I got a new LOC Magnum Rocket

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

ColumbiaNX01

Red blooded white American male
Joined
Oct 30, 2009
Messages
1,755
Reaction score
21
Location
Somewhere
Hey folks I got a new LOC Magnum that I plan to fly on 38mm/480 casing and 38mm/720 casing. I plan to eventually get my Level 2 Certification on a J350W in the 38mm/720 case. Are there any I motors from the 480 casing that I could use on the Magnum in the meantime before I get my Level 2 cert that can get a decent altitude from 1000 and higher?
 
Years and years ago when I built my Magnum, the smallest motor I dared fly it on was the J350W. That flew it to about 1650'. A J460T (54mm) got it a little higher, to around 1900'. Other motors included a J415W and K670GG, but never anything less than that J350W. I would imagine an I300 would lift it, but it'd be hard pressed to go over 1000'.
 
An I600R should do it. It is a full "I" motor although it takes the 38/720 case. Or an I285R, which takes the 38/480 case. Why Redlines? They have alot of initial thrust and should be able to lift the Magnum fairly easily. In fact, you might get more than 1,000 ft. You will need a 54/38 motor adapter though.
 
We used to fly our Bruiser all the time on I284Ws and I435Ts to about 1100-1200 feet. (My dad actually originally L1 certed with an I435T in the Bruiser... it was a coool flight!) The I300T would pick up the Bruiser no problem, too. I'd expect a stock built Magnum to do quite well on an I300T or an I285R and put it somewhere around 1000-1200'.

I once saw Ken Finwall do his Bruiser on an H242T... the nosecone was halfway on to make sure the chute would come out, but it did after staggering to 500' or so. Not something I'd try, but it should be reassurance that your Magnum will do fine on twice the propellant!

And don't forget to post a nice build thread. I have a Magnum in a box in the garage back in California waiting for me to finish school... I can't wait to build it, so for now I must live vicariously through build threads...
 
Years and years ago when I built my Magnum, the smallest motor I dared fly it on was the J350W. That flew it to about 1650'. A J460T (54mm) got it a little higher, to around 1900'. Other motors included a J415W and K670GG, but never anything less than that J350W. I would imagine an I300 would lift it, but it'd be hard pressed to go over 1000'.

hmm,,, did you build yours stock ?

sounds WAY overweight to me.

a J350 should put a Magnum over 2k easy..... mine on Kosdon J1000 ( 880 nsec ) went 2900 +

A K550 will go WELL over a mile.

I have flown mine on an I161 for a good flight. also I357 ( both 38/360 casings ) .

An I211, I300 or anythign non blackjack in a 480 should fly it fine, short delays, and let her rip :)

~ AL
 
I certified L2 with a Cesaroni J330 in a stock Magnum. I would not be comfortable flying it with anything less. There's a lot taking place in a short amount of time, like making sure the chute has enough time to fully unfurl.
There's plenty of formula's out there to help you figure this out. Why take a chance on all of the hard work, sweat and effort you put in to it, not to mention the money?

wick
 
How can anyone even make a motor recommendation without knowing the Rockets weight???? Is it SD DD?
 
Last edited:
The lightest that my Magnum ( circa 1997) weighed was around 15 lbs loaded on the pad. That's with DD & a stock 16" payload section. The smallest motor that I ever flew it on was a Kosdon I 500 ( renamed later to a J 450) It hit just over 1,000ft in altitude. Here's a treat of a video of it with 2 F104 Silver Streaks to boot & still only did 1100ft.

[YOUTUBE]<object width="480" height="385"><param name="movie" value="https://www.youtube.com/v/OOTGr6etMLc&hl=en_US&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="https://www.youtube.com/v/OOTGr6etMLc&hl=en_US&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object>[/YOUTUBE]
 
The lightest that my Magnum ( circa 1997) weighed was around 15 lbs loaded on the pad. That's with DD & a stock 16" payload section. The smallest motor that I ever flew it on was a Kosdon I 500 ( renamed later to a J 450) It hit just over 1,000ft in altitude. Here's a treat of a video of it with 2 F104 Silver Streaks to boot & still only did 1100ft.

[YOUTUBE]<object width="480" height="385"><param name="movie" value="https://www.youtube.com/v/OOTGr6etMLc&hl=en_US&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="https://www.youtube.com/v/OOTGr6etMLc&hl=en_US&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="480" height="385"></embed></object>[/YOUTUBE]

Even after reading your comment, I still was somehow surprised that didn't end badly... :)
 
How can anyone even make a motor recommendation without knowing the Rockets weight???? Is it SD DD?


Good point, Gary. I assumed it was in the 6-10 lb. range and based my recommendation on what I've flown successfully in that range. But someone else mentioned theirs weighed in at 15lbs. Seems a bit heavy, but nonetheless, it is what it is. So be sure to check the motor specs carefully against what your rocket weighs and choose accordingly...
 
Good point, Gary. I assumed it was in the 6-10 lb. range and based my recommendation on what I've flown successfully in that range. But someone else mentioned theirs weighed in at 15lbs. Seems a bit heavy, but nonetheless, it is what it is. So be sure to check the motor specs carefully against what your rocket weighs and choose accordingly...

