Dusting off the cobwebs

[Andrew Bodley]

Extracted has the same set up I have. Except mine doesn't have the ear muffs, still trying to justify getting some. Though I do wear a pair underneath. I used to have a light weight grinding visor. More comfortable to wear for extended length of time, but your neck gets dirtier.
I have with these with beard and clean shaven with no issues. Just getting used to having to wear glasses. It's more fiddley getting the face mask down over the glasses without being knocked out of alignment.
If I was starting from scratch if definatley look at the versaflo system. As it's a newer system so should be able to get parts for longer.
Andrew

[J. Hillard]

God, this thread is amazing. So much knowledge in a few pages. Ever think of giving classes mac ?

Either way, beautiful work!

[Mac]

Well.... the fluting on the knee wings has been a right pain in the ass to grind, but I think I finally have them under control.



I got a lot of mileage out of this arrangement here. That's a 2" wavy edged disc. They conform well enough to get the grinder marks out of the tight spots.



Getting the 2" pad on my machine took this gismo here.



I sketched it up in my notebook, was all set to turn it on the late. While I was looking for commercially available collets, I came across an image of exactly what I had sketched out! http://www.flapperadapter.com/ The nice man took my $40, and I had my adapter in a couple of days. That's a lot cheaper than the time I would have spent on it, but not as much fun. I did end up making a wrench for it, though. (visible in the dust collector) I should have just bought one, but could not find one cheap enough on line.

Returning to the question of collets, I saw that the one in the adapter looked like the most typical one that gets sold for air powered die grinders. I took a gamble and ordered a 1/8" collet from an Ebay vendor, and that payed off. Now I can spin tools with either a 1/4" or 1/8" shank.



The plan calls for deep notches between the pivots and the wing. I left the transition nice and round up to this point so that it would not fail in the raising, or crack in the quench. It's also been convenient to not have a sharp point or a notch there for the sanding operations, but now it's time to deal.



The bulk of the material came out with a Dremel tool and a cutoff wheel. This had to happen with calm nerves and concentration because of the risk to the nearly finished parts. A slip of the cutoff wheel at this point would be very difficult to fix.



They are all cleaned up and ready for the final polishing.



I am torn about how sharp to make the notches. They look very deep and sharp on the statue. There are extant examples with sharp notches as well.... but my sense of structural propriety makes me want to leave them a bit round to avoid stress concentrations. I have to think about this one.

Mac

[Mac]

Ever think of giving classes max ?

That's sort of what I'm doing now. You're auditing, I believe.

Mac

[J. Hillard]

Crap, just realizing I could be taking notes as I read

Looks like I'll have to read through this thread for the 3rd time

[Mac]

I should have done this next step before earlier in the process, but I forgot it in my enthusiasm. The pivots of the knee are going to be sliders, and the holes in the underlaping plates must be extended into slots. The slots must be set an an angle that will keep allow the articulated joint its usual range of motion without risk of popping. To do that, we first establish the width of the underlaps by flexing the joint and marking them with a sharpy pen.



Then, we remove one of the temporary pivot sceews and let that side telescope a bit while maintaining the same overall flex. The location of this extreme end of the slot-to-be is marked with the pen.



This one is a bit short, but you get the idea.



You can see where I "fudged" the placement a bit before punching the hole. Once we have the two ends of the slot punched, we center punch a location in between.....



...and punch that as well.



The waste points are filed out with a half-round needle file, but I didn't take a pic of that. (next time)



For the moment, I only slotting the upper articulations. I am not sure if I will do the lower ones or not. Can anyone link to any pics that show conclusively whether or not the lower pivots of Gothic knees are slotted? Thanks!

Mac

[Tom B.]

Here you go

Here is photo of A62's left leg, showing some square end slots peaking out and one oddly shaped rounded one.


Also looks like they are in Goll 2884

Here they can be seen in the mate to the one above

This one is Goll #2412 (click on photo for slightly larger version)

[Mac]

Thank you, Tom!


Pursuant to that, I have put slots in the lower articulations as well. They are a bit shorter than the ones I put in the uppers. When the knees are temporarily assembled, there is a pretty significant amount of motion available .



