Hinge Plates - Improved Manufacturing (Long Weekend Update Part 1)

In preparation for the next breast/back plates, I cut out some more brass for hinges.  These are a fair bit wider than some of the earlier ones - I think I will try to make these into carlisle-style hinges.  Anyways, I took a slightly different approach to making these hinges and it turned out much faster than the previously detailed method.  The finished plates also look better than my previous attempts, in part because the painter's tape in step#5 reduced the number of hammer marks left on the tube and plates.  Documented below is the "new and improved" hinge-making method.  I skipped pictures for most of these steps, since they are already documented in detail in the posts starting here. 

1. Measure & Cut brass plates and hinge pin.

2. Anneal middle of plates until literally red hot, then quench in water.  Ditto for the ends of the hinge pins.

3. Mark middle line on hinge plate and hand-fold it over.

4. Use a rubber mallet to further fold and flatten on a "soft" surface - I used a piece of firewood as my base.

 

At right - rubber mallet.  I bought this many years ago and I can't remember why.  Anyways, this weekend it finally proved its worth.  Much faster than the jeweller's pliers and better results, too.

 

5. Insert hinge pin, and apply painter's tape to help hold it in place.

6a. Use radiused head of brick hammer to finish flattening the plate, starting near the middle of the plate and working in towards the tube/pin.

6b. Use the brick hammer's wedge to finish forming the tube.  You will probably need to stop and flatten the hinge plate once or twice while doing this.  Pictures from the last thread.

7. Tap the top of the hinge tube gently to free the hinge pin.  If your hinge pin is already loose, you probably still have room to close the tube a bit more.

8. Lay _half_ the hinge plates on top of your paper guide and mark the slots for the tubes.  Do not mark the other half of the plates at this time.

9. Cut the tube slots on the marked plates. Make sure the cuts are all the same depth.

I used my dremel for this, but this time I made several improvements over my previous attempts.  First, I managed to find some thin cut-off disks which made the cutting faster and less wasteful.  Second, I made a metal "tongue" to allow me to clamp my dremel in a vise.  This greatly improved my accuracy by keeping the tool perfectly still while I moved the piece around it.  I am looking forward to using this when I try to shape my latest hinges in the Carlisle pattern.

10.  Lay your cut plates out flat and pair them up with the uncut plates, and mark the cuts for those.  At this point it's a good idea to keep track of which plate goes with which, to get the best fit.

11.  Cut the second set of plates and compare them with their mates.  Make any necessary adjustments to the size of the tube "teeth".

12a.  Using a combination of dremel and cold chisel, nip off the unwanted tube sections.  Note that you will need a backstop softer than the chisel -- I used a hunk of aluminum that was donated to me.

                I found a reversible nail set which would also accept my homemade cold chisel.  This made this step go a lot faster and helped save wear on the hammer face.  After nipping off the tubes, I used the dremel to smooth off the cut surfaces.

12b.  Flatten the hinge plates again if needed.  (Using a cold chisel will often bend the plates slightly.)  Try inserting the hinge pin (one hinge plate at a time) to see if you've gotten things back into alignment.

13.  Perform final cleanup with needle files.  Test fit your hinges and insert the hinge pin. 

14.  Cut hinge plates into final shape.  (Coming in a future update...)

15.  Peen the hinge pin and enjoy!

Progress

I have one shoulder unit assembled, and all the hammer work done for the next one.  Pictures and details coming tomorrow-ish.

Attaching Hinges

Over the weekend I also took my first stab at cutting hinge plates into more ornamental shapes.  I decided to use a cold chisel to do the bulk removal, thinking that this would be faster than dremel-ing or sawing.  Anyways, the results were terrible -- too terrible to show.  I'm not certain that this is even worth practicing more since one of the major issues I had was the hinge plate curling up like a dried leaf after one or two chisel cuts.  Maybe this is just bad technique on my part, but it certainly wasn't encouraging.

Anyways I tried to clean them up a bit with the dremel, with mixed success.  I am still learning what a dremel can do so this is a slow process.  No pictures of this process since the results aren't great, and I didn't use historically correct patterns for these hinges because I wanted to start with something simpler.  You'll see them in the next few pictures anyways.


Attaching hinges - Take 1

Note:  I have not polished or cleaned up my hinges at this point.  If this wasn't a prototype, I would probably have cleaned them up a bit before moving to this stage -- although nothing is final until riveted.  Also -- these hinge shapes are not historically accurate.

