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wbyman

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I have looked at the Apogee Aspire for $20.00 and the Loc Aura for $27.00 but both have problems with fins coming off on landing, from what I have read. Is there any better choice for a similar rocket in the $30.00 or less price range ? Thanks
 

dixontj93060

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Pay more and get a TTW kit. For example:
  1. Binder Design with 4 or 5 mid to high power kits ~$45 with instructions that actually teach you something.
  2. Aerotech Mustang ~$45.
  3. Estes Exucutioner ~$35 + $5 to upgrade to 29mm MMT.

I have looked at the Apogee Aspire for $20.00 and the Loc Aura for $27.00 but both have problems with fins coming off on landing, from what I have read. Is there any better choice for a similar rocket in the $30.00 or less price range ? Thanks
 

troj

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It's $43, but the LOC Weasel meets what your goals, other than costing a bit more than you asked for.

-Kevin
 

JAL3

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I subbed a 12" X chute for the streamer in my Aura. After that, I stopped having the popped fin problem with this rocket. Before that, it happened almost every flight.
 

ScrapDaddy

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I have looked at the Apogee Aspire for $20.00 and the Loc Aura for $27.00 but both have problems with fins coming off on landing, from what I have read. Is there any better choice for a similar rocket in the $30.00 or less price range ? Thanks
Well that's why you use epoxy fillets :D
 

TheAviator

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I have looked at the Apogee Aspire for $20.00 and the Loc Aura for $27.00 but both have problems with fins coming off on landing, from what I have read. Is there any better choice for a similar rocket in the $30.00 or less price range ? Thanks
The Estes Stormcaster is a perennial favorite. Use a C6 and get a nice low flight or load up an E30 and go for broke!
 

JAL3

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Well that's why you use epoxy fillets :D
That helped, of course, but not near enough. This one comes down too fast on a streamer unless you are in a soft field.

Epoxy fillets just made more repairs necessary since the fin would pop taking the fillet and the underlying paper with it.

The rebuilt Aura still has epoxy fillets but no longer pops a fin every flight since getting the X chute.
 

Handeman

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The Estes Stormcaster is a perennial favorite. Use a C6 and get a nice low flight or load up an E30 and go for broke!
I'll second the Stormcaster. I put mine into orbit on a F24W. It went up and never came down! Had to be in orbit, right?:confused:
 

MarkII

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I'm not sure why either kit would be any more prone to losing fins upon landing than any other kits in that approximate size. Fin detachment is more often a matter of bonding technique and choice of recovery device than any inherent flaw in the design. Surface mounted fins that have been properly bonded and filleted should be able to survive repeated recoveries without detaching as long as an appropriate recovery device is used and it deploys properly. If fins are popping off, the most obvious question is whether the device (streamer, in the case of the Aura) is slowing the rocket's descent sufficiently to prevent a hard, damaging landing. All that may need to be done is to use a larger, longer streamer or a small parachute that features a large spill hole or is reefed. Additionally, the builder should take the simple steps necessary to strengthen the fins and their attachment to the airframe. Making simple modifications to kits to make them conform better to the type of flying that the builders plan to do and to better suit them to the conditions in the fields in which they will be launched (and recovered) is something that rocketeers with even a little bit of experience do all the time. Fins that will survive streamer recoveries from 1,000 ft. onto a sod farm will probably need reinforcement to be able to survive streamer recoveries from 4,000 ft. onto playa. That fact doesn't imply that there is some fundamental flaw or shortcoming with the kit, though.

EDIT: (When I started to write this post, there were no replies yet in this thread.) John Lee's post above indicates that the issue with the Aura may be it's use of a streamer for recovery.

Notwithstanding all of the above, though, have you looked at Semroc's SLS line of kits? The SLS Javelin and the SLS Sky Hook are both $30, and the SLS Jaguar is $27. The SLS Scorpion, which is larger than any of these, is only $31.50. All of these kits feature TTW fin mounting, and they can be built to accept either 24mm or 29mm diameter motors. Semroc's kits are renowned for their clean design, their quality and their value. The SLS line features Semroc's tougher, thicker-walled LT-type tubing, laser-cut basswood fins instead of balsa and upgraded recovery devices.

