Mac's blog

[Mac]

By way of a test, I took that knuckle plate I started the other day that did not fit the mandrel...
...and worked it up in a more conventional way to see what that template would get me.



From there I made some changes and cut a pair of them out of .050" stock. The new pattern is a bit longer between pivots, and wider across the knuckles. I have also left enough material at the ends that I might be able to finish them up on the mandrel... we'll see.



I've bossed up the knuckles from the back with a series of hammers and dishing forms....



... and have begun working them down from the outside on the anvil horn, with a cross peen.



I hope that I will get usable knuckle plates out of this. I suspect that they will not be as tall as the ones I spec'd out, but perhaps they will be OK.

Mac

[Mac]

Getting back to one knuckle at a time, seeing as the knuckle blank is a strip, more or less, why not extend both ends beyond what you could possibly need and then rivet handles to them, and trim the excess off later? That way you could hot forge to your heart's content.

I've got a bit of extra length, just in case I can still use the mandrel, but not enough to really serve as handles. If these don't work, and I have to try again, I may well make them longer, as you suggest.

Mac

[Mac]

I had another go at this today, but didn't get very far before I gave up.

The process that I envisioned contains two essential flaws...

--Getting from an essentially flat piece to the desired knuckle shape requires too much shaping to be done in one step. It's too difficult to raise the work down "over the air" without getting wrinkles.
--The pointy little nipples are too sharp to serve as mandrels, especially early in the process.

Mac

I was thinking the same thing as I read the post this morning. In the industry that deep of a draw would be handled with a progressive die. Much liked you dished 4 domes to start there would be another middle process of stretching the valleys down because that's a larger chunk of material and will require more force than raising the tips.

In metal spinning, if one were to make a shape like an individual knuckle, one might use one or two intermediate chucks to "break down" the work.

Yea... this thing I envisioned is really far to optimistic to happen without getting most of the shape some other way. I am hoping that I might be able to rough out the knuckles "the hard way" and then finish them up a bit on the mandrel. I'll know more about whether that's going to work this afternoon.

Question: would it not make more sense to process the steps as 4-domes then the valleys between the domes then collapse the domes into cones THEN create the sharp tips? I've got to think that the tips could be done over a single 'nipple' stake that is moved from knuckle to knuckle... or is that too much hot-work close to your fingers?

Sean

Ultimately, it will probably be best to do the very points without an internal support. If I were going to re-imagine the tooling for such an operation, I would have a semifinal form that was as tall as I needed the knuckles, but the points would be rounded. The final form would be the same but only as tall as the the current mandrel is, without the nipples. I would then hot raise the points over the empty space above the knuckle bodies.

Mac

[Mac]

...I will do some more experiments before I just grind the nipples off.

Mac

I nominate this for quote of 2018.

Long ago, I had an apprentice in the shop who had experienced a similar thing in his high school wood shop. The sanding belt of a drum sander came apart and slapped him across the chest a few times before he was able to get away from it. He claimed that it had been surprisingly unpleasant.

Mac

[Woodswork Armory]

Quick question, what blades are you using for your Dewalt? I have the same one laying around and I want to try cutting metal with it rather than using tin snips all the time.. my hands can't take much more tin snip abuse.

[Mac]

Quick question, what blades are you using for your Dewalt? I have the same one laying around and I want to try cutting metal with it rather than using tin snips all the time.. my hands can't take much more tin snip abuse.

I use 18 tpi metal cutting blades. The best ones are no longer made... In fact the second best ones are no longer made either, but I keep an ebay search for them. They are Black and Decker 31020

The thing to look for is a blade that is thick from side to side, and narrow from front to back. A lot of modern metal blades are exactly the opposite, and they are weak and don't turn well.

Mac

[Mac]

More of the same.



Reaching the edge.



As they stand, the crotches between the knuckles could use to be worked down some more. I fear that if I do that cold, it will tend to spread the knuckles apart, and I can't afford that. I think I will take the cold worked test piece and see if I can do that same thing to it with spot heating. That may or may not happen today. I should give my arms a bit of a rest.

Mac

[Rene K.]

Very cool to see i had to make the same pieces today

[Mac]

Very cool to see i had to make the same pieces today

Excellent! Do you have any pics?

Mac

[Mac]

I'm preparing the knuckle tool for the next idea. The nipples are gone, and the crotches between the knuckles have been deepened.
There are also bolts on both sides to serve as the places where the vise will grab.



Those bolts will provide space for binding wires to pass around the work and tool.



We'll see how this works tomorrow.
Mac

[Rene K.]

Hi Mac,

That was my work for yesterday. It is all dished out cold from C45 and was only heated for a second punching to make the domes deeper without crackings in the tips. You see i made me a similar jig, but not so fancy. I made it a year ago, but i was not so happy. Now i use it just as an tool for some steps in making the knuckle riders.

[Mac]

Hi Mac,

That was my work for yesterday. It is all dished out cold from C45 and was only heated for a second punching to make the domes deeper without crackings in the tips. You see i made me a similar jig, but not so fancy. I made it a year ago, but i was not so happy. Now i use it just as an tool for some steps in making the knuckle riders.

