Spinner-mounted cannon questions

[Lusche]

Originally posted by BaldEagl
Thanks Lusche.  Great diagram.

One last question then.  Was there something to guide the bullet to the spinner?  Surely it didn't "free-fly" from the muzzel.  That would seem pretty dangerous while manouvering but it would also seem that any type of "guidance" would also have an adverse effect and would have to be within pretty close tolerences.

As far as I know it's just a hollow tube. Any kind of "guidance" would not be different from being a barrel itself.

Remember that even a slow MK108 round has a minimum muzzle velocity of 500 m/s. Even when assuming that the distance between end of actual barrel and the muzzle at the spinner is 2m (probably more like 1m), the round would need only 0.004 seconds for that distance.

[Tilt]

Originally posted by BaldEagl
Thanks Lusche.  Great diagram.

One last question then.  Was there something to guide the bullet to the spinner?  

On Yaks and Lagg3's the barrel protruded right thru the spinner.

Particularly noticable on the Yak9T (even more so on the 45mm version)

[Greebo]

There would have been a blast tube from the barrel to the end of the spinner to protect the engine from the muzzle blast.

[Hornet33]

Originally posted by Geary420
Have you ever seen a crank shaft before?  Unless they have magical bullets I don't see that one working out so well.

Sorry was thinking prop shaft when I wrote that....oppps

[Zwerg]

See here:
http://forums.hitechcreations.com/forums/showthread.php?s=&threadid=194726

And here (2nd link in 1st post):
http://www.xs4all.nl/~rhorta/wk4.htm

[Stoney74]

Oddly enough, once the cannon was mounted, its BZO couldn't be changed.  I believe the factory range was set for 400 meters.  And yet, we can move the distance in or out in AH.

[wrag]

Originally posted by Hornet33
The hub firing cannons actually fired through a hollow crank shaft in the engine. The weapon was mounted directly behind the engine.

I've always had a problem with that explanation.

If it ACTUALLY passed through the crank shaft of a DB engine then that is one strange shaped crankshaft!

And I've seen pictures of a DB crankshaft.

Don't think it's possible!

Why?  Take a look at a CRANKSHAFT!

If you try to put something straight through a crankshaft then the piston rods, as they CIRCLE around will hit it, OR the crankshaft will NOT turn.

Most pictures I've seen the engine is inverted and the cannon LOOKS like it might pass through the oil pan, but looks more like it sets just above the crankshaft and passes through the reduction gear.

If I'm wrong PLEASE show me a picture of said creation.

[A8balls]

You have it right Wrag. The barrel passed thru the "lifter valley", between the cylinders and through the reduction assy. Although it seems, when I'm at the rifle range, the barrel of my Garand IS running thru a crankshaft.

[Wayout]

[Treize69]

Originally posted by Wayout

Thats like porn to aerophiles...

[Widewing]

In both the DB 601 and the DB 605, the most common versions, the cannon was installed behind the engine. Rounds fired passed through a blast tube located in the V of the block, between the cylinders and heads. Rounds exited through the hollow prop shaft in the reduction gear.

The image below is an early 109F-1, with the 15mm cannon installed. the 20mm was installed in like manner.



This image shows the DB 601 turned upside down. You can see the propshaft  centerline is outside the engine block. A tube is installed in the V, through the propshaft.



In this last image, you see a cut-away DB 601. You can clearly see that the crankshaft is well above the centerline of the propshaft.



My regards,

Widewing

[BaldEagl]

Thank you all.  Very informative and answered most of my questions.