An "R"-powered rocket build

[Rail Dawg]

If anyone is curious here’s the current plan for this rocket:

12” G-12 fiberglass airframe with 4-5 wraps of carbon.

Approx 20’ tall.

Fiberglass nosecone (preferably G-12 with metal tip).

8.75” motor mount with several 3/4” birch plywood centering rings.

All-aluminum fin can by Binder Design. Nike Smoke-style fins with beveling. Fin can will be bolted into the airframe and 3/4” centering rings.

The fin can, motor mount and airframe will act as one unit to handle motor thrust.

Up to 15% “R” motor. Still deciding which propellant. Have 2 of the best amateur motor builders in the country working (and teaching me to research and mix) on the propellant and new motor casing.

8” ID x 8’ motor casing with bolted upper enclosure. Aluminum thrust ring and plate along with a nozzle carrier on lower end.

Big Red Bee 900 MHz GPS tracker in nose cone.

(2) Marsa 33LHD altimeters.

Expected altitude 42,000 ft. Mach 2.1

Weight approx 500 lbs. 300 lbs after motor burnout.

Still determining launch location. Build should be complete by May of this year unless issues with obtaining parts.

It’s going to be (currently) a basic dual-deploy rocket with one drogue and a very large parachute.

Still thinking about ejection charges. Probably black powder with multiple redundancy.

There it is guys. You can see a lot of your inputs have been incorporated into the design.

Chuck C.

 

[djs]

Up to 15% “R” motor. Still deciding which propellant. Have 2 of the best amateur motor builders in the country working (and teaching me to research and mix) on the propellant and new motor casing.

If you're on the research section of the forum, would you be willing to post more details about this? I mean, what grain configuration, etc that you're using, and the decisions that go into making the motor?

 

[Ez2cDave]

Chuck & All,

Sorry to have "dropped off the radar" . . . I have been visiting my in-laws from Dec 31 - Today ( 6 hour drive ) . . .

Adapt & Overcome !

Dave F.

 

[Ez2cDave]

If anyone is curious here’s the current plan for this rocket:

12” G-12 fiberglass airframe with 4-5 wraps of carbon.

Approx 20’ tall.

Fiberglass nosecone (preferably G-12 with metal tip).

8.75” motor mount with several 3/4” birch plywood centering rings.

All-aluminum fin can by Binder Design. Nike Smoke-style fins with beveling. Fin can will be bolted into the airframe and 3/4” centering rings.

The fin can, motor mount and airframe will act as one unit to handle motor thrust.

Up to 15% “R” motor. Still deciding which propellant. Have 2 of the best amateur motor builders in the country working (and teaching me to research and mix) on the propellant and new motor casing.

8” ID x 8’ motor casing with bolted upper enclosure. Aluminum thrust ring and plate along with a nozzle carrier on lower end.

Big Red Bee 900 MHz GPS tracker in nose cone.

(2) Marsa 33LHD altimeters.

Expected altitude 42,000 ft. Mach 2.1

Weight approx 500 lbs. 300 lbs after motor burnout.

Still determining launch location. Build should be complete by May of this year unless issues with obtaining parts.

It’s going to be (currently) a basic dual-deploy rocket with one drogue and a very large parachute.

Still thinking about ejection charges. Probably black powder with multiple redundancy.

There it is guys. You can see a lot of your inputs have been incorporated into the design.

Chuck C.

Chuck,

We really need an accurate approximate liftoff weight and actual motor specs, ASAP.

The new "bird", if less mass, will likely reach a higher airspeed, certainly at lower altitude, possibly affecting fin planform and specs.

Budget is still $50, 000, right ? ( ducking & running . . . LOL ! )

Happy New Year !

Dave F.

 

[Ez2cDave]

If you're on the research section of the forum, would you be willing to post more details about this? I mean, what grain configuration, etc that you're using, and the decisions that go into making the motor?

Chuck,

I am NOT on the Research Forum . . . Please email me any pertinent info, if possible, that involves the motor profile ( not "chemistry", just Time-Thrust related ), airframe specs & materials, recovery, IF you post them on the EX Forum !

[email protected]

NOTE : The use of CARBON FIBER on the airframe tubing MAY INTERFERE with the TRANSMISSION of any DATA, including TRACKING, GPS, and VIDEO !

Thanks !

Dave F.

 

[Rail Dawg]

Guys I’m not on the Research forum and have pledged to not discuss the motor here except for casing dimensions and total motor weight.

Got to stick to my word lol.

Take care.

Chuck C.

 

[Ez2cDave]

Guys I’m not on the Research forum and have pledged to not discuss the motor here except for casing dimensions and total motor weight.

