Hi everyone. I am attempting to design a harmonically oscillating piston cylinder device and I need to incorporate some mechanical springs. To ensure the device works the way I want it too the relaxed length of the spring needs to be in the middle of the piston stroke. This means the spring needs to be able to both compress and extend with an attachment mechanisms that will also allow this. My question is regarding the spring type, will a standard compression spring work for this application? They seem to fall within my force rate range but do not seem to be able to be attached easily to be extended. I am looking for a relatively quick solution, so any type of custom spring (e.g. stamped) won't do. Also, does anyone know of some standard attachment designs for these types of springs? The total stroke of the device is 1''(2.54 cm) so the spring will need to be able to compress and extend half of that distance each way. I also need a deflection rate to be near 191 lbf/in (32 N/mm). Any help would be appreciated, thanks.