Hi!
I continue with my "direct-extruder" exercise:
I need a spring for the tensioner (space between those washers):
I have searched the forum and discovered a spring macro. However, this seems to be "just" one helix, not a physical spring that I could just drop into the design.
How do you add springs to your projects?
I have tried to find in FreeCADParts and Bolts without success (I get lost among references, so maybe there is one and I failed to find it)
Thanks in advance,
abdullah
Spring mechanical part
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Re: Spring mechanical part
Springs suffer like screws from the poor quality of the OCCT-helix-function. Additional there is the question what is the length of the spring for the model. A spring has no fixed length. So a macro would need to know the compressed length of a "standard"-spring in the special situation. Just some thoughts.
In general a spring can be modeled with a part-helix. A circle is than swept along the helix with the parameters checked: make solid and Frenet. The first and last turn may have a different pitch in a real spring. The ends have to be cut. And here starts the fun, as in a lot of cases this fails. I have not tried myself, but read it in the forum.
Ulrich
In general a spring can be modeled with a part-helix. A circle is than swept along the helix with the parameters checked: make solid and Frenet. The first and last turn may have a different pitch in a real spring. The ends have to be cut. And here starts the fun, as in a lot of cases this fails. I have not tried myself, but read it in the forum.
Ulrich
Re: Spring mechanical part
hi
try this macro Macro_FCSpring_Helix_Variable you make the profile of the spring and sweep and cut
mario
try this macro Macro_FCSpring_Helix_Variable you make the profile of the spring and sweep and cut
mario
Maybe you need a special feature, go into Macros_recipes and Code_snippets, Topological_data_scripting.
My macros on Gist.github here complete macros Wiki and forum.
My macros on Gist.github here complete macros Wiki and forum.
Re: Spring mechanical part
If you are looking for springs, go to some vendor, browse the catalogue and download models.
Main page of producer Gutekunst (no login required):
https://www.federnshop.com/en/
There's an online catalogue available where you can enter geometry/size, range of movement and force and select the matching stock part, from which you get direct links to the product in the CAD downloads page:
http://cad.federnshop.com/default.aspx?cul=en-US
Regards
Ektus.
Main page of producer Gutekunst (no login required):
https://www.federnshop.com/en/
There's an online catalogue available where you can enter geometry/size, range of movement and force and select the matching stock part, from which you get direct links to the product in the CAD downloads page:
http://cad.federnshop.com/default.aspx?cul=en-US
Regards
Ektus.
Re: Spring mechanical part
Thanks to you both!!!
That macro is very cool.
I went to the catalogue. I did manage to select a "compression spring", but I did not find the "range of movement" or diameter. I am not a mechanical engineer. I "just" wanted a spring for a M4 bolt with two M4 washers (I know this sounds "stupid" to a mechanical engineer). It is a good link to have it handy though...
EDIT: I managed to make the catalogue "work" by going to the calculations first and then from there to the catalog. This is very cool. Thanks!!
That macro is very cool.
I went to the catalogue. I did manage to select a "compression spring", but I did not find the "range of movement" or diameter. I am not a mechanical engineer. I "just" wanted a spring for a M4 bolt with two M4 washers (I know this sounds "stupid" to a mechanical engineer). It is a good link to have it handy though...
EDIT: I managed to make the catalogue "work" by going to the calculations first and then from there to the catalog. This is very cool. Thanks!!
Re: Spring mechanical part
Much better now!!
Re: Spring mechanical part
You're welcome.abdullah wrote: EDIT: I managed to make the catalogue "work" by going to the calculations first and then from there to the catalog. This is very cool. Thanks!!
To select a spring by mechanical dimension, select wire diameter d (e.g. 1mm), outer diameter De (your screw diameter (4mm) + 2 times wire diameter + gap, e.g. 7mm) and uncompressed length L0. Then apply "search" and you will get a selection of stock products that match those parameters within the tolerances shown to the right of the search values, see screenshot. You may use any other combination of available dimensions, though, by changing the variables to the left of the input fields.
Regards
Ektus.
Re: Spring mechanical part
@ektus
Thanks for sharing the resource for springs.
P.S. As for modeling springs in FreeCAD as already mentioned it can be done manually or macros are available and there are issues involved like performance hit. Maybe in the future similar approach could be taken as with Fasteners WB. Users inserts spring in "simplified form". Maybe just as helix or helix with less turns. But there would be a property that could be changed to "make solid" if needed.
Thanks for sharing the resource for springs.
P.S. As for modeling springs in FreeCAD as already mentioned it can be done manually or macros are available and there are issues involved like performance hit. Maybe in the future similar approach could be taken as with Fasteners WB. Users inserts spring in "simplified form". Maybe just as helix or helix with less turns. But there would be a property that could be changed to "make solid" if needed.