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  1. #1
    Join Date
    22nd February 2017
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    264

    Rumble-C kits available.

    Click image for larger version. 

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ID:	321637It is a rudder only RC BG for B4-2 or C6-3 motors. There is an article on it in the May/June Sport Rocketry for 2017.

    I don't use the SpektClick image for larger version. 

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ID:	321635rum "brick" radio, but the Turnigy 5X, with the rcvr board out of the case, and put on a plate with an indoor flier tiny servo. Radio system is $25, servo $4.50, battery $2, charger $10. Kit price is $25, without radio eqpt. Contact

    xolvejohn
    @
    gmail.com

    Here is some intro data and pics:
    If building kit for free flight use (no radio control), it is best to fly with B4-2, as use of C6-3 will be hard to recover, especially in ANY wind. Trim to circle.

    If building kit for radio control, you will also need the following items:

    -Turnigy 5X radio system (includes rcvr) Hobbyking.com 9331000002-0

    -HK linear servo “ “ HK3D-1.7L or 1.7R

    -Turnigy lithium cell “ “ N160.1S.25

    -E-Flite USB charger E-Flite EFLC1008 (various venders)

    Building the radio module requires fine soldering skills, if unable to do, contact me for possible availability of pre-built radio module.


    Background

    In 1969, Bob Singer designed the BumbleBee 1/2A boost glider, to beat the Competition Model Rockets (Howard Kuhn) Manta, a type of delta flying wing. With its low aspect ratio wing giving better boost altitude than “sailplane” wing gliders, it succeeded, turning in 2 minute glides.

    The RumbleBee-C is a 4X upscaled version, with rudder only RC, and a VECTOR POD which offers enhanced reliability. Tilting the fixed pod down by 2.5 degrees offsets the “down moment” of the normal thrust line, to ensure straight boost. The motor module is ejected with a streamer, providing CG shift for glide trim. This is actually how the first front engine BG’s worked. I find it lighter and more reliable than pop pods.

    RC boost gliders have a reputation of being hard to fly. FAI S8 RG’s can be, due to marginal boost stability. The only CG shift comes from propellant burn-off, with some up elevator at apogee providing the trim adjustment for glide. Boost can be a terror, because the elevator must be constantly “jinked” to provide vertical flight. Beginners often just loop them into the ground.

    The RumbleBee will boost straight on its own. Having zero incidence (no up elevator), it will still transition and glide well (CG must be correct). Some say auto-elevators or slight incidence is required on BG’s, but as long as the stabilizer is LOWER than the wing, turbulence off the wing will provide some push down on the stabilizer (ref. G. Harry Stine). I have never seen a death dive with this glider. Using rudder only control makes this bird easy to fly. Elevator control is not really necessary.Click image for larger version. 

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  2. #2
    Join Date
    16th August 2016
    Location
    Paragould, Arkansas USA
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    442
    Thanks for posting.

    "Lock S-foils in attack position....."

  3. #3
    Join Date
    20th January 2011
    Location
    Cache Valley, UT
    Posts
    1,068
    Once I get moving into the new house, I want to get one. Looks like a good way to get into this aspect of the hobby!
    Ken
    Let's do some stuff!

  4. #4
    Join Date
    22nd February 2017
    Posts
    264
    Thx. Hey, that canard glider looks like a KLINGON BATTLE CRUISER. I hope you talk Klingon while flying it.

    Thanks Ken, too. Note the kit comes with tech support. I can save you shipping on radios from china, only place they come from, shipping is $15. I have 2 radio sets in stock. And the other junk too.

    So I doubled the 'Bee again, for D12 motors, check it out. Still rudder only, although could do elevator too.

    Handles one D12 ok, but I wanted more alt, so staged it. OBVIOUSLY A MAJOR MALFUNCTION.

    ANYBODY WANT A KIT OF THE C, free shipping thru this weekend!!!!!!!!!!!!!!!!!!!!

    Tail ripped off, one wing fluttered and shredded. Fixable, need to try a composite low thrust E, after breaking open
    da piggy bank..Click image for larger version. 

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  5. #5
    Join Date
    18th January 2009
    Posts
    185
    Quote Originally Posted by XolveJohn View Post
    Thx. Hey, that canard glider looks like a KLINGON BATTLE CRUISER. I hope you talk Klingon while flying it.

    Thanks Ken, too. Note the kit comes with tech support. I can save you shipping on radios from china, only place they come from, shipping is $15. I have 2 radio sets in stock. And the other junk too.

    So I doubled the 'Bee again, for D12 motors, check it out. Still rudder only, although could do elevator too.

    Handles one D12 ok, but I wanted more alt, so staged it. OBVIOUSLY A MAJOR MALFUNCTION.

