Quantcast

Boosted Dart, Anyone?

The Rocketry Forum

Help Support The Rocketry Forum:

RocketFeller

Well-Known Member
Joined
Sep 15, 2009
Messages
1,187
Reaction score
71
Having successfully completed our build of a carbon fiber upscale of the Binder Design Dragonfly, our school rocketry team is looking towards the next couple years' project. This year's rocket was big, slow, and dumb. For next year, we would like to build something small, fast, and smart.

I like the idea of a boosted dart. It has a lot of similarities to a two-stage flight with a bit less complexity. It also seems somewhat safer to set up and fly.

The current idea is to build a minimum diameter 98mm rocket next year. This rocket would serve as the booster for the boosted dart, with the interstage coupling and the dart to be completed in 2017/2018.

The booster will be made from carbon pre-preg with a Max Q fin can and a 6:1 ogive fiberglass nosecone. It will have a standard DD setup that will be replaced by the ISC in the finished product.

The dart will most likely be a FG tube for RF transparency. It will also have a Max Q fin can. I would like to go with a 54mm dart, as we hope to utilize a Kate system ( a very cool GPS device built by Vern K of Multitronix) and that is the required MD. I have seen that some people machine the nosecone from solid brass/copper, while others use solid urethane cones. I was thinking of using either a fiberglass cone partially filled with resin or possibly a tungsten/resin mixture. I will have to play around with simulations to see how to get the most altitude out of it.

I am not exactly sure what to do for the ISC. I have read some build threads and it looks like centering rings and a central pin or rod seems to be the most common setup. I think that I would like to incorporate a separation charge to ensure it separates at the proper time. However, I have also read that drag separation can be utilized and sometimes K.I.S.S. is the way to go.

I would love to hear from people who have flown a boosted dart, or for that matter from people who have thought about flying one...

Thanks!
 

CzTeacherMan

Well-Known Member
Joined
Aug 8, 2014
Messages
2,849
Reaction score
168
Subscribed. Boosted darts fascinate me, but have yet to undertake one. Kool project idea
 

Salvage-1

Certified
Joined
Mar 18, 2012
Messages
2,621
Reaction score
3
ooh nice idea... Watching..

I have done a couple of UBD's (Unintentional Boosted Dart). The stage separation event occured, but the sustainer didn't light. Not quite what you are looking for.
 

Winston

Lorenzo von Matterhorn
Joined
Jan 31, 2009
Messages
8,616
Reaction score
886
I have done a couple of UBD's (Unintentional Boosted Dart). The stage separation event occured, but the sustainer didn't light. Not quite what you are looking for.
UBD. I'll have to remember that for the next time I see a multistage failure.
 

Solarover12

Well-Known Member
Joined
Dec 19, 2014
Messages
283
Reaction score
1
I did that once, and am currently working on another boosted dart. In my opinion boosted darts are the way to go if you're going for altitude, and much simpler than a conventional two stage. Good luck dude.
 

RocketFeller

Well-Known Member
Joined
Sep 15, 2009
Messages
1,187
Reaction score
71
I
Subscribed. Boosted darts fascinate me, but have yet to undertake one. Kool project idea
Thanks, I am looking forward to it!

ooh nice idea... Watching..

I have done a couple of UBD's (Unintentional Boosted Dart). The stage separation event occured, but the sustainer didn't light. Not quite what you are looking for.
UBD- gotta love it!

UBD. I'll have to remember that for the next time I see a multistage failure.
Right?

I did that once, and am currently working on another boosted dart. In my opinion boosted darts are the way to go if you're going for altitude, and much simpler than a conventional two stage. Good luck dude.
Thanks, it should be fun!
 

raptor22

Well-Known Member
Joined
Jun 30, 2015
Messages
96
Reaction score
0
Sounds good! We are working on our first boosted dart project at my school as well, I'll enjoy seeing this one come together.

What school are you with?
 

