OBELISK

Have some feature requests, feedback, cool stuff to share, or want to know where FreeCAD is going? This is the place.
Forum rules
Be nice to others! Read the FreeCAD code of conduct!
pekkio
Posts: 28
Joined: Wed Jun 14, 2017 2:39 pm

OBELISK

Post by pekkio »

Hi to everyone and thank you for your time. How can I obtain an obelisk by creating a pocket on two faces of a parallelepiped, but not obtaining what I have on my screenshot? :(
I am quite sure there is a problem of dependency and probably I should use other systems such as loft for example.
Please your help will be really appreciated !!!

OS: Mac OS X
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.16.6712 (Git)
Build type: Release
Branch: releases/FreeCAD-0-16
Hash: da2d364457257a7a8c6fb2137cea12c45becd71a
Python version: 2.7.11
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 6.8.0.oce-0.17
screenshot.png
screenshot.png (181.31 KiB) Viewed 2113 times
obelisco.FCStd
(13.44 KiB) Downloaded 42 times
ulrich1a
Veteran
Posts: 1957
Joined: Sun Jul 07, 2013 12:08 pm

Re: OBELISK

Post by ulrich1a »

The approach in FreeCAD 0.16 will be a helper pad. This allows to attach the pocket sketch to the right place. The helper pad will be than removed by the pocketing action.

Ulrich
Attachments
obelisco_helper_pad.fcstd
(25.9 KiB) Downloaded 44 times
paullee
Veteran
Posts: 5098
Joined: Wed May 04, 2016 3:58 pm

Re: OBELISK

Post by paullee »

A good exercise for practising FC for myself also!

Alternative approach with 2 sketches + expressions in spreadsheet, so the form can update according to input in the spreadsheet field.

Hope other have another approach to learn more :)

Screenshot from 2017-09-02 21-40-04.png
Screenshot from 2017-09-02 21-40-04.png (139.13 KiB) Viewed 2075 times
Screenshot from 2017-09-02 21-40-10.png
Screenshot from 2017-09-02 21-40-10.png (158.23 KiB) Viewed 2075 times
In fact, the mathematical formula (almost forgotten since high school) take me more time, and NormandC's hint below help the top part.
https://forum.freecadweb.org/viewtopic.php?t=4230
ulrich1a
Veteran
Posts: 1957
Joined: Sun Jul 07, 2013 12:08 pm

Re: OBELISK

Post by ulrich1a »

paullee wrote: Sat Sep 02, 2017 1:48 pm Hope other have another approach to learn more
Here you go. My favorite approach for such parts is the draft clone method.
1. Make a side-view sketch of the part.
2. Pad the sketch symmetrically in the Part-Design-Workbench (Be sure to pad it big enough.)
3. Create a Draft-Clone of the Pad.
4. Rotate the Clone by 90° with the Placement. (You have to choose the correct axis!)
5. Make a common of both in the Part-Workbench.

Ulrich
Attachments
obelisco_draft_clone.fcstd
(10.65 KiB) Downloaded 50 times
paullee
Veteran
Posts: 5098
Joined: Wed May 04, 2016 3:58 pm

Re: OBELISK

Post by paullee »

ulrich1a wrote: Sat Sep 02, 2017 2:26 pm
paullee wrote: Sat Sep 02, 2017 1:48 pm Hope other have another approach to learn more
Here you go. My favorite approach for such parts is the draft clone method.
1. Make a side-view sketch of the part.
2. Pad the sketch symmetrically in the Part-Design-Workbench (Be sure to pad it big enough.)
3. Create a Draft-Clone of the Pad.
4. Rotate the Clone by 90° with the Placement. (You have to choose the correct axis!)
5. Make a common of both in the Part-Workbench.

Ulrich
Apparently this is a cleaner method! Thank for sharing!
renatorivo
Veteran
Posts: 2611
Joined: Tue Feb 21, 2012 8:07 pm
Location: Torino - Italy

Re: OBELISK

Post by renatorivo »

Very simple procedure
- Create a Pad with Sketch001
- Cut Pad from Pocket
you can complete with expressions in spreadsheet
obelisco1.png
obelisco1.png (28.18 KiB) Viewed 2058 times
obelisco1.FCStd
(22.62 KiB) Downloaded 49 times
Jee-Bee
Veteran
Posts: 2566
Joined: Tue Jun 16, 2015 10:32 am
Location: Netherlands

Re: OBELISK

Post by Jee-Bee »

I had some difficulties with loft during creating a obelisk...
I had created 2 sketches but was unable to select the sketches for the loft. When preselecting i get an error!!

OS: Mac OS X
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.11575 (Git)
Build type: Release
Branch: (detached from e3066d1)
Hash: e3066d1424a96ee16845f700154b3f7c8f51bb9f
Python version: 2.7.13
Qt version: 5.6.2
Coin version: 4.0.0a
OCC version: 7.1.0
Attachments
Obelisk.FCStd
(14.08 KiB) Downloaded 38 times
Screen Shot 2017-09-02 at 19.02.40.png
Screen Shot 2017-09-02 at 19.02.40.png (22.57 KiB) Viewed 2037 times
Screen Shot 2017-09-02 at 19.02.10.png
Screen Shot 2017-09-02 at 19.02.10.png (58.71 KiB) Viewed 2037 times
pekkio
Posts: 28
Joined: Wed Jun 14, 2017 2:39 pm

Re: OBELISK

Post by pekkio »

@renatorivo Brilliant solution, as usual from you.
@bee jee I believe Mac users have some more problems unfortunately. I got crashes from a simple sweep then I passed the file to my friend with WIN 7 and the sweep went fine.
paullee
Veteran
Posts: 5098
Joined: Wed May 04, 2016 3:58 pm

Re: OBELISK

Post by paullee »

paullee wrote: Sat Sep 02, 2017 3:02 pm
ulrich1a wrote: Sat Sep 02, 2017 2:26 pm
paullee wrote: Sat Sep 02, 2017 1:48 pm Hope other have another approach to learn more
Here you go. My favorite approach for such parts is the draft clone method.
1. Make a side-view sketch of the part.
2. Pad the sketch symmetrically in the Part-Design-Workbench (Be sure to pad it big enough.)
3. Create a Draft-Clone of the Pad.
4. Rotate the Clone by 90° with the Placement. (You have to choose the correct axis!)
5. Make a common of both in the Part-Workbench.

Ulrich
Apparently this is a cleaner method! Thank for sharing!
Another alternative simply with lofts + 2 sketch + 1 point - as attached.
(All could be 'linked' via spreadsheet)

Now, I am not sure but there should be some criteria/scenarios for choosing between options by Boolean Common of 2 solids or Lofting :)

It may depends on availability of information / design e.g. a section, subsequent ease of modification etc.
Screenshot from 2017-09-03 11-24-04.png
Screenshot from 2017-09-03 11-24-04.png (128.16 KiB) Viewed 1999 times
Jee-Bee
Veteran
Posts: 2566
Joined: Tue Jun 16, 2015 10:32 am
Location: Netherlands

Re: OBELISK

Post by Jee-Bee »

pekkio wrote: Sat Sep 02, 2017 7:54 pm @renatorivo Brilliant solution, as usual from you.
@bee jee I believe Mac users have some more problems unfortunately. I got crashes from a simple sweep then I passed the file to my friend with WIN 7 and the sweep went fine.
In that case i ask on the developer forum.
Post Reply