projectile testing - any volunteers?

[dewey-1]

Remember these?

jeepkahn was using these in this discussion, hence the CAD model.

Make your tailfin assembly and press fit it on!

http://www.spudfiles.com/forums/nail-da ... 19586.html

[jackssmirkingrevenge]

Use an aluminium sheet, should go through it like a nail through aluminium.

I see it's not just the government in the UK that lowers or redefines standards in order to appear to be meeting its targets ;P

Those ramsets might be just the ticket... (and lol @ that old discussion )

[al-xg]

Ram set nails are a pain to get in Europe.

I was planning on making a two part mould so my own plastic fins could be moulded straight on to the metal rod.

[Gun Freak]

I saw them at Home Depot a while ago, and thought of this thread

[Hotwired]

Just a masonry nail with a little plastic collar.

[dewey-1]

They are called powder pins in Europe.

http://powers.powerseurope.nl/index.php ... &prodId=35

[jackssmirkingrevenge]

Managed to retrieve a couple of fragments from the last test, clearly I had been overly optimistic about the size of parts I was looking for... two pieces from the wadding, and one of the rear fins

[dewey-1]

Here is a 3 inch Ramset variation for you.

[jackssmirkingrevenge]

Cheers Duane, brilliant work as always!

I see you've optimised it for 4 passes with a ball mill

Any idea how not "decapitating" the nail will affect CG vs CP?

[dewey-1]

You can always "square up" the fins after the ball mill cuts. The end tapers of fins are all at 22.5 degrees. A 1/2 inch ball mill would make the fins thinner.

You could trim the head down but that is such a small amount it may not have that much effect.

The greatest change of turning head down would be to get slightly taller fins and slightly lighter fin assembly.

How long was the fin assembly on your 3/4 prototype?
Have you located a local source for the Ramset nails, powder pins or masonry nails?

I will e-mail you a CP spreadsheet (xls) calculator to try out.

[POLAND_SPUD]

Remember these?

I hate to admitt it but ready made ammo might be the right solution - even if it isn't perfect it is bound to be cheaper than anything machined

[dewey-1]

Remember these?

I hate to admitt it but ready made ammo might be the right solution - even if it isn't perfect it is bound to be cheaper than anything machined

I agree but JSR needs something to justify his investment and besides it keeps him off the streets!

[jackssmirkingrevenge]

You can always "square up" the fins after the ball mill cuts.

Basically what I did with the last one I made.

How long was the fin assembly on your 3/4 prototype?

I can only tell you as much as the photos show :-/

Have you located a local source for the Ramset nails, powder pins or masonry nails?

What I have are masonry nails, I'm not sure the Ramsets are especially harder...

I will e-mail you a CP spreadsheet (xls) calculator to try out.

Received, cheers!

JSR needs something to justify his investment and besides it keeps him off the streets!

I will admit that I've found an evening of creating swarf is infinitely more enjoyable and satisfying than most social events, though there is a minimum level of liver abuse that has to be catered for

[al-xg]

Who needs a social life when you've got a lathe, eh ?

[Gun Freak]

JSR needs people to "test" the trinkets he turns out on his machines