Articulation Question

[coreythompsonhm]

So the first thing I did after I cut out the lames for these arms was to dish them. Then I continued on like I always do, then noticed when I got the rerebrace attached, the joint will only flex slightly more than ninety degrees. Upon inspection, it appears that the lames have flattened quite a bit during the curling process.

So if you were in this situation, what would you do ?

I thought of taking a hammer to the inside of the lames on a flat surface, but not really sure what shape of a hammer to use on this.

Of course, there are pictures!


Malina's arms by coreythompsonhm, on Flickr


Malina's arms by coreythompsonhm, on Flickr

[wcallen]

It looks like that top articulation moves just fine.

Arm lames are pretty flat generally. Some seem completely flat, some seem mostly flat to me. They don't seem to have (generally) had the same design goals when making arms as legs.

I don't see a picture of the whole arm together, so I don't know what the whole thing does.

Mac talked about this at the Texas Hammerfest. The general goal is to get over 90 degrees of movement, but not really huge amounts. This is about what your arm really does when you are wearing the type of clothes that will be worn under armour.

Look at how much these bend:

http://www.allenantiques.com/A-186.html
http://www.allenantiques.com/A-27.html
http://www.allenantiques.com/A-171.html
http://www.allenantiques.com/A-172.html

Put the whole arm together, see how it compares.
Then make sure that the inner lames are the right size and shape to allow for the movement you have in the lames and not bash into the other part of the arm.

Generally then is the best time to make sure the wing is shaped correctly to fit with the rest of the arm. We talked about that too this weekend. I used my 16th c. arms as the example, but the idea is consistent for many arms. When the lames lock up, the wing should fit to the bent arm.

Wade

[Konstantin the Red]

Do just what you're thinking of: hammer on air, propping the lame on the flat anvil face, preferably using a soft-face mallet like the Garland Split Head, striking at the spot just above the spot the lame rests on the anvil on. The process also works to keep the side-to-side curvature right just by positioning the lame as needed to put that bend in too, so everything's accomplished in the same pass. Right now both the upper and lower edges of your lames are both going pretty much the same direction: they're like |. Where you need to end up of course is more like a flatter ).

You may need to have the rerebrace end curve in slightly also in a similar flattish curve but not a very extensive one, lest the end chafe -- and you can still bulge that end up before putting the curve in, so as to mesh with the lame. The idea is to put the lock-up spot a little farther along in the flex. Or you may need to go to a five-piece elbow -- even in the fourteenth they very often had five-piece elbows, two lames above and below, while knees stayed three-piece for some time. There's also no law against a four-piecer, two lames and one, to get those hundred thirty degrees of bend.

Third and last pic in the Malina series is a lame, correct? (Eventually we arrive at your green CdeB. Any luck there, btw?)

[wcallen]

All of the 14th c. arms I have seen with 3 lames use the last lame to form a rotator that lets the vambrace turn sideways, it doesn't articulate in the normal sense.

And you don't need more dish in the lame.

The main goal of dishing most arm lames is to get them "mostly flat" instead of "actually recurved" - a shear cut will cause the end to flair just a bit and even just curling it up will aggravate that. So flat lames aren't flat, they are flaired. Which is wrong.

So you could hit things on an anvil to dish it more, but I woudn't. Save that for a project that needs it.

Wade

[coreythompsonhm]

Sorry I didn't put the arm back together for the picture, I was in a time crunch to get out of the shop and start dinner so I just snapped a couple of pics of what was there.

Looking at your examples Wade, I'm not too particularly worried anymore; I have about the same range of motion as your first example. I might just assemble them again, temporarily strap them up and swing a sword around for a bit and see how they feel, as long as I can squeeze my arms into these.

I am using a three lame articulation with the last lame to be the rotator for the vambrace. I will probably add a slight curve into the rerebrace edge as Konstantin suggested, just to get a tad more motion like the originals.

Konstantin, that third picture was a in progress pic about half way through the raising process of the test couter. I also repatterned the two front panels on the cdeb and the body fits awesome now, just need to work on the arms and finally start on the real deal. (I just realized how little I actually post pics of anything I do, even on flickr)

[coreythompsonhm]

Btw Wade, I would really like to take a look at A-186 whenever I end up being able to make it to one of your discussions.

[wcallen]

A-186, the c. 1430 arm which was owned by Blair and (it appears) restored at the Tower.

Yes, well worth looking at. It is one of the few pieces I have that actually overlaps with the armour most people around here want to make.

Wade

[Pitbull Armory]

Hi, When I make a joint that I feel is too tight, I put it over a ball stake thats close to the same size or a little smaller than I need, and use a dead blow hammer to *settle all the lames together tap by tap,
This always gives the joint a little more range of motion, and makes the lames sit nicely. If you need more range of motion you could drill a little bigger holes on the inner lames to add more slop I guess, but I would just do what I mentioned first, if that dont work just make a few new lames.


Have a good weekend

Pb