Supersonic Apogee Aspire Build

The Apogee Aspire is a high altitude lightweight rocket that can be easily built to go supersonic with just a few simple modifications to the building of the rocket. If you want to go high and fast on the cheap, you need basically 3 things:
· A strong, lightweight minimum diameter rocket
· A big high thrust motor
· Good aerodynamics
With the Apogee Aspire, it’s a pretty simple formula:
· Strengthen the fins and the body tube
· Run an Aerotech G80-13T Single Use Motor
· Airfoil the fins, make smooth streamlined fin fillets, cut angles on the launch rod guide tube, and smooth the body tube and smooth the joint from the nose cone to the body tube
Don ‘t put the engine block ring in !! If you leave it out, then you can run any size 29mm motor you want all the way up to an Aerotech I 200W reloadable motor if you want to go real high and real fast. If you do this, I strongly advise you have multiple ground trackers with binoculars, a highly visible streamer, and large wide open space to launch your rocket at. The rocket will hold together and will be stable in flight. With the RMS 29mm !200W, you’re practically flying the motor itself so be prepared.
The first thing I did was to cut out all the balsa fins, put them all together and sand the all edges of the fins flat. I want all the fins the same size. Then I set up my 6” bench sander to make 60 degree airfoils on the leading and trailing edges of each fin using a 120 grit sanding disk. After I make the airfoils, I then take a sanding block with 180 grit sandpaper and sharpen the airfoils on each fin. While doing this, I also want each airfoil to be identical on each fin, so I try to get these as close as possible to each other. After I do this, I laminate the fins using copy paper and Elmer’s Max wood glue just as Apogee instructs. I use CA glue just on the edges of each fin to make the edges hard. When the CA dries, I sand the airfoils and edges smooth using 180-grit sandpaper on a sanding block.
The next step, I glue the paper body tubes together using the coupler provided in the kit. Elmer’s Max wood glue is fine for this step . Then I scuff up the body tube using 120-grit sandpaper. I then mix up some Aeropoxy from GLR and apply a good coat of Aeropoxy to the entire body tube, stand the tube on its end and let it dry. When the body tube is dried, I then sand the Aeropoxy coat it smooth using 120-grit sandpaper. Then I apply a second coat of Aeropoxy laminating resin to the body tube and let it dry. Doing this will not only strengthen the tube enough for supersonic flight, but also for harder landings and overall durability while at the same time keeping the rocket as lightweight as possible. Aeropoxy it tough stuff and I highly recommend it. It’s the best out there as far as I’m concerned. It’s alittle pricy, but its strong lightweight, and easy to work with & sand – well worth the price. When the body tube is dried, I start out with 120-grit sandpaper and sand the tube lengthwise till it is fairly smooth. Then I finish sand the tube using 180-grit sandpaper until it is very smooth and slick as glass. Now the tube is ready for fin mounting. I use three fins on my Aspire instead of four to reduce drag on the rocket. Save the 4^th fin for a pattern. I use CA to initially glue the fins on to the body tube. Be sure and get the fins on very straight to prevent corkscrewing during flight. When the CA dries, I use Aeropoxy epoxy resin glue to make the fin fillets. Once I apply the glue, then I use a small popsicle stick to make the fillets smooth and uniform. Then I stand the rocket up and let the fillets dry. The fillet epoxy will run a little and that’s ok. Using you finger, carefully with the epoxy from off the body tube beneath each fin, rounding off the fillet on the underside of each fin. You may have to do this two to three times until the glue stops running down. I do this to get the fillets as smooth as possible using the least amount of epoxy. When the fillets are dry, I take a round dowel and lightly sand each fillet with 180-grit sandpaper glued to the dowel to make the fillets smooth as glass. And to blend the fillets into the fins and body tube smoothly.
Next I wash the nose cone and sand it using the 180-grit sandpaper to smooth the nose cone and remove the mold lines. The new plastic nose cone is hard and plenty strong for supersonic flight. Just mask it off, prime the nose cone and set it aside ( I use Krylon automotive sandable gray or black primer in a spray can. At this point, your rocket should something like this.

