random question

Whitetre · Post by **Whitetre** » Fri Dec 19, 2008 5:05 pm

I see alot of stuff in the ole archive here, referring to "spun" tops, in regards to helmets...

Can anybody clear this up for me? does it refer to machined (read lathed) helmets?

thanks a ton, in advance

InsaneIrish · Post by **InsaneIrish** » Fri Dec 19, 2008 5:09 pm

some thing like that.

It refers to a way to make the top/bowl the helmet. "spun" means they take a flat disc and spin it on a turning lathe, shaping it like they shape metal salad bowls.

What you end up with is a perfectly round "spun" dome for your helmet. It is a cheap and fast way to turn out a bunch of domes for helmets. Unfortunately I have never met someone that had a perfectly round head.

Whitetre · Post by **Whitetre** » Fri Dec 19, 2008 5:17 pm

ahh! ok! i think i read a post/thread somewhere about that process just the other day, I jsut hadnt put 2 and 2 together.

Thanks a ton

Jan van Nyenrode · Post by **Jan van Nyenrode** » Fri Dec 19, 2008 5:21 pm

Well, pity most of us are caucasian but my wife is asian and she has a rounder head then I have. Ofcourse one observation is not significant but of the asians have seen in my life makes me believe they have rounder heads then caucasian.

Cheers,

Max

Lorenz De Thornham · Post by **Lorenz De Thornham** » Fri Dec 19, 2008 5:47 pm

Just in passing, I believe there has been some research into some Roman helmets being spun.
Also on some Bascinets I have observed 'Lines' that are parallel and reminiscent of the results of polished up spinnings but cannot figure how they would have done it back then so l am still puzzled by these lines!

Ouzel Von Schwartzwolfe · Fri Dec 19, 2008 7:33 pm

A spun top is a good way to start a helm.
trick number 1 for a spun top
cut it in half taking 1 to 2" out of the center to fit
then weld it all back together.

you can even cut the center out in ways to add a off center or center point and other stuff

mattmaus · Post by **mattmaus** » Fri Dec 19, 2008 7:47 pm

Ouzel Von Schwartzwolfe wrote:A spun top is a good way to start a helm.
trick number 1 for a spun top
cut it in half taking 1 to 2" out of the center to fit
then weld it all back together.

you can even cut the center out in ways to add a off center or center point and other stuff

Or cut them down the middle and push the excess width out into a comb or ridge or something too....

Spinning thins the metal, and that can be problematic... but that's another can of worms.

Luca Sogliano · Post by **Luca Sogliano** » Fri Dec 19, 2008 8:11 pm

Some Roman helms were, indeed, spun. However, I have not seen evidence of any medieval helmets being produced in such a fashion, and as a trend, it's generally datable to 20th/21st century India.

Lorenz De Thornham · Post by **Lorenz De Thornham** » Fri Dec 19, 2008 8:22 pm

Yes I agree, although how is it that so many have the parallel lines down the sides, they are usually only faint corrosion marks, given that the top of the dome can be around 4mm, I think that is about 3/16ths or so, that would be a heck of a lump to spin now let alone back then?

Konstantin the Red · Post by **Konstantin the Red** » Fri Dec 19, 2008 10:29 pm

Max Keeren wrote:Well, pity most of us are caucasian but my wife is asian and she has a rounder head then I have. Ofcourse one observation is not significant but of the asians have seen in my life makes me believe they have rounder heads then caucasian.

Cheers,

Max

Asia Minor and southeastern Europe, too, seem to show more broad, rounder heads than other places.

Spinning apparatus is related to the lathe, but isn't quite an ordinary lathe: it is equipped with stout thrust bearings to handle the forces along its axis of turning that arise from pushing steel with the tools, which are applied much as lathe tools are, but to push the metal onto a form within its final form rather than to take metal off in shavings. A great deal of aluminum cookware is made this way.

I had thought the process didn't thin the metal unless there was a stretching-out process (which is possible) involved.

Agnarr · Post by **Agnarr** » Sat Dec 20, 2008 3:39 am

I used to have a guy here who looked like charlie brown. Irish i think.

Lorenz De Thornham · Post by **Lorenz De Thornham** » Sat Dec 20, 2008 8:22 am

I seem to remember that some people on this forum become upset if people discuss head shapes :lol:

Jon Terris · Post by **Jon Terris** » Sat Dec 20, 2008 9:12 am

Lorenz De Thornham wrote:I seem to remember that some people on this forum become upset if people discuss head shapes

That'll be the bloomin Cavaliers then eh? They've always hated the Roundheads.

Sorry, I'll get my coat.

JonT

Konstantin the Red · Post by **Konstantin the Red** » Sat Dec 20, 2008 9:11 pm

Would that be your buffcoat?

Forecast: general light silliness with scattered plotzing.

Lorenz De Thornham · Post by **Lorenz De Thornham** » Sun Dec 21, 2008 6:56 am

Watch out for the pointy headed people :lol:

I have heard or wood spinning lathes, I seem to remember being told of some guys in the States using them and sticks to apply the pressure, seems it would make a nice clean spinning without the lines left when done with metal tools?