The metal tabs on the crotch lames of the cuisses have served their purpose now, and can be cut off. You will recall that they were there to stabilize the parts during construction and heat treating.



A quick slice with the Dremel cutoff wheel....



A little grinding...



....and a bevel on the inside.



Mac

[Tom B.]

Your are welcome.
Here is one of the legs I posted above showing the same range of motion exercise you did.

Mac

[Ernst]

On foot vs. in the saddle knee flexion?

[Mac]

On foot vs. in the saddle knee flexion?

I have to admit that I really don't know what the true benefits might be of this feature. It's only rather recently that enough good pictures have come to be available that we can see that sliders are common in knee armor.

It's not really a motion that the human knee has. On the other hand, when the leg armor extends up above the hip joint, there are forces trying to deflect the top of the cuisse, and that may well be accommodated by a varus or valgus deflection through the knee armor. It may also tend to accommodate misalignment in the way the armor is worn. In any event, it can not help but be more comfortable to wear.

Mac

[Rene K.]

Sliding rivets and slotts are very important at knee articulations. Without them it is hard to move the legs comfortably in any direction. Also your leg is not just straight. In the knee you have a step point to the shin. While bend the knee, this step disappears and the leg is straight in his angle. Thats what i observed over the years.
I noticed this sliding articulation on all legs i handled and have seen on pictures.

[Sean Powell]

On foot vs. in the saddle knee flexion?

I have to admit that I really don't know what the true benefits might be of this feature. It's only rather recently that enough good pictures have come to be available that we can see that sliders are common in knee armor.

It's not really a motion that the human knee has. On the other hand, when the leg armor extends up above the hip joint, there are forces trying to deflect the top of the cuisse, and that may well be accommodated by a varus or valgus deflection through the knee armor. It may also tend to accommodate misalignment in the way the armor is worn. In any event, it can not help but be more comfortable to wear.

Mac

I would speculate that if the leg armor becomes malrotated that a small amount of flex in the non primary axis will allow full range of motion. If you flex the knee to 90 degrees and then pronate/supinate the cuise it should rotate the knee and demi-greave in the same direction like a universal joint rather than 'swipe' the demi-greave around like a windshield wiper. I can't think of why this motion would be necessary but it may make it a little more comfortable and doesn't seem to detract from safety or protection.

Sean

[Mac]

Sliding rivets and slotts are very important at knee articulations. Without them it is hard to move the legs comfortably in any direction. Also your leg is not just straight. In the knee you have a step point to the shin. While bend the knee, this step disappears and the leg is straight in his angle. Thats what i observed over the years.
I noticed this sliding articulation on all legs i handled and have seen on pictures.

Rene,
How much motion do you find you need? I think that the cuisse that Tom showed pics of has more motion than what I have just made. Would you make the slots longer?

Mac

[Mac]

I would speculate that if the leg armor becomes malrotated that a small amount of flex in the non primary axis will allow full range of motion. If you flex the knee to 90 degrees and then pronate/supinate the cuise it should rotate the knee and demi-greave in the same direction like a universal joint rather than 'swipe' the demi-greave around like a windshield wiper. I can't think of why this motion would be necessary but it may make it a little more comfortable and doesn't seem to detract from safety or protection.

Sean

The thing about dealing with various misalignment is pretty compelling. It would be nice to play with this a bit, but this armor is way to big for me to wear.

Sometimes I regret no longer having an excuse to make armor for myself.

Mac

[Tom B.]

I would speculate that if the leg armor becomes malrotated that a small amount of flex in the non primary axis will allow full range of motion. If you flex the knee to 90 degrees and then pronate/supinate the cuise it should rotate the knee and demi-greave in the same direction like a universal joint rather than 'swipe' the demi-greave around like a windshield wiper. I can't think of why this motion would be necessary but it may make it a little more comfortable and doesn't seem to detract from safety or protection.

Sean

The thing about dealing with various misalignment is pretty compelling. It would be nice to play with this a bit, but this armor is way to big for me to wear.

Sometimes I regret no longer having an excuse to make armor for myself.

Mac

I am very tempted to go back and add slots on my current leg harness.
There already are many projects on my plate but I might have to add this to my winter harness improvement list.

