How to create bicep rotation on a mannequin easily

[DennisFett1142]

Not sure where to drop this thread but since I've been working different approaches to creating bicep rotation in mannequin arms that don't possess it for the better part of two years and FINALLY have an approach I'm really happy with...I figured I'd share with the group.

First of all, this is specific to this type of mannequin and arm. This mannequin has great mobility except for the bicep rotation.

My first attempt at creating rotation involved large rubber gaskets and screws that made it really difficult to change the rotation...and impossible without taking the suit off. My second attempt was better, where I used PVC couplings and pipes to join the two pieces of the bicep together after I cut them in half. Oh yeah...you MUST cut the bicep in half. The challenge with that approach was that the PVC pipe only stayed for a bit and would loosen so I had to find the right rotation and then add duct tape around the bicep so it wouldn't break free. My third and I hope final attempt gives me the ability to rotate with the suit on and without fear of the two pieces breaking apart.

First, as I stated, you must cut the bicep in half at roughly the center point between the shoulder and elbow joint. Try to cut it at it's fattest point.

Next, get a male and female threaded PVC adapter in the correct size. For mine, the 2 inch version fit like a glove with just a touch of dremeling of excess fiberglass inside the arm.

Here are the male and female threaded couplings I used:

I attached the female coupling to the upper bicep and the male to the lower bicep so that the threaded part of each was exposed outside the cut joint:

It's important to line of the two pieces on the same area of the arm so that when joined it looks as natural as possible.

Here's what it looks like put together. It works really well and is really easy to adjust and holds that position really well. This eliminated the problem I had with my ESB where I had to remove the suit twice because the rotation wasn't quite right. This is for my Arena Fett so I'm excited to test it out when I get the remaining soft goods.

Oh yeah...here's a couple of pics of the helmet and armor from my WIP Arena Fett:

 

[Jango_fett_jr]

Very smart solution!

In case this is helpful to you or others, I picked up a few of these elbow joints to modify my completely static mannequin. You can add articulation to the elbow, and the screw slots allow you to rotate the bicep and forearm. I made a lot of other adjustments by cutting up limbs and screwing them back together with chunks of lumber, but those elbow joint allow me to fine-tune the arms as needed.

Spider Joint-SJ-1

www.spiderhillpropworks.com

 

[DennisFett1142]

@Jango_fett_jr That's awesome! Having a few of those joints in key places makes a static mannequin fully poseable! Those static mannequins are much more affordable. Where were you 8 Fetts ago?!?!

 

[Ord Mantell]

Excellent thread. Thanks Dennis. Not sure how I missed it this long.

Spider Joint-SJ-1

www.spiderhillpropworks.com

Are you able to adjust these Spider Hill joints with the suit on? Or do you have to have access to the bolt to tighten and untighten?

Another method is to use thick gauge wire at the elbow. This method also allows adjustments with the suit on, and can have full range of motion in bends and rotations.

 

[Jango_fett_jr]

Excellent thread. Thanks Dennis. Not sure how I missed it this long.

Are you able to adjust these Spider Hill joints with the suit on? Or do you have to have access to the bolt to tighten and untighten?

Another method is to use thick gauge wire at the elbow. This method also allows adjustments with the suit on, and can have full range of motion in bends and rotations.

You can’t adjust them once the suit is on. I locked them in place and then taped some foam around the elbow joints to bulk them up, then dressed him. So of course making adjustments requires undressing.

EDIT: They actually can be adjusted if you don't tighten the elbow nut all the way. From the product page: "They also now contain a set of fine locking teeth on the mating surface that give the joints the ability to lock and hold their position even under increased loads."
And the screws that go through the slots at the top and bottom can also be left loose so the elbow/forearm can be rotated.

I like the idea of using wire, I didn't think of that method because my Webley replica is aluminum, so I just assume any wire will eventually bend.

 

[DennisFett1142]

The irony of the situation is that my Arena Fett will likely require no bicep rotation and will have unnecessary joints underneath! I guess it is better to have it and not need it than to need it and not have it