    ANYBODY WANT A KIT OF THE C, free shipping thru this weekend!!!!!!!!!!!!!!!!!!!!

    Tail ripped off, one wing fluttered and shredded. Fixable, need to try a composite low thrust E, after breaking open
    da piggy bank..
    You might consider using Spruce or a small-diamter Carbon Fiber tube for the fuselage on the larger versions.

  6. #6
    Join Date
    22nd February 2017
    Posts
    264
    The D fuse did not break!

    The D ver, and the C, both use basswood fuse's. SIG does not seem to have spruce anymore.

    I considered carbon, but the round shapes are hard to glue stuff to, and bigger sizes are expensive.
    I know they have square ones too.

    But thanks for tip. Might at some time try a foam wing with carbon rods embedded for reinforcement.

    I do get my carbon pushrods from RCfoam.com

  7. #7
    Join Date
    22nd February 2017
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    264
    RB-C kit free shipping offer extended thru June. GET ONE IN THE AIR!

    Click image for larger version. 

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  8. #8
    Join Date
    22nd February 2017
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    264
    Here is a side view. Done in FreeCad. Can't beat the price. About as powerful as SolidWorks!

    Click image for larger version. 

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  9. #9
    Join Date
    21st March 2011
    Location
    central America
    Posts
    2,100
    Are plans available on-line for the base glider? I've done extensive searches for free plans, but through off-line archiving (I hope!) and hard drive crashes, I have no idea where they might be, if I still have them.

  10. #10
    Join Date
    22nd February 2017
    Posts
    264
    If you mean the original Bumble Bee 1/2A glider in 1969, it is here:

    http://www.ninfinger.org/rockets/Mod...2n03_12-69.pdf

    The complete plans for my RumbleBee version are in the May/June 2017 Sport Rocketry.

    Here is a site with lots of old rocket plans, enjoy:

    http://www.oldrocketplans.com/cmr.htm

  11. #11
    Join Date
    21st March 2011
    Location
    central America
    Posts
    2,100
    Thanks! I lost most of my bookmarks in the hard drive crash, too.

  12. #12
    Join Date
    22nd February 2017
    Posts
    264
    Kits still $25. Free shipping during September! Priority mail. Get one in the air!

    I am building a brushless powered D size version for fun. Good field across the street. Relax after work. More rocketeers should get into Eplanes, good flying practice for RC BG.

    Top view:
    Click image for larger version. 

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  13. #13
    Join Date
    22nd February 2017
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    264
    This is my first attempt at an electric RumbleBee-D for flying practice. Has rudder and elevator control.

    Brushless motor is the second smallest Turnigy outrunner, just enough power, need slightly bigger one.

    Wing 3/32" balsa. Flies ok, but has problems with hard landings. Wood fuse not rugged, or the wing.

    Need to use carbon fiber boom, and stronger wing, mounted with rubber bands or nylon shear screws.
    Had to go to a 9" prop to get enough thrust.

    Click image for larger version. 

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    May try using balsa plywood. Coat 1/16" sheet with CA, and spray accel on another, then clamp together.

    Anyone looking for a nice, slow practice Eplane, check out the Slow Stick, Hobbyking has one, usually out of stock,

    and GWS always has. The cheap ones use brushed motors. Get something in the air!

  14. #14
    Join Date
    26th November 2009
    Posts
    5,246
    Good gosh, I built a Bumble Bee when they first came out in the rocket mags. I didn't have any basswood for the boom and used balsa. Was very very careful and it flew many times before I broke it. Kurt

  15. #15
    Join Date
    22nd February 2017
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    264
    Those were the good old days, moon landing, healthy NAR competition. SIG seems to have dropped the

    spruce sticks, they are now basswood, which is fine for BG's. But the electric planes are heavier, this D size
    plane was 6 oz. Gets up to some speed, so you don't want to impact the ground the wrong way.

    There is one UAV that is actually designed to fall apart when it lands, the kind the soldiers hand launch, looks pretty
    much like a model plane. Everyone seems to be going to flying wings these days, I like the old standard configuration.

  16. #16
    Join Date
    5th March 2017
    Location
    Pittsboro, NC
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    Quote Originally Posted by XolveJohn View Post
    Those were the good old days, moon landing, healthy NAR competition. SIG seems to have dropped the

    spruce sticks, they are now basswood, which is fine for BG's. But the electric planes are heavier, this D size
    plane was 6 oz. Gets up to some speed, so you don't want to impact the ground the wrong way.

    There is one UAV that is actually designed to fall apart when it lands, the kind the soldiers hand launch, looks pretty
    much like a model plane. Everyone seems to be going to flying wings these days, I like the old standard configuration.
    Can this be built minus the electronics (i.e. just a regular ole self-guided BG? I really like its looks). Do you have a D engine version kitted? If not are the original kits still available for purchase?
    NAR# 103899

    "As I hurtled through space, one thought kept crossing my mind—every part of this rocket was supplied by the lowest bidder".
    — John Glenn, Jr.