Got to stick to my word lol.

Take care.

Chuck C.

Chuck,

We are going to need Time-Thrust "numbers" for performance calculations !

I don't need any "mechanical specs" ( Nozzle Specs, for example ), just what we need for safety, accuracy, and success.

Dave F.

 

[Ez2cDave]

I did a P motor rocket, 9 1/2" diameter, Mach 2, 32,000 feet.
Nose cone was outer layer of fiberglass epoxy (for finish sanding) and inter layers carbon fiber epoxy getting thicker as diameter increased. No issues.
Made aluminum cones, 2 1/2" and smaller. Making walls thin and light can be troublesome. I now have access to an ancient and huge tracer lathe and have considered trying it again. Making a cone for this project would require an enormous lathe and boring bars.


M

Making LARGE Nose Cones ( SORAC ) . . . PDF below.

Dave F.

 

[ksaves2]

Chuck,

I am NOT on the Research Forum . . . Please email me any pertinent info, if possible, that involves the motor profile ( not "chemistry", just Time-Thrust related ), airframe specs & materials, recovery, IF you post them on the EX Forum !

[email protected]

NOTE : The use of CARBON FIBER on the airframe tubing MAY INTERFERE with the TRANSMISSION of any DATA, including TRACKING, GPS, and VIDEO !

Thanks !

Dave F.

As long as the NC is glass there shouldn't be an issue with tracking. In fact, put an RDF beacon on the apogee harness with the CF shielding airframe, once the apogee charge blows you'll start hearing the signal as a backup indication the rocket is apart at apogee.
Of course primary indication would be GPS altitude on the BLGPS. Kurt

 

[Paulb06]

Good question.

Many high power Mach 2 rockets have flown successfully with a carbon-wrapped airframe with a fiberglass nosecone.

May consider some Kevlar but am certain the rocket as built will take the stress.

Appreciate the input.

Chuck C.

A glass nosecone is a good plan...keep in mind that Python Rocketry's standard layup is 2 plys of 6 oz cloth. Each ply of glass will add approx. .008" to .010"... even with high density foam behind it, I would want more than that.

 

[Ez2cDave]

If anyone is curious here’s the current plan for this rocket:

Expected altitude 42,000 ft. Mach 2.1

Weight approx 500 lbs. 300 lbs after motor burnout.

Still determining launch location. Build should be complete by May of this year unless issues with obtaining parts.

It’s going to be (currently) a basic dual-deploy rocket with one drogue and a very large parachute.

Still thinking about ejection charges. Probably black powder with multiple redundancy.

Chuck C.

Chuck,

A few points to ponder :

(1) 42,000 ft AGL / Mach 2.1 ( theoretical numbers only, until an actual motor has been tested and a liftoff weight is determined ).

(2) 300 lb. under Main Chute ( looking at a 40 ft. diameter chute - BARE MINIMUM . . . 50 ft would be excellent ).

I have been thinking about either a "Deployment Bag" or a "Split-Canister" containing the Main to facilitate easy ejection from
the airframe. Either device would be extracted by a "Pilot Chute" ( fully extends chute to aid in opening ) . . . Perhaps, some
type of "Reefing" system, also, to reduce Opening Shock on the Main.

(3) Ejection Charges, at Altitude ( be SURE to determine how BP performs at 42,000 ft AGL, or higher - Air Pressure, Ignition, &
Performance ) . . . If Drogue charge fails, rocket will streamline in, guaranteeing a SHRED at Main Deploy.

Adapt & Overcome . . . Failure is not an option !

Dave F.

 

[Ez2cDave]

Tracker talk had me thinking.
Wherever you launch the rocket may have to be recovered from a location a vehicle can not be driven. This may be the middle of a sorghum field in Kansas or the dunes at Black Rock (could be miles). Hauling a couple hundred pounds through soft sand or a plowed field needs to planned for.

M

Mark & Chuck,

That is a serious consideration. What about hiring a small helicopter ( with Pilot, naturally ) for a few hours ?

He could fly you out to the rocket, where a "sling" could be attached, and transport you and the rocket back to the launch site.

Dave F.

 

[Rail Dawg]

Chuck,

A few points to ponder :

(1) 42,000 ft AGL / Mach 2.1 ( theoretical numbers only, until an actual motor has been tested and a liftoff weight is determined ).

(2) 300 lb. under Main Chute ( looking at a 40 ft. diameter chute - BARE MINIMUM . . . 50 ft would be excellent ).

I have been thinking about either a "Deployment Bag" or a "Split-Canister" containing the Main to facilitate easy ejection from
the airframe. Either device would be extracted by a "Pilot Chute" ( fully extends chute to aid in opening ) . . . Perhaps, some
type of "Reefing" system, also, to reduce Opening Shock on the Main.