RocketFeller

Well-Known Member
Joined
Sep 15, 2009
Messages
1,187
Reaction score
71
Sounds good! We are working on our first boosted dart project at my school as well, I'll enjoy seeing this one come together.

What school are you with?
Thanks! I teach at a small public school called Silver Crest. I do LPR with our rocket club and have been working with a group of middle school students.
 

Micromeister

Micro Craftman/ClusterNut
TRF Lifetime Supporter
TRF Supporter
Joined
Jan 19, 2009
Messages
15,074
Reaction score
38
Location
Washington DC
Having successfully completed our build of a carbon fiber upscale of the Binder Design Dragonfly, our school rocketry team is looking towards the next couple years' project. This year's rocket was big, slow, and dumb. For next year, we would like to build something small, fast, and smart.

I like the idea of a boosted dart. It has a lot of similarities to a two-stage flight with a bit less complexity. It also seems somewhat safer to set up and fly.

The current idea is to build a minimum diameter 98mm rocket next year. This rocket would serve as the booster for the boosted dart, with the interstage coupling and the dart to be completed in 2017/2018.

The booster will be made from carbon pre-preg with a Max Q fin can and a 6:1 ogive fiberglass nosecone. It will have a standard DD setup that will be replaced by the ISC in the finished product.

The dart will most likely be a FG tube for RF transparency. It will also have a Max Q fin can. I would like to go with a 54mm dart, as we hope to utilize a Kate system ( a very cool GPS device built by Vern K of Multitronix) and that is the required MD. I have seen that some people machine the nosecone from solid brass/copper, while others use solid urethane cones. I was thinking of using either a fiberglass cone partially filled with resin or possibly a tungsten/resin mixture. I will have to play around with simulations to see how to get the most altitude out of it.

I am not exactly sure what to do for the ISC. I have read some build threads and it looks like centering rings and a central pin or rod seems to be the most common setup. I think that I would like to incorporate a separation charge to ensure it separates at the proper time. However, I have also read that drag separation can be utilized and sometimes K.I.S.S. is the way to go.

I would love to hear from people who have flown a boosted dart, or for that matter from people who have thought about flying one...

Thanks!
If no one else will I'll ask... What type recovery scheme do you intend on using in the boosted dart? In the real rocket world. a boosted dart has no recovery system, intended to send it's telemetry back to the base station before splashing down in the open ocean far down range of any personal or property.
Unintended boosted darts or Lawn Darts are dangerous.

If your school project is to produce a boosted dart configuration with some sort of RC or Timed ejection I have no problem.
If on the other hand the intent is to simply fly it with no recovery attempt, I have a major problem with such a flight as it violates our the safety code. One of which states we will deploy a recovery device so our rockets can be flown again. More important than that is such a flight sets a super bad example to your students.
Please! Safety First Always!
 
Last edited:

Binder Design

Well-Known Member
Joined
Jan 18, 2009
Messages
1,721
Reaction score
185
If on the other hand the intent is to simply fly it with no recovery attempt, I have a major problem with such a flight as it violates our the safety code.
Considering the high performance design, this will be flown at a TRA sponsored launch with FAA class 3 waiver. That is an extensive process to ensure the flight conforms to all regulations.
 

RocketFeller

Well-Known Member
Joined
Sep 15, 2009
Messages
1,187
Reaction score
71
If no one else will I'll ask... What type recovery scheme do you intend on using in the boosted dart? In the real rocket world. a boosted dart has no recovery system, intended to send it's telemetry back to the base station before splashing down in the open ocean far down range of any personal or property.
Unintended boosted darts or Lawn Darts are dangerous.

If your school project is to produce a boosted dart configuration with some sort of RC or Timed ejection I have no problem.
If on the other hand the intent is to simply fly it with no recovery attempt, I have a major problem with such a flight as it violates our the safety code. One of which states we will deploy a recovery device so our rockets can be flown again. More important than that is such a flight sets a super bad example to your students.
Please! Safety First Always!
There will definitely be recovery gear in both the booster and the dart. We haven't ironed out any details yet, as it is summer and I want the kids to be involved in the design process as much as possible.

