The first item on our list was making the helmet open.



Figuring out how to make the helmet work was pretty tricky. We definitely wanted it to be wireless so it could be easily taken off but there's barely any room in the helmet for servos, let alone electronics. When Greg brought the helmet to me it had tracks already molded in the top for two small pivoting links that were attached to the top of the faceplate. The faceplate had two pivoting arms that allowed it to flip up and slide back. The first system I installed to motorize the helmet used two identical high voltage digital mini servos with a rod system that moved the faceplate and chin at the same time. As the servos pulled the rods the arms raised the faceplate and a second pivoting rod pushed the chin section open. While this system worked well it was eventually scrapped as it took up too much space around the sides of the helmet, especially in the temple area where the arm pivots were located.



Here's a video of the first helmet test. You can see the RFID reader and XBee radio on a breadboard test circuit at the beginning of the video-









The revised system works a bit different and is much simpler. I altered the original helmet system by changing it from a multi link/multi pivot system to a simple three pivot system. The arms that lifted the faceplate were removed as were their four pivots. The tracks in the top of the helmet were kept but the links had a tendency to bind as they pivoted so the links were reconstructed from scratch as fixed points and epoxied to the top of the helmet faceplate using ProPoxy 20 epoxy putty in a fixed position.



The servo mechanism was changed so one mini servo would open the faceplate while another would open the chin- that way the timing could be changed so the faceplate would open first and then the chin would open. When closing the helmet the chin would close first, then the faceplate. The faceplate servo has a brass arm that is silver soldered to a hinge that is fiberglassed into the top center section of the helmet. The brass plate that is soldered to the hinge tube is extended back a ways in order to support the helmet section as it would otherwise be too flexy to work properly. Both of the servos are attached to the helmet using high strength Velcro.



The chin servo was swapped out for a micro servo and it pushes a 4-40 threaded rod that opens the chin section- it's a pretty simple arrangement. Eventually the chin servo was relocated closer to the center of the chin section to make more room for one of the battery packs.

Here's the video of the revised helmet animatronics. Notice the removal of the arms needed to lift the faceplate-











On the electronics side, a split battery pack was constructed using six AAA NiMH cells for a total of 7.4V to power the high voltage digital servos. Originally we had planned on using LiPo packs but felt that NiMH cells would be a lot safer and less hassle in terms of battery management- see the FAQ section for more info. The two battery packs were wired up to an Arduino ProMini (3.3V version) along with a XBee radio. Power to the ProMini was stepped down to 5V using a Pololu DC/DC converter. The electronics were covered with heat shrink for protection. I use a Hitec X1 MF charger to charge the helmet battery packs.

A sealed push button power switch was added along with a transistor to turn on the LED lights for the eyes. The eyes were constructed using white SMT LEDs (any small LEDs will work) with milk jug material being used for the lenses. The lenses have a slit at the top so the wearer can see out and black foam sheet was used to block out the light on the inside of the helmet.

Finally all of the electronics were secured in the chin section of the helmet. Everything just barely fit in there without being able to be seen when the helmet is open. Overall we're very pleased with how the helmet turned out. It opens very quickly and we can change the speed of the servos along with the timing of the opening/closing sequence very easily.



So now the question is: "What if my helmet doesn't have tracks molded in the top of the helmet?"



If you have a Iron Man helmet from a kit or made it yourself using the pepakura method you can add molded tracks. Another friend of mine had a MkIV helmet he wanted to animate as a display piece. I used the same mechanical system as Greg's MkIII helmet but the MkIV didn't have tracks molded in the top of the helmet so I added them. The first thing I did was take a small round plastic rods and coat them with a thin layer of Vaseline- this is VERY important! The Vaseline acts as a mold release so you can remove the rods later. The rods were placed on the underside of the helmet where the tracks were to be located- it is important to get the tracks as parallel as possible or the links will bind as the faceplate opens.



Next I mixed up some ProPoxy 20 epoxy putty and built it up over the plastic rods. Once the epoxy putty cured I laid up some lightweight fiberglass cloth on top with some epoxy resin. The fiberglass cloth will reinforce the epoxy putty and make sure it doesn't debond from the underside of the helmet. Then I removed the plastic rods and cut the slots in the top of the helmet so the ball link guides could slide in the grooves. The slots in the top of the helmet must be narrower than the molded grooves so the ball link doesn't come out as the faceplate slides back.

I silver soldered the ball links that attach to the top of the faceplate but there is another, simpler option. You can buy nylon balls in all different sizes- drill a hole through the ball and attach it to one end of the "L" shaped rod by flattening the rod slightly (this will help hold the ball on the rod) and put a drop of superglue on it to secure it.

One thing I found really helpful was to attach my rods to the faceplate with superglue (use an accelerator spray- baking soda also works) and slide the faceplate back to make sure it has a smooth motion. Once you get the positioning right then use the epoxy putty to secure them.