Looking for 2 stage BT-80 kit

[captbk]

I have looked all over and cant seem to find any kits with body tubes larger that 1.6" BT-60. I could probably scratch build one but I would rather do a kit. Is there such a thing? Looking for something with 24mm motors and a 2.6" or BT-80.

 

[Eric]

Contact Steve at Mach1 Rocketry. He can make you a kit to meet your design needs.

 

[kuririn]

Combining 24 mm BP booster/sustainer motors and a bt-80 sized body is a tough challenge.
Here are a couple of 29mm BT-80 size two stagers:
https://www.apogeerockets.com/Rocke...eroDactyl-TS?zenid=mfd33eib4mis2pjpd1thqm2h86
https://www.apogeerockets.com/Rocke...s/Aerobee-Hi?zenid=mfd33eib4mis2pjpd1thqm2h86
First one uses gap staging and BP motors. Relatively simple.
Second one uses composite motors and air start (electronic ignition) of the second stage. Much more challenging.

 

[Gary Byrum]

There may be some out there but I have no clue on kits that were BT60 2 stagers or bigger. Most people take an existing kit and modify it for staging. I, on the other hand prefer to craft my own and this little BT60 jewel flies like a pro.

 

[captbk]

I thought about modifying a kit but the only ones that come to mind are LaunchPad kits. Are they still availible/in business?
I like the first one from Apogee also. I'll have to do some thinking if I'm going scratch or kit?

 

[kuririn]

Alas, The Launch Pad is no more. Uncle Mike's still has some plan packs though. Maybe you could do an upscale of this:
https://www.apogeerockets.com/Rocket-Kits/Skill-Level-3-Model-Rocket-Kits/Rip-Roar
Don't know if a 24mm BP motor has enough kick though. Maybe an E12/E12? Happy building!

 

[MaxQ]

I have looked all over and cant seem to find any kits with body tubes larger that 1.6" BT-60. I could probably scratch build one but I would rather do a kit. Is there such a thing? Looking for something with 24mm motors and a 2.6" or BT-80.

I built one...nice kit.
Uses the honkin F15-0/E16-8 BP motors.
https://www.apogeerockets.com/Rocket-Kits/Skill-Level-3-Model-Rocket-Kits/AeroDactyl-TS

 

[Wayco]

I built a couple of Apogee's "Rip Roar" back when I started out. Fun kit that was gap staged and always worked:
https://www.apogeerockets.com/Rocket-Kits/Skill-Level-3-Model-Rocket-Kits/Rip-Roar

 

[MALBAR 70]

This one is BT 80, but alas, it is OOP. I imagine if you looked around you could find one.

https://www.rocketreviews.com/sunward-aerospace-solar-eclipse--by-jeff-lane.html

 

[captbk]

Combining 24 mm BP booster/sustainer motors and a bt-80 sized body is a tough challenge.
Here are a couple of 29mm BT-80 size two stagers:
https://www.apogeerockets.com/Rocke...eroDactyl-TS?zenid=mfd33eib4mis2pjpd1thqm2h86
https://www.apogeerockets.com/Rocke...s/Aerobee-Hi?zenid=mfd33eib4mis2pjpd1thqm2h86
First one uses gap staging and BP motors. Relatively simple.
Second one uses composite motors and air start (electronic ignition) of the second stage. Much more challenging.

Im finding out the biggest "challenge" in scratch building a BT-80 size two stage is weight. I also wanted to know if it's possible to stage a composite motor (AT 24-40) in the booster, to a black powder motor in the sustainer?

 

[Wallace]

Yes. But not without electronics....

 

[kuririn]

Im finding out the biggest "challenge" in scratch building a BT-80 size two stage is weight. I also wanted to know if it's possible to stage a composite motor (AT 24-40) in the booster, to a black powder motor in the sustainer?

Don't know, haven't tried it. Two problems that I see right off the bat:
1. There are no AP motors that I know of that have a zero delay. I suppose you could drill a reload delay charge down to a minimum, but it wouldn't be zero, I imagine.
2. BP motors use the blowby gases of the booster propellant to ignite the sustainer. Much less powerful than an ejection charge. Don't know if an AP motor's ejection charge can be used to ignite a BP sustainer. Might have to remove the plastic cap, remove some of the charge grains, and put something like masking tape over it. Might still blow up your coupling.
Has anyone tried this?
(EDITED)

 

[Gary Byrum]

Im finding out the biggest "challenge" in scratch building a BT-80 size two stage is weight.

That depends on how you build it. I've been building low powered rockets that fly on mid power motors for years now. You just need to make sure you upgrade the motor mount, and swap the shock cord to Kevlar. I built this Arapaho upscale 5-6 years ago and for 24mm motors. It'll fly on D's but not much joy there. I think I've been burning SU- F motors in this one. And plywood is not really necessary for the CR's. If you use some heavy duty Letramax or something along those lines, you'll do fine. FYI, the nose is a PNC 80K, the tube is BT 80, fins are all balsa, (not the smartest idea) and it's light as a feather. Posing next to his little twin built from scratch also.

 

[Wayco]

Apogee really nailed the sweet spot with the Rip-Roar, 2.2" diameter tubing made it light enough to get it up on a D12, but you had to be really careful with the build to keep it light enough. Now, with the E12, you can modify it a bit and still get good liftoff speed. I built a couple of these back in 2015, modified them several different ways, even tried a cluster for the booster, but it was too heavy for tumble recovery and broke fins off. Added a streamer, still no joy, streamer got toasted by the sustainer motor.

 

[Gary Byrum]

Then there's this 2 stage job.....It a BT 80, PNC 80K and flies on 18mm motors. Does quite well too. It could easily sport 24mm motors but prolly need nose weight.

