Misplaced holes in polar pattern on a revolution

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mperrando
Posts: 4
Joined: Sun Mar 10, 2019 9:57 am

Misplaced holes in polar pattern on a revolution

Post by mperrando »

Hello everybody.

I have been using FC for a short time, and I am making my second real project.

I have come into a strange behaviour of polar pattern applied on a hole that stands on a revoution surface.
The holes produced by the polar pattern are present, but they are rotated.

I would like to know what am I doing wrong or if it could be a FC bug.

NOTE: making a polar pattern from a pocket works as expected (see the other image)



Thanks in advance for your kind help!

MP

OS: Mac OS X
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.13541 (Git)
Build type: Release
Branch: releases/FreeCAD-0-17
Hash: 9948ee4f1570df9216862a79705afb367b2c6ffb
Python version: 2.7.14
Qt version: 5.10.1
Coin version: 4.0.0a
OCC version: 7.2.0
Locale: English/UnitedStates (en_US)
Attachments
FreeCAD 2019-03-10 11-11-57.png
FreeCAD 2019-03-10 11-11-57.png (41.72 KiB) Viewed 1355 times
FreeCAD 2019-03-10 10-59-18.png
FreeCAD 2019-03-10 10-59-18.png (63.26 KiB) Viewed 1355 times
polar-pattern-hole-revolution.FCStd
(73.77 KiB) Downloaded 25 times
chrisb
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Re: Misplaced holes in polar pattern on a revolution

Post by chrisb »

Hi MP, welcome to the forum.
A recompute of the whole document fixes this: Right mouse click on the filename, select "Mark to recompute". Use Ctrl-R or equivalent icon or menu entry to recompute.
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
mperrando
Posts: 4
Joined: Sun Mar 10, 2019 9:57 am

Re: Misplaced holes in polar pattern on a revolution

Post by mperrando »

Hi Chris, and thank you for you prompt reply!

Sorry to inform you that the procedure you suggest does not change anything. :?

I tried also to mark and recompute only the Part or the Pattern, but every time, after making "Refresh", nothing changes...

Any other clue? :)
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meme2704
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Re: Misplaced holes in polar pattern on a revolution

Post by meme2704 »

Hi
Correcting the problem is good, but it should be interfering with the cause,
I think there is 2 reasons:
the first is that the sketch is not constrained,
the 2nd is that the Hole tool is not suitable for drilling a single hole
freecad-heini-1
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Re: Misplaced holes in polar pattern on a revolution

Post by freecad-heini-1 »

mperrando wrote: Sun Mar 10, 2019 11:39 am Hi Chris, and thank you for you prompt reply!

Sorry to inform you that the procedure you suggest does not change anything. :?

I tried also to mark and recompute only the Part or the Pattern, but every time, after making "Refresh", nothing changes...

Any other clue? :)
Here's a short animgif for you:
Please_recompute.gif
Please_recompute.gif (120.66 KiB) Viewed 1329 times
kisolre
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Re: Misplaced holes in polar pattern on a revolution

Post by kisolre »

Recompute fixes it in 0.18 but not in the OPs 0.17 version. I tried to remedy the file in 0.17 but did not succeed. It is probably a bug that was already fixed in 0.18
chrisb
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Re: Misplaced holes in polar pattern on a revolution

Post by chrisb »

meme2704 wrote: Sun Mar 10, 2019 11:54 am the first is that the sketch is not constrained,
That should, of course, be corrected.

the 2nd is that the Hole tool is not suitable for drilling a single hole
Why that?
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meme2704
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Re: Misplaced holes in polar pattern on a revolution

Post by meme2704 »

the Pocket tool is a little more adapt :?: ? no :?: ? for a single hole, without milling or tapping (which does not work)
chrisb
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Re: Misplaced holes in polar pattern on a revolution

Post by chrisb »

The hole offers predefined clearances, counterbore, countersink, ... but I get now what you mean.
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NormandC
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Re: Misplaced holes in polar pattern on a revolution

Post by NormandC »

Hello mperrando,

Welcome here.

While it's true that it's recommended practice to fully constrain a sketch, it's not obligatory, and in this specific case it has absolutely no relevance to your problem. The second argument, that "the Hole tool is not suitable for drilling a single hole" is just utter hogwash, chrisb listed its advantages over a pocket. There is nothing wrong with your use of it.

As kilsore surmised, the real issue is a bug in the 0.17 version pertaining to the Hole feature and which was only fixed in the 0.18 development branch somewhere around last October or November (not sure but this might be the fix git commit b65faeff771 - I know that v0.18.14995 from 10/18/2018 didn't include the fix). 0.18 is in the last leg of its development and should be released very soon, most of us regulars have been running it for quite some time, so we tend to forget about bugs that were in 0.17.
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