ST1DinOH Posted February 12, 2008 Posted February 12, 2008 the basic idea here being to build a balance large enough to weigh shells. i'd probably use large zip lock baggies on either end as the baskets. the question i have is what ratio is good for lifting shells? i'd like to make a dead center balance so each side is equal, but i'd also like to add a ratio balance where i can place the shell on one 1/2 and add lift to the other to give me the propper ratio... so first and foremost what would be the propper ratio to use... but secondly is it not possible to propperly construct a balance that can be adjusted by simply moving the pivot point so that it can do both 1:1 and X:1 ratios. the reason i ask is once i adjust the center point to acchieve that ratio...the baskets are now not of equal wieght distribution on the balance bar. so two equivilent baskets will be out of balance even after i add the propper ratio of weighted material to each end. i hope that made sense basicly lets say my baskets weigh 2 grams. once i adjust the pivot to acchieve a different ratio the whole thing gets screwed up because of the 2 gram baskets... am i just uber-over complicating things here or is the idea of a multi function homemade balance a pipedream.
Bonny Posted February 12, 2008 Posted February 12, 2008 the basic idea here being to build a balance large enough to weigh shells. i'd probably use large zip lock baggies on either end as the baskets. the question i have is what ratio is good for lifting shells? i'd like to make a dead center balance so each side is equal, but i'd also like to add a ratio balance where i can place the shell on one 1/2 and add lift to the other to give me the propper ratio... so first and foremost what would be the propper ratio to use... but secondly is it not possible to propperly construct a balance that can be adjusted by simply moving the pivot point so that it can do both 1:1 and X:1 ratios. the reason i ask is once i adjust the center point to acchieve that ratio...the baskets are now not of equal wieght distribution on the balance bar. so two equivilent baskets will be out of balance even after i add the propper ratio of weighted material to each end. i hope that made sense basicly lets say my baskets weigh 2 grams. once i adjust the pivot to acchieve a different ratio the whole thing gets screwed up because of the 2 gram baskets... am i just uber-over complicating things here or is the idea of a multi function homemade balance a pipedream. As far as the balance goes, why bother? Get a scale with enough capacity, weigh the shell, calculate lift, weigh it and done.I'm sure a few members will chime in here on ratios...I don't have much experience with large shells... there are tables available but if you are using homemade lift it will vary quite a lot. I've read about guys that use 1/16 shell weight and as much as 1/10 shell weight...
ST1DinOH Posted February 12, 2008 Author Posted February 12, 2008 As far as the balance goes, why bother? Get a scale with enough capacity, weigh the shell, calculate lift, weigh it and done.I'm sure a few members will chime in here on ratios...I don't have much experience with large shells... there are tables available but if you are using homemade lift it will vary quite a lot. I've read about guys that use 1/16 shell weight and as much as 1/10 shell weight... well first off a piece of wood, and 2 freezer bags cost next to nothing, a digi scale will cost at least 60-100 dollars. cost wise i'd much rather come up with an effective way to scale the shells weight and then balance it with the approriate ratio of lift. i can build that scale with stuff i have laying around. i'm using 4F goex for lift, if anyone thinks thats wrong for 3's please let me know... but yeah if it varries that much (1/10 all the way to 1/16) then it may not be the best idea. in fact...i think i may have just figured out my own damn question. *smacks self in head if i have a beam, and attach a basket on each end...then throw 1 quarter in one basket, and X quarters in the other... i can just slide the damn beam left or right on the pivot untill it's level. lol now does anyone happen to know the propper ratio for 3 inch and higher shells when using 4F goex powder?
Mumbles Posted February 12, 2008 Posted February 12, 2008 4Fg is pretty fine stuff. 1/16 should likely be fine. Commercial powder is pretty consistent. The ounce per pound rule really is derived from large canister shells, when using 2FA. It's not quite as meant for smaller shells, or for other lifting granulations. 4Fg is plenty powerful though, and will fire the shells up quite well. I personally use 1oz of lift to lift my canister shells. With the finer granulation, you could probably get away with 15 or 20g though. i do have to admit, 1oz of 1Fg(4FA), gets them up pretty high. For smaller shells 1/10 should work just fine.
crazyboy25 Posted February 12, 2008 Posted February 12, 2008 a digi scale will cost at least 60-100 dollars. Well actually mine cost 10 bucks and it goes up to 600g more then enough for a 4" shell and I highly doubt you are making anything bigger then that.
