Thoy Falcon

The Rocketry Forum

Help Support The Rocketry Forum:

Joined
Aug 6, 2009
Messages
21
Reaction score
1
Location
Phoenix, Arizona
I am currently building a THOY Falcon. A real blast from the past. 67 inches long, 4 inch diameter, 30 ounces - mine will probably be heavier. 54 mm engine mount, with adapters for 38 mm and 29 mm engines.
Now the bad news. I am not certified for High Power - not even Level 1. So I plan on flying this with 29 mm G engines. I don't think an F engine has enough oomph to get it high enough for a safe recovery - even with a short delay.
So, anyone out there ever flown this bird? And what engines did you use?

Thanks to all.

Bob in Phoenix
 

rocketlabdelta

Stuck on the hedonic treadmill
TRF Supporter
Joined
Feb 18, 2020
Messages
71
Reaction score
53
Location
South Bend, IN
Hi Bob!

You're going to have a tough time getting this in the air on non-HPR motors. You need to be HPR certified to purchase a motor with an average thrust of over 80 Newtons (source).

The single-use Aerotech G80 is designed to be the most powerful motor you can buy without a certification and it's initial thrust is about 100 Newtons (thrust curve) which translates to about 22 lb (350oz) of force.

Most RSOs will require a 5:1 thrust to weight ratio which means as long as you stay under 70oz ready-to-fly you should be OK but it'd be wise to look at one of the rocket simulation programs out there to be sure and to choose the right delay.

 

lawndartman

Well-Known Member
Joined
Mar 12, 2011
Messages
608
Reaction score
17
I had one years back. It flew very nice on a G64. Mine was stock. Most of the time it was a small 'H' bird. Try a H128 for your Level 1. Mine flew great!
 

green dragon

Well-Known Member
Joined
Oct 25, 2009
Messages
228
Reaction score
26
4" bird under 3 lbs should fly on most any mid to high thrust G .... we used to fly the LOC Ulyimate on single G78 and a pair of D12's all the time
 

Mike Haberer

DaHabes
TRF Supporter
Joined
Jan 7, 2019
Messages
875
Reaction score
604
I am currently building a THOY Falcon. A real blast from the past. 67 inches long, 4 inch diameter, 30 ounces - mine will probably be heavier. 54 mm engine mount, with adapters for 38 mm and 29 mm engines.
Now the bad news. I am not certified for High Power - not even Level 1. So I plan on flying this with 29 mm G engines. I don't think an F engine has enough oomph to get it high enough for a safe recovery - even with a short delay.
So, anyone out there ever flown this bird? And what engines did you use?

Thanks to all.

Bob in Phoenix
I'd be surprised if you got a 67" long, 4" diameter rocket to come in at 30 ounces. My 52", 4" Patriot comes in a 40 ounces and only gets to 500 feet on a G80T, which is the bare minimum I can fly it with. I agree with the other poster to put an H in it and get your L1. It would be a perfect L1 bird with an H135W or H100W (both Aerotech DMS). If you can only fly it on a G80, then pull down a copy of Openrocket and sim it after you complete the build and get the final weight and CG to make sure it's safe to fly.
 

teepot

Well-Known Member
TRF Supporter
Joined
Dec 8, 2019
Messages
1,850
Reaction score
1,441
Location
Pahrump, Nevada
I'm skeptical that a G80 would even get a 70 ounce rocket off the pad. 35 ounces sure.
 

Mike Haberer

DaHabes
TRF Supporter
Joined
Jan 7, 2019
Messages
875
Reaction score
604
I'm skeptical that a G80 would even get a 70 ounce rocket off the pad. 35 ounces sure.
It will, but not with the preferred margin of safety. Max TTW is 5.2, Average TTW is 3.7. It would be the definition of low and slow, and don't fly it with any wind.
 

kc9qzf

TRA/NAR Member
Joined
Sep 12, 2015
Messages
62
Reaction score
16
T.H.O.Y. Also made a version with 7 29mm motor mounts called the Nighthawk. I am too tired to go downstairs and measure it, but it was based on the same airframe.
 

Syclone

Well-Known Member
Joined
Jan 19, 2009
Messages
231
Reaction score
18
I've flown my old Falcon on G motors a few times back in the day. G80 and G64 motors put it up about 500'. I flew a small backup altimeter for deployment, but otherwise it was built stock.
 

J Blatz

Well-Known Member
Joined
May 8, 2010
Messages
1,038
Reaction score
46
I’d bet any man jack in here that the new style DMS G80 with a 4 to 6 second delay would deliver a great flight. Build it light and you will be fine.
 

UhClem

Well-Known Member
Joined
Feb 6, 2009
Messages
1,884
Reaction score
318
This reminds me of a three way drag race of Thoy Falcons on the Aerotech J135 at Argonia long ago. One had a forward closure failure which set it to burning. Forever after known as The Flaming Falcon.
 

Steve Fitton

Well-Known Member
Joined
May 28, 2009
Messages
134
Reaction score
8
I had several Falcons and Nighthawks. The Nighthawk would give a nice flight on 3 engine clusters such as 3 G-40s or 80s. My Falcons flew on H-180, J-180s and J-275s
I think it will fly on a G-80 if you keep it light. Then you can go get your L1 with it! :)
 
Joined
Aug 6, 2009
Messages
21
Reaction score
1
Location
Phoenix, Arizona
THOY FALCON Update: I set up my electronic balance and weighed all the pieces. Nose cone, payload section, main body tube, motor mount, fins, 29 mm adapter, an AT 29/40-120 motor case, a G64-10 reload (yeah,I'll shorten the delay), even the chute and the launch lugs. Grand total? 1575.7 grams, or 55.6 ounces!! The card that came with the kit says 30 ounces. An old THOY catalog I have says 30 ounces. Not even close!
So I went to Thrust Curve and input all this stuff. It says an AT G76G will lift this bird to an incredible 151 meters - 495 feet. So it should be easy to track.
But the thrust to weight is only 4:1.
It looks like I will require my Level 1 just to fly this thing.
Bob
 

bad_idea

Well-Known Member
TRF Supporter
Joined
Mar 19, 2021
Messages
58
Reaction score
34
Location
North Texas
Perhaps I've misunderstood the rules, but I had thought that anything over 1,500g loaded would be a high power flight anyway, regardless of thrust to weight or impulse.