Anybody know who was doing this?

RalphS · Post by **RalphS** » Sun Dec 21, 2008 9:00 am

Spinning:
http://se.youtube.com/watch?v=NsUDMZsPbxM

Not quite spinning, but related and not limited to round shapes:
http://se.youtube.com/watch?v=GxysBla3N ... re=related

Jan van Nyenrode · Post by **Jan van Nyenrode** » Sun Dec 21, 2008 9:18 am

Hey ralph,

The last video looks interesting. But I've got no clue how that works. Do you have an incling?

Max

RalphS · Post by **RalphS** » Sun Dec 21, 2008 10:06 am

I think it was discussed here earlier, and IIRC it's a small punch that strikes down rapidly, without a matching support beneath it.

Also fun to see:
http://se.youtube.com/watch?v=bVhz1ijEfqA in particular the "necking in" at timemark 3:18 and onwards

mattmaus · Post by **mattmaus** » Sun Dec 21, 2008 10:30 am

Konstantin the Red wrote:I had thought the process didn't thin the metal unless there was a stretching-out process (which is possible) involved.

Pretty much anything you do to metal is going to thin it one way or another.

Planishing... pinching metal between hammer and stake, is going to thin it some. Can't be helped.

Wether or not any given technique thins metal significantly enough to be a problem is another story.

I've been told that the depths of the lines/ridges left on spun items has a great deal to do with the skill of the guy spinning them, and the quality of the spoons he pushes it with.

If I were going to make a helmet out of a spun top, I would want to cut a bit out of the center to oval it up, and then I would also grind off the lines/marks left by spinning.

Depending on how nice a top you got... grinding the spin marks off will significantly thin your metal, wether or not the spinning process does or not. All of them that I have seen are pretty deep marks.

If they get thinned or not, the last time I looked at the SCA rules, it says right in there that it does, and that a thicker blank must be used if you use a spun top.

Master Maelmarden looked at getting some made up localy (or maybe semi-localy) and got them priced down to like $20-$25 a pop. The kicker was that to get them that low he'd have needed an order of 500 of them or some other ridiculously huge number.

Maeryk · Post by **Maeryk** » Sun Dec 21, 2008 10:32 am

Lorenz De Thornham wrote:Just in passing, I believe there has been some research into some Roman helmets being spun.
Also on some Bascinets I have observed 'Lines' that are parallel and reminiscent of the results of polished up spinnings but cannot figure how they would have done it back then so l am still puzzled by these lines!

Same way they do it now, minus the electricity.

There's very little difference between a "spinning" set up and a wood lathe.. if you have the wood lathe, you can easily convert it to do spun metal.

The hardest part of the tech would be getting a flat uniform sheet to work with to begin with.

Maeryk · Post by **Maeryk** » Sun Dec 21, 2008 10:35 am

Lorenz De Thornham wrote:Watch out for the pointy headed people

I have heard or wood spinning lathes, I seem to remember being told of some guys in the States using them and sticks to apply the pressure, seems it would make a nice clean spinning without the lines left when done with metal tools?

Anybody know who was doing this?

I've done it on a converted wood lathe. The tool rest was replaced with a rest that had two vertical posts on it, to rock the tool on, and the "headstock" was a wooden form turned to what the eventual inside of the bowl was to be.

We used brass (IIRC) spoons, which left no real marks on the metal.

Lorenz De Thornham · Post by **Lorenz De Thornham** » Sun Dec 21, 2008 11:34 am

I heard ovals can be done also. I had a mandrel made and a bunch spun on it but was really not happy with the results, too thin and some split or split when working them so I never sold any on, just don't like the idea of someone being clobbered and partially scalped, made me think of some of the Indian stuff I have seen where they have polished through the weld!

The form though can be worked into any helmet shape, I cannot see the point in making a one piece then cutting it up?

The second video reminds me of another video I have seen where the form is underneath the sheet and is very slowly raised, the tool is spinning and gradually forces the metal over the form, seems an incredibly slow way of making anything to me, but interesting none the less.

Like the brass spoon idea!

Norman · Post by **Norman** » Mon Dec 22, 2008 1:33 pm

Lorenz De Thornham wrote:Just in passing, I believe there has been some research into some Roman helmets being spun.

Roman and Ottoman (Turkish)

And you can spin not just round - the Turkish ones are pointy (somewhat onion domish)

Lorenz De Thornham · Post by **Lorenz De Thornham** » Mon Dec 22, 2008 4:41 pm

Hi Norman, I was referring to the cross section, yeah lengthways they can be pretty much any shape, sometimes they even make a mandrel that is removable for vases and the like, should have got one of those lathes when I had the chance, but heck can't do everything!

Lorenz De Thornham · Post by **Lorenz De Thornham** » Wed Dec 24, 2008 10:53 am

The bit at the end is interesting; http://uk.youtube.com/watch?v=kqQdQYOPSzk

Baron Alcyoneus · Post by **Baron Alcyoneus** » Sat Dec 27, 2008 1:13 am

Cheeseburger.

That was a random answer for a random question.