1569 replies to this topic

[Karl]

Karl, yes using blackmatch does not work for the time fuse on shells, whenever I tried it on my micro shells, they went off in the morter like a mine.

Yugen-Biki, nice shell, and thanks for the picture

Well hopefully I will have some ballshells & proper time-fuse on my hands pretty soon, so I can start making
real shells!

[Sprengman]

Some Photos from my 8" and "The Breaker"

Look at http://www.geocities.com/sprengman10/
All files wich starts with "my8in..." are about my 8"

I lift the 6" and 8" with extremly coarse grained Blackpowder. The particles are not finer than 3mm and it goes up to about 6mm.


http://www.geocities...chmaschine1.jpg
http://www.geocities...chmaschine2.jpg

Here you can see my Powderbreaker that crushes the pressed BP-Cakes in different sizes. Note, the mandrels with the bigest sizes between will get some milled tooth to get a better grip to the big "Rocks" of BP.

[seymour]

I get the following message:

"Sorry, this GeoCities site is currently unavailable.

The GeoCities web site you were trying to view has temporarily exceeded its data transfer limit. Please try again later. "

[Karl]

Yeah thats the problem with free websites!

I would suggest going with a free Tripod account!

But from what I could see before I got the same error as Seymour, your shells look very nice Sprengman! Very professional

Edited by Karl, 08 January 2006 - 12:33 AM.

[Mumbles]

Hi Mumbles

I am sure your shells would have looked fab in the air.
How much dextrin are you using? I use 7% to bind for corned lift.

Generally I use 5% dextrin. I have heard about SGRS's superior binding power and used only 2%. I still don't know what went wrong. I might give SGRS one more shot. I will make my very best BP, and see if it was just perhaps the BP that was the problem before. I doubt this is the case, but it is always possible. The granules seemed to burn just fine when lit on their own. I still feel SGRS is almost too sticky to be used as a binder in lift. It's a bit too gummy for my liking. By the time it is wet enough to properly adhere everything together, it sticks to everything. I bet it would be better if I pressed into pucks though.

[Sprengman]

Binder in the Lift?

The lifting powder is in most cases nothing than Blackpowder. And I never heared something about blackpowder with any kind of binder. The lift is simply pressed 75/15/10.

http://www.geocities...lverkuchen2.jpg

Here you kann see a standart "Cake" of 250g blackpowder pressed near to its maximum destiny. After drying over a period of some weeks it will be crushed in the powder breaker and sieved into different Grain sizes.

[JamesH]

They are using a binder because they are using pulverone. This is done to make the grains harder and less liable to crumble.

[Yugen-biki]

If the BP is pressed hard enough like Sprengman?s "pulverkuchen", no binder is needed to get very hard granules.

[Pieman]

I 'riced' my last batch of BP for lift powder. That involves adding water to the BP and pushing it through a sieve (about 10 mesh). No binder or press was required and it made great durable lift powder.

[Pretty green flames]

Good evening everybody

For the past few hours i have been working on a 2" canister shell.
It is filled with white stars and granulated BP as the break charge. It is timed with a 2.5second spolette
and it's it has a propellant charge of 15grams of 10 mesh BP. It's total weight is 85grams.

I have only spiked it verticaly becouse with my 1 inch inserts i have been getting a lot of airborn mines.

And here are some pictures
Canister in my hand
Canister on table
Canister besides mortar

Please tell what you think.

Edited by Pretty green flames, 19 January 2006 - 08:35 PM.

[RegimentalPyro]

Seems to be well constructed from what I can see.

I don't know the power of your lift so I can't really comment with any authority, but 15g to lift 85g seems a little high. I generally use 15g to lift my 3" shells which weigh in at 120g-140g.

Could this be why your inserts were flowerpotting?

[Maineiac]

Looks like a nice shell. I agree on Regimental Pyro's comments concerning lift. Seems a bit snappy for a shell of that dimension and weight.
How about a safety cap for that black match?
Video?

Edited by Maineiac, 20 January 2006 - 11:14 AM.

[Pretty green flames]

Hello

Well the reason i use so much lift is becouse the BP is made from general hardwood mix which as you know isn't exactly the most suitable for lift. So i added a bit more just to be sure it gets to a good height.


Video, yes there will be a video, sometime this weekend when i get to fire it.

How about a safety cap for that black match?

Done

EDIT: If i were to post a video of my lift will you be able to give an estimate on how much to use.

Edited by Pretty green flames, 20 January 2006 - 04:52 PM.

[RegimentalPyro]

EDIT: If i were to post a video of my lift will you be able to give an estimate on how much to use.

Well it's hard to gauge distances and heights with a video, but sure - we'll give it a go. I guess if the video has sound and we know the distance from the mortar to the camera we can triangulate distances etc.

[Pretty green flames]

Just an update, i have test lifted a dummy shells and the results were frightening, a damn blast and a cracked mortar. This is proof enough to convince me that 15 grams is a bit much. I am going to lower down to 8grams.

And here is the BP i am going to use. Do you think 8-9 grams is resonable for this quality BP