Spring OD Expansion Measurement and Calculation

[weisusu]

How you would measure compressed spring outer diameter? The spring free length is 0.150". OD at free length is 0.120". Wire diameter is 0.060". ID is 0.100". Material is stainless steel. I would like to compress the spring at 0.050" and measure the OD expansion. What would be an accurate way to measure the OD at compressed state? Is there an equation that I can use to calculate the OD expansion?

 

[israelkk]

This is a double post to your post on the GD&T forum. It is better to ask the moderator to move the posts in the GD&T to this post and delete this new post.

 

[israelkk]

Sorry this is a new spring. However, as I said in the other forum you need to get Wahl's book if you want expansion in other deflections than to deflection to solid length. The common software in the market calculate the maximum expansion when the spring is compressed to solid length and not in between.

 

[unclesyd]

You should talk to Keyence about your problem of measuring the OD of the spring either with a laser micrometer or displacement meter. You can have the data plotted out as the spring moves. You can take your data and run it in Table Curve and get you an approximate equation.

http://www.keyence.com/products/vision/micrometer/micrometer.php?id=1af12e2f9250cad37a9dd53215bfeff9

http://www.download.com/TableCurve-2D/3000-2053_4-10308067.html