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Allegro Razor Blade Sharpener

Swiss precision from the last century

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Danny M2Z25/03/2015 11:48:36
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892 forum posts
283 photos

Allegro razor blade sharpener.

Until relatively recently, razor blades for 'safety razors' were made from carbon steel.

I use them for cutting 'indoor' grades of carefully selected (expensive) balsa wood for competition model aircraft (Class F1D, designed to fly indoors for +30 minutes using rubber power).

It is important to make a 'clean' joint with no crushing for Unlike stainless steel razor blades, carbon steel razor blades may be 'snapped' to a very fine point, which is very useful for my hobby. It is also useful for sharpening small double edged model plane blades.

A lovely lady friend gave me this razor blade sharpening device that she had inherited from her father-in-law who was a Norwegian trawler captain during WWII.

I was/am fascinated by this precision tool and did some homework. In WWII steel and razor blades were in short supply so many a device was utilised to re-sharpen razor blades to gain a few more shaves.

As the first photograph illustrates, razor blade manufacturers were forced to reduce the thickness of blades due to wartime steel shortages.

Rubbing a blade around the inside of a glass was a popular trick and I found a few commercial sharpeners based on this technique, but my Allegro is very special. It's Swiss ancestry dates back to 1927.

It has a carrier that wipes the blade across a diagonal 3 position stone (coarse, fine and leather strop) tilts the blade on the return stroke for the other edge (via a cam) and at the end of the return stroke the blade is flipped 180 deg to repeat the process for the other side.

It also has a variable 3-position adjustment for blade pressure and replacement stone assemblies were available on request. Pure Swiss precision.

If you know anybody who flies competition indoor free flight models (F1D, EZB etc), watch their eyes light up if you offer them some unused carbon-steel razor blades!

* Danny M *

thinner wwii blades.jpg

allegro - 01.jpgallegro blade carrier.jpgallegro - lower edge of blade wiping stone.jpgallegro - other edge of blade wiping stone on return stroke.jpgallegro blade mounted.jpgallegro - blade flipping over at end of stroke.jpg

allegro - blade pressure adjustment.jpg

Michael Gilligan25/03/2015 11:59:51
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16365 forum posts
714 photos

Thanks for starting this, Danny

... I will be back.

MichaelG.

Versaboss25/03/2015 12:48:31
458 forum posts
51 photos

Memories...

I remember my father used exactly the same apparatus and I was very fascinated about how it worked.

Say around 1950 that was...

Unfortunately I have no idea what happened with it later when my father bought an electric Philips shaver.

Regards, HansR.

pgk pgk25/03/2015 12:50:39
1912 forum posts
288 photos

My dad had a block of green glass with a curved inwards radius to rehone his blades. Woolworths 5 o'clock brand if memory serves....

I recall ophthalmic surgical kits in the late 60's (still) having a kidskin drum for testing the sharpness of a reusable scalpel before attacking a cornea...

Nigel Bennett25/03/2015 13:01:28
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362 forum posts
11 photos

A story I heard was about a chap in the Army during the war. He used to write to all manner of companies, back home, saying how wonderful their products were. The flattery produced results - he got loads of stuff sent to him by companies. He met his match with Wilkinson Sword, however. He wrote to them, saying that their blades were excellent; he had only got one razor blade, and it had lasted for six months.

Wilkinson sword wrote back, thanking him for his kind words. Enclosed with the letter was a single razor blade, with words to the effect of "Please find enclosed a further six months supply..."

Edited By Nigel Bennett on 25/03/2015 13:01:58

Gordon W25/03/2015 14:01:38
2011 forum posts

I had one of the sharpeners when I was a kid, did not know what it was, now long gone. Don't have time to shave now. Off-topic, who made a semi-conductor for a crystal set by scratching a razor blade ?

Neil Wyatt25/03/2015 14:03:34
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18232 forum posts
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I have a Rolls Razor which combines a hefty hollow-ground blade (with a wire safety bar) and a case that provides semi-automatic grinding and honing. Sadly the honing strop is broken.

No, I haven't used it in anger!

Neil

Jon Gibbs25/03/2015 14:14:56
739 forum posts

Neil,

My old Dad used to have a Rolls too. Natty piece of kit and I have no idea what became of it.

Jon

Phil Whitley25/03/2015 17:05:42
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1257 forum posts
147 photos

Hi All, Gordon W I would like to know more about the scratched razor blade semiconductor, Do tell us!

Phil

UK

KWIL25/03/2015 19:29:38
3308 forum posts
63 photos

Surgical scalpels offer extremely fine and very sharp edges. Surgical stitch cutters have a curved and very fine point which can be very useful.

Clive Foster25/03/2015 21:18:24
2373 forum posts
76 photos

My godfather swore by his Rolls Razor, my father swore at his! Different folk have different opinions. However godfathers one was got new, used and honed as per book (after every shave?) whilst Dad got his used from a workmate so it may not have been correctly looked after. Allegedly it took very little deviation from proper care to spoil a Rolls to the extent that it would never shave properly again. Possibly a major reason why they fell off the market. Razor production ceased before the notorious asset stripping I think.

