Ithorian: Miscellaneous improvements

 This would have been a great reference shot if it were bigger. Still, it gives a good sense of proportion and another view of the hands & feet

This would have been a great reference shot if it were bigger. Still, it gives a good sense of proportion and another view of the hands & feet

During my head movement tests, I found that the side to side axis (the azimuth movement) was binding. I stopped by the hardware store to find a bearing, but nothing was appropriate. So, time to build my own.

I found this patio door roller with bearings that's the perfect size. Add in a couple of flat end caps that fit the PVC bones of the neck, and I'm ready to put together a smoother joint.

Drill and countersink the outer ring which will screw into the larger end cap

End cap gets pilot holes and a large clearance hole for the inner ring. Rough the surface for epoxy

The final set of parts for the joint. A clearance hole for the bolt has been drilled into the smaller end cap

I decided to epoxy the outer ring to the large end cap for additional support

Apply epoxy just to the edges, not the bearing

Screws and epoxy should hold these two securely 

The smaller end cap will be bolted to the inner bearing ring

The fender washer adds support to the assembled joint with very little friction

A short section of PVC connects the new azimuth joint (left /right rotation) to the elevation joint made by the PVC x joint (up/down rotation).

I'd been having some problems with the springs and the S connectors slipping off when moving to the limits of motion. I decided to add some washers to the bolts holding the springs, and crimp down the openings on the S connectors.

Washer added to the bolt and the loop on the spring crushed down smaller

The S connector openings were crushed smaller or completely closed onto their components

I also decided to glue together several of the PVC pieces that make up the neck to keep them from slipping and provide some additional support. Bring out the PVC adhesive!

A short section of PVC was glued to the large end cap of the new joint. Next, the pieces of the neck are laid out to be glues

The PVC glued is applied to each end of the tube and then then pressed into the joint. Keeping the joints flat on the table insured they were aligned properly.

The neck and new joint are installed back onto the base structure along with all of the other improvements. You can see that the steering bar on the new joint is now higher, making the push rods and the horizontal support tube farther apart.

I put the costume back on to see how all of these little improvements affected the movement. It was much smoother and more "solid". By that I mean the springs didn't rattle around, but maintained a level of tension that kept the pieces firmly attached to the joints. However, the new joint raised the steering bar higher up from the base support, and that had the effect of reducing the range of motion, as well as making the horizontal part of the neck thicker. I'm pretty sure some lever arms added added between the steering bar and the cross piece at the end of the base structure would solve both problems, but I'll wait to tackle that improvement until the next time I work on this costume. I'll also try to illustrate the geometry of the mechanism a bit better so that it's clear how I can reduce the neck thickness and get a bigger range of motion mechanically.

 A profile shot to get a sense of the proportions. The hump covering my head is perfect relative to the eyes and the rest of the neck. However, the thickness of the horizontal part of the neck needs to be reduced. Plus, I now have to go outside to get a full body picture!

A profile shot to get a sense of the proportions. The hump covering my head is perfect relative to the eyes and the rest of the neck. However, the thickness of the horizontal part of the neck needs to be reduced. Plus, I now have to go outside to get a full body picture!

Today I received the silicone rubber I'll be using for eyelids and the overall skin coat. But, there's a lot more foam work to do, as well as the eye movement and blink actuators. I'll be taking a break on this cosplay until after San Diego Comic-Con in order to get things ready for that show.

Because, you know, it's COMIC-CON!