Angle through Knee Articulation

[Indianer]

Hello guys,

I'm back at knees. It has been established that a leg is not straight, and leg armor needs to follow that curve.

I have been looking at originals for hours. I need someone to help me see..

° I see top lames freuently sticking out farther than bottom ones, those could be completely hidden while the top ones show ~1 inch of metal.
° I see the topmost lame being installed in a slanted position, at a slight angle to the axis down the cuisse.
° I see the second lame (where present) and the cop frequently continuing the slanted-to-axis trend.
° I do not really see, but someone stated, cops may taper to distal.

Now...I think there is something else going on with the cops. Something I can not put my finger on... some of them seem to be distorted. Not symmetrical. Like when the left and right edge were laid out straight down, the center crease would still run top-bottom towards the wing. And this is posing a great affront to my 3D imagination...which is nil. Still, manages to be offended.

I'd be grateful for some input here. I really don't understand what it is I seem to see.

[Mac]

Hello guys,

I'm back at knees. It has been established that a leg is not straight, and leg armor needs to follow that curve.

It's true. Legs are not straight. If the armor is to fit closely, it must follow the shape of the leg through the knee joint.

I have been looking at originals for hours.

More people should do this!

° I see top lames freuently sticking out farther than bottom ones, those could be completely hidden while the top ones show ~1 inch of metal.

This is about perspective and the camera position. Most images are taken from above the knee. This makes the upper lames more visible than the lower ones.

° I see the topmost lame being installed in a slanted position, at a slight angle to the axis down the cuisse.

I think of it more in terms of the cuisses being installed with a slight angle to the knee. That amounts to the same thing, but I like to start with the knees and then make the cuisses fit them.

° I see the second lame (where present) and the cop frequently continuing the slanted-to-axis trend.

If the knee is to be closely fitted, the entire assembly needs to be slightly convex on the medial side and slightly concave on the lateral side. In practice, that lateral concavity is seldom enough to overcome the overlaping nature of the assembly, and ends up being more or less straight.

° I do not really see, but someone stated, cops may taper to distal.

Some cops seem to be narrower at the distal end than at the proximal end. Even if the cop itself is not tapered this way, the entire assembly of lames has that effect.

Mac

[Mac]

I've sketched some lines on that leg from Curtatone di Mantova. The profiles that are slightly concave are in blue. The profiles that are slightly convex are in red. The lines that are fundamentally straight are in black. These knees are just about as "curvy" as they come. Most are somewhat straighter. An important thing to consider is that some knees employ sliding rivets, rather than building the curves in.



Mac

[Gordon Thompson]

Yes, sliding rivets... When I started to build gothic legs, I assumed that sliding rivets are helping to arrange cop and lames to follow leg curves in a knee area.

[Indianer]

Now...I think there is something else going on with the cops. Something I can not put my finger on... some of them seem to be distorted. Not symmetrical. Like when the left and right edge were laid out straight down, the center crease would still run top-bottom towards the wing. And this is posing a great affront to my 3D imagination...which is nil. Still, manages to be offended.

I think I found it. On some examples the top-wingside scalloping (or cutout) of the cop appears to be deeper, which is how they got the lames and poleyn as a whole to look straight.

Where that is not done, and upon closer inspection the cop appears symmetrical, the assembly as a whole just doesn't look right. Or is that just me?

[Sean M]

Derek Guy the men's tailoring social media person has said that good tailored wool pants are often worked with steam and an iron to help follow these curves.

[Indianer]

° I see the second lame (where present) and the cop frequently continuing the slanted-to-axis trend.

If the knee is to be closely fitted, the entire assembly needs to be slightly convex on the medial side and slightly concave on the lateral side.

Installing lames in a slanted position has the effect of a narrower pivot spacing on the lateral side. It's not magic... Install the lame slanted, spacing is off. All those years I tried to wrap my head around it the wrong way, starting from the pivot distance, not the lame. Anyway, there was discussion on it:

From Designing a knee, trying to get it right:

I looked at my notes on the 'Sigmund gothic', and was surprised to see that the spacings are identical. This can be done because of all the sliding rivets in the poleyn (another great benefit is that the rivets can all be put in nice straight rows when the leg is straight, unlike Italian leg harness).

I looked at Golls Gothic and his Italian knees now. I can not see what he means. Can anyone clarify?

[Indianer]

Mac, I got to watching your presentation here - at 20:50 what you are saying is, upper knee lames should grip the belly of the Vastus medialis – they get a slight dish across the medial edge. Did I interpret that right?
->

Much obliged!

[Kristoffer]

I am jumping in with some hopefully helpful input here.

To make things easier when designing leg articulation you can think of the knee assembly, the cop and lames, as symmetrical on both sides as the "default". To accommodate the "S" curve in the leg, you can tilt the connection between the cuisse and upper knee, and the connection between the greave and the lower knee. If more curve is needed, you can add some tilt on the lames of the knee as well. On gothic knees in particular, this can be done using sliding rivets since the "slop" of the sliding rivets will deal with any curve the knee feels like it needs. Other types of knees that does not have sliders might have to have different spacing between rivets on the two sides to allow the whole assembly to have enough curve and look good.