the Scarlet Letters

Great looking armature!! Your skills as an armature machinists are getting along fantastically! Keep up the great work!

:)

the sumo pose is anerable!

Well-done Sven, good progress. I see a big improvement in craftsmanship.

Drift is a nasty troubling problem. It can be caused by lots of things but one common cause is the misalignment of the ball seats on a set of sandwich plates.

Now you see the beauty of LIO's thru hole method and drilling the plates stacked - Amazingly simple and effective.

Of course the step block will eliminate the misalignment problem because the non step half of the sandwich is free to move a bit and will naturally align with the ball.

Don't you just love those scotch bright deburring wheels?

Good progress I like how you did the jointed ball on the foot, and that ankle joint is holding a pretty serious lean!

super ultra Powerfull Sven!!!

Chris, gl., Mark, Justin -- thank you!

@Chris: So glad to see you here! I didn't know you were reading... Welcome!

@Mark: I feel pretty confident about the alignment of the holes... I hope that's not the issue.

(Plus, with the play that the screws' through-holes allow, I would think that there's some self-centering action going on -- except for on the joints with 3 balls.)

My thinking at this point is that it has to do with bottom point of the socket -- perhaps this is a problem with the shape of the ball-nosed end mill?

I've seen sockets that have a small hole cut into the bottom of their cup... Maybe this corrects for the shape of the cutter?

Even if it doesn't, I figure drilling a hole there will give you a hybrid socket/open-hole joint that ought to have the best of both worlds. Must do some tests...

Nice! Sleek and streamlined, like a Porsche compared to the Buick that is the man of Steel. A shame about the drift problem. That's the price you pay for stepping up to the next level of craftsmanship..... as LIO and Trikfx are so fond of saying, the actual fully machined BS joints are so much more finnicky than open holes. The slightest offset in tolerance and you've got problems.

Now you're at a point where you have to decide..... keep going forward and hope to gain enough skill to defeat the problem, or step back to the open hole system for its durable simplicity. I know what my choice would be (and I suspect you do too). But it sounds like you have something in mind with the step block system.

Are you aware that often B&S armatures are lubricated with grease? maybe that would help eliminate drifting? I'm sure Mark could tell you a lot more about it that I ever could though.... you're way outside of my range of knowledge here.

Hey Mike --

I suspect what's going to happen with me is this: On the one hand, I'll keep working on more sophisticated, professional-like armatures -- and on the other hand, I'll start putting open-hole armatures inside of puppets.

My sense is that when a particular armature design no longer feels challenging to me -- when it becomes a hum-drum matter to whip one up -- that's when I'll begin feeling comfortable burying the metal in foam. Open-hole joint armatures are almost at that point now...

I had heard about using grease in B&S armatures -- but somehow I thought there was controversy around the practice... Like, on the one hand using grease will make the motion smoother -- but on the other, it makes it more difficult for a joint to hold a pose. Do you recall ever having seen this discussion?