In order to attach your hinges, you will first need to put holes in them.  Time to break out your metal punch or drill!  I used a center punch to lay out starting divots before punching.  This turned out to be somewhat of a waste of time -- when I went to punch the actual holes I found that on the ones near the hinge tube were a little bit too close to allow the jaws of my metal punch to close.  After fooling around with things for a while, I gave up and just started (carefully!) freehanding the hole placement.  This turned out to be faster than trying to key the punch tooth into the divot, and hinges are small enough that accuracy was not a real problem.  I think on my next set of hinges I will skip the center punch entirely and just freehand it from the start.


Anyways, I took my new "hole-y" hinge and taped it onto the central upper should plate, as seen below.  I later discovered I had in fact placed it too low -- more on that in a minute.  You can see below that I have used painter's tape to hold the hinge in position.  This is because I need to make sure it holds very still while I mark the hole locations with the center punch.  One issue I had to watch out for -- the diameter of my center punch is less than my rivet diameter (1/8"), so I had to be careful to center the punch tip inside the hole before striking.

No matter how consistent you might think you are being, chances are pretty good that the holes in your hinges won't be interchangeable.  It's not a bad idea to mark which hinge face will go with which plate to simplify your life later -- since I was going to do an immediate test assembly with screws, I just left the tape on the face of the hinge as seen below.  Note that I have also marked my shoulder plate with "(B)ack" and "(F)ront".

After attaching the hinge to one plate, it's time to mark the holes for the other plate.  This is where it's important to have some appropriately sized screws and nuts - the only way to make sure that the central plate lines up correctly with the front and back plates is to have the hinge already attached on one side when positioning the holes on the other plate.  Seen below -- I am using my stump to support the work while taping down the hinge.  To be honest, I could have used more tape on this stage since the weight of the central plate tended to pull on the hinge quite a bit depending on the position I put it in.  I think I'll use more tape in the future to make sure things turn out OK.

After some punching and threading, I have attached my first hinge!  Huzzah!

 

But wait!  What's this?  Something isn't right with my new hinge install!

While I was careful to make sure that the long plate would be under the central plate, it seems that I wasn't careful enough.  The long plate is overlapping so much that it is catching on my "rivet heads" and can't flex far enough.  While this might go away when I replace the screws with rivets, it will be much safer to avoid the issue completely.  The pink arrows illustrate where the hinge would have to be moved on each plate to correct the problem.  Since this is a prototype I'll just ignore it for now and do a better job on the next hinge.

Attaching hinges - Take 2

Same basic steps as before - except this time I got the overlap right!

Coming soon -- assembly and leathering of a complete shoulder unit!  This will be a bit of a hybrid between Corbridge shoulder plates and my Newstead breast/back plates.  Note that for historical accuracy, vegetable tanned leather should be used instead of second-hand belts.  :)

(Belated Weekend Part 3) My First Breastplate - Front & Rear

For the front breastplate I decided to try a much sharper fold.  Basically I repeated the steps from my previous post, except that the final passes involved smashing the fold with a 2-pound swedish crosspein hammer.  I will not be doing this again since it doesn't really save that much work and the result isn't nearly as attractive.



For the rear breastplate, I decided to try rolling the edge.  The first thing about this that I should mention is that I did it backwards -- I rolled it on the inside instead of the outside of the plate.  Oh well.

Rather than try to reinvent the wheel, I will direct you to read the armour rolling tutorial located here since that is what I was working from anyways.  Some pictures of the process:

Rebated cold chisel as my stake.

 Planishing hammer:

I had some trouble closing the roll properly, and I dinged it up a bit trying to convince it to obey me.  End result isn't terrible but is certainly not spectacular.  I will be practicing this some more in the future since it seems to be within my reach and has the potential to look great.


Anyways, below you can see all three plates laid back out on the table in their original configuration.  You can see how much metal was trimmed and folded!

Up next - attaching hinges and then leathering a complete shoulder section together.

(Belated Weekend Part 2) My First Breastplate - Midcollar

I started by cutting out a rectangular piece, and then broke it out into the separate sections.  This might seem like a mistake, since the midcollar plate has to slightly overlap the other two, but you will find that once you've accounted for material lost in folded/flared edges it won't matter.  The plate labelled "scrap" will probably be reused for a shoulder or manica lame(s) -- it's not actually going to waste.

PS - I am using soapstone to write on the sheet metal here.  This is convenient since you can remove it later with only a rag.

An important point to keep in mind about the breastplate sections is that they are going to be rubbing against your neck.  This is not a place where you want rough metal edges!  Typically ( and historically) these edges are finished slightly differently from other edges as a result.  There are three basic options:

• Flared;
• Folded; or
• Rolled.