Mark K.
 
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cjl

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That helped, of course, but not near enough. This one comes down too fast on a streamer unless you are in a soft field.

Epoxy fillets just made more repairs necessary since the fin would pop taking the fillet and the underlying paper with it.

The rebuilt Aura still has epoxy fillets but no longer pops a fin every flight since getting the X chute.
A thin (and yes, I mean thin) layer of tip to tip glass should solve that, if you don't want the additional drift caused by the slower descent rate under chute. Of course, that brings the assembly somewhat out of the "beginner" category.
 

JAL3

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A thin (and yes, I mean thin) layer of tip to tip glass should solve that, if you don't want the additional drift caused by the slower descent rate under chute. Of course, that brings the assembly somewhat out of the "beginner" category.
THus far, I have not one scrap of experience with fiberglass. I know I need to learn but it just doesn't seem to be a priority with me.
 

dave carver

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If nothing else use paper to re-enforce the fin-to-bodytube interface. Yah, it's not fiberglass or carbon fibre or graphite but plain old paper does a real good job of strenghtening a rather weak joint.
 

troj

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Tip-to-tip would be horrific overkill on an Aura.

If you wanted to reinforce the fins, a 1" wide strip of fiberglass at the fin roots would be more than sufficient to do the job.

-Kevin
 

cjl

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Tip-to-tip would be horrific overkill on an Aura.

If you wanted to reinforce the fins, a 1" wide strip of fiberglass at the fin roots would be more than sufficient to do the job.

-Kevin
Horrific? I was thinking a single layer of 1.5-2oz glass. I doubt if you'd add more than half an ounce of weight to the rocket if you don't horribly overuse the epoxy.
 

WillMarchant

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You might want to look at the Loc Graduator. It's about $50 from the Internet discount shops...
 
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MarkH

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The Estes Eliminator has a plastic fin can so you don't have to worry about popped fins. It will go 1400 feet on an Estes E. MSRP is about $30, but can be found cheaper on-line.
 

qquake2k

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I'll second the Stormcaster. I put mine into orbit on a F24W. It went up and never came down! Had to be in orbit, right?:confused:
I'll third the Stormcaster. It's only $11 at Hobbylinc.com, has through the wall fins, and if you use an E motor hook instead of the included D hook, you can use D12 or E9 motors. It's a light rocket, and should fly pretty high on an E9. You could also use Aerotech E15 or E30 motors for really high flights.
 

troj

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Horrific? I was thinking a single layer of 1.5-2oz glass. I doubt if you'd add more than half an ounce of weight to the rocket if you don't horribly overuse the epoxy.
Yep, horrific.

Tip-to-tip fiberglassing has got to be one of the most over-used construction techniques.

I'm not sure exactly when the fetish for lots of composites started, but the hobby sure seems to have it, and have it bad.

Fin flutter is hardly an issue on an Aura, especially on mid-power motors, so there's no need for anything beyond a bit of reinforcement at the fin root, to help reduce problems due to landing damage. And those can be mitigated by using a parachute instead of a streamer.

-Kevin
 

Handeman

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I'll second the Stormcaster. I put mine into orbit on a F24W. It went up and never came down! Had to be in orbit, right?:confused:
I'll third the Stormcaster. It's only $11 at Hobbylinc.com, has through the wall fins, and if you use an E motor hook instead of the included D hook, you can use D12 or E9 motors. It's a light rocket, and should fly pretty high on an E9. You could also use Aerotech E15 or E30 motors for really high flights.
Or go into orbit on an F24W! :eyepop:
 

qquake2k

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Or go into orbit on an F24W! :eyepop:
According to Estes, the dry weight on the Stormcaster is only 2.9oz. I'm pretty sure that F24 propelled your Stormcaster to well above escape velocity. It's probably half way to Saturn by now!
 

