SpudFiles

dewey-1 wrote:The rear seal could be either an o-ring or a flexible flat disk attached near the back of the sabot. I initially considered drawing that it but decided to leave out. I will update the model to show a seal.

A 16 ga shotgun shell cartridge is about the right size for 3/4 in Type M copper barrel. With a rim OD of .815 inch, trim the rim to fit your barrel.

http://www.dave-cushman.net/shot/shotshellloads.html

Go with a pound of flechettes and 16 ga used shot gun shells.

I tried this as a wad:



( Very easy to make)

The cg was not far enough forward and it tumbled.

How do you keep the $8.95/pound Flechette centered as it is driven down the barrel?

BTW Good thread.

Thank you dewey-1 for your great ideas an drawings.


BoyntonStu

Here you go dewey... shaft diameter is .15", point taper length is .35", head diameter is .29", "fin" diameter is .405", fin/collar length is .35", collar "sleeve" diameter is .205"(when on shaft), head thickness of nail is .10", overall length is 3.10"....

Weight cg is rendered moot, even at 100+ yds they penetrate straight in, no tumble whatsoever...

Anything else???

jeepkahn wrote:Here you go dewey... shaft diameter is .15", point taper length is .35", head diameter is .29", "fin" diameter is .405", fin/collar length is .35", collar "sleeve" diameter is .205"(when on shaft), head thickness of nail is .10", overall length is 3.10"....

Weight cg is rendered moot, even at 100+ yds they penetrate straight in, no tumble whatsoever...

Anything else???

i like your dart design.

Anything else???

The dart looks like a winner in flight.

Where do we get the fins?

Next question; The nail hea and the fins in a 0.811' ID copper barrel will let most of the air bypass the dart.

What would you suggest to seal the dart ride down to the muzzle?

BoyntonStu

I'd use an empty shotgun shell(as suggested earlier), with the plastic split on 4 sides, and use 3/4" foam pipe wrap split into 2 pieces, to hold it centered inside the shell...

psycix wrote:What the heck do you use your towels for!?
Actually, I do not want you to answer that question. Go play with your towels or epoxy or something.


I've successfully stabilized a drill bit with a simple piece of rope. Stabilizing is easier then most people think.

Please elaborate and a photo would be appreciated.

BoyntonStu

boyntonstu wrote:

psycix wrote:What the heck do you use your towels for!?
. Go play with your towels or epoxy or something.

Please elaborate and a photo would be appreciated.

BoyntonStu

NOOOOOoooo!!!! No Pictures of JSR and what he's using towels for...

what are those nails sold as?

and no pics of the warm wet towel shenanigans, either.

boyntonstu wrote:Where do we get the fins?

They look like normal power driver nail, you could check at a hardware store or home depot

Call your local hardware store and ask for powder actuated fasteners...

They are hardened steel, and are used for attaching to steel I-beams and such...

The fins are actually collars designed to hold the nail centered/true in the barrel of a powder actuated nail gun...

you can see the ones I use in this pic of one of my ammo organizers...

Stu; Local Home Depot should have them.

http://www.homedepot.com/h_d1/N-5yc1vZ1 ... ogId=10053

Jeep;

Thanks for dimensions. I was all done drawing then discovered your reply
I will have to change my drawings.

Just the taper was way off on the nail.
I used .300 and .145 as the specs state.

My tail OD is 005 off. I used .400.
I have .340 instead of .350 for length
I have .185 instead of .205 for collar OD.

Not bad for working off a photo.

Here is the nail only. Click to enlarge

Gee! i never saw a nail that looked like a piece of art before. Beautiful.

OK at 10 cents each, a lot of money for adding a piece of plastic to a nail and no seal.

Here's what I came up with:

I make a cylindrical wax candle using a length of 0.811" M barrel tubing.

I tried this: I used a 3/4' copper end cap as a seal.

I lubed the copper with a few drops of vegetable oil.

I placed the mold in the freezer for about 15 minutes to make the initiial poured wax quickly solidify and not leak out.

Using a small SS dish with a handle attached, I heated a 29 cent huge xmas candle purchased from Goodwill with a 1,500 watt heat gun and poured it into the mold.

It hardened and it was very easy to push out of the tubing.

I now have an exact barrel fit length of wax.

My next step is to cut the wax into pieces and insert a hot nail through each piece. (Centering the nail is a problem to overcome)

I can then melt some off the front with the heat gun to create a point.

Do you think that a 1' piece of pointed wax sabot backed up against the head of a 2-1/2' nail (like the fins in your drawing) will stabilize it?


BoyntonStu

Stu the real trick is the fins which creates a CP behind the CG of the nail.

I still would like to know the balancing point of your nails.

Maybe create a cookie cutter to cut fins in your pre-molded wax cylinders.
A thin walled seal could be put on the inside of the nail head prior to insertion into your finned wax cylinder.

I personally think $.10 a dart is reasonable.

Any way you look at it, you need a sabot or some means to keep the tip of the nail centered in the barrel.

dewey-1 wrote:Stu the real trick is the fins which creates a CP behind the CG of the nail.

I still would like to know the balancing point of your nails.

Maybe create a cookie cutter to cut fins in your pre-molded wax cylinders.
A thin walled seal could be put on the inside of the nail head prior to insertion into your finned wax cylinder.

I personally think $.10 a dart is reasonable.

Any way you look at it, you need a sabot or some means to keep the tip of the nail centered in the barrel.

A wax point and a rear wax or closed cell foam seal?

jeepkahn wrote:NOOOOOoooo!!!! No Pictures of JSR and what he's using towels for...

*chuckle*

I saw Jeep's post about these nails months ago and spent several unsuccessful hours tryiny to track some down in the UK. Now you've got me trying again, these would be really useful. All I seem to be able to find are the ones with solid collars not the finned collars:
http://cgi.ebay.co.uk/ramset-2-drive-pi ... 1c0d9fe0fe