  17. #17
    Join Date
    22nd February 2017
    Posts
    264
    Yes, you can make a free flight version. The kits are still available, free shipping. Reply to my email and will get one out!

    No D kit, still trying to perfect it. Need better wing, want to survive 2 stage D12 which is quite a rough ride.

    I am building a C version with a balsa fuselage now, like a model plane, trying to improve the aerodynamics.

    xolvejohn@gmail.com

  18. #18
    Join Date
    28th May 2015
    Posts
    36
    Oh boy...

    I don't want to come in here and be perceived as a know-it-all bashing the efforts of others, but I just can't sit around and say nothing when erroneous information gets circulated about an aspect of the hobby that I dearly love. I have absolutely no reason to believe this misinformation is intentional, merely that it's a misperception based on some *very* longstanding ideas about free flight that are really a misinterpretation by the rocketry community. I've lived my entire life watching these errors wind their way through the rocketry community and it seems like we're constantly having to address them. Then again, there is another set of errors that winds its way through the free flight community that must constantly be put to death. Please understand therefore, that I fly both and have enjoyed much success in flying all sorts of model airplanes. I've flown free flight competitions of a variety of types for quite a while. I have not ever flown rockets competitively, but if you look up the Flite Test videos on my aircraft, you'll see that they fly just as well as any.

    Also, this is NOT a plug for my or anyone else's products. I welcome competition. It brings out the best.

    So then...

    Quote Originally Posted by XolveJohn View Post
    Here is some intro data and pics:
    If building kit for free flight use (no radio control), it is best to fly with B4-2, as use of C6-3 will be hard to recover, especially in ANY wind. Trim to circle.
    I just don't agree with this. I've flown C swing wing gliders (no, not the heavy draggy ones from the plans on the NAR website), off a piston, on a windy day, to altitudes that strain the eyes. It's all in how big of a field you have. A serious rocket/boost glider enthusiast would do well to look into how the free flight guys recover their airplanes. 10 minute flights off a 5 second engine run, or even a mere rubber band, are commonplace. We do our best to fly on big fields, sometimes tens of thousands of acres. Trimming to circle isn't nearly so much about recovery as it is staying in the thermal. Many of the FAI guys trim their models to take a full 5 minutes to completely a single circle in calm conditions. I've seen others that were trimmed to fly in a perfectly straight line until they encountered a thermal, at which point the increased airspeed would cause the circle to drastically tighten. Up, up and away! Until the fuse burns through. Then it comes back down, you go get it, and the process starts again. What, no fuse? Oopsies!

    Quote Originally Posted by XolveJohn View Post
    RC boost gliders have a reputation of being hard to fly. FAI S8 RG’s can be, due to marginal boost stability. The only CG shift comes from propellant burn-off, with some up elevator at apogee providing the trim adjustment for glide. Boost can be a terror, because the elevator must be constantly “jinked” to provide vertical flight. Beginners often just loop them into the ground.
    Yes, they can be difficult to fly, but only if either the design is deficient or the trim settings are incorrect. If your radio can't support multiple flight modes, you should buy a new radio. They just aren't that expensive anymore. You should have a launch mode that gives you neutral trim and a glide mode that gives you a stable, hands-off glide.

    Quote Originally Posted by XolveJohn View Post
    The RumbleBee will boost straight on its own. Having zero incidence (no up elevator), it will still transition and glide well (CG must be correct). Some say auto-elevators or slight incidence is required on BG’s, but as long as the stabilizer is LOWER than the wing, turbulence off the wing will provide some push down on the stabilizer (ref. G. Harry Stine). I have never seen a death dive with this glider. Using rudder only control makes this bird easy to fly. Elevator control is not really necessary.
    I have serious concerns about this trim strategy. No offense to Stine, he was a great flier, but that simply is not a correct or safe way to fly a glider and ignores a century of efforts in designing good gliders. I assume Stine got this information off someone back in the day who was either poor at explaining how things should be done or who wasn't a particularly good glider flier. Unfortunately entirely too many articles in free flight are written by the latter because the experts are busy flying and/or aren't the ones who know how to write a persuasive article. I digress... Bottom line, we just don't fly them that way in the free flight world, even with locked down models, and if it's not safe there, it sure as heck isn't safe on a rocket. I've been flying free flight catapult and hand launch gliders since I was a kid, and I very quickly learned through bitter experience that the people suggesting 0-0 launch incidence were not being honest about aerodynamics. The idea that a model can remain stable in glide using only the downwash of the wing hinges on the model never being perturbed out of the high angle of attack flight regimes. In the real world, this only happens indoors, and only under perfect conditions then.