ST1DinOH Posted February 12, 2008 Author Posted February 12, 2008 4Fg is pretty fine stuff. 1/16 should likely be fine. Commercial powder is pretty consistent. The ounce per pound rule really is derived from large canister shells, when using 2FA. It's not quite as meant for smaller shells, or for other lifting granulations. 4Fg is plenty powerful though, and will fire the shells up quite well. I personally use 1oz of lift to lift my canister shells. With the finer granulation, you could probably get away with 15 or 20g though. i do have to admit, 1oz of 1Fg(4FA), gets them up pretty high. For smaller shells 1/10 should work just fine. oh? i thought FFFF was the largest grain goex other than cannon. unfortunatley they don't carry cannon grain anywhere around here and i'm still without a ball mill. so i'm stuck at FFFF goex for a little whiel. so 1:16 FFFF goex sounds good for a 3inch and larger? (sorry to ask a redundant question but the Fa and Fg still confuse the hell out of me) thanks for that ratio...i'll probably be adding the lift tonight to that crazy buzzball shell. a digi scale will cost at least 60-100 dollars.Well actually mine cost 10 bucks and it goes up to 600g more then enough for a 4" shell and I highly doubt you are making anything bigger then that. woah where'd you get a digi likethat for 10 bucks? and does it weigh out to tenths of a gram or just whole grams? BTW...the biggest shell i'd ever try making would be a 6...but i'm a ways from that. (unless the buzzball shells need more airtime than a 4 will give me )
crazyboy25 Posted February 12, 2008 Posted February 12, 2008 Here's my scale its accurate to 1/10 of a gram. http://search.ebay.com/search/search.dll?q...rty=MetaEndSort
ST1DinOH Posted February 13, 2008 Author Posted February 13, 2008 Here's my scale its accurate to 1/10 of a gram. http://search.ebay.com/search/search.dll?q...rty=MetaEndSort thats a nice scale for 16 bucks... just curious...how big is the dish/plate. is it a decient size or is it a small one? many of these inexpensive scales have very small inconvienient weighing surfaces... i assume it has a tear function as well correct?
0nE.sh0t.kIll Posted February 13, 2008 Posted February 13, 2008 Lmao, the shipping for one of those to get to my house is $13. That's hell of a lot more than I'd like to pay for shipping.
Mumbles Posted February 13, 2008 Posted February 13, 2008 Shipping is how these people make their money. It's not subject to ebay fees. Anyway, no, the more F's there are, the finer the grain is. There is no conversion factor between Fg, and FA. Fg is glazed powder meant for rifle shooting and such. FA is a blasting grade powder. They are two separate systems for two separate uses. U.S. Blasting Powder Grain Size GRADE MESH RANGE FA 3 - 5 2FA 4 - 12 3FA 10 - 16 4FA 12 - 20 5FA 20 - 50 6FA 30 - 50 7FA 40 - 100 Meal D - 50 Fine Meal - 100 X-Fine Meal -140 Black Powder Grain Sizesg Type GRADE MESH Cannon 6 - 12 Saluting 10 - 20 Fg 12 - 16 2Fg 16 - 30 3Fg 20 - 50 4Fg 40 - 100
ST1DinOH Posted February 13, 2008 Author Posted February 13, 2008 Shipping is how these people make their money. It's not subject to ebay fees. Anyway, no, the more F's there are, the finer the grain is. There is no conversion factor between Fg, and FA. Fg is glazed powder meant for rifle shooting and such. FA is a blasting grade powder. They are two separate systems for two separate uses. U.S. Blasting Powder Grain Size GRADE MESH RANGE FA 3 - 5 2FA 4 - 12 3FA 10 - 16 4FA 12 - 20 5FA 20 - 50 6FA 30 - 50 7FA 40 - 100 Meal D - 50 Fine Meal - 100 X-Fine Meal -140 Black Powder Grain Sizesg Type GRADE MESH Cannon 6 - 12 Saluting 10 - 20 Fg 12 - 16 2Fg 16 - 30 3Fg 20 - 50 4Fg 40 - 100 ok sorry... i'm not thinking very clearly today living in this mini blizzard. i have a can of FFFF and a can of F. i used the FFFF for coating my rice hulls for burst... i'm using F for lift. i should edit thoes earlier posts... so just for clarification mumbles, what ratio would you recomend i use when using F goex as lift. is that 16:1 still good or should i change that up? sorry for the confusion.
TheSidewinder Posted February 13, 2008 Posted February 13, 2008 ST1, My personal experience has been with 2Fg as lift, rather than 1Fg, but I don't think the difference will be much. You should be fine using a 1:1 linear conversion once you figure out how much, if any, difference. For shells under a pound, anyway, I think it won't matter at all. Just as FYI for anyone interested, the "lift scale" for a given powder isn't a straight line, it has a curve. It works out to an ounce per pound (1/16 ratio) for a fairly broad range, though, and I suspect a lot of folks just use that and stay within the weight range for which the formula works correctly. For large shells you use 1 ounce per pound for the first "X" pounds (I forget the weight cutoff point 20? 30?) then 1/2 ounce per pound for the weight ABOVE that. i.e Assuming the cutoff *IS* 20 pounds, an 80 pound shell would take (20 x 1) + (60 x 0.5) or 50 ounces of lift. And I *THINK* that scale changes again above another weight cutoff. I'm now hoping someone knows of a table that accurately plots a large range. But there may be too many variables to do that, I dunno. For less than a pound, you have to experiment. Some have said 1/10 works for them when they fire small shells. But 1/10 is only good for a narrow range itself, I think. My 3" cannister shells ranged in weight from 1/2 pound to just barely over a pound. I lifted the 1/2 pounders with ~25g of FFg. At one pound or slightly higher (a few ounces), I used 1 full ounce (28g) of FFg. I got *great* lift (and break, for that matter) on all of them. The contents sometimes left a lot to be desired, though. I'll work on that in the future. I think I could have gotten away with lifting ALL of them at 1 ounce, to be honest. But why waste good Goex?
Mumbles Posted February 13, 2008 Posted February 13, 2008 The cutoff is 10lbs. I don't believe there is an even higher cutoff. However, if you're really making 80-100lb srhells, you can probably use you intuition. There is also the sabot method, which greatly cuts down on the amount of lift needed. It however doesn't work for light shells. I probably wouldn't use it on a shell that weighed less than 10 or 20lbs.
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