[done] Developing a spreadsheet based loaf pan

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jeno
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Re: Developing a spreadsheet based loaf pan

Post by jeno »

Ulicad wrote: Wed Mar 22, 2023 8:50 pm Hello jeno,
the point you show for attachement would be ideal as an origin for constructing the 1st cutout, but its postition is depending on values in the spreadsheet.
Consequently speaking, would'nt this point then be part of the cross-sections Pad, possibly leading to TNP (and it definitely did before)?
...
Depending on the wishes of mechnical workshops, the inner (and outer) fillet radius may be set to 0mm in the spreadsheet! A generallly functional and suitable expression (based on school geometry) did not occur to me yet.
I don't see a simple solution to avoid TNP in case you want to incoroporate every option (dependent and independet radii and no radii)
My pov is to keep it simple and stupid. One model/file with radii and one model/file for the angular version.

cheers
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papyblaise
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Re: Developing a spreadsheet based loaf pan

Post by papyblaise »

or accept a radius = 0.1mm as insignificant and acceptable for a sharp corner
Ulicad
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Re: Developing a spreadsheet based loaf pan

Post by Ulicad »

Hi all,
the work happiy seemed to develop into a more productive mode :P

The base for sketching onto a datum-plane seemed to be ready:
so-nice.png
so-nice.png (108.98 KiB) Viewed 1096 times

Now, after editing some realistic, seemingly unproblematic values within the spreadsheet, the coherence vanished to a large extent :shock:
breakage.png
breakage.png (85.68 KiB) Viewed 1096 times

Considering my actual awareness regarding TNP, I have no clue how this can happen. The datum is attached to the origin.

Since this has the highest priority before finalizing less problematic points, I hope you can find the time to have a look into it.

Regards
Uli

Edit:
A workaraound also failed (deleting horizontal and vertical distance contstraints firstly, changing the values in the spreadsheet secondly and applying these as constraints again in the sketch). There is a problem with this point upper right.
recompute-failed.png
recompute-failed.png (96.95 KiB) Viewed 996 times
Attachments
zko.loafpan.model2.0.base-07.078.FCStd
(18.4 KiB) Downloaded 16 times
breakage1-loafpan.model2.0.base-07.FCStd
(18.36 KiB) Downloaded 15 times
Last edited by Ulicad on Fri Mar 24, 2023 8:01 pm, edited 1 time in total.
Regards, Ulicad / Uli
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chrisb
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Re: Developing a spreadsheet based loaf pan

Post by chrisb »

Check the sketch:
Attachments
SnipScreenshot-fb63ad.png
SnipScreenshot-fb63ad.png (23.36 KiB) Viewed 1062 times
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chrisb
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Re: Developing a spreadsheet based loaf pan

Post by chrisb »

Looks like yet another case of "thou shall prefer geometric constraints!"
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loafpan_cb.FCStd
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Ulicad
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Re: Developing a spreadsheet based loaf pan

Post by Ulicad »

chrisb wrote: Fri Mar 24, 2023 5:43 pm Check the sketch:
Could now narrow this down (it also happened before without deliberate change - I remember):

Before editing the height value in the spreadsheet (cell C7), the height is specified correctly for the uper right point in the sketch.
height-as-expression-for-top-right-vertex.png
height-as-expression-for-top-right-vertex.png (107.53 KiB) Viewed 1025 times

After editing its value (a few mm only), the sketcher 'flips' to the left upper point. The further consequence is a distorted fillet in the lower right.
[attachment=0]after-edit-of-height.png]
Attachments
after-edit-of-height.png
after-edit-of-height.png (109 KiB) Viewed 1025 times
Regards, Ulicad / Uli
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chrisb
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Re: Developing a spreadsheet based loaf pan

Post by chrisb »

Ulicad wrote: Fri Mar 24, 2023 6:38 pm After editing its value (a few mm only), the sketcher 'flips' to the left upper point.
IIRC I have already recommended the document in my footer. There are some techniques described which can help avoid flipping. One of them helps here. I tried with changes of ±15mm.
loafpan_cb2.FCStd
(15.24 KiB) Downloaded 20 times

Life is chaotic - so is Ulicad
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Re: Developing a spreadsheet based loaf pan

Post by Ulicad »

Edit2:
The interpretation of the angle notations were mistaken and confused ...
The post is irrelevant at this time.

_____________________________________________________________________

chrisb wrote: Fri Mar 24, 2023 10:19 pm... There are some techniques described which can help avoid flipping. ...


Thanks to your post I reconstructed the complete body, now respecting MUCH more the underlying school-geometry in combination with the FC-concept of the constraints!

Practically the whole cross-section is defined by entering and positioning a sole point in the upper right - and it works very fine :D

One important element though still is missing: a well placed datum plane.
Even after various trials to safely and clearly attach a datum plane to the origin, I could not even find the logic behind the angular attachement.

For testing purpose, Cell C37 is linked to the 'Around y-axis' of the Datum plane parameters. Editing the values in the spreadsheet seems to have erratic results to me.

Once this point is clarified, the door to the complete pan is wide open!

Regards
Uli

Edit:
Concrete info on what I experience as 'strange':

In a new Cell, Alias is set to new_test_angle, we have the value 82,7°
In Datum Plane Parameters, 'Around Y-axis' is set to new_test_angle, showing greyed out 82,7, which is OK

Now, when measuring the angle of the Datum plane by 'measure angular', I receive 7,3°

This corresponds to nothing I found, except for the 0,3 + 0,7 = 1).

editCell-angular.png
editCell-angular.png (99.9 KiB) Viewed 885 times
[/s]
Attachments
loafpan.model2.0.base-10.FCStd
(16.68 KiB) Downloaded 14 times
compare-datum.png
compare-datum.png (84.16 KiB) Viewed 885 times
Regards, Ulicad / Uli
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IanP
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Re: Developing a spreadsheet based loaf pan

Post by IanP »

Getting away from Freecad issues, what an excellent idea for a product.
It hits all the right buttons for a successful business idea,
  • Simple design
    Easy to manufacture (only 3 pieces)
    Made from the right materials (EG teflon coated aluminium) would be appealing to customers
    Has a large potential market - especially when people are looking to home cook / save money
    Space saving design that would fit in oven drawers or cupboards.
    Easy to take apart even when the loaf has stuck to the sides.
Had I thought of this then I would have used a 5 piece design where the base would be separate from the sides so that it could be packaged for sale more easily and put 'slide hooks' on the tabs.
However
Congratulations on great product design for real life purposes
Ulicad
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Re: Developing a spreadsheet based loaf pan

Post by Ulicad »

Hi all,
before taking care of matters further upwards in the thread, I am happy to show at least some progress, thanks to your help!
Here is the latest copy of the loaf pan, having one comprising of a very first cutout. The cutouts are to be copied and multiplied on the quarter pan (4 nos. in total).

(Please note: Hardly anything really is finalized ...)

loafpan.107.png
loafpan.107.png (96.57 KiB) Viewed 758 times
Attachments
loafpan.107.FCStd
(31.29 KiB) Downloaded 19 times
Regards, Ulicad / Uli
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