How Do I Straighten These?

You will find that Hose and Soft Axle pieces will have permanent curves and bends. Used ones that you buy will probably have a bend to it. Nothing wrong with that unless you want one that is straight. What you are building you might want it curved but sometimes these pieces are bent in ways that they are probably useable. I did an experiment.

Both of these pieces fit in the holes of Technic bricks. I stacked a lot of those bricks together so I can slide them through the holes. Lined up over time the piece will straighten back up. I tried it and it does work but could take months and needs to be in kept in a warm area so they can straighten up. The soft axles some or more rigid than others. The softer ones worked great but the rigid ones will take longer.

The ribbed ones did a lot better. These are softer and were faster to stay that way. These ones took a couple of weeks to straighten. The soft axles can take months. So if you need or want to make these straight again, this does work.