1. fill the tube with low melt point alloy (cerrobend, Woods metal etc), bend as you would bend wire/rod, then boil tube to melt out alloy. Sometimes a rubber tube is handy to mouth-blow the last bits out. Do be very careful not to inhale or suck on the rubber tube- the metal is toxic (and hot if it has been in boiling water).

2. Find a close fitting steel spring that fits over the tubing. It may support it against kinks during bending well enough. In my experience for small diameters under say 1/4" this method sometimes does not work so well.

3. Make some wood or aluminum radiused formers for your vise and pull the tube around them. Formers for this method need to have oversized cheek pieces on both sides of the central radiused piece which in thickness should be only a few thou over the tube size to be bent. With the vise supporting the cheek pieces well I have had some succes with this method, but it gets tricky if there are bends in many different planes especially those close together.

4. Make a proper ME tube bender to one of the designs published over the years in the magazine.

Good luck. JD

I haven't tried it but came across the idea of plugging one end to fill and freeze full of ice before making the bend