Nickmaslo Posted July 20, 2015 Posted July 20, 2015 (edited) My first 3" Shell. Constructed in the Italo-American style, per Fulcanellis manuscript published via Pyrotechnica IX circa 1974. It weighs 15.8 OZ's finished, BUT it's over 4" diameter. Contains about 6-7 Oz of Crysanthemum-6 stars, T. Shimizu's Formula. Lift cup contains 1 Oz of 2FA Lift. Burst charge boosted with 1tsp of Magnalium boosted perchlorate flash. Will post video when fired. It won't fit in a 4" mortar. Need a 4.5" or 5" mortar. Edited July 20, 2015 by Nickmaslo
Mumbles Posted July 20, 2015 Posted July 20, 2015 Looks pretty good. How do you plan to fire it, if it's over 4" in diameter though? Do you have an over-sized mortar?
TYRONEEZEKIEL Posted July 20, 2015 Posted July 20, 2015 Your construction looks nice. You even took the time to make a bucket to your passfire. There seems to be some extraneous skirting which increases your diameter. I have the same question as mumbles. If its over 4" diameter how do you plan to fire it?
TYRONEEZEKIEL Posted July 20, 2015 Posted July 20, 2015 Now that I think about it, One thing you could do is make it a 2 break. Follow the color-to-report shell instructions from the same fulcanelli articles and instead of making the bottom break a report, use your current shell. . With a 4" shell you wouldnt have to worry about adjusting spollette timings. 1
Nickmaslo Posted July 20, 2015 Author Posted July 20, 2015 I am not sure, pasted in it wouldn't fit in the 4" pipe so I may have to order one. I have a feeling I'm going to need a shovel to bury the mortar in a bit.
Nickmaslo Posted July 20, 2015 Author Posted July 20, 2015 (edited) I used a 2.5" ****OD****(Sorry Mumbles, Corrected 4:55PM) PVC former with about a 1/2" of duct tape wrapped around increasing the diameter of the former going down about 5". 3" skylighter pre-holed end discs. I had to widen the diameter on the 2.5" PVC pipe because the end discs were over hanging about 3/8ths of an inch in diameter. ***SORRY MUMBLES, POST CORRECTED - I AM AT WORK WAS RUSHING TO TYPE THIS AT DESK , EDIT AT 4:57PM**** Edited July 20, 2015 by Nickmaslo 1
Nickmaslo Posted July 20, 2015 Author Posted July 20, 2015 (edited) I'll have to post a picture after work tonight. My question is - should I have spiked a 3 inch shell or not? Could that be where I messed up the size? I messed up somewhere dangit. Edited July 20, 2015 by Nickmaslo
Mumbles Posted July 20, 2015 Posted July 20, 2015 I'm getting a little confused here, did you make a 3" shell or a 4" shell? Based on the weight to mentioned in the first post, it sounds like a 4" shell. However, you keep talking about 3" disks and 2.5" PVC, and calling it a 3" shell (title and post #8). To build either sized shell you want a former 1/2" smaller than the nominal diameter. IE 3.5" actual diameter for a nominally 4" shell, and 2.5" for a 3" shell. Plastic pipe (any material really) will often be about the right size. 3" PVC or HDPE will usually have an OD of 3.5" and be perfect for 4" shells. 2" PVC or HDPE is often a little undersized (2.375"), and may need a little buildup. It sounds like you used a 3" actual diameter former, with actual 3" diameter disks. This would produce something too small for a 4" gun, but too large for a 3" gun. You might be able to find some cardboard mortar for your uses, but unless you plan to consistently make this size of shell, it may not be worth it. If it's actually too large for a 4" gun, and you used a 3" diameter former, there is something very wrong.
