Aces High Bulletin Board

General Forums => Aircraft and Vehicles => Topic started by: scottydawg on January 17, 2007, 07:39:01 AM

Title: Spinner Guns
Post by: scottydawg on January 17, 2007, 07:39:01 AM
Can anyone explain to me (or direct me to an explanation) how spinner guns work? Is the gun inside the engine?  I mean, a hollow crankshaft? Or is the reduction gear for the prop offset so that the gun is above or below the engine?

Thanks in advance.
Title: Spinner Guns
Post by: Viking on January 17, 2007, 09:33:46 AM
The latter.
Title: Spinner Guns
Post by: MiloMorai on January 17, 2007, 09:44:43 AM
Scotty how would a hollow crankshaft work? How does one time the 'bullets' to miss the connecting rods?

DB601 crankshaft
(http://www.enginehistory.org/Sarah%20Clark/Finding%20Aid/DB601Crank.jpg)

cutaway drawing of a Db engine, http://www.aviation-history.com/engines/db605.htm
Title: Spinner Guns
Post by: scottydawg on January 17, 2007, 10:44:48 AM
Quote
Originally posted by MiloMorai
Scotty how would a hollow crankshaft work? How does one time the 'bullets' to miss the connecting rods?

DB601 crankshaft
(http://www.enginehistory.org/Sarah%20Clark/Finding%20Aid/DB601Crank.jpg)

cutaway drawing of a Db engine, http://www.aviation-history.com/engines/db605.htm


Good point. Didn't really think about it.  So... do you have an answer or did you just post to tell me I'm a handsomehunk?
Title: Spinner Guns
Post by: MiloMorai on January 17, 2007, 12:12:48 PM
If you want to take that way OK. :rolleyes:

Take a look at the cutaway drawing which shows the position of the blast tube.
Title: Spinner Guns
Post by: Bronk on January 17, 2007, 12:17:06 PM
Bloody Germans and their upside down  engine.
:D

Bronk
Title: Spinner Guns
Post by: scottydawg on January 17, 2007, 12:24:16 PM
Quote
Originally posted by MiloMorai
If you want to take that way OK. :rolleyes:

Take a look at the cutaway drawing which shows the position of the blast tube.


I see. Thanks.  Overhead cams, eh? How German.
Title: Spinner Guns
Post by: Bronk on January 17, 2007, 12:35:35 PM
Quote
Originally posted by scottydawg
I see. Thanks.  Overhead cams, eh? How German.


Since it's an upside down engine .
Makes them  underhead cams. :D


Bronk
Title: Spinner Guns
Post by: scottydawg on January 17, 2007, 12:40:03 PM
Quote
Originally posted by Bronk
Since it's an upside down engine .
Makes them  underhead cams. :D


Bronk


:rofl :rofl  True.
Title: Spinner Guns
Post by: Krusty on January 17, 2007, 12:59:48 PM
A succinct way of saying it is that the engine is an "inverted-vee", and the gun sits between the arms of the "vee".
Title: Spinner Guns
Post by: Spikes on January 17, 2007, 06:10:26 PM
if its in the nose like a G14 and K4, id assume its just shooting out of it

sometimes if you look closely, you see the rounds spin a little
Title: Spinner Guns
Post by: Wes14 on January 17, 2007, 06:16:01 PM
Dude Spikes if its a rifled barrel its gonna spin no matter if the dam prop is spinning/stopped/full WEP:p
Title: Spinner Guns
Post by: Spikes on January 17, 2007, 06:16:52 PM
i mean that go in tiny circles
Title: Spinner Guns
Post by: mussie on January 18, 2007, 03:05:33 AM
From the same site:
(http://www.aviation-history.com/engines/v1710-5.jpg)