In any case, sounds like a good reason to get your L1. :cool:
 

teepot

Well-Known Member
TRF Supporter
Joined
Dec 8, 2019
Messages
1,850
Reaction score
1,441
Location
Pahrump, Nevada
The published weight is without a motor I believe. It might not include the chute unless it came with the kit. More that likely without the electronics too or the adapter. That should bring your weight closer to the published weight. I believe what you have is your level 1 rocket.
 

waltr

Well-Known Member
Joined
Jul 18, 2021
Messages
83
Reaction score
59
Sorry guys but the rocket weight determines the CLASS not L1. L1, L2, L3 or not determines which Motors you may buy and launch, not rocket size or weight. However, you will need bigger (L1 or up) motors and cert if the rocket's weight is high.

Definitions:
https://www.nar.org/high-power-rocketry-info/

Note that one can fly on a G motor without L1 even if over 1.5kg which is a Class 2 (high power) without L1 cert.
 

UhClem

Well-Known Member
Joined
Feb 6, 2009
Messages
1,884
Reaction score
318
Note that one can fly on a G motor without L1 even if over 1.5kg which is a Class 2 (high power) without L1 cert.
Amazing. You liinked to a page which says that a rocket with a mass over 1.5kg at launch is a high power rocket and you still get it wrong.
 

bad_idea

Well-Known Member
TRF Supporter
Joined
Mar 19, 2021
Messages
58
Reaction score
34
Location
North Texas
Sorry guys but the rocket weight determines the CLASS not L1. L1, L2, L3 or not determines which Motors you may buy and launch, not rocket size or weight. However, you will need bigger (L1 or up) motors and cert if the rocket's weight is high.

Definitions:
https://www.nar.org/high-power-rocketry-info/

Note that one can fly on a G motor without L1 even if over 1.5kg which is a Class 2 (high power) without L1 cert.
From that NAR page:
Certain F and G motors also require Level 1 certification for purchase and use (this includes: hybrid motors, motors designed to emit sparks, motors that exceed 80 Newtons average thrust, motors containing 125 or more grams of propellant, or are in rockets weighing more than 1500 grams.
That reads to me like NAR will not allow a flight over 1,500g without a high power cert.
 

waltr

Well-Known Member
Joined
Jul 18, 2021
Messages
83
Reaction score
59
You guys are right I think, but.
Reading the regs is confusing since there is definition of Class 1 and class 2 rockets then L1 cert requirements.

To me it seemed that class 2 does not require L1 cert but Does require FAA waiver.
Still confused by the difference.

Reading Class1 verse 2 def., if you have a 500gm rocket but it has an aluminum nose cone tip then it is a Class 2 rocket requiring FAA waiver but not L1 cert. Same if the rocket has a fiberglass BT (Class 1:
"(3) Is made of paper, wood, or breakable plastic;
(4) Contains no substantial metal parts; and
"

Does a 500gm fiberglass rocket with an E motor require L1 cert? or just
FAA waiver?

 

Tractionengines

Well-Known Member
TRF Supporter
Joined
Aug 29, 2020
Messages
269
Reaction score
155
Location
Northeast Ohio
Fiberglass BT doesn't require anything special. For example:The Small Mach1 BT20 thru BT60 rockets that are less than 1500grams (ready to fly) and can fly on A thru G motors that are less than 80N of thrust can be flown like any small or mid power rocket. The epoxy "cures into breakable plastic" the fiberglass is just a filler.

No Lx or Waiver required just because of fiberglass.
 

waltr

Well-Known Member
Joined
Jul 18, 2021
Messages
83
Reaction score
59
OK, I was not sure if fiberglass BT was considered 'breakable plastic". Thanks.
It is a Mach 1 Saberhawk with BT55 I have.
 

Ez2cDave

Well-Known Member
Joined
Jan 18, 2009
Messages
4,938
Reaction score
1,552
Hi Bob!

You're going to have a tough time getting this in the air on non-HPR motors. You need to be HPR certified to purchase a motor with an average thrust of over 80 Newtons (source).

The single-use Aerotech G80 is designed to be the most powerful motor you can buy without a certification and it's initial thrust is about 100 Newtons (thrust curve) which translates to about 22 lb (350oz) of force.

Most RSOs will require a 5:1 thrust to weight ratio which means as long as you stay under 70oz ready-to-fly you should be OK but it'd be wise to look at one of the rocket simulation programs out there to be sure and to choose the right delay.
The maximum liftoff weight for a Model Rocket is 1500 grams / 53 oz. . . . Anything heavier will require an FAA waiver. If you exceed 100 Newtons of thrust ( per motor ) or 320 Nt-Sec of Total Impulse, it's an HPR rocket, requiring certification AND an FAA waiver.

If you modified the rocket for TWO 29mm mounts, a pair of G80's would work. ( just under the Safety Code limits ), provided it weighs less than 1500 gr / 53 oz., at liftoff.

Dave F.
 
Top