Wednesday, 27 July 2011

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.  :)

Tuesday, 26 July 2011

(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!

Sunday, 24 July 2011

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!

Friday, 22 July 2011

Up Next: Breastplate

I'm hoping to prototype my first breastplates this weekend.  It will depend on certain other factors, however.

In other news, someone over at RAT has informed me that when anealling brass, I should be letting it get literally red hot.  I'll see what I can do for hinges 3 & 4...  I'll need at least 4 hinges to assemble a complete shoulder section, which is the "stretch goal" for this weekend.

Hinge #2 - Much Better, but not quite there yet

Proof that I learn from my mistakes:


I completed hinge #2 in about 1.5 hours.  That should drop even more once I find the right size of cold chisel to take off the unwanted tube sections.  On the other hand, I haven't cut the plates into an ornate shape yet -- that will obviously add time back in.  All in all, though, I can already see how I could "assembly-line" the process to make a whole batch of hinges at once and save a lot of time that way as well.

Above: You can also see that I tried one of the polishing attachments for my dremel on the top-left plate. I'm not impressed -- waaaaaay too much effort for the result.  I will have to try pickling and/or light sanding next.

One thing I don't like about hinge #2 is that I didn't get the barrel quite as tight as the first one.  I think I need to add a third annealing step in the middle of the hammering process.  Like this:
  1. Anneal
  2. Hand Fold
  3. Plier Fold
  4. Anneal
  5. Hammer
  6. Anneal
  7. Hammer
  8. Cut
  9. ...etc.
One other thing I learned -- when using a dremel on metal, both hands should be wearing gloves.  When I was shearing off a tube section it fell on the hand holding the dremel and gave me a pretty good burn.  Ow.

Thursday, 21 July 2011

My First Hinge (ugh) Part 3


Seen above - several sketches of hinge and fitting designs.  I am laying the first hinge plate down on the graph paper to mark the tube cuts.
It turned out that the bizarro-style hacksaw that I purchased was simply not up to the task.  Too much flex in the blade to saw quickly.  Fortunately, I had a better alternative anyways:



Don't forget eye and hand protection when using something as dangerous as a dremel.  Hot flakes of metal are flying around!  On a similar note, best to do this outside - I use my balcony.

 Below:  This is actually the first project I've used a dremel on.  It kicked once or twice when I wasn't holding on to it very well, gouging the brass.  There is an attachment for Dremels called the detail grip -- I was much happier once I stopped to put it on.



Below - I was trying to compensate for the thickness of the cut made by a dremel wheel, and I overdid it a little bit.  You can see these parts aren't going to match up properly.  Back to the cutting for me.



Okay, cutting the slots is complete...  now how the heck do I get rid of the unwanted tube sections?  I originally planned to nip them off with a cold chisel, but I haven't yet found one small enough for the job.  I decided I would have to weaken the unwanted parts and bend/twist them off.  I tried several methods and wasn't very satisfied with the results from either.  More details when I figure out a decent method or find an appropriately sized chisel.


After finally getting rid of the unwanted tube sections, all that is left is test fitting and filing down the high points.




At last, I can insert the hinge pin and watch my new creation flop around!


You can see that the hinges don't quite line up- one is higher than the other, and the tubes don't slot together very well.  I'm satisfied with a good first attempt, though -- I learned a lot!

Tomorrow I might cut and file the plates into shape and peen the hinge pin.  We'll see.

My First Hinge (ugh) Part 2

 In order to get that nice barrel definition I'm looking for, I had to turn to yet another new tool.  Allow me to introduce you to the common masonry / brick hammer.


Before you're ready to use this bad boy for metal working, however, there's a bit of work to be done first.  The wedge needs to be rebated (a fancy word for "sanded/ground down smooth") with a file or a grinder.  You need to have all of the edges rounded so that they don't cut or mark up the metal you're going to hit.  This isn't hard work, it's just boring.  Fortunately, I was already mostly done.

Getting back to the hinge -- Since I was going to be hammering it I decided to anneal the brass again.  Back out to the balcony, back into the quench pot, then back inside.

I threw the hinge (with pin inside! Don't forget that part!) onto my "anvil" and started tapping it gently.  You're not trying to hit a home run here, not much force is needed.  I started off aiming about halfway between the hinge axis and the plier-folding line.  I did this for both sides.


 After a bit of that, I was ready to tilt the hinge up and start aiming much closer to the hinge pin.  This is the final stage of closing the barrel.  Again - light taps, both sides.



On one plate, I realized I had shaped the barrel a little bit too closely... the pin didn't want to come out!  This was fixed by some gentle taps against the edge of the hinge tube to open it back up slightly.




Here is what one plate looked like after I was finished hammering.  Not bad for my first time, eh? 

My First Hinge (ugh) Part 1

This was a bit of an adventure, and ended up involving more tools than I expected to use.  Fortunately I had what I needed more or less ready to go.  

The first thing you need to do is figure out what size and pattern your hinges are going to be.  For my prototype, I wanted a hinge "face" about 4 cm square.  I added 13mm for the hinge barrel (for a 1/8" rod), but it turned out that this was not enough.  Anyways I cut out two blanks 40x93mm -  Although now that I think about it, I might have done 40x83 by mistake, which would explain why I came up short at the end.  Oh well, there's always the next hinge.

I then went outside on my balcony and lit the propane torch.  After dialing the flame down to around 1.5", I annealed (heated) the middle of my plates, moving the flame back and forth along the hinge axis.  Something sizzled slightly near the beginning - it was probably some kind of protective coating or film on the brass.  (This piece was donated to me, so the exact specs aren't known)
I wasn't certain of how long exactly I should be heating it, so I gave it "a while" (more than 30 seconds) on each side before quenching it in water.  I'll ask RAT about annealing times and see what they say.

Back inside, I hand-folded the plates around my hinge pin.  I wasn't very careful with one of them and it ended up slightly crooked, as seen below.



The next part would probably be easier with a vise, but I don't have one in my apartment.  Therefore I had to use the jeweller's pliers and something else.  I will console myself with the thought that this method is probably more authentic.  


 Now that I've taken it as far as it can go by hand (above), I started pinching down the sides.  Note that I am using  jeweler's pliers (below) so as not to scratch the surface.  You have to do this slowly, alternating sides.
 

Eventually you'll get to this phase, where the pliers aren't doing too much anymore, and there is a slight bulge in your hinge barrel.


Continued in the next post...

Center Punch & Metal Punch


When preparing to make holes on the lames, an automatic center punch is invaluable.  It has a long spring in it, so you don't even need a hammer. Just pick the spot you want, push, and it whacks a nice little divot in the metal.  (hard to capture well in a photograph)

This divot is very useful as a guide for positioning your drill bit or metal punch.  Since I wanted something quieter than a drill (remember, I'm in an apartment!), I went out and got a metal punch.  It's basically like a pair of pliers - (squeeze to operate) but with interchangeable bits on the jaws.  There is a toothed piston (the punch) and the shaft it mates with.  The little tooth on the piston is the best part -- when you insert the lame into the jaws, you can slide it around a bit until the tooth catches in that divot from the metal punch.  Presto!  Perfectly centered, every time!