Cyrano thread

[radlimus]

What kind of thread (size) has the cyrano speargun?
I mean the thread for the pump connection.

 

[devondave]

It's 14mm , ( size of the pump thread ) .

 

[radlimus]

Thank you for the information.
I need the exact describtion, diameter, thread pitch, form and winkle of the thread.

I want to build a connector.

 

[popgun pete]

I measured my "Cyrano" pump thread with vernier callipers, it is 14 mm OD and counting the threads there appear to be 10 per centimetre (M14). However you also need the nose diameter, 10 mm, that inserts into the well in the gun's inlet valve body and the dimensions of the "O" ring groove that holds the sealing "O" ring mounted on that nose. I am not taking the "O" ring off to measure the groove as it is hard to get if off without damaging the "O" ring. May I suggest you take a "Cyrano" pump end and have it copied, or use the pump end itself for the adaptor, you can unscrew it from the pump body. Unless you have a lathe and are a competent machinist I suggest you use an existing pump end. If you do not have the correct pump then look for one on eBay. People who have their guns stolen or lose them at sea often still have their hand pump, so there should be no problem in finding one. The later "Sten" series uses the same pump as does the Sporasub "Stealth", all guns issuing from the same factory.

 

[radlimus]

The size is: M14x1, i bought a screwing die (37 Euro:blackeye) and search now a 30 Bar compressor, maybe a fridge compressor will work.

 

[radlimus]

It is made!
Now i can fill my Cyrano with a small electric fridge compressor.
I will start a new thread a give more informations and maybe a few pictures.

 

[popgun pete]

Might I suggest that you incorporate an over-pressure or blow-off valve which you can set to the desired operating pressure in your speargun's connection to the modified fridge compressor. A lot will depend on the pressure pumping capability of the compressor, it may struggle to reach the desired operating pressure for the gun, so you will have plenty of time to switch the compressor off. Alternatively if high pressure is easily reached then the gun will pump up very rapidly, pneumatic spearguns only have a relatively small internal volume, so you do not want to overshoot the mark by too much. My experience with 12 volt portable compressors is that they struggle after 250 to 300 psi., so there is no danger of blowing the gun apart as they can usually take up to 600 psi. I do not know what the pressure capability of a fridge compressor is, but you need to be careful. This comment is more for the benefit of those readers who may know less about it than you do.

 

[slingshaft]

Radlimus, I'm really looking forward to details about your device! Cheers.

 

[popgun pete]

I just did a little research into fridge compressors, compression ratios are generally not cited because there is another term for measuring their function as a refrigeration unit which relates the (inlet) suction to (outlet) discharge pressure and is called the S/D ratio. In rotary (e.g. sliding vane) type pumps the S/D ratios appear to be between 4 and 6 depending on the particular unit. When using these fridge compressors as an air compressor they are no longer in a closed circuit moving already pressurised gas around (Freon was one type of refrigerant, but is no longer used as CFC's were banned due to their ozone depleting effects). Instead these units are pulling atmospheric air at the inlet and discharging pressurised air at the outlet. The compression ratio is then about 10:1 or a pressure of 10 Bar at the outlet, however it depends on the type of compressor being used in the actual fridge unit being modified. People convert these units for air delivery systems in a range of applications judging from various forum discussions about them, principally because the compressors can be cheaply sourced from scrapped refrigerator units after the gas has been purged from the balance of the refrigeration system. It will be interesting to learn what pressure you can get your converted system to pump to.

 

[radlimus]

Hi,
here some details:

I put the compressor on a wooden board.
The compressor has 95 Watt and need 220 Volt.
I took the compressor out of a fridge.
the other parts are selfmade or modified bicycle parts.

The manometer is a modified air hand compressor for bicycle suspension units, the max. pressure is 28 bars but it work also with 30 Bars.
I can reduce the pressure if necessary with the red button.
The tube is a hydraulic tube of a hydraulic bicycle brake.

This is the M14x1 connector between the speargun and the compressor.

I put the hole units in a metall case.

The compressor works fine but need about 30 seconds to get warm.
Maybe it a problem of the very cold conditions in my workshop:head.
In less than a minute i reached 28 Bars.
I got the idear from clever italian spearfishing forum posts, there are a lot of similar constructions, all of these are working.
You find in youtube interesting videos, filling compressor and more.

:naughtyBut you have to be very carefully, pressure is energy and 30 Bars can made a lot of trouble.....

You have to use hydraulik parts and check the system very often.
I have experience with high pressure system and know what i do (i believe that, not my wife..:t).
Feel free to ask me if you have more questions about the compressor.

 

[popgun pete]

Wow, 28 Bar is great, that unit will do all that you want in terms of pressurising a pneumatic speargun. That is over 400 psi. Do you know what type of compressor unit is inside the black housing? I know that it is an ex-fridge unit, but there seems to a range of compressor types used over the years, rotary compressors replacing reciprocating piston types in domestic or household units.

