ChloRure Posted July 14, 2012 Posted July 14, 2012 I did some 3 inchs test and 2 four inchs last week. 4 inchs had about 30grams of lift (weight of about 300-310grams before lift charge added). They did go high enough and was good I think. 3 inchs now had about 14g of lift in them (weight at 140g). Some of them did not go high enough and started to fall back. So here is 2 questions... What is the perfect mesh size for lift powder, right now im using kitchen strainer with a size of 1/16. Size look a little small imo... when I search on forum I see 2fg, 2fa... difference between them is pretty big no? I plan on buying a 12 mesh sieve, is it a good size for lift powder ? The other question is more about the time fuse, I am using 1/4 time fuse and use 3 sec delay for 3 inch and about 3.25sec for 4 inch. When you cut like 1/4 of the fuse to attach a black match to help ignition... does the 1/4 inch still count on the delay or it is completly out? Thanks
Mumbles Posted July 15, 2012 Posted July 15, 2012 It depends on preference, like most other things in pyro. 2FA is -4+12 mesh. 2Fg is -16+30 mesh. From your description, it sounds like you have something similar to 2Fg. The amounts you used sound about right. I lift 4" can shells, and everything 5" and up with 2FA. I lift 4" ball shells and everything 3" and below with something fairly similar to 2Fg. I find a little confinement around the lift to make the shells preform more consistently. Usually just a lift cup is sufficient. When just lightly taping a liftbag or something onto a shell I had some go just fine, and some sort of flop out of the gun and break a hundred feet or more too low. More lift may also solve your problem. With relatively small shells, the rules of thumb sort of go out the window. The length of the timefuse used to determine the delay does not include the amount that is crossmatched. If your timefuse burns at 3 seconds an inch, you'd need 1 inch of delay to get your 3" shells to break at the right time. You may however end up cutting a 1.5" long piece of fuse. Each end would be split 1/4" for the blackmatch. This would leave you with 1" total between crossmatching to get your desired delay.
LehighValleyPyro Posted July 15, 2012 Posted July 15, 2012 2Fg works great for lift powder. If you want that get a 16 mesh screen. The 1/4 inch is out. The black match lights the time fuse where it enters immediately. Did stars hit the ground? If not, maybe the quick fix is to make the time fuse shorter. I like to keep the shell as close as possible to me without the stars hitting the ground.
ChloRure Posted July 15, 2012 Author Posted July 15, 2012 Some of them hit the ground, mostly glitter. But maybe my time fuse was not exactly the same size each time... 1/8 off. Ill tru to get something around 14 mesh .. Think it will be the right spot since i dont think ill ever go bigger then 5 inchs. Also, since they were cutted stars, size can be different so pretty sure some of them were a littoe big. I want to get a star plates but i like parlon bound stars and i think plates are not suitable for those.
Mumbles Posted July 15, 2012 Posted July 15, 2012 There is actually quite a bit of wiggle room on a properly lifted shell. There is around a 1 second buffer both before and after it reaches apex where it is relatively still and breaks very well. 1/8" of an inch of time fuse shouldn't really make a difference.
Arthur Posted July 16, 2012 Posted July 16, 2012 Are you sure that your lift is as fast as it can be? slightly slow BP will lift bigger shells more easily that small shells as the rise time in the mortar is longer.
ChloRure Posted July 16, 2012 Author Posted July 16, 2012 Are you sure that your lift is as fast as it can be? slightly slow BP will lift bigger shells more easily that small shells as the rise time in the mortar is longer. Yeah maybe this batch was a little slower, I tried new willow charcoal and it was a little wet... so it caked after about 10 hours milling time. I dryed it now and will do another batch.
eb11 Posted July 23, 2012 Posted July 23, 2012 (edited) i made a 2" shell out of a toilet paper tube i weighed it and it is 126 grams i was wondering if 13 grams of 4fg would lift it out of may 2" tube it fits snug in the tube new at this and tring to learn thank you Edited July 23, 2012 by eb11
dagabu Posted July 23, 2012 Posted July 23, 2012 i made a 2" shell out of a toilet paper tube i weighed it and it is 126 grams i was wondering if 13 grams of 4fg would lift it out of may 2" tube it fits snug in the tube new at this and tring to learn thank you If the base is solid enough, 13g will send it up solidly. -dag
eb11 Posted July 23, 2012 Posted July 23, 2012 i have 2 inch hpde pipe with a 1.5 inch plug on a 3/4 plywood that is 2ft by 2ft just trying it all out have a settup for 80 morters just testing everthing
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