Does anyone know if Ducan butterfly axles are press fitted into the halves, inserted while the plastic solidifies, or glued in?
I’m interested to know from a platic design perspective.
I have firmly press fitted the AL axle I to my latest Knick-KNack prototypes, and every thing seems just fine but I’m wondering if it could cause stress cracking in time.
So: if the Duncan butterfly ) which is also a polycarbonate yoyo) has a press fitted axle, then it is clear that this method does not render the yoyo susceptible to stress cracking.
I’m fairly sure they’re press fitted. They could be inserted while the plastic solidifies but you can take them apart with a bit of force and they seem to go back together without any issues, so they’re not glued in.
Not sure if this helps but I happen to have a photo of one taken apart:
All of mine were crooked too. It does look like it was inserted into soft halves, but it could just be inconsistencies with the molding or just not fitted very precisely.
