Vitamins
If using threaded pins
5 M5 x 16
1 M5 x 12 ( or 6 M5 x 12)
3 M5 x 45
1 M5 x 35
4 M5 nylock
If using through pins
5 M5 x 45
2 M5 x 35
7 M5 nylock
Also
1 M10 threaded bar x 200 mm
7 M10 nuts
2 M10 washers
Instructions
Print the parts in the orientation shown. Most parts at standard settings, the arms I print at 60% infill.
Clean up and ensure the pivots rotate cleanly in the sockets
Make sure any threaded parts work well
Fix one end of the M10 threaded bar to the short pivot using 4 M10 nuts and the two washers making sure it can spin freely
Put a M10 nut into the long pivot (if not using the threaded option) and wind the long pivot along about half way
Attach the handle spinner to the handle making sure the spinner can spin freely
Attach the handle to the other end of the threaded bar using two M10 nuts
Now assemble the short arm (apart from the through pin) using the short jaw, M5 x 35, nylock and M5 x 16, M5 x 12 if using the threaded pin. Making sure the short pivot can rotate freely.
Lastly assembly the long arm around the short arm using the long jaw, M5 x 45, mylock, and M5 x 20
Enjoy
Notes
I did do a version using M8 threaded bar but the movement was too slow. Printed in PLA which means the jaws are slippy, I may try gluing a bit of rubber to one side to help grip things.
Also, banana for scale, but it's a big banana. Also I would make the stls in the right orientation if I knew how in Fusion 360.
Yes, I don't have M5 x 35 in stock, and I don't want to cut down an M5 x 45, they're on order.
A quick test on my bathroom scales showed clamping force over 35kg