Why, this one of course, shown here in a side by side with its plasma cannon self. The missile launcher is from the Dark Angels Ravenwing accessory sprue. The plasma cannon is the one from the Space Marines Devastator box. I had planned for these conversions before the new sentinel box came out, but only recently fount time to make it. The missile launcher was a fairly straight forward conversion, the most difficult parts being where to cut the missile pod arm and drilling for the magnets. The plasma cannon arm was a bit more challenging.
The basic bitz are from the SM Devastator set. The cabling just wasn't going to work for this conversion, as it was designed to curve around a SM torso. So they and the arm were removed. Finding the replacement cable was easy, as I had leftovers from a long completed electrical project. While the thinner red wire was good to go, making the blue into articulated cabling required more effort. I needed to cut roughly equal lengths in the wire's outer insulation without pushing the insulation off the end, and avoid cutting the inner copper wire. Easy enough to do, but a bit time consuming. The nice thing about doing it this way was, once spaced, friction pretty much kept the insulation pieces in place, even after some rough handling.
Cutting to length was the next challenge. I attached the magnets first, in order to free up my hands for fitting the wire. Once I had the desired wire length, I drilled holes in the power pack and the cannon's front receptacle, stripped a short bit of insulation from the end of the wires, added a bit of glue, and inserted the wire center into the drilled holes, much like pinning. After the glue dried, I bent the wire until I was happy with how it looked. It's rigid enough to hold its shape when the plasma cannon is being attached or removed from the Sentinel. Just to be sure, I added some super glue to help with that. In hindsight, I would have spread the gap a bit wider to better show off the wire core.
Though using a plasma cannon from the new Sentinel kit would probably have been much easier, I'm happy with the results of this conversion. Always nice to know there’s different options.