I am currently designing a small (approx 4.5"W x 3.5"L x 1"T) plastic case. Everything is sorted out but the hinge, as I do not have experience with hinge design. That being said, I see two options: (1) source a hinge from a supplier - that way I avoid the design portion, or (2) learn how to size a plastic hinge. I should note that if I were to design the hinge, it would be a plastic part, integrated into the mold for each case half. The case will be used as a display case for sales reps, so loading will be low. The hinge can be a simple barrel type hinge, no return mechanism, stop, or additional friction (to impede rotation) necessary. The case will be carried around in a brief case or pocket, and used to present our product.
I have questions related to each of the two options.
Option (1): Can you recommend any suppliers for a case of the size I specified? I am having trouble locating them.
Option (2): Do you have any recommendations on where I can find common practices on hinge design, or even better, plastic hinge design? I could do some stress analysis or even FEA on a hinge design, but I feel this would be somewhat trivial as I do not have an accurate representation of the loading. My analysis would also treat the material as linear elastic, and I am unsure as to how accurate this would be for a fatigue analysis on a plastic part. I have looked around for texts and been unsuccessful in finding anything thus far. My search on eng-tips yielded this thread: but it is old, and the links are dead.
Do you have any tips for designing a plastic hinge? In terms of sizing, the primary dimension of concern is the wall thickness of the barrel that surrounds the hinge pin. My initial thought is that there may be a common practice for specifying the barrel thickness based on loading conditions, hinge pin diameter, and barrel material. For example, based on certain loading conditions and a selected plastic, the outer diameter of the barrel should be some quantity multiplied by the hinge pin diameter. Maybe I'm totally wrong here, just a thought.
Please let me know if any further clarification is necessary.
I have questions related to each of the two options.
Option (1): Can you recommend any suppliers for a case of the size I specified? I am having trouble locating them.
Option (2): Do you have any recommendations on where I can find common practices on hinge design, or even better, plastic hinge design? I could do some stress analysis or even FEA on a hinge design, but I feel this would be somewhat trivial as I do not have an accurate representation of the loading. My analysis would also treat the material as linear elastic, and I am unsure as to how accurate this would be for a fatigue analysis on a plastic part. I have looked around for texts and been unsuccessful in finding anything thus far. My search on eng-tips yielded this thread: but it is old, and the links are dead.
Do you have any tips for designing a plastic hinge? In terms of sizing, the primary dimension of concern is the wall thickness of the barrel that surrounds the hinge pin. My initial thought is that there may be a common practice for specifying the barrel thickness based on loading conditions, hinge pin diameter, and barrel material. For example, based on certain loading conditions and a selected plastic, the outer diameter of the barrel should be some quantity multiplied by the hinge pin diameter. Maybe I'm totally wrong here, just a thought.
Please let me know if any further clarification is necessary.