Handeman

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According to Estes, the dry weight on the Stormcaster is only 2.9oz. I'm pretty sure that F24 propelled your Stormcaster to well above escape velocity. It's probably half way to Saturn by now!
That's my story & I'm sticking to it! :cyclops:
 

cjl

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Yep, horrific.

Tip-to-tip fiberglassing has got to be one of the most over-used construction techniques.

I'm not sure exactly when the fetish for lots of composites started, but the hobby sure seems to have it, and have it bad.

Fin flutter is hardly an issue on an Aura, especially on mid-power motors, so there's no need for anything beyond a bit of reinforcement at the fin root, to help reduce problems due to landing damage. And those can be mitigated by using a parachute instead of a streamer.

-Kevin
I agree that flutter isn't a problem, but tip to tip isn't really for flutter (or at least it shouldn't be). Tip to tip is to cause the entire fin can to behave more like a single piece, distributing loads and significantly reducing the chance that the fins will pop off on landing or have a weak spot at the root. A single layer of 1.5-2oz glass is almost never horrific overkill, as it makes a great reinforcement for the most common landing damage. Besides, one layer of 1.5-2 oz glass is extremely light if done correctly, and the strength to weight ratio of the reinforcement is excellent.

I agree tip to tip isn't always necessary, but for fin reinforcement against landing damage when you have a fairly weak tubing material, it is an excellent choice (so long as the fiberglass used is fairly light). I have even reinforced low power rockets with tip to tip 0.5oz fiberglass (after shredding them on D13s and D24s), and the weight added is extremely minimal - 0.1-0.25oz typically, even for models with very large fins (for a low power). The strength gained is incredible though.

Now, I've seen rockets with 5-6 layers of tip to tip carbon/kevlar, and I'm somewhat puzzled about that. It's completely unnecessary, and adds far more weight than a correctly applied reinforcement technique. That is an incorrect application of tip to tip, and you would be right to criticize it. However, a single layer of light glass to prevent landing damage isn't really in the same category - it adds minimal weight for significant damage resistance.

As for the parachute suggestion? It would mitigate the landing damage, but it also increases the drift, which increases the chance of loss or an off-field recovery. Generally, given the choice, I'll take the closer recovery with the slight reinforcement over the increased drift. Of course, I'm somewhat guilty of putting the largest recommended motors in a kit whenever I can (sometimes larger), so I am often flying rockets quite high, and drift can be an issue.
 

troj

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Your philosophy differs radically from mine.

First, except when going for pure performance and very few exceptions, composites are overkill on any mid-power rocket. I'm almost inclined to say the same for anything in the H range, as well.

Second, if the answer is "I have to reinforce it or the fins will break off on landing," then unless your rocket weighs a lot, my answer is that your recovery system is too small, especially when dealing with such a small rocket.

Third, if the answer is "it'll drift too far" when you're flying it on a field that's too small for the rocket/motor combination.

The issue folks have reported with the Aura is a recovery problem. It's best handled by addressing the recovery system, not by overbuilding.

-Kevin
 

cjl

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First, let me say that I've never owned an Aura, and therefore I'm not sure how fast it comes down with the stock recovery device.

That having been said, a recovery speed of 22-25 ft/s is perfectly safe, and on many of my higher flying rockets, I use speeds in this range due to drift (not so much for field size - where I fly, the field is practically limitless - but for the sake of visibility and ease of recovery). At this speed, many pure wood and paper rockets have difficulty with the landing. When this can be prevented with half an ounce to an ounce worth of fiberglass on a 1-1.5 pound rocket, it doesn't seem to me that the weight is being severely compromised. Rather, the weight is increased almost imperceptibly for a significant increase in durability. If the aura with the stock recovery device is coming in at >30fps, I agree that the recovery system should be changed.

