h&k machineguns Posted October 15, 2006 Posted October 15, 2006 I'd like to know if anyone has measured the speed,lift power, of various rocket motors from 4 once end burner Black powder,to 3 pound Whistle rockets all the way to maybe the big composite motors that the big boys use on the big 100 pound plus rocket bodies. I'd love to see some type of comparison chart on these,or something that's an estimate at least. Also when I hear the term 3" shell ... I have no idea what that means as far as how much it weighs. Thanks
cplmac Posted October 15, 2006 Posted October 15, 2006 Can't help you with the rocket info, but a three inch shell simply means the outside diameter of a three inch shell, ball or cylinder. THe weight will very significantly depending on whether it is a ball or cylinder, and on the composition inside. For example, a salute is lighter than a comet even though both are three inch shells.
Pretty green flame Posted October 15, 2006 Posted October 15, 2006 Can't help you with the rocket info, but a three inch shell simply means the outside diameter of a three inch shell, ball or cylinder. THe weight will very significantly depending on whether it is a ball or cylinder, and on the composition inside. For example, a salute is lighter than a comet even though both are three inch shells. A 3" shells means that it is fired from a 3"ID mortar, the shells itself is somewhat smaller depending on the type. A typical plastic round shell is 3/8" smaller than the mortar. I agree with cplmac on the weight issue, it really depends on the contents, heavy zinc spreader shells will weigh more than most other types. But as a general rule of thumb, a 3" shell wll weigh somewhere in the region of 150g which is about the max a 1lb BP core burner will lift. EDIT: Found a chart for BP core burner lift capabilities Okay, here are recommended safe payloads.For those who can’t handle UK numeric system – like myself, 1 pound (lb) is about 450grams.There are 16 ounces (oz) to a pound, so an ounce is about 28g and change: Rocket size – Payload2oz – 1/2oz4oz – 1 oz8 oz – 2-3oz1lb – 4-6oz2lb – 8-10oz3 lb – 12-14oz4 lb – 16oz6lb – 18-24oz Q: What is the source for this numbers:A: Wolter Pyro Tools technical documentation,although it is similar and has been verified with other tool makers. Q: Is the range of payload weight represent minimum maximum payload?A: No. The upper end of the range represent the maximum payload you can shoot safely,but the left represent a recommended usage minimum. If you want to put a payloadsmaller then the minimum then you can, but it will be cheaper to build a smallerrocket that can handle that weight. Q: So I should never go above the maximum?A: Well, every composition is different, and of course,if you manage to create a procedure that consistently allows you to lift a biggerpayload to a safe height, then that’s great. But play safe and test many times beforedeciding to send your bigger rockets to the local show. Q: Is this valid for other type of fuel or stabilizing arrangement?A: No. This is specifically for CORE-BURNING bp composition type rockets.Any rockets that use whistle, KNO3/Sercose, end burning, fin stabilized,spin stabilized etc has different payloads. P.S. It is considered to beunsafe to put a payload on any spin stabilized rocket… but this really hasnothing to do with the question 1
BigBang Posted October 15, 2006 Posted October 15, 2006 Well, for HPR, I can't list every thrust curve just because there are hundreds. I will say that some or the larger EX motors can have thrusts well over 2000 lbs for 5 or 10 seconds. You can search for different curves here as they have compiled most motors.
Recommended Posts