P-39 Engine, Driveshaft Reductionbox and hub Cannon

An interesting statment on the P40 From the same page as the above pic
Quote
The few turbo-supercharged Allisons that were made, were allocated to P-38s, making the high-altitude performance of that plane its best feature. All 14,000 P-40s got gear-driven superchargers, and as a result, were never first-class fighter planes. Donaldson R. Berlin, the P-40's designer, has said that P-40s experimentally equipped with turbo-superchargers outperformed Spitfires and Messerschmitts and that if it had been given the engine it was designed for, the P-40 would have been the greatest fighter of its era. This may be to some extent the bias of a proud parent, but there is no doubt that the deletion of the turbo-supercharger ruined the P-39 .
Title: Spinner Guns
Post by: 2bighorn on January 18, 2007, 06:45:18 AM
Quote
Originally posted by mussie
and that if it had been given the engine it was designed for, the P-40 would have been the greatest fighter of its era.
Blah, P-40 was nothing but P-36 with inline instead of radial engine.

YP-37 was build with turbosupercharged engine in mind but proved to be too much for Curtiss/Allison combo
Title: Spinner Guns
Post by: Krusty on January 18, 2007, 11:49:21 AM
Keep in mind these experimental types were done in '39 or so, when the only spits were the spit1s and the only me109s were either Ds or E-1 types.

It's very easy to believe a P40 can be inferior without turbo, and then become superior with turbo. They don't say by how much, all it would need is 10mph advantage, and that was easily attainable at that time.
Title: Spinner Guns
Post by: Apeking on January 18, 2007, 07:16:33 PM
(Picture of P39)

That rings a bell - is the 37mm cannon in the P39 the exact same 37mm cannon on the front of the game's PT boat? The ammunition magazine looks very similar.
Title: Spinner Guns
Post by: Tony Williams on January 20, 2007, 04:45:51 AM
Quote
Originally posted by Apeking
(Picture of P39)

That rings a bell - is the 37mm cannon in the P39 the exact same 37mm cannon on the front of the game's PT boat? The ammunition magazine looks very similar.

Probably - many PT boats were armed with the 37mm M4 designed for the P-39s. A few boats had the more powerful 37mm M9, which was designed for aircraft but didn't see service in them.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and discussion forum (http://forums.delphiforums.com/autogun/messages/)
Title: Spinner Guns
Post by: Tony Williams on January 20, 2007, 04:46:41 AM
Quote
Originally posted by scottydawg
I see. Thanks.  Overhead cams, eh? How German.


The Merlin had them too.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and discussion forum (http://forums.delphiforums.com/autogun/messages/)
Title: Spinner Guns
Post by: scottydawg on January 20, 2007, 07:52:42 AM
Quote
Originally posted by Tony Williams
The Merlin had them too.

Tony Williams: Military gun and ammunition website (http://www.quarry.nildram.co.uk) and discussion forum (http://forums.delphiforums.com/autogun/messages/)

I knew that.
Title: Spinner Guns
Post by: B3YT on January 22, 2007, 04:13:14 PM
so how did it work with the Rolls Royce kestral engines that were fitted to the spanish war 109's?
Title: Spinner Guns
Post by: Krusty on January 22, 2007, 04:28:02 PM
Buchons were bastardized 109s. Some Buchons based on G models had wing-mounted guns, some had gondolas. It wasn't a true 109. I wouldn't be surprised if they did not have the hub cannons installed, but it's still possible they figured something out.
Title: Spinner Guns
Post by: MiloMorai on January 22, 2007, 05:20:56 PM
Quote
Originally posted by B3YT
so how did it work with the Rolls Royce kestral engines that were fitted to the spanish war 109's?
The Bf109B-1 used a Jumo210 engine.

The Bf109As also used a Jumo engine.

The Bf109V1 used the Kestrel engine.
Title: Spinner Guns
Post by: JB35 on January 22, 2007, 05:56:26 PM
(http://upload.wikimedia.org/wikipedia/commons/c/c6/Daimler_Benz_DB_605.jpg)

Found this interesting