Nickmaslo Posted July 20, 2015 Author Posted July 20, 2015 (edited) I used a 2.5" PVC pipe former built up to match the size of the end discs which are 3" (I made sure the diameter of the shell was a bit smaller so the end disc would need to be pushed in with a wooden dowel). I used about 4 turns of 70lb kraft paper. They are 8 1/2" x 11" sheets. So 3 sheets of 5" x 11" wraps rolled around the former to make the shell. Totaling- 5"W x 33"L wrapped around the former (was about 4 turns). Clarified a bit better mumbles ? Edited July 20, 2015 by Nickmaslo
Nickmaslo Posted July 20, 2015 Author Posted July 20, 2015 (edited) I will go home a re calculate everything. I was very methodical and prepared for a good 2 hours before I got into construction. I used the end discs I ordered from skylighter as a reference to my case former. Skylighter ID : DK3004 Edited July 20, 2015 by Nickmaslo
Nickmaslo Posted July 20, 2015 Author Posted July 20, 2015 (edited) Post #1 & #7 edited and corrected Mumbles, should be a bit clearer now I meant to make a 3" Shell but I think I ended up with a 4" shell somehow! Edited July 20, 2015 by Nickmaslo
Mumbles Posted July 21, 2015 Posted July 21, 2015 That's your problem then. To make a 3" shell, you need to use a 2.5" actual diameter disk and 2.5" actual diameter former. I bet if you measure the OD of your shell, it's right around 3.4". If you need to find an appropriate former, most standard beverage cans are right around 2.5" OD. If you look around your home, there are a lot of items that could probably work. I used a contact solution container filled with sand for many years. It works, but doesn't have a cavity to accept a fuse, which can come in handy. It's probably fairly adventurous for a first shell, but as Tyroneezekiel mentioned, there is a way to turn this into a multi-break shell. Your best best might just be to disassemble it, and build it with a case of the proper dimensions.
Nickmaslo Posted July 21, 2015 Author Posted July 21, 2015 Well I did get this far. So I assumed that a 3" should accept a 3" end disc , of course common sense doesn't prevailed in the world of Pyro haha. So what can I do with this entire 50 pack batch of 3" end discs?!
nater Posted July 21, 2015 Posted July 21, 2015 A 3" shell is called that because it is fired out of 3" ID mortar. Naturally,the finished shell must be a little smaller than the mortar it is to be fired from. To account for the buildup required to finish a shell, the former and discs the casing is made from are smaller. The tables for former and end disc size are in Fulcanelli I, you might want to reread it before your next shell in case you missed something else. Please ask questions if you need clarification. As for the discs, 50 discs will make you 12 shells. I would probably look for something they will fit on to use as a former and use them as rocket headers. I would not bother to source a mortar for 12 shells.
Dragonflightpyro Posted July 21, 2015 Posted July 21, 2015 I used a 2.5" ****OD****(Sorry Mumbles, Corrected 4:55PM) PVC former with about a 1/2" of duct tape wrapped around increasing the diameter of the former going down about 5". 3" skylighter pre-holed end discs. As I'm new to shell construction, I am just curious, was the 1/2" of duct tape you mentioned 1/2" total? Or was it 1/2" all around increasing the diameter by 1"?
gregh Posted July 21, 2015 Posted July 21, 2015 Deductive reasoning has nothing to do with shell building... He started with a 2.5" former OD and increased its size to match a 3" end disc. It was 1/2" total.
Nickmaslo Posted July 21, 2015 Author Posted July 21, 2015 Deductive reasoning has nothing to do with shell building... He started with a 2.5" former OD and increased its size to match a 3" end disc. It was 1/2" total. Wow could you nail it any more percise?! Haha its ok. So now I have a 5" ID mortar. I can use those 3" end discs for a 3.5"former and make a 4" shell?
Nickmaslo Posted July 21, 2015 Author Posted July 21, 2015 I have IX and XI and I'm looking at the page. According to page 14 under "Construction and Filling of Shell Cases" a 3" shell actually has a 2.5" former and end disc, a 4" shell actually has a 3.5" former and end disc, so on and so forth until 8" or more.
gregh Posted July 21, 2015 Posted July 21, 2015 (edited) Now you're on the right track. I read it through several times before I tried my first cylinders. Lots of great information in those articles! Hang in there. ps: either ditch the 3" discs or cut them down to 2.5" Edited July 21, 2015 by gregh
Mumbles Posted July 21, 2015 Posted July 21, 2015 If you had a slightly over sized 3" mortar, you might be able to use the disks for pistons in mines and comets. Unfortunately there aren't a ton of options here. Otherwise, you can start making inserts for much larger shells.
pyrokid Posted July 21, 2015 Posted July 21, 2015 Let's not forget that rockets can be used to lift irregularly shaped shells.
gregh Posted July 21, 2015 Posted July 21, 2015 Oh yeah, I forget about the "other half" of this hobby sometimes... 1
Maserface Posted July 21, 2015 Posted July 21, 2015 I'll make it easy on ya, sell me your 3" discs and buy the correct 3.5" discs.
Nickmaslo Posted July 21, 2015 Author Posted July 21, 2015 (edited) Deleted Edited July 21, 2015 by Nickmaslo
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