Have you done flutter analysis on that fin profile and it's material stack up of balsa and paper reinforcement at the "supersonic" speeds you have planned? They look to have a fairly tall span compared to root length which is typically problematic on high velocity flights.

Texas Rocketman said:

The Apogee Aspire is a high altitude lightweight rocket that can be easily built to go supersonic with just a few simple modifications to the building of the rocket. If you want to go high and fast on the cheap, you need basically 3 things:
· A strong, lightweight minimum diameter rocket
· A big high thrust motor
· Good aerodynamics
With the Apogee Aspire, it’s a pretty simple formula:
· Strengthen the fins and the body tube
· Run an Aerotech G80-13T Single Use Motor
· Airfoil the fins, make smooth streamlined fin fillets, cut angles on the launch rod guide tube, and smooth the body tube and smooth the joint from the nose cone to the body tube
Don ‘t put the engine block ring in !! If you leave it out, then you can run any size 29mm motor you want all the way up to an Aerotech I 200W reloadable motor if you want to go real high and real fast. If you do this, I strongly advise you have multiple ground trackers with binoculars, a highly visible streamer, and large wide open space to launch your rocket at. The rocket will hold together and will be stable in flight. With the RMS 29mm !200W, you’re practically flying the motor itself so be prepared.
The first thing I did was to cut out all the balsa fins, put them all together and sand the all edges of the fins flat. I want all the fins the same size. Then I set up my 6” bench sander to make 60 degree airfoils on the leading and trailing edges of each fin using a 120 grit sanding disk. After I make the airfoils, I then take a sanding block with 180 grit sandpaper and sharpen the airfoils on each fin. While doing this, I also want each airfoil to be identical on each fin, so I try to get these as close as possible to each other. After I do this, I laminate the fins using copy paper and Elmer’s Max wood glue just as Apogee instructs. I use CA glue just on the edges of each fin to make the edges hard. When the CA dries, I sand the airfoils and edges smooth using 180-grit sandpaper on a sanding block.
The next step, I glue the paper body tubes together using the coupler provided in the kit. Elmer’s Max wood glue is fine for this step . Then I scuff up the body tube using 120-grit sandpaper. I then mix up some Aeropoxy from GLR and apply a good coat of Aeropoxy to the entire body tube, stand the tube on its end and let it dry. When the body tube is dried, I then sand the Aeropoxy coat it smooth using 120-grit sandpaper. Then I apply a second coat of Aeropoxy laminating resin to the body tube and let it dry. Doing this will not only strengthen the tube enough for supersonic flight, but also for harder landings and overall durability while at the same time keeping the rocket as lightweight as possible. Aeropoxy it tough stuff and I highly recommend it. It’s the best out there as far as I’m concerned. It’s alittle pricy, but its strong lightweight, and easy to work with & sand – well worth the price. When the body tube is dried, I start out with 120-grit sandpaper and sand the tube lengthwise till it is fairly smooth. Then I finish sand the tube using 180-grit sandpaper until it is very smooth and slick as glass. Now the tube is ready for fin mounting. I use three fins on my Aspire instead of four to reduce drag on the rocket. Save the 4^th fin for a pattern. I use CA to initially glue the fins on to the body tube. Be sure and get the fins on very straight to prevent corkscrewing during flight. When the CA dries, I use Aeropoxy epoxy resin glue to make the fin fillets. Once I apply the glue, then I use a small popsicle stick to make the fillets smooth and uniform. Then I stand the rocket up and let the fillets dry. The fillet epoxy will run a little and that’s ok. Using you finger, carefully with the epoxy from off the body tube beneath each fin, rounding off the fillet on the underside of each fin. You may have to do this two to three times until the glue stops running down. I do this to get the fillets as smooth as possible using the least amount of epoxy. When the fillets are dry, I take a round dowel and lightly sand each fillet with 180-grit sandpaper glued to the dowel to make the fillets smooth as glass. And to blend the fillets into the fins and body tube smoothly.
Next I wash the nose cone and sand it using the 180-grit sandpaper to smooth the nose cone and remove the mold lines. The new plastic nose cone is hard and plenty strong for supersonic flight. Just mask it off, prime the nose cone and set it aside ( I use Krylon automotive sandable gray or black primer in a spray can. At this point, your rocket should something like this.