Since I don't like the "flared" look by itself, and since it is reputed to be significantly less forgiving of mistakes, I decided to ignore it in favour of practicing my folding and rolling.  On my next breastplate section I will attempt the combined folded and flared edging shown in the famous lorica segmentata diagrams by Peter Connolly.


Disclaimer:  I am not a smith of any sort, I'm just some guy with a bunch of newly-purchased hammers who read some tutorials on the interwebs.  I will be telling you how I have done things, and whether or not they worked for me.  That doesn't mean that they are the easiest or best way to get things done.

In this post, I will be covering the midcollar, where I chose to use a gentle fold for the part going against my neck.  Unfortunately it appears that I forgot to take a picture of starting the bend -- I'll remedy that in a future post.

Anyways, I used soapstone to mark a fold line about 1cm back from the edge.  Laying the plate more or less flat on the anvil, I shift it so that the fold line is level with the edge of the anvil.  (With that 1cm section hanging over the edge)  Once it is aligned, I can start lightly tapping along that overhanging edge, aiming just past the edge of the anvil. The key here is to do a little bit at a time along the whole edge. To better understand why this is necessary, please read the excellent writeup over here.  While you're there, read the whole rolling armour edges tutorial -- I certainly did.

Anyways, the trick is to just keep shifting that plate, keeping the fold line just on top of the edge of the anvil.  When you've completed one or two passes, you should have something like this:
Note: The edges of my brick hammer's face have been rounded out with files.  I should really radius and polish the whole face of the hammer before starting work on the final pieces.

After a few more passes, you should be approaching a 90° bend.

 

As you try to surpass that 90° mark, it might help to switch orientation with the fold on the face of the anvil, and the body of the plate hanging off the side:

After you reach that stage, you can lay the plate flat on the anvil and brace it with your hand.  You should be aiming the hammer for the top of the edge here -- be careful since a miss will likely ding the anvil.  Your hammer stroke should be expecting to "slip off" the top of the fold.

Getting closer -- Hammer strokes should still be slipping off the edge of the fold.

On the last two or three passes, be careful to strike along the edge, NOT directly on the fold.

 

If you did the last step correctly, you should have a nice-looking rounded edge:

Next update tomorrow-ish will cover the rest of the weekend material  (other two breastplate parts), and hopefully the assembly of a complete shoulder unit.

(Belated Weekend Part 1) Miscellaneous

As previously mentioned, I visited a friend's place on the weekend and did some work there last weekend. There are a lot of pictures so I'm breaking this up into several parts.  First, I'll deal with some miscellaneous stuff.

When I packed up all my gear and materials, I was surprised at how easily it could be collapsed into a transportable package.

1. Brass Sheet (kickplate from a door?)
2. The remainder of my uncut steel, about 2' x 2'.
3. All hand tools and patterns fit into this plastic tray.
4. Dremel Case and sketchbook
5. Brass Rod Stock (1/8" & 3/16")

JB (my friend) has a very nice workshop, and a number of nice things that I don't - like a bench grinder.  When I was talking to him about my issues with hinges (specifically about nipping off the unwanted tube sections), he had a bright idea.  Since I was having trouble finding a cold chisel small enough, he pointed out that we could make one.

We started with this double-ended screwdriver bit, since it was some form of tempered steel that was already more or less the right shape. All that needed to be done was to put an edge on the flat end, and to grind down the phillips end as a strike point (so that it wouldn't ding the hammer face too much).  Anyways, this was fairly easy although a bit slow since we made very frequent pauses to dip the bit in water --  we wanted to keep it from getting too hot on the grinder and ruining the temper.

Below, you can see the results of our first test using a piece of aluminum as the strike plate.  (You want something softer than the chisel as the backstop...)  It works surprisingly well, too.

Not pictured - I made two more hinges, bringing my total up to 4.  This is to support the assembly of a complete shoulder section in the near future.



JB also had a small anvil which hadn't seen the light of day for a few years.  He dug it out for me and suggested that I put it to use -- he didn't have to ask me twice!

At left, I am radiusing one edge of the anvil very slightly.  This is to provide a smooth surface to bend metal over -- the unfinished edge would marr or possibly cut my work.

Next update:  Using that anvil!

Real update tomorrow or tuesday

Spent the weekend out of town at a friend's place.  I got some work done while I was up there and now I even have a small anvil which he lent me.

I have a complete shoulder section (including breastplate) ready to assemble -- just need to finish attaching the hinges and then do the leather.  Unfortunately I seem to have left my digital camera behind at his place so I won't be able to give you a proper update for another day or two.

Stay tuned for several types of hammers and three different options of finishing the edges that go against your neck.  Also some progress on hinge-making!