[Gregoire de Lyon]

Hi Mac-

You seem to get a lot of mileage from your Dremel cutoff wheels. Can you show us a picture of what you are using, exactly? Most of the Dremel pieces I've tried seem to die a rapid and costly death...

Thanks!

[Mac]

That's dremel 409 cutoff discs....



... mounted on a 401 mandrel (or equivalent).



The beauty of the 409 is that it is thin and cheep. Yes, you have to be careful or they will break and send bits everywhere, but they are cheep to replace when that happens.

Beware the new and improved discs.....! The 420s are thicker and stronger, but they don't last any longer because they have to cut a wider kerf. Meanwhile they are more expensive per piece. The 426s are stronger and thicker yet, with the same sorts of drawbacks. They might be useful for something, but I have not discovered what.



The best thing about the 409s is that you can stack three of them on one arbor...



...and get a thing that works like an 8215...



...but it only costs about $0.45 to replace it, rather than $5.00.

I usually keep a couple of these in different states of decay, and use the one that suits the task.



When the discs get too small, they end up in the bone yard. Sometimes you need a little one for something, but I have to admit that they mostly just pile up there till I throw them away.



Mac

[Signo]

The thing about dealing with various misalignment is pretty compelling. It would be nice to play with this a bit, but this armor is way to big for me to wear.

Sometimes I regret no longer having an excuse to make armor for myself.

Mac

I think the need is easily explained : those kind of legs raise very high to the wearer's waist, to I suppose, their upper lacing point is pretty much fixed regarding its position relative to the waist bone, with a straight leg, the rotation of the foot, seen from the top , from left to right, will induce a torsion of the whole leg harness, those slot at the knee make things comform better to the body during any movement. Earlier leg harness, being shorter in the cuisse, will probably had more play in respect of the waistbone, so, they could stay in place without sliding rivets.

[Gregoire de Lyon]

Thanks! Helpful as always!

[wcallen]

Wouldn't it be fun if we could have a study of what articulations have slots and which don't?
I generally get to play with later legs (and that not very often), which don't seem to have slots. They are generally a lot shorter.

Wade

[Rene K.]

@mac: i make slots in all parts of the knee articulation. It does not makes the knee less solid, but gives you a high comfort in movement. The movement in genuine legs is often different, from "unwalkable" to absolute mobility. It's right, larter legs are more and more simple and have often no slidingrivets.

I added a scetch with the middle lines of the straight leg, whis the knee articulation should follow. While bend the knee, the line become a straight one and the poleyn gets in position.

[Sean Powell]

Another contributor might be the bicondylar angle between tibia and femur. The bone angle is not the central anatomic axis of the limb with muscle but it may contribute.

http://boneandjoint.org.uk/sites/defaul ... %201_3.jpg

[Mac]

Another contributor might be the bicondylar angle between tibia and femur. The bone angle is not the central anatomic axis of the limb with muscle but it may contribute.

http://boneandjoint.org.uk/sites/defaul ... %201_3.jpg

If you are building bespoke armor, that angle can be incorporated into the joint without need of slots. On the other hand, if you are building cuisses as an "off the peg" thing, the slots will allow the joint to accomodate a wider range of potential wearers.

Mac

[Mac]

One of the Great Mysteries of Armor is the question of how they made the lines that outline Maximillian flutes and define the "valleys" on armor. These are usually described as "engraved", but that's misleading. If we define engraving as a process that makes a line by removing metal with a graver or burin, we can readily see that this is not how armorers did it. The line qualities are different, and the mistakes are different. Anyone who has looked closely at real armor and has used a graver of any sort to try to produce these lines knows this.

With this armor, I once again find that I need incised (I prefer that word to engraved in this context) lines, and don't have a process that really does the trick. The reflexed crest and the "lips" on the knee cops would look better if they had lines as shown here in red pen.



Yesterday's experimentation involved an 8" cutoff wheel, stiffened by a pair of MDF flanges, and run at about 600 RPMs.



I true up the working edge with a multi-point diamond dresser every time I remount the wheel. The edge is dressed to be slightly round.