View attachment 94769

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The aspire body tube is strong enough for the G80 without the epoxy coat. That is adding weight. The part that will fail first is the balsa fins.

And take all the fun out of the build? No computers being used. Apogee has already done all the work.

The fins are laminated with paper and glassed as well. The entire rocket is glassed - except for the nose cone. Aeropoxy is pretty tough stuff. The fins are incased in it completely even at the fin to body tube joint. The joints are epoxy to epoxy - not balsa to paper tube. I don't believe the fins will be a problem. With a big the G, an H or a I motor, I don't think the tiny additional weight the glass coating adds will make much of a difference in performance.

I've studied several threads having to do with Aspire builds and have studied the rocksim file and build suggestions from Apogee as well. Most guys aren't flying on G, H or I motors either. Aeropoxy glue to glue joints are about as strong as it gets short of metal construction. The rocket is basically a flying piece of solid lightweight aerospace epoxy glue now. I've eliminated all paper to paper and paper to balsa joints/contact points. Everything is Aeropoxy glue to glue. Fins come off when using glue to paper and/or glue to balsa joints.

Did you glass it or just put epoxy on it?

I have looked at this kit a few times. I may get one to tinker around with. I don't think you would have had a problem with just the paper on the balsa and ca on the edges to harden them up some.

Actually there is no fiberglass cloth used. I use Aeropoxy PR2032 Laminating Resin and Aeropoxy ES6209 Epoxy Adhesive. This makes it strong but lightweight. It a nice kit. Easy to build. A little speed/altitude demon. Apogee has done all the computer modeling/simulation work on it. All you really have to do is build it and fly it basically. I chose to epoxy it for added strength and durability. Streamers are kinda hard on rockets as they come in hard. Balsa fins usually don't survive landings too well as it is - especially with a a big G, H or I motor installed in the tail end. you outta build one DM. I think you would like the build.

I do want to. I don't know if I would coat it in epoxy myself but if it works then work it.

I put a 29mm mount in an Estes Big Daddy and papered the fins. A lot of people said that the balsa would break even with the paper but it flew great. I shreaded a parachute on it once on an F motor and it came in and slammed into frozen packed ground and rock. One small crack that I fixed easily was the only damage. The nose cone was even buried in the ground and it didn't even scratch the paint that much. People underestimate balsa and paper fins.

I prefer wood glue over epoxy for bonding on any wood to paper or paper to paper or wood to wood bonding with added epoxy fillets, but wood glue is pretty dang good for adhering those two materials together.

How many flights you got on it?
Gotten any of them back?

Thinking of putting something in it to demonstrate it went Mach 1?

DM1975 said:

I do want to. I don't know if I would coat it in epoxy myself but if it works then work it.

I put a 29mm mount in an Estes Big Daddy and papered the fins. A lot of people said that the balsa would break even with the paper but it flew great. I shreaded a parachute on it once on an F motor and it came in and slammed into frozen packed ground and rock. One small crack that I fixed easily was the only damage. The nose cone was even buried in the ground and it didn't even scratch the paint that much. People underestimate balsa and paper fins.

I prefer wood glue over epoxy for bonding on any wood to paper or paper to paper or wood to wood bonding with added epoxy fillets, but wood glue is pretty dang good for adhering those two materials together.

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The paper to balsa setup is like you say, pretty strong in it's own self. and Elmer's Max wood glue with paper or balsa is pretty darn strong as well. Like you, I think people tend to underestimate it's strength. As far as putting your nose cone in the ground, my friend, you need to get you one of those new subterranean rocket retrieval implements....... from Whamo. Lol, we have one and I tell ya, I love it. It sure helps getting those inverted rockets out of the ground.....more commonly known as a shovel....lol. My Estes V-2 did that. What a rocket that was. I'll never buy one again.

