Basically will in a lathe a round sheet of metal (blank), be spun over a form (mandrel). This will be done successively, with the help of a handhold spinning tool. The movements of the tool, has to be smooth and even, otherwise could the material crack or be deformated. At more advanced spinning, will the form only give minor support. Often has the spinner to work in several steps, then with different tools.

In the image are A the lathes headstock, B is a mandrel (form to spin on). C is a follower. This will press the round sheet (blank) firmly, between the mandrel and the tailstock. D is the shaft of the tailstock. Number 1-5 shows different stages, when the round sheet changes into an item.

 

 


afTRYCK

afTRYCK Metal Spinning

The following comes from afTRYCK, which you can download HERE. There are only parts visible here, without any real links between them.

 

 afTRYCK Metal Spinning
HISTORY 2
More reliable proof comes from the Roman Empire. The helmets carried by the legioners were to some extent made by spinning. This at least when we talk of such made of brass. Helmets of steel should by some information, been to hard to work. The quality of aviable materials may also be something to consider. Metal spinning demands sheets of good standard. I presume that most items of this sort were battered with a hammer. Items as helmets were though made in large numbers. As maybe the only alternative, must spinning have been a radical step forward.

 
Well it`s known that the Romans used waterpower to run other kinds of machinery. In theory so could the streaming water had been the provider for work of heavier spinning. But if this was anytime a reality, is a totaly different question.
afTRYCK Metal Spinning

HISTORY 9
When we now take a look into the industrial days, so will we  meet a flat-belt driven lathe, that get its power from above.  This was a product of the 1800-s but was still hanging around  a good way into the next century. The point of using one central  power-supplier, feeding several machines, was most of all  economical.
 
The picture shows a headstock with different sized pulleys.  From one of them is a flat-belt seeking its way upwards to  the transmission.

afTRYCK Metal Spinning
SPINNING 4
When a blank (the work-piece) are located at its position (between the mandrel and a follower) will it often be somewhat of-centre. This is corrected by loosing somewhat on the tailstocks wheel, and then with a
tool pushing the blank into a centered position. This tool can be a piece of steelrod or similar.

 

The work-piece has in most cases to be lubricated. This to reduce the friction that occures between the tool and the blank. A good lubricator should be so stiff that it not splashing around. A smaller amount are often better then the opposite. It shall also be easy to remove afterwards.

afTRYCK Metal Spinning

SPINNING 10
If you can´t make it in one step, do it in twice (or more).  Here has the part been pre-spun once, and then placed over  a second mandrel (dividable or only partly supporting), to  be worked once more.
 
Spinning with only partly support of a form (mandrel) can be seen as "spinning in the air".

afTRYCK Metal Spinning

EQUIPMENT 1
The metal spinning lathe, can be described as more of a  sturdy wooden-lathe, then an ordinary metal (capstan) one.  Special features are the robust tailstock and the toolrest  with holes (for a supporting steelpin).
 
The picture shows a lathe with:
1- Headstock/Transmission housing
2- Mandrel(form you spin on)
3- Follower(Holdes the blank between the mandrel and the  
   tailstock)
4- Tailstock
5- Toolrest/Toolpost

 

afTRYCK Metal Spinning
EQUIPMENT 10
To fold back a rim and for example make it rounded, will a special tool be used. These can be fixed, but also in form of a rotating role. The picture shows only the tip of the tools. In reality has they a  long wooden handle, similar to the spinning tool. 

 

You can though fold a rim with just a piece of wood or a bit of flat metal. But the quality of the work will in the long run, probably be better with real equipment.

 

afTRYCK Metal Spinning
SUPPLEMENT 1
Different shapes makes the work more or less easy. If you have high demands on looks and measures, so is a cylinder somewhat harder then a taper. This because a straight surface unveils even smaller misstakes. The taper are good in such a way that it gives more and more support, during work. 