As for composites being overkill on any mid power rocket? I somewhat agree, with reservations. The way that the majority of rocketeers use composites (5-6 oz fabric, multiple layers, thick FG/carbon tubes and fins) is vastly, incredibly, ridiculously, and preposterously beyond the needs of any mid power rocket. However, used properly, composites can allow for the construction of very lightweight, durable mid power rockets. The key is to use extremely thin layers of composite - if done properly, this can allow for lighter and more durable rockets than most paper and plywood kits. For example, I've found that balsa skinned with 1-2 layers of 1oz glass is an extremely good fin material (often, I will make the fins of plain balsa and do a single layer of tip to tip 1oz glass), and rockets built with this as fin material often end up lighter than they would have been with plywood as the fin material, as well as being more durable and weatherproof (yes, I sometimes launch in light rain, or with snow on the ground, so waterproofing is nice). They stand up quite well to F, G, and H motors too. Composite doesn't have to mean heavy, and if done properly, composite structures should be lighter than an equivalent non-composite rocket. The problem isn't the use of composites, the problem is the misuse of composites.
 
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MarkII

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I'm really not trying to join this particular debate, but I do have a couple of questions. First, at what point does a superlight veil of fiberglass cease to have any advantages over more humble materials like Tyvek or cardstock? IOW, when the FG used in the lamination is quite thin and light, does it really add significantly more strength than, say, Tyvek, cardstock, silkspan or even gauze? When you get down to that thin of a reinforcement layer, does it really matter which one of the commonly used reinforcing materials you go with?

Second, fusing items together so that they function as a single unit - isn't that the definition of bonding? As in, when you bond fins to the bottom of an airframe, you transform the fin set and the airframe into a single unit, don't you? Reinforcing the joints strengthens them, but even if they are bonded together without laminations for extra strength, the end result is a single unit anyway, right?

Mark K.
 

cjl

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I'm really not trying to join this particular debate, but I do have a couple of questions. First, at what point does a superlight veil of fiberglass cease to have any advantages over more humble materials like Tyvek or cardstock?
Thin fiberglass should give you significantly more strength for a given amount of additional weight than cardstock, and I prefer working with fiberglass. You'd be amazed how much strength a single, lightweight "veil" layer of fiberglass will add when used tip to tip over balsa.

IOW, when the FG used in the lamination is quite thin and light, does it really add significantly more strength than, say, Tyvek, cardstock, silkspan or even gauze? When you get down to that thin of a reinforcement layer, does it really matter which one of the commonly used reinforcing materials you go with?
Yes. I would make the case that when it is thin, it matters more. When you use thick, heavy reinforcement layers, almost anything will be strong enough, simply because you're using so much of it. When you use a thin layer however, it means that the stress needs to be supported by a much thinner reinforcement, so you need a higher strength material. I'd be stunned if gauze (to take one of your examples) could come close to the reinforcing capability of .5-1oz fiberglass, and it would probably soak up more epoxy/glue during application as well (making the finished product heavier)
Second, fusing items together so that they function as a single unit - isn't that the definition of bonding? As in, when you bond fins to the bottom of an airframe, you transform the fin set and the airframe into a single unit, don't you? Reinforcing the joints strengthens them, but even if they are bonded together without laminations for extra strength, the end result is a single unit anyway, right?

Mark K.
True enough. However, when you bond two dissimilar materials, you get stress concentrations where the material changes. For example, where the fillet meets the body tube, there is a stress concentration, which is why the tube will delaminate if there isn't a sufficient amount of glue penetration. Tip to tip noticeably reduces the stress concentrations by having continuous reinforcement fibers that go across the entire fin can. Basically, tip to tip should (in theory) result in a significantly more robust structure than an equal amount of fiberglass used just to reinforce the fins and tube separately due to the reduction of the stress concentrations. Does it make a huge difference? Probably not, but it will reduce the chance of popping a fin on landing.


Believe me when I say that thin fiberglass layers are shockingly strong. People so often use a tremendous quantity of composite, without really thinking about how much is necessary (and I will admit, I have done that before as well). A relatively small amount, properly applied, can give incredible strength at a light weight, which is what the idea of composite construction was supposed to be from the start. If properly built, a composite rocket should always be lighter than a wood/paper rocket of equivalent capabilities, and this is clearly something that many people need to work on.
 
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MarkII

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Thanks; that explains it well for me. Where can a person buy such lightweight FG fabric? And is that the lightest version that is available?

Mark K.
 

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