MaxQ said:

How many flights you got on it?
Gotten any of them back?

Thinking of putting something in it to demonstrate it went Mach 1?

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Lol..................I'm still building it. It doesn't have too many flights on it. Pardon me....I'm still laughing.

Like I say, I'm still building it. Well I take that back. I did toss it in my living room to test the fin strength and it flew for about 6 feet with no problem on its first flight. and yes I did successfully recover the rocket. Didn't even use any active recovery. Should have seen the thing bounce off the floor...........darn superball.

Yes, I will put a Jolley Logic altimeter 2 in it. It's cheap but should read o.k.

darn, I'm still laughing on that one........pardon me.

Thanks for sharing your tips on this build so far. While reading thru it, I wanted to ask for a bit more information as your procedure with the Aerepoxy has me wondering if this may be something I should try. Is the first coat you put on the body tube the laminating resin or is it filler? Your second coat you mention the laminating resin so I am thinking you used the laminating resin on the first coat. The reason for my question is, I am wondering if when you do this procedure do you also get the added benefit of filled tube grooves? I have read numerous threads about filling in spirals on body tubes with Elmer's fill-n-fill and I haven't had the results I was hoping for (I am sure there is something I am doing wrong).

Maybe just one more comment... Study epoxy and composites a bit. Epoxy although an adhesive, is, by itself, fairly brittle. Coating the rocket with epoxy alone will do little to improve shear strength, i.e., provide much/any benefit if your fins begin to resonate in a flutter condition at your planned Mach 1+. But making a composite matrix with fiberglass (cloth, or at the very least fiberglass filaments) will result in a substantial increase in strength.

Texas Rocketman said:

Actually there is no fiberglass cloth used. I use Aeropoxy PR2032 Laminating Resin and Aeropoxy ES6209 Epoxy Adhesive. This makes it strong but lightweight. It a nice kit. Easy to build. A little speed/altitude demon. Apogee has done all the computer modeling/simulation work on it. All you really have to do is build it and fly it basically. I chose to epoxy it for added strength and durability. Streamers are kinda hard on rockets as they come in hard. Balsa fins usually don't survive landings too well as it is - especially with a a big G, H or I motor installed in the tail end. you outta build one DM. I think you would like the build.

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Iv'e got an Aspire around here....wonder what Kind of Beefing up it needs to survive an AT 24mm F101-15 SU...any ideas?

Once upon a time I designed a rocket to go supersonic on an Aerotech D21...

dixontj93060 said:

Maybe just one more comment... Study epoxy and composites a bit. Epoxy although an adhesive, is, by itself, fairly brittle. Coating the rocket with epoxy alone will do little to improve shear strength, i.e., provide much/any benefit if your fins begin to resonate in a flutter condition at your planned Mach 1+. But making a composite matrix with fiberglass (cloth, or at the very least fiberglass filaments) will result in a substantial increase in strength.

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Agreed. An epoxy coat by itself will do very little other than add weight. To increase strength, you'd be much better off with a lightweight fiberglass cloth. I've used half ounce fiberglass cloth before, and it adds almost no weight while adding substantial strength to a rocket like this - I used it for tip to tip on a deuces wild that I fly on composite D motors.

Yeah, that's why I was asking when he said he glassed it. The fiberglass cloth is what adds the strength, the epoxy just bonds it to the material and allows the cloth to retain rigidity and shape. Hardening a cardboard tube would be better accomplished with soaking in a thin CA instead of a coat of epoxy.

Like cjl said, a very light glass cloth will do wonders to strengthen everything. I am going to build an Estes Interceptor E with dual deployment and a 38mm motor mount. A light fiberglass tip to tip is gonna be a must for that to survive for sure. For the aspire it would help, but I don't believe it is even needed. The epoxy coating that is on it now is even less conducive to the overall goal here in my opinion. That doesn't mean it is gonna explode off the pad or anything like that, but it is a step backwards as it really doesn't add any permanent strength to the rocket at all.