Dad switched to a Phillishave and never looked back until having to switch to wet shave in his mid fifties. Same for me. Neither Dad or I could get a shave with a foil head razor although my brother does just fine with a foil yet can't get a shave with a rotary. Beards are funny. These days I get several months out of a mach 3 Gillett head.

Clive

Bill Pudney25/03/2015 23:59:20
464 forum posts
16 photos

I once worked at a company where the previous program, before I started there, had been the design and build of a machine to put the final edge on carbon steel razor blades. Not the SS ones, but the proper, double edged blades carbon steel ones that Danny mentions.

By the time that I got there, the machine had been delivered, but they hadn't tidied up after it. As a result there was a steel mesh stillage, it would be familiar to anyone in industry, about 1.5 metres square by about 1 metre deep, full of double edged carbon steel sharpened blades. On the First Day Guided Tour, I was told "help yourself, they're going for scrap next week". This was about 1973 or 4, at the time I wasn't into aeromodelling, otherwise I would have snaffled the lot!!

Anyway, there we go!

cheers

Bill

ronan walsh26/03/2015 00:05:29
542 forum posts
32 photos

I still use a de safety razor. I find if you take your time with it, it gives a lovely shave, rush it and it will end in a bloodbath. The blades are also remarkably cheap compared to the latest ones with 3, 4 or 5 blades in each "cartridge" that are advertised by football players on the telly. I can buy a dozen de blades for about a fiver, compared to well over a tenner for 3 of the fancy type.

Using old shaving tackle is making a comeback, its almost like a hobby, a lot are using the old straight or cutthroat razors. Wouldn't have the courage for one of those myself.

 

http://www.shaving-shack.com/straight-razors-cut-throat-razors/

Edited By ronan walsh on 26/03/2015 00:08:04

Alan Johnson 726/03/2015 02:40:30
92 forum posts
13 photos

Razor blades are still sold in Malaysia. I have a fried here who uses them. Perhaps they are also availabe in other parts of the world.

Gordon W26/03/2015 10:02:04
2011 forum posts

Razor blade semi-conductor- I just assumed all you older electronic types would know, sorry if you are young. It was a common thing when I was young, just after the war (2nd). The blade was scratched and this corroded, a thin wire was put on the scratch, then wiggled about until a signal was picked up. A more modern take on the "cat's whisker" and a substitute for a diode in a basic crystal set radio. A proper diode was a weeks pocket money, a transistor ,when they came on the market, was a weeks paper round. BTW the razor blade seldom worked.

ronan walsh26/03/2015 20:58:49
542 forum posts
32 photos
Posted by Gordon W on 26/03/2015 10:02:04:

Razor blade semi-conductor- I just assumed all you older electronic types would know, sorry if you are young. It was a common thing when I was young, just after the war (2nd). The blade was scratched and this corroded, a thin wire was put on the scratch, then wiggled about until a signal was picked up. A more modern take on the "cat's whisker" and a substitute for a diode in a basic crystal set radio. A proper diode was a weeks pocket money, a transistor ,when they came on the market, was a weeks paper round. BTW the razor blade seldom worked.

when i was messing about as a kid with crystal sets, i used to use a bit of coke from the fireplace. I believe this is how the pow's in prison camps all over the world did it during the war.

jason udall26/03/2015 22:22:24
2026 forum posts
41 photos

try googling FOX HOLE RADIO.

i personally think crystal radios worked better when less stations were in use and when transmitters were more powerful...(see less stations above)...

with modern diodes( gold doped germanium) i have had little success for broadcast stations..taxis and the like..yeah but broadcast ..no

ronan walsh26/03/2015 23:06:33
542 forum posts
32 photos
Posted by jason udall on 26/03/2015 22:22:24:

try googling FOX HOLE RADIO.

i personally think crystal radios worked better when less stations were in use and when transmitters were more powerful...(see less stations above)...

with modern diodes( gold doped germanium) i have had little success for broadcast stations..taxis and the like..yeah but broadcast ..no

Thats a pity, but all you need is bbc radio 4, its like going back to the 50's !

Neil Wyatt27/03/2015 08:10:15
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18232 forum posts
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I rigged up a crystal radio a couple of years ago using an 'electronics kit' bought at a bootsale for a pound. It picked up remarkably well, I'm sure got some foreign voices - this was with about 40 feet of aerial and a proper ground stake.

Neil

ronan walsh28/03/2015 14:23:39
542 forum posts
32 photos
Posted by Neil Wyatt on 27/03/2015 08:10:15:

I rigged up a crystal radio a couple of years ago using an 'electronics kit' bought at a bootsale for a pound. It picked up remarkably well, I'm sure got some foreign voices - this was with about 40 feet of aerial and a proper ground stake.

Neil

Yup, that was my finding too, a good long wire aerial, well insulated at both ends, and a good earth, a bit of copper mesh buried in the ground is recommended. Sadly in this new fangled world of the iphone and t'internet, kids wouldn't have much time for messing about with crystal sets anymore.

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