Only spyder threaded ones would work
From the pictures it doesn't look like you would need an elbow at all. The hopper should fit directly into the feed neck.
As long as the hopper has the standard .68 attachment and the marker also has the standard .68 feeder elbow. So if the hopper fits on the marker your good to go.
The solvent for permanent marker is denatured alcohol (hardware store). But it will also require plenty of elbow grease.
The Sandbox Muscle Area.
the elbow
The "elbow" (can't remember the true name) is at the top back of the front leg where the leg connects to the shoulder.
Acetone! And elbow grease. It is the only thing that worked when my son & the neighbor kids colored on my front porch.
A balding girth is used to prevent the saddle from sliding and rubbing the horse, it can also be used to give the horse more movement at the elbow.
i have seen a few made with a fire extinguisher and some PVC, but they should never be used in a game since there is no way to regulate how fast the paintball comes out of the barrel, as to how they make them, search around for pictures, all you really need is the PVC, some fittings and elbow grease
Most elbows should twist on the regulator. If it does not, your best bet would be to weld it on, or send it back to the manufacture. Luckily though elbows are meant to be replaced after some time so the task should be manageable.
right elbow and left elbow
your elbow