I have also learned not to trust pictures or meseums. I have went to a few museum's and looked at their collections of armor and suprisingly found suits assembled incorrectly. I have never been sure if this was because they thought that is how it was worn or if it was a mistake- but as assembled it would not have been servicable, maybe it was the limits of the mount it was held on. But it does go to show that you have to be careful.
In armor I wourk primarilly from one reference -Techniques of Medieval Armour Reproduction: The 14th Century, althogh I make my own patterns and will borrow from any period or completly make them from my imagination- not dissimular to how actual armorers worked. There are also parts that I choose not to make at all and rather source them- again not uncommon even back in the 14th century.
The story of that was for archer knees, I forged out a pair of gothic cops, they still hang im my workshop in fact, then the lames. I got very frustrated in this as I could not get the movement and clearences to work properly, with a shy of 1/8" draft between the pieces I could only get a 30% to maybe 40% deflection- ok for stolling but not good for say, sitting, kneeling or so forth where near 90 is needed. So I chucked them across the workshop in frustration. After cooling down I thought about it and ordered a set from another smith. When I got them- they were very nice and combat weight- I laughed. Not only was he using very loose "floating rivets" but his draf was nearly 3/4"- no wonder I was only getting 30%.
Lesson: I was way to hard on myself, I am an engineer and accustom to working with tight tolerences and machined parts, so like a mechanic I look at everything as it should fit just right, not slop about. Funny thing is (and before we get back into this again yes I know this is an observation not any rule), slop was actually part of the designs- it allowed armor to move quickly with the body.
I was so keen on the specifications of high gothic armor- which is very tight and works of art in many senses of the word, that I just jumped into it. The designs I was replication were made by masters, with decades of experience, specific tools, forms and assistance we just don't have, so if your forging something out remember, in many ways armor making and black smithing are nearly lost arts and your ressurecting that trade, likly from reading books not from learning from a master (which I would love to do). Don't be to hard on yourself.
So I mentioned tools and forms, stragely Armoring will require you to make many of your own tools, to be sure you can buy tools but they may not be quite right. I started with a selection of ball-pein hammers, as many autobody hammers as I could find, pieces of flat steel stock, some angle iron, a few stumps, and my nice set of wood chisles.
Why chisles and gouges if you can find them? Well you will need to carve out a few dishes, and you will need to almost continually make forms that serve as moulds for more complex parts. I catually made a backplate mould to help get the spine fitting and shoulderblade cups, it works great (ok it smokes a bit when you drop hot plate onto it) but it makes creating the complex curves much quicker.
As a side note, an commercial armorer made a pair of greeves that were heavilly fluted (a process I love but very time consuming on an anvil) he pressed these out with a large press and a form, my guess would be a 50T+ press, but the results are breathtaking. Fuctionally I would feel bad for an SCA opponent with these- the fluts make the armor very rigid, and since the primary weapon material is cane- the raised ribs of the flutes in this case are rather sharp and would cause some weapon damage if struck hard. Beautiful work though. I estimate that to hand forge them out would take maybe 100 or so hours without a proper form. This could be ton with a lighter press if the material is heated- the form would be betst to be milled from steel though. This would be fairlt small for our practical shop- a top "setter" the "male" point that would sink the material and a bottom "cup" the "female" side that you press into- both dully v shaped- maybe stock being 1"wx2"dx2"h, this would require many, many pressing cycles but could be used for many things, the less deep the form, the more it could be used on curved parts so for me, I may look at making one around 1"wx3/4"dx3"h...pondering this now.