Depends on the modifications and ammount of epoxy, etc - my original, no electronics, stock from the box Magnum weighed in at something like 8 lbs dry. 10-12 on the pad, depending on motors.
my dual deploy model with extra bulkheads, chutes, etc comes in 18 ish loaded ( never have weighed it dry, hmmm ) .

the stock kit is not that heavy and should not weigh much over similar height 4" birds.
I cringe when I hear about 4" x 84" rockets weighing in 10-12 lbs, when they should be in the 4-5 lb range.
Been doing this a looong time and no need to overbuild that much unless you're seriously going mach 1.5 or hitting them with huge motors, etc.

carry on, decide if you want dual deploy ( easier to add now then retrofit ) , build it up, then weigh the bird for motor choice.

~ AL
 
I cringe when I hear about 4" x 84" rockets weighing in 10-12 lbs, when they should be in the 4-5 lb range.
Been doing this a looong time and no need to overbuild that much unless you're seriously going mach 1.5 or hitting them with huge motors, etc.

When they have 3" holes in them, they tend to come out even heavier than that for me...
 
Depends on the modifications and ammount of epoxy, etc - my original, no electronics, stock from the box Magnum weighed in at something like 8 lbs dry. 10-12 on the pad, depending on motors.
my dual deploy model with extra bulkheads, chutes, etc comes in 18 ish loaded ( never have weighed it dry, hmmm ) .
My Magnum, fairly close to stock but set up for dual deploy, weighed 10 lb. dry. It got 2000 feet on a J350, 4800 feet on a K550.
 
Exactly a 4"x 84" bird @ 4-5lbs? Not gonna happen

I beg to differ. In the picture I have attached, both rockets are 4" in diameter. The one on the right is made from LOC parts specifically as an H-J bird. The one on the left is MODEL ROCKET LEGAL. That's right, it flies regularly on G64-4's. Quite well, I might add. It belongs to one of the NARHAMS members, though I can't remember who off-hand.

Oh, for those of you who might nitpick a little, it is a foot short of 84", but I don't think 12" of airframe would make that much of a weight difference.

IMG_0796.jpg
 
I beg to differ. In the picture I have attached, both rockets are 4" in diameter. The one on the right is made from LOC parts specifically as an H-J bird. The one on the left is MODEL ROCKET LEGAL. That's right, it flies regularly on G64-4's. Quite well, I might add. It belongs to one of the NARHAMS members, though I can't remember who off-hand.

Oh, for those of you who might nitpick a little, it is a foot short of 84", but I don't think 12" of airframe would make that much of a weight difference.

Well certainly. It was designed to fly on G64's and I am sure it uses something along the lines of Balsa fins. The Magnum is NOT designed to fly on G64's.

My 4"x84" birds don't fly on G64's. The one in the works now is looking at an M1297W. His flies on G64's, not M1297's. To each their own, but seeing as this is the HPR forum, I am going to assume that a Magnum won't be flying safely on a G80.
 
Well certainly. It was designed to fly on G64's and I am sure it uses something along the lines of Balsa fins. The Magnum is NOT designed to fly on G64's.

My 4"x84" birds don't fly on G64's. The one in the works now is looking at an M1297W. His flies on G64's, not M1297's. To each their own, but seeing as this is the HPR forum, I am going to assume that a Magnum won't be flying safely on a G80.
What's this about 4" rockets:confused: The Magnum is a 5.5" bird :)
 
Why are you comparing apples to oranges?
The topic involves HP rockets not LP or MP rockets.



JD



I beg to differ. In the picture I have attached, both rockets are 4" in diameter. The one on the right is made from LOC parts specifically as an H-J bird. The one on the left is MODEL ROCKET LEGAL. That's right, it flies regularly on G64-4's. Quite well, I might add. It belongs to one of the NARHAMS members, though I can't remember who off-hand.

Oh, for those of you who might nitpick a little, it is a foot short of 84", but I don't think 12" of airframe would make that much of a weight difference.
 
Exactly a 4"x 84" bird @ 4-5lbs? Not gonna happen
Why not? You shouldn't have any trouble building a 4" x 84" bird in that weight range that does well on H - J motors.


I cringe when I hear about 4" x 84" rockets weighing in 10-12 lbs, when they should be in the 4-5 lb range.
Been doing this a looong time and no need to overbuild that much unless you're seriously going mach 1.5 or hitting them with huge motors, etc.
~ AL

I don't thing you should have phrased it quite like that, "should be in the 4-5 lb range". "Can be ... " might have been a better phase. Anyway, I think you're right. I have a 4" x 94" rocket that weighs in at 8.8 lbs w/o motor, but with all electronics and recovery. It is definitely heavier then it could be, but I plan on flying an L1400 in it at Mach 1.4 so I glassed the tubes and did TTT glass on the fins, which probably added 2 - 3 lbs. Without that, it would probably be in the 5-6 range an could probably have been done a little lighter.
 
The real problems stem from people insisting on extreme internal fillets & foaming all hollow spaces inside their rockets; that isn't occupied by a shock cord, parachute, or altimeter.

:bangpan:





JD
 
Back
Top