Finding the stock length of a bent rod
- Thread starter OTE_TheMissile
- Start date
swertel
Alibre Super User
When bending rod, you end up with a stretching of the material. I'm going to ignore that part of it because it should, hopefully, be negligible.
The rod length is 1.500 + .500 plus the arc length.
You need to measure the internal angle of the radius and then
l = .01745*r*a
where r is your 2.156 radius and a is the angle you will measure.
The rod length is 1.500 + .500 plus the arc length.
You need to measure the internal angle of the radius and then
l = .01745*r*a
where r is your 2.156 radius and a is the angle you will measure.
OTE_TheMissile
Alibre Super User
Oh yeah, s'pose I should probably throw the bend angle in there too, huh? I thought I was forgetting something ~oops 
~
OK, but I have to ask where you got the .01745 from. Is that a universal factor for figuring this out or does that change depending on angle, radius, rod diameter, etc.?
~OK, but I have to ask where you got the .01745 from. Is that a universal factor for figuring this out or does that change depending on angle, radius, rod diameter, etc.?
JordanCClark
Alibre Super User
OTE_TheMissile said:
It's pi/180...
OTE_TheMissile
Alibre Super User
~playing with calculator~ Ah, so it is 8)
Thanks guys!
Thanks guys!
OTE_TheMissile said:
The perimeter (length) around a full circle is 2*pi*R, or pi*D. If the angle you are looking for is, say, 15degrees, the arc length is 15/360 x perimeter.
For information, the line around the outside of the bend will extend while the line inside will compress. An ideal bend will have as much material in tension as in compression. In reality, most materials yield in tension rather than compression which means that the neutral axis moves towards the inside of the bend. For tight bends where the bend radius is is less that about 3 times the material thickness this effect may need to be taken into account. In the example drawing the bend radius is about 3.5 times the material thickness, so the neutral axis should remain central.
OTE_TheMissile
Alibre Super User
This is the arm part of a foot pedal used in our new 2009 Harley Davidson centerstand, so if the bend is a tiny bit off due to deformation it's not a big deal.