cjccmc
Mechanical
- Oct 11, 2012
- 111
I used to have a Associated Spring design guide that would advise these things but the online references I have found do not include a way to get these specifics. I am looking at a compression spring (square ground ends) .240 dia, .018 wire, 2.0 free ht that will apply load to a locking pin (plunger). I would like a fairly loose fit between the pin and hole so that the pin will have compliance to engage in a mating part. The pin will be .75 inches down in the spring hole when the free protruding end (approx 3 inch long pin) has to pass thru a supporting bushing 1.5 inches away. I calculated that the pin needs to be .015 smaller than the hole diameter to get the desired compliance (play) to fit thru the support bushing. (Due to the part tolerances the support bushing and spring hole can not be perfectly aligned.)
What issues are most important in determining the relative sizes of the spring, hole and pin? If I had to pick a quick set of sizes for this spring I would go with .240 dia pin and .255 dia hole to get the play I want. Will these sizes work and avoid any jamming or other detrimental conditions? Are the shapes of the pin end (small chamfer) and hole end (flat or conical?) which contact the spring of much importance?
What issues are most important in determining the relative sizes of the spring, hole and pin? If I had to pick a quick set of sizes for this spring I would go with .240 dia pin and .255 dia hole to get the play I want. Will these sizes work and avoid any jamming or other detrimental conditions? Are the shapes of the pin end (small chamfer) and hole end (flat or conical?) which contact the spring of much importance?