Those will look nice! Please post some more pics as you progress with the gauntlets.

Your knuckle tool reminded me of how I had a single knuckle version of that somewhere in my storage area. I rooted through a couple boxes and coudn't find it, though. I really need to get all of the tools in those boxes reorganized and put somewhere where I will be able to find them.

Mac

[Mac]

This morning's test involves the knuckle plate I started a few days ago. That was the one that was too short to fit the mandrel.

I've wired it down so I can see how much material I need to weld onto the ends to continue the test.



Somewhere along the line, I took a round file and made some chamfers for the wires to sit in. This makes it a bit easier to get them tight.



The plan is to locally heat and hammer, while keeping the crotches down tight with the wires. The wires need to be removed, one at a time, to work in the crotches. This pic shows what I have after about an hour of dinking around with it.



I think I have a workable process here. I'll make a few changes to the mandrel, and then move on to the two plates I started yesterday.

Mac

[Halberds]

Thanks for the great pics and how to. Cool knuckle tool.

Hal

[Mac]

Thanks for the great pics and how to. Cool knuckle tool.

Hal

Thank you!

Mac

[Mac]

Sorry about the focus.



Both the knuckle plates are coming along. I do a bit of work on one, and then do the same on the other. That way I'm more likely to end up with two matching plates.

The edges of the plates overhang the mandrel. This will get trimmed a bit, but not till they are fully shaped.

I'm down to my last 10# of oxygen pressure, so it's time to go to the welding shop. It's been a couple of years since I was there. I hope they still think I'm a customer

Mac

[Indianer]

I am wondering Mac...how to put the tips in? Did you leave some space up there to compress into later?

[Mac]

I took the long way back from the welding shop.



Some Windex and a couple of paper towels got rid of most of the dirt and all of the bird poop. Next year I think I need to bring an old toothbrush to get the schmutz out of the lettering.

Mac

[Mac]

There were some last minute changes to the mandrel this morning. I ground the crotches a bit concave to give the knuckles a bit more "life".



I also dressed up a hammer to get into the space better.



After a few more times on and off the mandrel, I think the knuckle plates are finally ready for fitting.



The project used a surprising amount of binding wire, and has produced three more items for G.I. Job's dung heap.



Next, I need to cut the plates to length, and start getting them to fit the metacarpals. The cutting off of the screw-mounting extensions is a bridge burning process, so I hope I really am done with the mandrel.

Mac

[Mac]

I am wondering Mac...how to put the tips in? Did you leave some space up there to compress into later?

I have given up on the reflexed tips.

To make them work, I would have to start again, using one of the following....

--two different mandrels
--a mandrel with removable nipples
--willingness to change the mandrel shape in the middle of the process
--a different process altogether

So in the end, I am going to have to fall short of the rather ambitious plan of replicating Lorenz Helsmchmeid's glorious knuckles. That's a bit embarrassing, but only a bit.

Mac

[Woodswork Armory]

Mac I don't know if this was asked before but why not put up old scrap pieces or unfinished ones in stock on your website? i'm sure plenty of people would be happy to own something Mac related even if it isn't finished!

[Rene K.]

Hi mac,

a very fine result at the end. I shoud think about making a similar one for me. Is there not enough material in the tips after working them hot over your fine mandrel that it would not be possible to raise out the single tips a bit over a simple pointy stake ?

[Mac]

Hi mac,

a very fine result at the end.

Thanks!

I shoud think about making a similar one for me.

I look forward to seeing what you come up with.

Is there not enough material in the tips after working them hot over your fine mandrel that it would not be possible to raise out the single tips a bit over a simple pointy stake ?

I have enough volume to make either tall knuckles or pointy knuckles. There is not really enough for tall pointy knuckles.


Mac

[Mac]

Mac I don't know if this was asked before but why not put up old scrap pieces or unfinished ones in stock on your website? i'm sure plenty of people would be happy to own something Mac related even if it isn't finished!

There are couple of items in that heap that may get finished up and go on to have new lives, but nothing there will leave the shop in its current condition.

I have asked my wife to make sure all that junk is buried with me.

Mac

[Mac]

I spent much of afternoon and some of the evening getting the knuckles to fit the metacarpals. It's fussy business...



There is still some fine fitting to make them work a bit better, but I'm reasonable pleased with what I have so far.



Tomorrow I'll get them fitting a bit better, and make the narrow mitten lame that will serve as the transition into the bifurcated mitten.

Mac

[Mac]

Meanwhile....

I received my new welder cooling fan motor, and (wait for it) two American Welding Supply bumper stickers. They also sent two ball point pens, but they didn't make it out to the shop.



I suppose if I put one of the stickers right onto the welder, I'll at least remember where I bought the fan if it craps out too soon

Mac

[Mac]

Yesterday, I got the knuckle plates fitting a bit better to the metacarpals, and made up the narrow mitten lame.



There's just over 90° of motion there.