Rrwjr said:

Thanks for sharing your tips on this build so far. While reading thru it, I wanted to ask for a bit more information as your procedure with the Aerepoxy has me wondering if this may be something I should try. Is the first coat you put on the body tube the laminating resin or is it filler? Your second coat you mention the laminating resin so I am thinking you used the laminating resin on the first coat. The reason for my question is, I am wondering if when you do this procedure do you also get the added benefit of filled tube grooves? I have read numerous threads about filling in spirals on body tubes with Elmer's fill-n-fill and I haven't had the results I was hoping for (I am sure there is something I am doing wrong).

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Yes, both coats are laminating resin with no filler. Yes it will eliminate the grooves in tubes completely while at the same time strengthening the tube.

dixontj93060 said:

Maybe just one more comment... Study epoxy and composites a bit. Epoxy although an adhesive, is, by itself, fairly brittle. Coating the rocket with epoxy alone will do little to improve shear strength, i.e., provide much/any benefit if your fins begin to resonate in a flutter condition at your planned Mach 1+. But making a composite matrix with fiberglass (cloth, or at the very least fiberglass filaments) will result in a substantial increase in strength.

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You could use kevlar of fiberglass filler mixed in with the epoxy (both fillers are available for Aeropoxy) and yes they will defintely strengthen the epoxy laminating resin, but I don't think they will be needed. My object is to keep the rocket as strong, but as lightweight as possible. I could be wrong, but there's only one way to find out and that is fly it. It's a cheap rocket so if it doesn't work, bujy another one and try again.

cjl said:

Agreed. An epoxy coat by itself will do very little other than add weight. To increase strength, you'd be much better off with a lightweight fiberglass cloth. I've used half ounce fiberglass cloth before, and it adds almost no weight while adding substantial strength to a rocket like this - I used it for tip to tip on a deuces wild that I fly on composite D motors.

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Lots of work and expense for a rocket you may never see again.

Aeropoxy is pretty tough stuff. I'm not finished with the laminating resin yet. I still have two more coats to apply to the entire rocket. You guys are getting ahead of the game. Wait for me lol.

Fin flutter?........make good fillets. Distribute the loading of the fins to the airframe. Fillets not good........good chance of destructive fin flutter. A little flutter isn't going to hurt. Ever seen an aircraft wing flex? They do flex. Even supersonic air to air guided missile fins move and/or flex a small amount. They have to. Fin flutter I think is overated sometimes.

There is a marked difference between the resonant flutter we design against using hobby rocket materials and the wing flex you observe on aircraft.

Your flight as it stands will experience flutter. You may be fine. Look forward to picture posts of the flight. When is that planned? BTW, the I200W-14 looks to be optimum for this rocket and raises your velocity to Mach 1.8. Significantly higher than the G80.

Oh, one other question... In the picture you posted your fillets are done and you have primer on the rocket--is your Aeropoxy now being applied on the rocket in this stage (i.e., over the primer)?

Texas Rocketman said:

Fin flutter?........make good fillets. Distribute the loading of the fins to the airframe. Fillets not good........good chance of destructive fin flutter. A little flutter isn't going to hurt. Ever seen an aircraft wing flex? They do flex. Even supersonic air to air guided missile fins move and/or flex a small amount. They have to. Fin flutter I think is overated sometimes.

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The Aspire is a good canadate. I got some blue tube and made some CF fins and glassed the fins on my Min. Dia 29mm that I call Mr Zippy I have only tryed the F-52 so far and I think if I put more in it, it will be gone. It is very tempting to do it though. Good luck on the attempt.

I like that a lot. How do you have the recovery attached to the motor casing there?

That is a peace of aluminum pipe that I cut to that shape and JB welded it on. I can make them if anyone needs one.

Getmore said:

The Aspire is a good canadate. I got some blue tube and made some CF fins and glassed the fins on my Min. Dia 29mm that I call Mr Zippy I have only tryed the F-52 so far and I think if I put more in it, it will be gone. It is very tempting to do it though. Good luck on the attempt.

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Looks like a good MD solution.

LOL! Aspire on an I200=Shread