So.. Where do I get off using a modern cutoff wheel to try to simulate a Renaissance technology? My presumption is that those guys could have been using metallic laps, charged with grit. It's certainly what gem engravers did, albeit on a smaller scale. Breaking the problem down into smaller bites, I reckoned that one abrasive process can sub in for another, and I might as well start with a readily available and cheap tool. If that works, I can move on to trying to make a suitable lap.

Well....

On practice pieces, I can make some pretty convincing lines...



...but the technique is not without its problems. Curved lines present difficulties. The cut ends up a bit wide and ill defined. Worse, though, is the tendency for the disc to slip out of the cut and walk sideways.



I am sure that with enough practice, one could come to be pretty good at this, and avoid much of the trouble. The fact remains, however that the basic quality of the mistake is not like the authentic ones. When real lines "break", the tracks do not smear like this.

I may or may not push ahead with this technology for this project. If I use it, I will have to spend a lot of time on practice pieces before risking it on the armor.

The alternative is to try the same sort of thing with a sort of rotary file or saw. The problem here is finding a suitable blade. It has to be pretty hard, and have fine teeth. The blades for "cold saws" look promising, but they are coarser than I would hope. They are also rather expensive for an experiment.

Mac

[Rene K.]

@mac: thats right, but i allways thoght a bit more movement wouldn't be wrong.

[Signo]

Could they have used a chisel to cut little straight cuts, and then used a file to "join the dots" ? Something like - - - - - - that become ------------ once filed? Never looked at the problem in great detail, but I always thought about chiseled lines.

[Rene K.]

The mystery about that lines !
While making the last gauntlets i was trying to find out the technics they used on genuine parts once again. I was nearby to start a threat about it.
On genuine examples i have seen both types, chiseled and cutted. The best result i had now with using the edge of a small handsaw. But for the flutings on the kneewings i think a riffler file will do a good job.
A problem was to get the start on the polished surface without scraching ofer the metal.
You can have a look here: https://www.pinterest.com/kohlstruck/gothic-gauntlets/

[Rene K.]

a good source is to have a look at heavily rastaurated and grinded pieces, where the ground of the line is comming out.
I was thinking a slow speed metaldisk can be used for the most work, like a stone- or glas-engraver use it.

Chiseling will also do a good job, but you need a helper that holds the parts. Without it is a wobbly work.

[Rene K.]

@mac: most gothic parts only have the lines on one side of the fluting, mostliy on the outside of the curve to give them a looking like a step. Double lines are common with maximilian style flutings. Thats my experience.

[Otto von Teich]

Could they have used a chisel to cut little straight cuts, and then used a file to "join the dots" ? Something like - - - - - - that become ------------ once filed? Never looked at the problem in great detail, but I always thought about chiseled lines.

I would think a small chisel might to the job. tedious but should be workable I'd think.

[Tom B.]

At Wade's last armour study session Mark Berry (Clang Armoury) had some examples he made.
They looked pretty good, maybe I can get him to chime in.

Here are some real examples:

Two 16th century breastplates from Wades collection



Some of the most interesting marks I think are the marks at the flutes near the point of gauntlet cuffs.
Often the converging lines cross instead of just meeting.

Here is from Wade's collection, a 16th century gauntlet cuff


KHM A60


KHM A79

[Tom B.]

A couple of years ago at Wade's we took some photos with a microscope.
The first couple of images are of the same breastplates in my previous post.
Some are better than others.

[Mac]

Could they have used a chisel to cut little straight cuts, and then used a file to "join the dots" ? Something like - - - - - - that become ------------ once filed? Never looked at the problem in great detail, but I always thought about chiseled lines.

The thing about using a chisel is that the work has to be solidly backed under every cut. This will work for "valleys", much better than it will work for flutes.

I have seen a line around the wrist of a vambrace that was almost certainly was done with a chisel. You could even see the "bruise" on the back side from where it was supported.

Mac

[Rene K.]

Wi wonder why the allway cross the lines at pointy angles. That could be the result of using a wheel to get the lines right to the point of the edge. With a file or an chisel it would be easy to stop at that end.

Lets start this threat on a extra discussion to let mac show his work her