Today, I gathered up all the knuckle tools that I have made over the years so that I could have a little thinking about them....



...and then made up a new one that will (I hope) accord well with the one I used for the knuckle rider.



I was not sure how big to make the starting piece for the bifurcated knuckle plates. This was supposed to cover knuckles of fingers one and two, but it may be better suited for three and four. We'll know more tomorrow.



Mac

[Kristoffer]

These gauntlets are amazing Mac, I am so happy to see them being built. I have been fiddling with bifurcated gauntlets myself for a long time and is looking forward to steal as much knowledge as I can from you.

A question, how does the upper part of the knuckle rider interact with the big flutings of the metacarpal plates? Does the angle of the flutes cause a gap between the plates when the fingers are straightened or is there some magic that takes care of that?

[Mac]

This morning I finished roughing out the first bifurcate knuckles. It turns out that they will be for fingers 1 and 2 like I had planned.

Here I am hot raising the bosses back over a bicorn.



This is followed by refining the shape on the knuckle stake.



This afternoon, I started the knuckles for fingers 3 and 4. Now.... one should never change procedures in the middle of a thing like this, but I did it anyway and I'm glad of it. In the past (as recently as yesterday) I have begun pointy knuckles by bossing out a suitable depth cold. This requires hundreds of blows with a series of ball peen hammers. Instead, I thought I'd try it hot. After getting a bit of the bossing started, I used the punch shown here with this big ol' drilling hammer. The punch tends to chill the metal in the middle, and thus the thinning in the middle is minimal. This works faster, produces a better result, and involves a lot less joint stress than doing it cold.



The other modification I made to the procedure it to follow Dave Rylak's good advise and add some material to be cut away later. In this case, it's about 3/4" or so, some of which I turned out to let the vise-grips to better clear the tool and the vise.



I will use the same procedure for the thumb knuckles, and hope to document it a bit better there.

Mac

[Mac]

These gauntlets are amazing Mac, I am so happy to see them being built. I have been fiddling with bifurcated gauntlets myself for a long time and is looking forward to steal as much knowledge as I can from you.

Thank you!

Take what you need and pass it on.

A question, how does the upper part of the knuckle rider interact with the big flutings of the metacarpal plates? Does the angle of the flutes cause a gap between the plates when the fingers are straightened or is there some magic that takes care of that?

There are a couple of tricks to getting this right. No doubt the guys who did it all the time had no trouble at all, but we have to think it through carefully and try to figure it all out.

The first thing is that the flutes do not diverge at the same rate when they approach the knuckle. They have as sort of funnel shape. This makes it so that in the area where the knuckle plate will articulate, the flutes hardly diverge at all, and are almost parallel.




The second thing is that the flutes are not very deep. Deep flutes would make things harder.



The third thing is the the plate itself is shallow. In this pic, the pivot holes are lined up, and we can see that the greatest depth is something like 7/8" (22mm)



A shallow pivot depth means that it requires less underlap for a given range of motion. In this case, something just shy of 45° .....



..... only covers about 3/8" (9.5mm) in the middle. It's even less at knuckles #1 and #4 , where the interactions are likely to be most troublesome.



Mac

[Mac]

While I was out taking pics, I grabbed some of the new knuckles.

These are the knuckles for the first and second fingers. The red lines are where I plan to trim the plates. I'm also moving the pivots up (and in) from where I lightly center punched them before they were shaped.



The knuckles for the third and fourth fingers are still as I left them when I wrapped up for dinner.



Here we see trouble brewing. That narrow mitten lame is taking up too much of the available finger length. As it stands, there will be almost no "finger cannon" visible. When I put the parts on my hand, the space mostly goes away on fingers one and two, and on fingers three and four, the knuckles touch the mitten lame.




This is a problem that I had been anticipating with a mixture of excitement and dread since my first thoughts about this project.

I can't make the mitten lame any narrower, because of the size of the rivet heads and the need for material in the plates to support them. I can't make the main knuckle any narrower either.

I am going to experiment a solution that does not involve a mitten lame. It may be possible to have the two finger cannons riveted directly to one another between fingers two and three. The only way to find out is to make them up and see.

Mac

[Mac]

Here's what I currently have for the bifurcated knuckles.



I've been experimenting in cardboard to try to make the finger cannons articulate directly to the main knuckle rider, and to one another.



It just might work.



More later.

Mac

[Chuck Davis]

Hey Mac, On the bifurcated gauntlets of Charles the 5th, The plates on the inside are articulated on leather, so there are not plates rubbing on each other

[Mac]

Hey Mac, On the bifurcated gauntlets of Charles the 5th, The plates on the inside are articulated on leather, so there are not plates rubbing on each other

That's my fall back position, if I can't make it work this way.

Have you got any better images than this one?



Mac

[Tom B.]

Here are some images of the pair at the Met

https://photos.app.goo.gl/GQTVJpjKNrLSwcun6
https://photos.app.goo.gl/bun7HgW4AVtLGy5c6
https://photos.app.goo.gl/zgYCRXw8A54EwxWs9

Best I can do on my phone from China.