge shape (or rounded rectangle)

Post by rek »

I want to make this:
looks_easy_to_sketch_but_is_not.jpg
looks_easy_to_sketch_but_is_not.jpg (14.73 KiB) Viewed 1717 times
looks easy, but how do you start?

I tried to create a constrianed rectangle then put fillets on the corners but every time i try to make the ends round, i get an error. even if i kind of get close to having a lozenge shape and try to draw 3mm circles at the origin of the fillets or end circle radius, it won't let me. this ended up more of a challenge than I saw coming.

so then i tried creating circles at the ends, nope

I don't know, I've tried a ton of things and it doesn't want to play nice. It's not just a rounded corner rectangle, there's two half circles. i also need to put holes concentric to those circles.
lozenge_shape_fail_--_a_problem_i_never_thought_possible.jpg
lozenge_shape_fail_--_a_problem_i_never_thought_possible.jpg (51.77 KiB) Viewed 1717 times
Lozenge_shape_fail_sep_18_2021.FCStd
(8.93 KiB) Downloaded 26 times
I've seen old threads kind of about this, but they were doing the much easier and different thing of rounding the corners, not making two half circles at the end of a rectangle.
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Shalmeneser
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Re: Sketcher -- How to sketch a Lozenge shape (or rounded rectangle)

Post by Shalmeneser »

Sketcher_CreateSlot

You should follow tutorials. This is such a simple problem.
Look at the Chrisb book (in its signature) : https://forum.freecadweb.org/memberlist ... ile&u=5646 (https://owncloud.gwdg.de/index.php/s/eZ ... 9/download)
Bance
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Re: Sketcher -- How to sketch a Lozenge shape (or rounded rectangle)

Post by Bance »

:lol: :lol: :lol: :lol:
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Shalmeneser
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Re: Sketcher -- How to sketch a Lozenge shape (or rounded rectangle)

Post by Shalmeneser »

* Draw 2 lines + 2 arcs
* Select 2 points + Sketcher_ConstrainCoincident
* Repeat
* Select 2 adjacent lines + Sketcher_ConstrainTangent
* Repeat
* Select 2 arcs + Sketcher_ConstrainEqual
* Select 1 line + Sketcher_ConstrainHorizontal
* (Select center + axis + Sketcher_ConstrainPointOnObject)
rek
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Re: Sketcher -- How to sketch a Lozenge shape (or rounded rectangle)

Post by rek »

you seem to have unlocked the mystery of this, thanks. will try now.
I honestly forgot about the arc tool.
Shalmeneser wrote: Sat Sep 18, 2021 8:45 pm * Draw 2 lines + 2 arcs
* Select 2 points + Sketcher_ConstrainCoincident
* Repeat
* Select 2 adjacent lines + Sketcher_ConstrainTangent
* Repeat
* Select 2 arcs + Sketcher_ConstrainEqual
* Select 1 line + Sketcher_ConstrainHorizontal
* (Select center + axis + Sketcher_ConstrainPointOnObject)
stuff I did before I read the replies:

i couldn't do it in Sketcher and I studied other threads and someone said "I don't want to make it out of primitives" and I didn't think of trying that so I tried it and now I'm printing the part.
used_part_workbench_and_primitives_instead_of_sketching.jpg
used_part_workbench_and_primitives_instead_of_sketching.jpg (52.98 KiB) Viewed 1607 times
and after trying Shalmeneser's genius strategy of using arcs (instead of trying to use 2 adjacent fillets) i got the result to the left in this pic:
lozenge_shape_rounded_rectangle_on_steroids.jpg
lozenge_shape_rounded_rectangle_on_steroids.jpg (47.03 KiB) Viewed 1583 times
chrisb
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Re: Sketcher -- How to sketch a Lozenge shape (or rounded rectangle)

Post by chrisb »

A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
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Shalmeneser
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Re: Sketcher -- How to sketch a Lozenge shape (or rounded rectangle)

Post by Shalmeneser »

chrisb wrote: Sat Sep 18, 2021 10:31 pm ...
Sketcher CreateSlot is equal to Sketcher_CreateSlot ?
chrisb
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Re: Sketcher -- How to sketch a Lozenge shape (or rounded rectangle)

Post by chrisb »

Shalmeneser wrote: Sat Sep 18, 2021 10:34 pm Sketcher CreateSlot is equal to Sketcher_CreateSlot ?
Yes, that's what the forum's wiki tag does. Sorry, I had missed your post due to tab open for too long.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
rek
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Re: Sketcher -- How to sketch a Lozenge shape (or rounded rectangle)

Post by rek »

Wow someone created a tool for that. That was fast. Now that's what I call service, thanks Devs!

why does ignorance hurt so much while it's being removed? Thanks :)
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Re: Sketcher -- How to sketch a Lozenge shape (or rounded rectangle)

Post by drmacro »

@rek, the tool has been there for some time...

Also, note, if you ever change your signature because you change your hardware, it chaanges in all previous posts...thus any significance the specifications might have to old posts is lost for posterity.
Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
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