 

[radlimus]

I don`t know what kind of compressor is inside.
It is not possible to open the unit.
The fridge and the compressor are a little bit older, i will have a closer look at the type label and will post all informations.

 

[fjohnson]

good going! looks simple enough.
Fred

 

[radlimus]

Wow, 28 Bar is great, that unit will do all that you want in terms of pressurising a pneumatic speargun. That is over 400 psi. Do you know what type of compressor unit is inside the black housing? I know that it is an ex-fridge unit, but there seems to a range of compressor types used over the years, rotary compressors replacing reciprocating piston types in domestic or household units.

Type label:
ZEM
220V 50Hz
Cl.B 019 R12
S33 601
95W 0,65A
0058137

I think the best way would be to organize a fridge compressor and to try out. Good luck!
Maybe i build a second one, let´s recycle fridge compressors!
There is a second life for fridge compressors.....

 

[Old Man Dave]

Great info radlimus. I think a lot of old fridge compressors are going to have a new life.

Dave.

 

[radlimus]

Here is my building instruction in german:
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Bauanleitung

Bauteile:
1 Kompressor
1 Holzplatte
1 Dämpferpumpe (Comus, BBB)
1 Magura Hydraulikleitung (Niederdruck) Maguranummer: 0321227
1 Magura Füllstutzen von einer Scheibenbremse Louise 2001
1 Magura Leitungsstutzen (Felgenbremse) 0720411
1 Schalter (230V 100 Watt)
1 Kabel mit Stecker
1 Verbindungsbuchse (Messsingmutter)
1 Fahrradspeiche 2.0
1 Fülladapter Dämpferpumpe-Harpune
1 O-Ring
4 Holzschrauben
4 Unterlagscheiben
4 Gummipuffer

Werkzeuge:
Handsäge
Kreutzschlitzschraubendreher
Gewindebohrer M4
Gewindeschneider M14x1
Lochtalk (Schraubensicherungslack hochfest)
Entfetter
Drehbank

Kompressor aus einem Kühlschrank ausbauen, Verbindungen trennen, Kühlschrankkabel aufbewahren. Öl aus dem Kompressor ausleeren. Elektrische Leitung mit Schalten anschließen und Kompressor testweise laufen lassen. Kopressor mit den Holzschrauben auf eine Holzplatte schrauben Gummipuffer und Unterlagscheiben dabei verwenden). Luftansaugleitung sehr kurz absägen.
Die Luftausgangsleitung hat einen Überlappungsbereich, hier ist die Wandstärke der Leitung doppelt so stark. In diesem Bereich wird in die Leitung ein M4 Gewinde geschnitten (Innengewinde). Innengewinde entfetten. Hydraulikleitung ablängen. Louise Füllstutzen in die Hydraulikleitung einschlagen, Leitungsstutzen in die Leitung einschlagen.
Dämpferpumpe: Handstück entfernen und Zylinder kürzen, aus der Messingmutter den Innendurchmesser des Zylinders ausdrehen, Anschlußgewinde für den Leitungsstutzen reinschneiden. Messingmutter mit dem Schraubensicherungslack auf dem Pumpenzylinder aufkleben. Leitungsstutzen auf die Messinmutter verkleben.
Hochdruckpumpe: Der originale Stift für die Druckbeaufschlagung ist zu kurz und wird abgedreht und durch ein passendes Stück Fahrradspeiche 2.0 ersetzt (eingeklebt).
Den fülladapter zwischen Hochdruckpumpe und Harpune benötigt ein M14x1 Gewinde, eventuell kann dieses Bauteil auch aus der Harpunen Pumpe gefertigt werden.
Fertig! :friday
Die Magura Bauteile haben eine Drucksicherheit von 60 Bar.
Den fertigen Füllkompressor testweise in 4 Bar Schritten die Harpune füllen lassen und immer wieder auf Undichtigkeiten prüfen.
In meinem Fall war es wegen der großen Kälte notwendig den Kompressor einige Sekunden erst warmlaufen zu lassen bis er richtig Druck erzeugen konnte. Wie auf den Bildern zu sehen habe ich das Ganze in einen Koffer gepackt um es besser verwahren zu können. Die Fülldauer für eine Harpunenfüllung beträgt ca. 1 Minute. In meinem Fall ist der Fülladapter nicht mit der Hochdruckpumpe verbunden, wenn man nur 1 Fülladapter hat kann man aber die 2 Bauteile miteinander verkleben.
Die Dämpferpumpe ist im Fahrradfachhandel erhältlich und wird von mehreren Firmen angeboten (Comus und BBB), der Manometer ist bei BBB bis 30 Bar ausgelegt (Comus 28 Bar). Die Dämpferpumpe kostet ca. 30 Euro.




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