DaMounty Posted June 13, 2015 Posted June 13, 2015 (edited) Hi, Going to attempt firing some 35mm film canister shells tomorrow. did some dummy test fires tonight. film can filled with dog food (14.4g) using 2g of lift. I had an averge flight time of 5 sec. (approx. 180 ft). So now I'm sitting here trying to figure what fuse length for the shell I am to use. 2.2mm chinese visco ~ 32sec/foot Am I right in calculating that it is 2.7 sec/inch? To me an inch long fuse with 3/4" masking tape in the middle does not seem long enough. Any help would be greatly appreciated, as I would like to share some video of my sky art. DaM Edited June 13, 2015 by DaMounty
braddsn Posted June 13, 2015 Posted June 13, 2015 Your calculations are good. Thats the same speed as a lot of my visco. 1 inch should work perfectly! Use an inch and adjust from there if you need to.
rsambo Posted June 14, 2015 Posted June 14, 2015 Agree, your calculations are good. Just be a little careful if you use visco as you can't crossmatch and in my experience it's prone to not taking fire and leaving you with a dud. This can happen even if you prime as the core can flake at the end and you can lose powder causing a fireblock, it's also more prone to damp.
mikeee Posted June 14, 2015 Posted June 14, 2015 You can always dip the visco in a slurry of NC and pulverone and then cover the slurry with some BP.Most festival shell fuses are primed with this method if you take them apart.Dipping the end of the fuse in the NC slurry will encapsulate the fuse core.
DaMounty Posted June 15, 2015 Author Posted June 15, 2015 Thanks all, In the end I dipped the visco in ABS glue and covered with BP. DaM
nater Posted June 15, 2015 Posted June 15, 2015 (edited) Usually people make a slurry out of nitrocellulose lacquer and BP and use that to dip the end of the fuse in before dipping it in some fine BP. You might as well use something that is sticky and flammable for your fuse rather than a glue which could slow the flame down or block it entirely. Edited June 15, 2015 by nater
DaMounty Posted June 15, 2015 Author Posted June 15, 2015 Next two items I buy are going to be smokeless powder and acetone.
mikeee Posted June 15, 2015 Posted June 15, 2015 Cheap nail polish is made of mostly Nitrocellulose if you need to use something in a pinch.I have primed time fuse and visco fuse with this when I ran out of NC and it worked fine.
nater Posted June 15, 2015 Posted June 15, 2015 I forgot about nail polish, that also reminds me liquid bandage products also have nitrocellulose and works well to slurry prime fuses.
Stef727 Posted December 9, 2015 Posted December 9, 2015 (edited) I just use Meal powder with 15% dextrin for priming visco fuse or chinese time fuse, it's hard as a rock when it's dry. Edited December 9, 2015 by Stef727
Ubehage Posted December 9, 2015 Posted December 9, 2015 Hi, Going to attempt firing some 35mm film canister shells tomorrow. did some dummy test fires tonight. film can filled with dog food (14.4g) using 2g of lift. I had an averge flight time of 5 sec. (approx. 180 ft). So now I'm sitting here trying to figure what fuse length for the shell I am to use. 2.2mm chinese visco ~ 32sec/foot Am I right in calculating that it is 2.7 sec/inch? To me an inch long fuse with 3/4" masking tape in the middle does not seem long enough. Any help would be greatly appreciated, as I would like to share some video of my sky art. DaMFor normal Visco, I once learned that it will burn 1 cm/s, meaning ~2.5 s/inch.So your calculations is not far from what I work with. Seems to be right.
OblivionFall Posted December 9, 2015 Posted December 9, 2015 (edited) Hey DaMounty if you would like, in January or Febuary I will be getting some bickford time fuse, 3mm visco fuse, 2.4mm visco fuse, 1.8mm visco fuse. That is If things go well. The 3mm visco would probably be a better option for you than your 2.2mm. Pretty sure I use the same 2.2mm. It's circulating through pyros all over canada. And also you could use some time fuse, too. Let me know if you want any. Pyro to pyro I could give it to you for the price I bought it for as long as you pay shipping. Edited December 9, 2015 by OblivionFall
DaMounty Posted December 9, 2015 Author Posted December 9, 2015 Thanks for the offer, I'll keep it in mind. ...DaM
schroedinger Posted December 9, 2015 Posted December 9, 2015 (edited) Don't be sure that 3 mm is better suited, with all 3mm visco i experienced until now, i had to find that is lower quality then 2 mm. Also one trick you can use if you use visco for timing, you only need to prime the outside, just leave 1" of bare fuse on the inside. Also with a 5 sec if flight i would rather use a timing of 1.5 s then 2.5. Edited December 9, 2015 by schroedinger
DaMounty Posted December 9, 2015 Author Posted December 9, 2015 (edited) I only use visco on the 35mm film can test shells. I'm pretty sure I have my spolettes dialed in. I will hopefully know by the end of this week. Firing my first spolette fused 2" shells DaM Edited December 9, 2015 by DaMounty
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