The booster transition/interstage coupling will house avionics that will deploy the parachute. We will do either a relatively small chute at apogee or do a larger chute using head-end DD, depending on the weight and altitude simulations. If we use a separation charge then that will also come from this set of electronics.

The dart will also have recovery gear. It will probably be standard dual-deploy configuration, but we may do some type of single-compartment DD configuration. I don't know what kind of avionics we will use for deployment, again depending on further design and research. We are hoping to send up a Multitronix telemetry unit, so we really want it back in one piece!

We have two RRC-3 units that we used in our last project, as well as an old G-Wiz MC. We will most likely use these for the booster recovery.

This is a school project with a group of five middle school girls, but we are doing everything in compliance with TRA code. Our last project had guidance from Mike Fisher who designed and provided the motor. Our final assembly was overseen by a L3 who is also a retired structural engineer and one of our club's RSOs. I appreciate your concern, because I didn't provide background and this is definitely not a project to be undertaken lightly.

Considering the high performance design, this will be flown at a TRA sponsored launch with FAA class 3 waiver. That is an extensive process to ensure the flight conforms to all regulations.
Yes indeed. If we build it right we will need to hold back on the motor for NXRS. I haven't done any calculations, but my gut feeling is that with the right motor this could easily break the 40,000' ceiling.
 
Last edited:

ksaves2

Lifetime Supporter
TRF Lifetime Supporter
Joined
Nov 25, 2009
Messages
5,887
Reaction score
276
Keep in mind, you have to allow the GPS satellite signals to reach your tracking device that sounds like you're going to be using the Multitronix device. You also have to get your tracking signals out of the airframe which in your case is going to be in
the 900Mhz range. Are you going to "tag" your booster so you can find it later. Certainly, you'll need something to track the dart. An entirely CF airframe is out of the question unless you have a surface mount antenna and have a window for the GPS receiver. Metal,carbon or CF nosecone? Nada, if you're going to put the tracker there. You made a good choice to use FG for the dart and a metal tipped FG nosecone broadens your options. Read up on darts and don't forget the boat tail on the dart.
You should have a good time with this with the proper venue. Think long and hard on tracking the dart 'cause you wouldn't want to expend all this effort and lose it from a tracking gremlin. Kurt
 

RocketFeller

Well-Known Member
Joined
Sep 15, 2009
Messages
1,187
Reaction score
71
Keep in mind, you have to allow the GPS satellite signals to reach your tracking device that sounds like you're going to be using the Multitronix device. You also have to get your tracking signals out of the airframe which in your case is going to be in
the 900Mhz range. Are you going to "tag" your booster so you can find it later. Certainly, you'll need something to track the dart. An entirely CF airframe is out of the question unless you have a surface mount antenna and have a window for the GPS receiver. Metal,carbon or CF nosecone? Nada, if you're going to put the tracker there. You made a good choice to use FG for the dart and a metal tipped FG nosecone broadens your options. Read up on darts and don't forget the boat tail on the dart.
You should have a good time with this with the proper venue. Think long and hard on tracking the dart 'cause you wouldn't want to expend all this effort and lose it from a tracking gremlin. Kurt
Thanks for the input!

I've communicated with Vern about the GPS receiver and as long as there is sufficient distance between the dome and the metal tip we should be fine. I think you are right about tracking, we will definitely want a back up tracking device.

The nose and and tailcone construction are going to take some research and calculations. For the nose we will probably use a FG cone filled with ballast. If we can get enough mass in it by filling it with RF transparent material we will do that, maybe clear marbles in resin/milled-fiber mixture or something similar. For the tailcone we will probably build our own conical cone that will mate to the ISC, or we may modify a purchased nosecone.

Right now we have more unknowns than knowns, but that is part of the fun.
 

ksaves2

Lifetime Supporter
TRF Lifetime Supporter
Joined
Nov 25, 2009
Messages
5,887
Reaction score
276
Thanks for the input!

