Constant force springs not working in constant torque retractor

We are trying to use a constant torque retractor but when we put a constant force spring it fails and bends the springs. What springs should we use, we found contorque springs but they don’t have the right one off the shelf. Thanks!
Our spring we use: McMaster-Carr

Our mechanism:

Example mexhanism: McMaster-Carr

Can you share some pictures of your mechanism?

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Bonus points if you include something for scale if it is not obvious and the rating of the CF springs.


Thanks just updated it!

From the looks of it there is probably a very specific type of CF spring it uses to spool off one spool and onto the other for the McMaster version.

Most of the CF springs I have seen in FRC are only designed to spiral one direction

if the geometry lets you it might be possible to separate out your spools and attach some dyneema string or something similar to the end of the spring and that could wrap around your second spool while the spring just pulls straight out.

These? These are not the same as a constant force spring (I think).

Not only that but there are warnings about bending the spring too much for constant force springs.

Could you share this link/ where the pdf is? Now I am curious.

Reverse bending will yield a standard constant force spring. That will ruin their function and fatigue them out.
You need a different type of spring. It will be much thinner…
We used these constant torque springs (or at least something very similar from this company) in 2018.

Vulcan-Design-Guide_Digital-Final.pdf (13.3 MB)

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