Springs with flat ends

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drmacro
Posts: 301
Joined: Sun Mar 02, 2014 4:35 pm

Springs with flat ends

Postby drmacro » Wed Oct 16, 2019 4:02 pm

Hi,

I have succeeded in making a helical spring following the various tutorials I've found.

But, since I want to represent a spring that has a flat end (i.e. it has the last coil perpendicular to the center line and ground flat I've tried a few different approaches and failed.

In part workbench, I tried to add a partial circle to the end of the helix. I got it to sweep. I then added an extruded plane and boolean it from the sweep. It did it, but the flat was not a solid (it showed up as a half pipe, thatif closed would have been the desired flat).

I tried something similar, adding the helix in part wb, then adding the circle to sweep in part design wb, then a another sketch with a simple pad. Then an exploded slice. This actually did cut correctly a produced a flat. But the resulting exploded slice has 2 slices. Not sure if that's the really good geometry or how to use the slice I want correctly for later operations. :?:

In any case, what I'd really like to know is the correct or best way to model this.
Spring.jpg
Spring.jpg (132.08 KiB) Viewed 563 times

OS: Ubuntu 19.04 (XFCE/ubuntustudio)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.
Build type: Release
Python version: 3.7.3
Qt version: 5.12.2
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/United States (en_US)
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pl7i92LCNC
Posts: 209
Joined: Tue Mar 12, 2019 3:03 pm
Location: RLP DE

Re: Springs with flat ends

Postby pl7i92LCNC » Wed Oct 16, 2019 4:30 pm

you need 3 helix to get this kind of part
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DeepSOIC
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Location: Saint-Petersburg, Russia

Re: Springs with flat ends

Postby DeepSOIC » Wed Oct 16, 2019 5:09 pm

It's complicated. Use a macro, like Macro FCSpring Helix Variable
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papyblaise
Posts: 1099
Joined: Thu Jun 13, 2019 4:28 pm
Location: France

Re: Springs with flat ends

Postby papyblaise » Wed Oct 16, 2019 5:15 pm

Hello
The hélicoîdal part of spring : no problem (maybe) but for the flat part :?: :?: :?:
Just a small calculation (first level of scool) : how mush I have to erase angle of torus :?:
in my exemple when I do a pitch of helix I ascend 5mm , if I need only 2mm (dia of wire) I have to do only (360x5/2)=144°
And I do a miror for the top
Attachments
flat ends spring.FCStd
(68.21 KiB) Downloaded 20 times
flat ends spring.PNG
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drmacro
Posts: 301
Joined: Sun Mar 02, 2014 4:35 pm

Re: Springs with flat ends

Postby drmacro » Thu Oct 17, 2019 1:10 pm

Yes, this part is correct. But, the part I ave not been able to figure out is shown in this addition to your example.

The plane shown cuts off a flat on the last coil. (When manufactured, this is ground flat, so as to lay on a mating surfac.
spring.png
spring.png (85.39 KiB) Viewed 484 times
Attachments
Forum-1.FCStd
(76.73 KiB) Downloaded 20 times
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papyblaise
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Re: Springs with flat ends

Postby papyblaise » Thu Oct 17, 2019 3:52 pm

Yes it's 2 solutions to finish a spring whith flat ends
one is just do the 1/2.5 end spire flat (my exemple
2 is grinding the end at half dia : as you ask
I do my exemple in Part Wb , stay in Part Wb , or in Partdesign , you have to do a copy in your Body
Attachments
flat ends spring2.PNG
flat ends spring2.PNG (60.25 KiB) Viewed 461 times
drmacro
Posts: 301
Joined: Sun Mar 02, 2014 4:35 pm

Re: Springs with flat ends

Postby drmacro » Thu Oct 17, 2019 5:23 pm

That is exactly what I'm describing. :)

But, I have not been able to get it to model. But, I've been trying to boolean away the flat. :(

I don't see a cad file of your example, but if you do a partial revolution of the flat cross section, how does the transition between the flatted "D" shape and the round helix cross section work?

Edit: I just figured out what I was doing wrong. Once I changed the fusion of the revolve/helix to a solid, then I could boolean the resultant solid and the cutting slab I'd defined.
Spring-2.png
Spring-2.png (93.53 KiB) Viewed 447 times
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pl7i92LCNC
Posts: 209
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Location: RLP DE

Re: Springs with flat ends

Postby pl7i92LCNC » Thu Oct 17, 2019 5:56 pm

hi woudt be good if you upload the final file for others facing the problem
did you make it with the macro or separet

and please mark as solved thank you
freedman
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Re: Springs with flat ends

Postby freedman » Thu Oct 17, 2019 6:49 pm

Sketch the ends off with a pocket.
Attachments
sweep1.JPG
sweep1.JPG (58.03 KiB) Viewed 434 times
sweep_helix.FCStd
(193.59 KiB) Downloaded 12 times
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GlouGlou
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Re: Springs with flat ends

Postby GlouGlou » Thu Oct 17, 2019 6:55 pm

in CurvesWB, you can find a useful feature to get quickly the right path.
and directly the shape, no sweep needed.
Attachments
Capture.PNG
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