Torsion spring design problem and solution

Learn how to specify torsion spring geometry based on a design problem. Spring calculation. Torsion spring rate, spring force, spring stress, spring design, spring length, spring load, torsion spring stress, torque, wire diameter, active coils, expansion under load,

[@satyajeetphalke]

How can i determine fatigue life of torsion springs ? Or number of cycles the spring will perform normally without losing torque?

[@iranlemos2125]

can you tell me what calculation you did to calculate the k?

[@iranlemos2125]

even with the comment down there i dont understanded

[@iranlemos2125]

Hello, im a little confuse in how i can find the young modulus to calculate the number of coils, can you help me?

[@PDWCreative]

It makes things easier if you pick out a modulus from a specific spring steel stocked by manufacturers. Alternatively you could input the number of coils you need into the coil equation and rework it. It makes things easier if you find a modulus from charts so you know the design is possible.

[@satyajeetphalke]

Why did you take k as 1400 while calculating number of active coils ?

[@PDWCreative]

The subject comes up at 10:00

[@arulkishorea9053]

@@PDWCreative ie) =1050/(270/360) = 1400
considering it with full rotation

[@hadim8426]

for calculating active number of coil, where did you get the value for k

[@PDWCreative]

The subject comes up at 10:00

[@huckabrew]

@@PDWCreative You say it's the spring stiffness of one complete 360° rotation. Why is that? Also, is that our original torque requirement of 1050Nmm over 360° instead of 270°? That would not be 1400. Still confused by this little bit. Thanks for you help and this video series in general.

[@PDWCreative]

@Steve Huckaby When stiffness is calculated early on it is based on the load, distance and rotation of 270 degrees. The problem never changes. But when working out the number of active coils I translated it across a full 360 degree rotation just for reference.

[@huckabrew]

@@PDWCreative Ah ok. Why do you use a 360° reference value instead of your 270° actual deflection? Wouldn't that under calculate your number of coils? Would you have to do that for all spring designs? Also, it looks you use the torque at 360° and not the actual rate. Thanks for responding. I'm just trying to understand this process so that i can apply it to my design requirements.

[@PDWCreative]

@@huckabrew whenever I have tried to calculate the spring it didn't work out unless a switched to a full rotation. The best thing to do is try the manual method but also try some free online calculators and check manufacturers notes. For this video I had a very specific challenge to overcome.

[@jianh1989]

9:54 how did you get k at 1400 ?

[@PDWCreative]

Subject is discussed at 10:00. One whole rotation