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Posted: Sat May 05, 2012 2:21 pm
by POLAND_SPUD
above 35mm is uncomfortable to machine on a small lathe
omg why use a lathe?? just use pvc/copper pipe, nose cone plus fins

Posted: Sat May 05, 2012 2:31 pm
by Petitlu
Ok
So the 30 or 33 mm inside
33mm best ..

Posted: Sat May 05, 2012 3:11 pm
by jackssmirkingrevenge
POLAND_SPUD wrote:omg why use a lathe?? just use pvc/copper pipe, nose cone plus fins
The idea is to use existing pipe for the body and machine the nose cone and fins, the latter would be sort of... on a lathe ;)

Posted: Tue May 08, 2012 8:58 am
by POLAND_SPUD
lol ramjet ammo - check the last two pages
http://www.dtic.mil/ndia/2004armaments/ ... n_COOP.pdf

Posted: Tue May 08, 2012 9:59 am
by jackssmirkingrevenge
POLAND_SPUD wrote:lol ramjet ammo
Comparing that to the Oto Melara Vulcano round actually ties in nicely with the scope of this thread.

Image

[youtube][/youtube]

It avoids the weight and complexity of having on-board propulsion such as rocket assisted rounds or the ramjet rounds you linked to, but still achieves tremendous range - 70km in a ballistic trajectory. By adding guidance that would allow the projectile to glide, this would extend it even further.

The Nazis were w-a-a-a-a-a-ay ahead of their time:

Posted: Tue May 08, 2012 10:23 am
by POLAND_SPUD
2:00 - 2:12 -> I think they explain what I meantioned earlier as far as gliding ammo is concerned - it needs some sort of guidance

damn you JSR I though I found something interesting and then you post this

though I am pretty sure you find it even more fap worthy than I do
lol at first I wrote 'more fap worthy than me' but then I realised what would you do with that

Posted: Tue May 08, 2012 10:38 am
by dewey-1
POLAND_SPUD wrote:I think they explain what I meantioned earlier as far as gliding ammo is concerned
damn you JSR I though I found something interesting and then you post this
And you criticize my spelling! :D
Got you! Fat fingers or Vodka?

Posted: Tue May 08, 2012 10:39 am
by al-xg
As a bit of a tangent from the reccord setting ranges, something like this would be pretty amazing fired from some sort of canon :)
[youtube][/youtube]

Of course larger bore, lower velocity and lower acceleration on launch would be requisites. You'd probably have to start off very slow, a lot could go wrong.

Anyone got some FPV gear ? :D

Posted: Tue May 08, 2012 11:30 am
by jackssmirkingrevenge
POLAND_SPUD wrote:2:00 - 2:12 -> I think they explain what I meantioned earlier as far as gliding ammo is concerned - it needs some sort of guidance
I'm quite sure that a properly trimmed projectile will glide without the need for guidance. The problem is that once you introduce lift dependent flight, the projectile becomes much more susceptible to environmental factors like wind and air pressure, so realistic accuracy is not achievable without guidance.
And you criticize my spelling! :D
He has the "but I'm not a native speaker! *hic*" defence :D
As a bit of a tangent from the reccord setting ranges, something like this would be pretty amazing fired from some sort of cannon
Awesome :D but it seems like a waste of RC gear for such a short flight.

Posted: Tue May 08, 2012 12:26 pm
by POLAND_SPUD
He has the "but I'm not a native speaker! *hic*" defence
Hey I am a Pole but I haven't drunk anything (yet) :-D
Awesome Very Happy but it seems like a waste of RC gear for such a short flight.
Sure but if you think of it you might as well put two servos on a projectile ;-)

Posted: Wed May 09, 2012 11:33 am
by jackssmirkingrevenge
Lookie what arrived from down under :D

Pretty compact... my only concern is the coil, apparently it cannot be potted.

Dewey, help? I've never really put a circuit together before, any basic advice?

Image

Posted: Wed May 09, 2012 5:42 pm
by dewey-1
Where to start?

Assuming you have a soldering iron of 25 to 50 Watt and the correct rosin core electronic solder (60-40 or 63-37) of about 1mm diameter then please start reading these links.

First: http://www.mil.ufl.edu/5666/6270/6.270B ... npter3.pdf

Second: http://www.1728.org/resisclr.htm

I recommend doing the coil as the last item to solder.
Build it to what the instruction sheet shows.

Post close up pictures of resistors or other components if you have problems with them.

Here is some more information based on parts list.

http://talkingelectronics.com/projects/ ... acker.html

PARTS LIST
1 - 220R (Red, Red, Brown, Gold)
1 - 330R (Orange, Orange, Brown, Gold)
2 - 1k (Brown, Black, Red. Gold)
1 - 47k (Yellow, Violet, Orange, Gold)
1 - 220k (Red, Red, Yellow, Gold)
1 - 5p6 ceramic
1 - 10p ceramic
1 - 39p ceramic
1 - 1n ceramic
1 - 22n ceramic
1 - 10u 16v PC mount electrolytic (Note Polarity!)
1 - 22u 16v PC mount electrolytic (Note Polarity!)
2 - BC 547 transistors (Note Polarity!)
1 - BC 557 transistor (Note Polarity!)
1 - 5 turn, 3mm dia enamelled wire (Put in last!)

Posted: Wed May 09, 2012 11:53 pm
by jackssmirkingrevenge
Cheers!

Especially for translating the colour coding on the resistors...

Silly question, should I strip off the enamel at the point where I solder the coil?

Posted: Thu May 10, 2012 12:59 am
by dewey-1
Definitely yes.

The color code was easy to remember even when I learned it as teenager.
You should easily remember this too.
It was used by the US miltary Electronic instructors during WWII.

Bad-------Black
Boys------Brown
Rap#-----Red
Our-------Orange
Young----Yellow
Girls------Green
But-------Blue
Violet----Violet
Gives-----Grey
Willingly-White

Posted: Thu May 10, 2012 1:04 am
by Petitlu
it is even more complicated for me!
:D