(3) Ejection Charges, at Altitude ( be SURE to determine how BP performs at 42,000 ft AGL, or higher - Air Pressure, Ignition, &
Performance ) . . . If Drogue charge fails, rocket will streamline in, guaranteeing a SHRED at Main Deploy.

Adapt & Overcome . . . Failure is not an option !

Dave F.

You’re right Dave it can’t just be a straight ejection. Pilot chute and reefing absolutely.

May have to look at cargo parachutes. Rocketman makes a great high-energy chute but the biggest is 36’.

Have always like the Rocketman chute because of fewer shroud lines.

Now if we separate the rocket and recover in two separate pieces that has advantages. But also disadvantages in complexity.

As usual lots to think about.

Chuck C.

 

[Ez2cDave]

You’re right Dave it can’t just be a straight ejection. Pilot chute and reefing absolutely.

May have to look at cargo parachutes. Rocketman makes a great high-energy chute but the biggest is 36’.

Have always like the Rocketman chute because of fewer shroud lines.

Now if we separate the rocket and recover in two separate pieces that has advantages. But also disadvantages in complexity.

As usual lots to think about.
Chuck C.

Chuck,

Once we get "good numbers" for Recovery Mass, it should be easier to develop the best approach to recovery logistics.

Never fear, the "Steely-Eyed Missile Men" are here . . . LOL !

Dave F.

 

[tfish]

Rocketman does make up to 60 foot chutes
https://the-rocketman.com/chutes-html/

If those are the wrong "style"...I'm sure Buddy can make what you need.

Tony

 

[0011001100]

You’re right Dave it can’t just be a straight ejection. Pilot chute and reefing absolutely.

May have to look at cargo parachutes. Rocketman makes a great high-energy chute but the biggest is 36’.

Have always like the Rocketman chute because of fewer shroud lines.

Now if we separate the rocket and recover in two separate pieces that has advantages. But also disadvantages in complexity.

As usual lots to think about.

Chuck C.

Contact him, he can make bigger chutes by request and I have seen one of his big custom chutes in person and they are beautiful. Also see if you can contact Tom C. as he as experience flying very heavy rockets and can give you advise.

 

[mccordmw]

There's always eBay for military cargo chutes.

 

[MClark]

What is the volume of a 50-60 foot chute?
Going to fill a long chunk of 12" tube.

M

 

[MClark]

Double post.
Oops

 

[Ez2cDave]

What is the volume of a 50-60 foot chute?
Going to fill a long chunk of 12" tube.

M

That will likely depend on whatever material it is made out of, plus the number, length, and type of shroud lines.

Dave F.

 

[Rail Dawg]

What is the volume of a 50-60 foot chute?
Going to fill a long chunk of 12" tube.

M

Good question.

Looking at the Rocketman web site his 36-foot Pro-Experimental chutes pack well into an 8" airframe.

If they will build a 60' Pro-Experimental chute I don't think it will be any problem fitting it into a 12" airframe.

I haven't had time to really think about getting the chute out and reefing the shroud lines correctly. I know with 300+ lbs of weight and a potential for high-speed deployment a lot of thought needs to go into this.

Chuck C.

 

[Rail Dawg]

Contact him, he can make bigger chutes by request and I have seen one of his big custom chutes in person and they are beautiful. Also see if you can contact Tom C. as he as experience flying very heavy rockets and can give you advise.

Thanks for the info I didn't realize Rocketman would do a custom build.

That is great news as I've had nothing but success with their chutes.

Chuck C.

 

[Rail Dawg]

For recovery (I always overbuild) I'm thinking of a robust motor upper enclosure for 3000# (or more) test Kevlar straps.

Also considering installing eyebolts on the lower thrust plate and drilling holes into the MMT centering rings to run additional straps to the upper recovery straps.

Just shooting from the hip right now.

Chuck C.

 

[Paulb06]

For recovery (I always overbuild) I'm thinking of a robust motor upper enclosure for 3000# (or more) test Kevlar straps.

Also considering installing eyebolts on the lower thrust plate and drilling holes into the MMT centering rings to run additional straps to the upper recovery straps.

Just shooting from the hip right now.

Chuck C.

I've always preferred nylon because of the shock absorbing characteristics of it....I'd like to know how many " g's" folks with accellerometers are recording at apogee?... I think you'll want more than #3000lb strap....in 6" rockets I've run 2" flat nylon webbing...7000lb......there is a way to pack them so they dont take up much space and deploy nice ....f you think in terms of 300lb @ 10 "G's"... you have 3000lb...I dont think a 10 G deployment is all that unlikely you'll want a good sized clevis to attach to the eyebolt on the motor...quick links won't cut it

 

[Ez2cDave]

For recovery (I always overbuild) I'm thinking of a robust motor upper enclosure for 3000# (or more) test Kevlar straps.