 

[captbk]

Then there's this 2 stage job.....It a BT 80, PNC 80K and flies on 18mm motors. Does quite well too. It could easily sport 24mm motors but prolly need nose weight.

View attachment 375440

Is this a scratch build? I like the fin shape.

 

[Gary Byrum]

Is this a scratch build? I like the fin shape.

95% of what I build is scratch and sometimes involves an OOP kit design. This was no kit and I'll get you the specs if you want them.

 

[dhbarr]

Don't know, haven't tried it. Two problems that I see right off the bat:
1. There are no AP motors that I know of that have a zero delay. I suppose you could drill a reload delay charge down to a minimum, but it wouldn't be zero, I imagine.
2. BP motors use the blowby gases of the booster propellant to ignite the sustainer. Much less powerful than an ejection charge. Don't know if an AP motor's ejection charge can be used to ignite a BP sustainer. Might have to remove the plastic cap, remove some of the charge grains, and put something like masking tape over it. Might still blow up your coupling.
Has anyone tried this?
(EDITED)

Don't try to get an AP delay below about four, or much of the time the fire will come out both ends.

 

[rharshberger]

AP to BP wont work for the above mentioned reason, AP requires the delay/smoke grain or a solid forward closure to prevent fire from coming out the flashole and quickly eroding an even larger hole in the forward closure as AP is lit at the top of the motor, BP to AP might work but not reliably as again AP motors are lit from the top not from the bottom like BP. It has been tried but no one I have heard of has gotten reliable AND SAFE results.

 

[blackjack2564]

Staging AP to BP has been done very successfully here is the "how To" Bill.

 

[kuririn]

Staging AP to BP has been done very successfully here is the "how To" Bill.

Thanks for posting that.
So, my take after reading that is the staging can be done using the minimum delay charge and pyrogen coated ignitors. BUT getting a straight flight could be problematical since you need a delay to burn. By which time the rocket could be going sideways.
So probably the easiest solution is to build it light and use 24mm BP motors (E12/E12)?

 

[kuririn]

Just throwing some thoughts out here: Instead of pyrogen coated igniters, would a quick burning safety fuse work just as well, if not better? One end wedged into the BP motor nozzle and the other end going through the bleed hole in the ejection well and directly contacting the delay element. Might reduce the delay gap and improve reliability. I know AT makes 24mm F reloads with a 3 second delay.
Capt, feel like experimenting? Thought/comments?

 

[GlenP]

The Estes pro series II E2X rockets are 2” dia and can be used with their PS II booster with BP 29mm motors, possibly upper sustainer stage could use a 24 mm with the 24-29mm adapter.

https://www.estesrockets.com/rockets/pro-series/rockets/e2x-kits

https://www.estesrockets.com/rocket...ccessories/009752-pro-series-iitm-e2x-booster

https://www.estesrockets.com/rocket...essories/009753-24-mm-to-29-mm-engine-adapter

This is their 24mm 1.6” dia two stager
https://www.estesrockets.com/rockets/by-engine/c11-and-d/007225-extreme-12tm

 

[Ez2cDave]

Yes. But not without electronics....

Yes, in the "nanny state" 21st Century, that is the "politically correct" answer.

However, back in the day, a mercury switch, battery, AG-1 flashbulb, and Jetex or Thermalite wick got the job done !

 

[rharshberger]

Just throwing some thoughts out here: Instead of pyrogen coated igniters, would a quick burning safety fuse work just as well, if not better? One end wedged into the BP motor nozzle and the other end going through the bleed hole in the ejection well and directly contacting the delay element. Might reduce the delay gap and improve reliability. I know AT makes 24mm F reloads with a 3 second delay.
Capt, feel like experimenting? Thought/comments?

Quickmatch would probably be a better choice (Thermalite might be the same/similar). My read on the paper CJ posted was that while reliable second stage ignition was achieved, flight profiles might be an issue. I will continue lighting my AP to BP stagers electronically, currently the only one I have is a scale-ish Nike-Cajun with a BT-188 booster.

 

[Ez2cDave]

Quickmatch would probably be a better choice (Thermalite might be the same/similar).

True Thermalite wick is a solid wire core, coated with a pyrogen, spiral-wrapped with multiple strands of nichrome wire, covered with a removable, protective "fiber wrap".

It came in slow, medium, & fast speeds . . . The slow speed is best for igniting composite motors, which require more heat for a longer time to ignite.

Unfortunately, thanks to "regulations" you can't get "real" Thermalite any longer ( in the USA ). When tightly sheathed inside a tube, it burns very fast !

HOWEVER . . . https://www.firefox-fx.com/specialfx.htm

https://www.rebelgunworks.com.au/products/cxa-thermalite-igniter-cord-10m-slow

https://wikivisually.com/wiki/Thermalite

Dave F.

 

[Ez2cDave]

More useful information . . .

Dave F.

 

[captbk]

After reading Cj's article I think a BT-60 size would be more what Im looking for. I would rather go higher with the skinnier/lighter rocket and do a streamer recovery and tracker in NC. I remember years ago someone here talking about using some type of fast fuse to stage. Cant find anything now.

 

[ColumbiaNX01]

After reading Cj's article I think a BT-60 size would be more what Im looking for. I would rather go higher with the skinnier/lighter rocket and do a streamer recovery and tracker in NC. I remember years ago someone here talking about using some type of fast fuse to stage. Cant find anything now.

You would have to use electronics to lite an upper stage composite motor as far as my pay grade goes. Black powder stacked on top of each other lights the 2nd stage.

I am sure there are other ways but not by the book.

 

[Ez2cDave]

I am sure there are other ways but not by the book.

You would be correct . . .