 

The item down-below are a half-deep dish/plate. These items are normaly only spun a short distance and has also good support from the mandrel and follower. But the diameter of the blanks can be quite big, so folding a rim on a large item like this can be heavy.

 

WORDLIST ENGLISH-SWEDISH

 Acid flux - Lödsyra
 Adjustment - Inställning
 Alloy - Legering
 Aluminium sheet - Aluminiumplåt
 Anneal - Glödga
 Argentan - Nysilver
 Artisan - Hantverkare
 Axelshaft - Drivaxel
 Ball bearing - Kullager
 Bearing housing - Lagerhus
 Bearing play - Lagerspel
 Base metal - Oädel  metall
 Bevel - Fas
 Blunt edge - Slö egg
 Border - Kant
 Brass sheet - Mässingsplåt
 Brazing - Slaglödning
 Burr - Grad, Skägg
 Calipers - Krumcirkel
 Candlestick - Ljusstake  
 Centralizer - Centreringsverktyg
 Centre - Dubb
 Centre distance - Dubbavstånd
 Centre height above bed - Dubbhöjd över prisma
 Clamp - Klämma
 Clamping plate - Planskiva
 Coarce thread - Grovgänga
 Concave - Konkav
 Convex - Konvex
 Copper sheet - Kopparplåt
 Craftsman - Hantverkare
 Cup - Bägare
 Curve shears - Rondellsax
 Deburring - Avgradning
 Dimension - Mått
 Easy to work - Lättbearbetad
 Edge(on sharp tool) - Egg
 Edge - Kant
 Female thread - Muttergänga
 Flange - Fläns  
 Flaw - (Metall)blåsa
 Follower - Försättare
 Handle - Handtag
 Hand wrought - Handsmidd
 Hardening - Härdning
 Hard to work - Svårbearbetad
 Jaw - Chuck
 Joint - Fog
 Jug - Kanna
 Lap - Fog
 Lapjoint - Falsfog
 Lathe - Svarv
 Linear measure - Längdmått
 Mandrel - Patron
 Metal circular blank - Rondell
 Metal spinner - Trycksvarvare, Metalltryckare
 Metal spinning - Trycksvarvning, Metalltryckning
 Nickle clad sheet - Förnicklad plåt
 Nipple for greasegun - Smörjnippel
 Of even thickness - Jämntjock  
 Ovality - Orundhet
 Pewter sheet - Tennplåt
 Play - Spel
 Pitch of centres - Dubbhöjd
 Precious metall - Ädelmetall
 Pulley - Remskiva
 Right hand thread - Högergänga
 Rivet - Nit
 Rolling mill - Plåtvalsverk
 R.P.M.(Rotations per minute) - Varv per minut
 Seam - Söm
 Shavings - (Metall)spån
 Smooth grinding - Blankpolering
 Solder - Lod, Lödtråd
 Soldered seam - Lödfog
 Soldering wire - Lödtråd
 Spelter solder - Mjuklod
 Spinning - Tryckning
 Spinning tool - Tryckstål
 Steel sheet - Stålplåt  
 Sweated together - Mjuklödd
 Tailstock - Dubbdocka
 Tailstock live centre - Roterande dubb
 Taper - Kona
 The lead of the thread - Gängstigning
 Thread - Gänga
 To batter - Driva
 To beat out bosses - Hammra ut bucklor
 To clamp - Spänna fast
 To cold work - Kallbearbeta
 To cut off - Kapa av
 To flat polish - Mattpolera
 To put together - Montera (ihop)
 To soft anneal - Mjukglödga
 To solder - Löda
 To tighten - Dra fast
 Toolpost - Anhåll
 Toolrest - Anhåll
 Warped - Skev
 Waste metal - Metallskrot 

 


METAL SPINNING 1912


By clicking the link HERE, can you study a section of the book METAL SPINNING PRINCIPLES OF THE ART, AND TOOLS AND METHODS USED (second edition, 1912). The text is probably written 1909, which gives an insight in how metal spinning was described more then a century ago.

 

 

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