Also considering installing eyebolts on the lower thrust plate and drilling holes into the MMT centering rings to run additional straps to the upper recovery straps.

Just shooting from the hip right now.

Chuck C.

Chuck,


Since the rocket will be under Drogue at Main Deploy, it's descent rate will likely be around 90 - 120 mph ( 135 - 195 ft/sec ), prior to Main Deploy.

300 lbs, traveling at 195 ft/sec ( 120 mph ) would deliver 177,278.226 ft/lb of energy ( If brought to a theoretical "dead stop", instantaneously ) . . .

OBVIOUSLY the Main Chute MUST open S-L-O-W-L-Y ( Reefing System ) . . . If the chute "BOOMS" open, it's TOAST ( a new "scientific term" - LOL ! )


Dave F.

 

[Rail Dawg]

I've always preferred nylon because of the shock absorbing characteristics of it....I'd like to know how many " g's" folks with accellerometers are recording at apogee?... I think you'll want more than #3000lb strap....in 6" rockets I've run 2" flat nylon webbing...7000lb......there is a way to pack them so they dont take up much space and deploy nice ....f you think in terms of 300lb @ 10 "G's"... you have 3000lb...I dont think a 10 G deployment is all that unlikely you'll want a good sized clevis to attach to the eyebolt on the motor...quick links won't cut it

I should have been more specific lol.

Will probably have (3-4) 3000# straps.

I like nylon too for the stretch but am concerned with many grams of BP torching the nylon.

Chuck C.

 

[Steve Shannon]

Chuck,


Since the rocket will be under Drogue at Main Deploy, it's descent rate will likely be around 90 - 120 mph ( 135 - 195 ft/sec ), prior to Main Deploy.

300 lbs, traveling at 195 ft/sec ( 120 mph ) would deliver 177,278.226 ft/lb of energy ( If brought to a theoretical "dead stop", instantaneously ) . . .

OBVIOUSLY the Main Chute MUST open S-L-O-W-L-Y ( Reefing System ) . . . If the chute "BOOMS" open, it's TOAST ( a new "scientific term" - LOL ! )


Dave F.

It won’t come to a dead stop.
It’ll slow to 20-25 feet per second over 100-200 feet.
A slider would extend that.

 

[Paulb06]

I should have been more specific lol.

Will probably have (3-4) 3000# straps.

I like nylon too for the stretch but am concerned with many grams of BP torching the nylon.

Chuck C.

It's fairly easy to protect the recovery system from black powder burns....my favorite way is to sew nomex sleeves that slide over the webbing for the amount of the webbing that will be exposed to heat , I put a short nylon leader on the drogue and build a bag that looks like a tadpole....IOW a bag with a shock strap sleeve sewn to one side of it with a couple grommets at the end of the tail....your shock strap will be fed thru the sleeve and attached to the motor and the grommets secured to the same clevis.....place your shock strap in the bag,...leave a length of shock strap the length of your chute lines out for now.....then pack the chute in the bag ( chute first then the chute lines) and then the remainder of the shock strap...... fold the top of the bag over with the shock strap and leader for the drogue coming out of the top.....make a nomex sleeve for any exposed shock strap ....during deployment what will happen is the drogue leader and the shock cord will extend, then the chute lines will extend and the chute will clear, inflate and finally the rest of the shock strap will come out of the bag.....the bag will stay just inside the booster tube

 

[Paulb06]

Chuck,


Since the rocket will be under Drogue at Main Deploy, it's descent rate will likely be around 90 - 120 mph ( 135 - 195 ft/sec ), prior to Main Deploy.

300 lbs, traveling at 195 ft/sec ( 120 mph ) would deliver 177,278.226 ft/lb of energy ( If brought to a theoretical "dead stop", instantaneously ) . . .

OBVIOUSLY the Main Chute MUST open S-L-O-W-L-Y ( Reefing System ) . . . If the chute "BOOMS" open, it's TOAST ( a new "scientific term" - LOL ! )


Dave F.

If the drogue is sized correctly , descent rate under drogue should be more like 50 fps....something like 16' diameter...

 

[Rail Dawg]

It won’t come to a dead stop.
It’ll slow to 20-25 feet per second over 100-200 feet.
A slider would extend that.

That's what I'm thinking too Steve.

Definitely going to put a lot of thought into the smoothest recovery possible with this large a rocket. Sliders and reefing for sure.

Chuck C.