I've communicated with Vern about the GPS receiver and as long as there is sufficient distance between the dome and the metal tip we should be fine. I think you are right about tracking, we will definitely want a back up tracking device.

The nose and and tailcone construction are going to take some research and calculations. For the nose we will probably use a FG cone filled with ballast. If we can get enough mass in it by filling it with RF transparent material we will do that, maybe clear marbles in resin/milled-fiber mixture or something similar. For the tailcone we will probably build our own conical cone that will mate to the ISC, or we may modify a purchased nosecone.

Right now we have more unknowns than knowns, but that is part of the fun.
Metal tip on a glass cone is not a problem. I've been told a filament wound nosecone with powdered carbon added to make it a black color can attenuate a signal also. Even though it's not a true carbon fiber filament, it may be in the same boat
as CF. I dropped a black nosecone for a non-black one for a project because of this. Also, I credit Fred Azinger for the recommendation to paint the rocket a light color to help stave off heating of the interior. White is good. Fred said he was with a group with a major project that had to wait on the pad in the heat. The electronics cooked, failed with catastrophic results. Kurt
 

bclark989

Well-Known Member
Joined
Dec 27, 2014
Messages
198
Reaction score
9
Sorry, noob question: What is the difference between a boosted dart and a two-stage?
 

RocketFeller

Well-Known Member
Joined
Sep 15, 2009
Messages
1,187
Reaction score
71
Metal tip on a glass cone is not a problem. I've been told a filament wound nosecone with powdered carbon added to make it a black color can attenuate a signal also. Even though it's not a true carbon fiber filament, it may be in the same boat
as CF. I dropped a black nosecone for a non-black one for a project because of this. Also, I credit Fred Azinger for the recommendation to paint the rocket a light color to help stave off heating of the interior. White is good. Fred said he was with a group with a major project that had to wait on the pad in the heat. The electronics cooked, failed with catastrophic results. Kurt
The electronics will be housed in the airframe of the dart. If we do go with a metal nosecone we will need to determine how far back in the airframe to situate the GPS in order to avoid interference. That is a good point about carbon fiber in the sun - it heats up fast and conducts heat very well. The dart won't be carbon fiber, at least not the bulk of it.

Sorry, noob question: What is the difference between a boosted dart and a two-stage?
No problem! A boosted dart has no motor in the second stage, it just separates at motor burnout and coasts to apogee. The dart is built to be heavy and aerodynamic so it goes much higher than the entire rocket would have gone.
 

bclark989

Well-Known Member
Joined
Dec 27, 2014
Messages
198
Reaction score
9
No problem! A boosted dart has no motor in the second stage, it just separates at motor burnout and coasts to apogee. The dart is built to be heavy and aerodynamic so it goes much higher than the entire rocket would have gone.
Oh! That is much simpler. Thanks for the clarification =)

Brian
 

K'Tesh

OpenRocket Chuck Norris
TRF Supporter
Joined
Mar 27, 2013
Messages
14,121
Reaction score
859
No problem! A boosted dart has no motor in the second stage, it just separates at motor burnout and coasts to apogee. The dart is built to be heavy and aerodynamic so it goes much higher than the entire rocket would have gone.
So, a boosted dart does have some kind of recovery system to prevent it from a ballistic return. Right?
 

Titan II

Well-Known Member
Joined
Aug 24, 2013
Messages
866
Reaction score
110
Yes for hobby versions such as this. It is discussed in post #11.
 

K'Tesh

OpenRocket Chuck Norris
TRF Supporter
Joined
Mar 27, 2013
Messages
14,121
Reaction score
859
Yes for hobby versions such as this. It is discussed in post #11.
Thanks for pointing that out... I just got up, and kinda glossed over that.
 

Titan II

Well-Known Member
Joined
Aug 24, 2013
Messages
866
Reaction score
110
Understood. I did something similar on another thread last week before my coffee.
 
Top