Challenges?

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FBXL5
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Re: Challenges?

Post by FBXL5 »

thomas-neemann wrote: Sat Mar 04, 2023 8:31 pm
You haven't even tried to take into account that the thickness varies over the length.

A constant thickness/rectangular volute spring is no big deal as can be seen in the PartDesign Examples:
Volute spring.png
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chrisb
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Re: Challenges?

Post by chrisb »

FBXL5 wrote: Sat Mar 04, 2023 7:24 pm Problem: How to measure a spiral's length?
With SegmentLength=0 you get a single segment, of whih you can measure an edge with the macro curveLength:
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curveLength.py
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thomas-neemann
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Re: Challenges?

Post by thomas-neemann »

FBXL5 wrote: Sat Mar 04, 2023 9:22 pm ...
it's just a quick suggestion for the production. at least it's right-angled below :-)


Bildschirmfoto_2023-03-05_08-09-22.png
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Bildschirmfoto_2023-03-05_08-08-33.png
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edit

here is the complete construction with different thicknesses in less than 3 minutes

https://www.youtube.com/watch?v=yc3ZqPvjO74

phpBB [video]
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wieszak17
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Re: Challenges?

Post by wieszak17 »

FBXL5 wrote: Sat Mar 04, 2023 7:24 pm Such a spring has to be split into several segments at every kink in the contours (4),
I think 2 is enough - you can ignore for start chamfers at and of plate, and only account change in thickness. Then after last step in your example just pocket out top and bottom to get that chamfers. Only lower one is strict on dimension, which would require some math to do if one want to be that close to original thing, the top one is with '~' meaning that this dimension is given roughly. And that is easy solution to problem found by thomas-neemann .
thomas-neemann wrote: Sun Mar 05, 2023 7:14 am here is the complete construction with different thicknesses in less than 3 minutes
Doing model of plate before rolling is not a target here, also it is not an issue - it is common of two simple Pads, or Pad and Chamfer like FBXL5 did it. I am building models of railroad rolling stock, not actual real sized ones. So what i would need is 3D printable model of ready to use spring. Honestly, i thought that you will do something similar to that ventilation duct you showed earlier, and that actually could be more or less acceptable solution as it would only lack of edit possibility. My second ideas was close to FBXL5's, but with three helixes. First was not using helixes at all but create a Sketch out of four arc's per one turn with radiuses calculated by hand.
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FBXL5
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Re: Challenges?

Post by FBXL5 »

wieszak17 wrote: Sun Mar 05, 2023 11:13 am I think 2 is enough - you can ignore for start chamfers at and of plate, and only account change in thickness. Then after last step in your example just pocket out top and bottom to get that chamfers.
Cutting off top and bottom is the easiest task.
I think I don't want to find out how to create a spiral with an increasing growth factor at the moment. Other solutions are not satisfying in my opinion.
After a few more trials I would say my first attempt was looking quite ok only by chance... :?

I bet the draughtsman who created the scetion had a finished spring to measure and documented it after the production process was stable.
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thomas-neemann
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Re: Challenges?

Post by thomas-neemann »

papyblaise wrote: Sat Mar 04, 2023 10:13 am ...
according to google trends, the number of searches for "cad speed" is increasing
Bildschirmfoto_2023-03-05_17-50-47.png
Bildschirmfoto_2023-03-05_17-50-47.png (3.2 KiB) Viewed 1198 times
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chrisb
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Re: Challenges?

Post by chrisb »

thomas-neemann wrote: Sun Mar 05, 2023 4:55 pm according to google trends, the number of searches for "cad speed" is increasing

Bildschirmfoto_2023-03-05_17-50-47.png
That looks to me like the right end of the last 7 days worldwide trend:
Bildschirm­foto 2023-03-05 um 18.27.15.png
Bildschirm­foto 2023-03-05 um 18.27.15.png (113.2 KiB) Viewed 1182 times
The last 12 months look like this:
Bildschirm­foto 2023-03-05 um 18.30.18.png
Bildschirm­foto 2023-03-05 um 18.30.18.png (84.05 KiB) Viewed 1182 times
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thomas-neemann
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Re: Challenges?

Post by thomas-neemann »

chrisb wrote: Sun Mar 05, 2023 5:31 pm ...
it is the current trend reversal, that's how it is also interpreted on the stock exchanges


edit
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Last edited by thomas-neemann on Sun Mar 05, 2023 5:43 pm, edited 1 time in total.
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bambuko
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Re: Challenges?

Post by bambuko »

thomas-neemann wrote: Sun Mar 05, 2023 4:55 pm ...according to google trends, the number of searches for "cad speed" is increasing...
for those not familiar with English slang :mrgreen: :lol:
SPEED = https://en.wikipedia.org/wiki/Amphetamine
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you can also download ... and try it here
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jfc4120
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Re: Challenges?

Post by jfc4120 »

How would you develop a square to round elbow in freecad? See images.

But like this, standard like a sheet metal shop would make or a pipe fitting shop would make out of gores.
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sq_rnd1.png
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Last edited by jfc4120 on Wed Mar 22, 2023 3:08 am, edited 2 times in total.
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