[NRVR-Members] Sept 25-26th Launch at SINKLAND (not Kentland) farms for the Fall Pumpkin Festival!!
Thomas Tweeks Weeks
tom at theweeks.org
Mon Sep 13 11:44:49 CDT 2021
Maybe we can help clarify the confusion about the thresholds for what makes a low/medium power (class-1) rockets & motors.. vs high power/L1 (class-2). This doesn't come up a lot.. and I've also been confused by it over the years..
But I bring this up bc we have a couple members asking about specific Gs they can fly at this class-1 launch. Correct me if I'm wrong Bob.... we've typically just advertised that at low/medium power (class-1) rocket launches, that flyers need to restrict their total, on-pad rocket mass to under 1500grams (3.3lbs) and only use a motor that contains less than 125 grams (4.4oz) of propellant (usually Gs and lower).. However there's a couple more class-1 motor restrictions:
Average thrust less than 80 Newtons <------------------
Contains 125 grams (4.4oz) or less of propellant
Not a hybrid rocket motors
So a class-1 rocket, or what crosses over into class-2 (high power) can also be based on the motor's AVERAGE THRUST. Anything with an avg thrust of 80 newtons or higher (e.g. a G79 motor would be a L0 motor or class-1 rocket, vs the G138 which would be a L1 motor, or make your rocket a class-2, "high power" rocket). From what I hear, there are even some motors (F240) that violate this general "G and under" rule of thumb, and as such, these motors are classified as L1 high power, and can not be a) purchased by non-L1 flyers, or b) flown at class-1/low-medium power rocket launches. This is usually clearly marked on vendor motor sites as seen here:
[ https://www.siriusrocketry.biz/ishop/aerotech-g138t-14a-hpr-reload-kit-hazmat-744.html ]( https://www.siriusrocketry.biz/ishop/aerotech-g138t-14a-hpr-reload-kit-hazmat-744.html )
On the ROCKET side of the class-1 equation.. a class-1 (model) rocket is an amateur rocket that:
1. Uses no more than 125 grams (4.4 ounces) of propellant;
2. Uses a slow-burning propellant;
3. Is made of paper, wood, or breakable plastic;
4. Contains no substantial metal parts; and
5. Weighs (on-pad) no more than 1,500 grams (3.3lbs/53 ounces), including the propellant.
Am I missing anything Bob?
Do you have anything to add or suggestions for folks to make it less confusing?
BTW.. Just as a PSA.. It looks like the thrust curve on Chris' page for the G138 Blue Thunder is wrong (I sent him a note on this already):
[ https://csrocketry.com/rocket-motors/aerotech-rocketry/motors/29mm/29/40-120-reloads/aerotech-g138t-14a-blue-thunder-rocket-motor.html ]( https://csrocketry.com/rocket-motors/aerotech-rocketry/motors/29mm/29/40-120-reloads/aerotech-g138t-14a-blue-thunder-rocket-motor.html )
[ https://www.thrustcurve.org/motors/AeroTech/HP-G138T/ ]( https://www.thrustcurve.org/motors/AeroTech/HP-G138T/ )
On Sunday, September 12, 2021 1:42pm, "Thomas Tweeks Weeks" <tom at theweeks.org> said:
So we're still shut out of Kentland, but I have reached out to an old NRVR friend.. the owner of Sinkland Farms down in Riner off Hwy8.. and she is SUPER excited to have us come fly with her again in September and possibly October!
[ https://sinklandfarms.com/ ]( https://sinklandfarms.com/ )
We'll be positioned on the back hill.. See calendar for GPS coords.
Note: This is a Low/Medium power (class-1) rocket launch. There's no FAA waiver, and all launches are restricted to 125grams of propellant (up thru most G motors) and 1500grams (3.3lb) rocket weights (on the pad). So NO BIG or HP will be allowed. We will provide standard low power pads and 1010 rails (may have mini/micro rails too I think).
Launch details are on our website and calendar here:
[ http://nrvr.org/calendar/ ]( http://nrvr.org/calendar/ )
If you've never been to the Sinkland Farms Pumpkin Festival, it's a TON of fun.. Bring your whole family to browse pumpkins, kettle cord, live music, petting zoo, meat on a stick, ice cream.. they have it all.
Group Motor Order Thru THIS FRIDAY:
If anyone wants in.. I've started a group order to get myself a few G motors at Chris Rocketry Supplies ( [ csrocketry.com/rocket-motors.html ]( https://csrocketry.com/rocket-motors.html ) ).. You have through THIS FRIDAY (@5pm) to place your order, and indicate in the shipping instructions "Add to Tweeks/NRVR shipment" and they will split the $50-60 hasmat/shipping costs between all of us (the more who order the cheaper it is). A good way to save a few bucks. But DO NOT WAIT.. After Friday, Chris will ship them to my house and you're on your own. I'll split out the motor orders and hand them out at the launch.
I'll leave the RSO limits to Bob.. but if he doesn't weigh in.. I'll say we want to keep most rocket flights under say 1500-2000ft.. and we're not sure about sparky motors yet.. so have various motor options on hand. I think we also get free parking/admission to the farm.. but I'll check on that.
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