Search found 1094 matches

by Lamp
Mon Jul 10, 2017 11:49 am
Forum: Support & Recovery & Misc.
Topic: Thrust:Weight ratio in OR
Replies: 10
Views: 2504

Re: Thrust:Weight ratio in OR

Hi Frank, Some motors have a very different initial peak thrust compared to the average thrust, for example, I know the Aerotech I200W has an average thrust of around 45 pounds but the initial thrust is over 100 pounds. Different motors have different curve shapes depending on the motor length, the ...
by Lamp
Tue May 02, 2017 9:58 am
Forum: Mid/High Powered Rocketry
Topic: The Magic Pre-Launch Check List
Replies: 15
Views: 1616

Re: The Magic Pre-Launch Check List

A checklist is only as good as you make it. To put every conceivable step into a generic checklist would make it unwieldy to use and besides, part of understanding your rocket and its preparation for flight is all part of becoming a good rocketeer. I am NOT saying a checklist is not a good idea, wha...
by Lamp
Wed Apr 19, 2017 10:51 am
Forum: Melbourne Amateur Rocket Society Inc.
Topic: MARS April Launch
Replies: 13
Views: 1640

Re: MARS April Launch

Looks like it was a great launch, pity I missed it. I have had so little free time over the last few months it has been hard to do anything other than work but that should change in a few weeks...next time!
by Lamp
Fri Mar 31, 2017 8:52 am
Forum: How to's
Topic: Different Epoxy for Different purpose??
Replies: 26
Views: 3400

Re: Different Epoxy for Different purpose??

For an L1 rocket (unless you are doing a glass tip to tip or rolling your own tube) all you really need is "hobby" epoxy like BSI. Blake sells this in the Aus rocketry shop. I tend to use either the 15 min or 30 min stuff to make sure I have enough working time. For higher strength require...
by Lamp
Sun Mar 26, 2017 7:10 am
Forum: Electronics
Topic: Jolly Logic Chute Release
Replies: 8
Views: 1088

Re: Jolly Logic Chute Release

OTT is correct, the reefed main will act as a drogue and depending on the type, configuration and length of your shock chord, your shock chord will also lower your decent speed. These things will not be taken into account by any of the simulation programs and they will all indicate you need a drogue...
by Lamp
Wed Mar 15, 2017 10:31 am
Forum: Higher, Faster, Further
Topic: 8" Fincan
Replies: 67
Views: 8173

Re: 8" Fincan

Congratulations Nic and the team.
Your builds are always exceptional Nic! :mrgreen:
by Lamp
Wed Mar 15, 2017 10:22 am
Forum: Mid/High Powered Rocketry
Topic: Stability, nose weight, and fin size at mach 1+ speeds
Replies: 30
Views: 2725

Re: Stability, nose weight, and fin size at mach 1+ speeds

I have not studied this anywhere near enough. A few years ago I built a 38mm min diameter with short span trapezoidal fins which had a static stability margin of 1.4 and a min calculated stability margin of 1 (in Rocksim). I launched it in WA and it flew beautifully until the Mach transition at abou...
by Lamp
Wed Mar 15, 2017 5:40 am
Forum: Mid/High Powered Rocketry
Topic: Stability, nose weight, and fin size at mach 1+ speeds
Replies: 30
Views: 2725

Re: Stability, nose weight, and fin size at mach 1+ speeds

Hi TRFfan2...the short answer is yes, it is highly likely your rocket will go unstable...with a narrow fin span, as your rocket moves through the Mach transition your effective fin area will decrease. I learned this a few years ago from experience. :wink:
by Lamp
Thu Feb 02, 2017 5:54 am
Forum: Mid/High Powered Rocketry
Topic: L2 - Model Rocket
Replies: 6
Views: 952

Re: L2 - Model Rocket

Hi Joeman, Most of the L2 and L3 kits normally come without instructions or AV bay components. I once read that the reason was that historically it was considered that if you were flying such serious motors that you wanted to fly L2 you would have enough knowledge from talking to more experienced fl...
by Lamp
Thu Aug 04, 2016 12:04 am
Forum: Low Powered Rocketry
Topic: What am I doing wrong?
Replies: 16
Views: 2214

Re: What am I doing wrong?

I think others have answered your problem, I just don't think the igniter is getting enough current. The wire "should" glow white hot under the current, but it does not matter if it lights the pyrogen and that lights the motor. Back in the early 70's we just used a short length of fine NiC...
by Lamp
Wed Aug 03, 2016 11:41 pm
Forum: Self Introductions
Topic: Heyyo from Canberra!
Replies: 7
Views: 1006

Re: Heyyo from Canberra!

Welcome to the forum OVC!

If you have any questions, just ask them and someone will answer. :D
by Lamp
Wed Aug 03, 2016 1:24 am
Forum: Self Introductions
Topic: Hello from SE Melbourne
Replies: 10
Views: 1426

Re: Hello from SE Melbourne

G'day Baq, welcome to the forum! :D As others have mentioned, the local club launch site in Victoria is near Serpentine. The main reason it is so far away is the launch site has regulatory approval and an altitude ceiling currently at 25,000'. Most of us fly high power rockets but there are also a l...
by Lamp
Tue Jul 19, 2016 2:23 pm
Forum: Melbourne Amateur Rocket Society Inc.
Topic: July Launch ??
Replies: 6
Views: 1074

Re: July Launch ??

Jase kindly put together a compilation of the stills photos I sent to him of the launch last weekend. He has called it "Rockin' Rockets.. :mrgreen: I cannot seem to imbed the youtube compilation but here is a link... https://youtu.be/ZEiP05rblpw" onclick="window.open(this.href);return false; Al...
by Lamp
Fri Jul 15, 2016 5:33 pm
Forum: Propulsion
Topic: Pro38 Forward Closure failures bulletin from CTI
Replies: 21
Views: 1922

Re: Pro38 Forward Closure failures bulletin from CTI

I believe the delay snuffing issue is due to a shock wave that develops inside the motor. We discussed this issue at our club meeting on Wednesday night. The current Tripoli recommendation is to use electronic ejection with V-Max motors in order to prevent a possible ballistic recovery.
by Lamp
Tue Jul 12, 2016 12:42 am
Forum: Self Introductions
Topic: N00B
Replies: 8
Views: 911

Re: N00B

Hi Steve, welcome to the forum and to rocketry. There are lots of people here who either didn't start until later in life or who like me, started as a kid had other interests and returned to it after many years. It is good you have started with flying some LPR and I'm sure the Canberra guys will loo...

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