    You've got two options to get an actual safe flight profile that other people can repeat. Emphasis: yes, you might be able to tweak yours to do it, but you have to keep tweaking, and you can't ever get the model damp, and are you really sure your customer is going to be able to repeat it? Remember, wood expands and contracts in less than perfect storage, has internal stresses, etc. What goes into the kit package is not representative of what comes out of it 5 years later when someone finally gets around to building the model.

    So what's the first option? Well, you've got a really cool kit there, and if you'd add an elevator, it would add, what, another 1.5g? On a C boost glider, that's nothing. I fly 18" locked down C rocket gliders with 3.5g servos and they get WAY up there even if you use really heavy wood for the fuselage. My Carbonette 19 goes to the edge of visibility on C's, and that's without even using a piston launcher. Yours probably lies somewhere in between. You've got nice cantilevered pushrods that make assembly much simpler than my airplanes, so why not go that little extra step and make it a super product? Yes, I know, it's more complex. I think customers can be understanding of that.

    Something else that helps, and I noticed you're starting to do this, is to extend the nose so that you get a longer moment about the rocket motor. This is key to getting really straight launches on these aircraft.

    The second option is to do what I did with the Carbonette series--pop pod on a long moment arm (and trust me, this is by far the lightest method--I have trouble with Carbonettes coming out too light and then I have to ballast them to get the best sink rate in less than dead calm conditions). With this long pod, you can load in your 3 degrees of stab incidence and the thing will still launch straight as an arrow. No elevator needed.

    There is a major cost to single channel R/C. You're limited in wind conditions to whatever the glide speed of the glider is. Any more, and the plane gets blown backwards. Also, you can't deal with turbulence or make efficient turns. When you step up to elevator and rudder, the aircraft becomes capable of basic aerobatics, but more importantly, you can nose over and run upwind after you've chased that thermal way downwind. Or you can run upwind after a thermal that might be up there. Again, watch some of my videos and you'll see a few hints of what's going on there. It really opens up a whole new world in rocket powered gliding when you can make full use of the airplane once it's up there.

    Again, I'm trying to help here. This is not in any way trying to take away from your product as there's room enough in this hobby for all of us. If your product is the best it can be, that actually helps me because people will buy it, fly it, enjoy it, and want to try other similar aircraft. On the other hand, once people have had as much fun as they can with my airplane, I'd like to be able to point them to yours as something else they can try. Keeps the excitement up and we all win.

  19. #19
    Join Date
    22nd February 2017
    Posts
    264
    Thanks for your comments, you sound like a very experienced glider flier. The RBC is not aimed at you, but at those just starting out, to give them success on the very first flight. Having an elevator is a major problem, as it takes time to master it, you need to jink it in 100mS intervals sometimes. I have watched many RCbg flights, including those at the Internats flyoffs going back decades.

    Rudder only works fine on this model, what I said about the trim is true. Of course having full house control on your bird is the best, but it won't have a glide weight of 1.5 oz anymore.

    The rocket field has changed, there is actually not much interest in gliders these days.

    But thanks again for your comments, I value all feedback.

    Perhaps some of my other products would suit you, visit www.transolve.com

    John

  20. #20
    Join Date
    28th May 2015
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    36
    Quote Originally Posted by XolveJohn View Post
    Thanks for your comments, you sound like a very experienced glider flier. The RBC is not aimed at you, but at those just starting out, to give them success on the very first flight. Having an elevator is a major problem, as it takes time to master it, you need to jink it in 100mS intervals sometimes. I have watched many RCbg flights, including those at the Internats flyoffs going back decades.
    With all due respect, you need to be looking at what's out there now, then. I don't know what this "jinking" is, but you don't need to do it. If you do, something's either wrong with your trim or your plane. Go look up my videos on the Carbonette 19. 100% hands off boost. Same is true of the R/C Switchblade I was selling for a while. It'll soon have an equally easy to fly replacement that's not as underpowered.

    Quote Originally Posted by XolveJohn View Post
    Rudder only works fine on this model, what I said about the trim is true. Of course having full house control on your bird is the best, but it won't have a glide weight of 1.5 oz anymore.
    With respect, what you said is not true. The issue is not rudder only, it's that you're advocating using wing downwash to maintain a stable glide. Go back and read what I wrote. That is not a safe way to operate. It's an actual safety risk. You're setting people up for a terminal dive from a couple hundred feet up. That's dollars out of their pocket and concerns over injuries. This paradigm is why we go to launches and have RSOs getting all upset about the safety of our gliders. It's what feeds the perception that gliders are somehow hard. It needs to stop. Gliders are not hard, if we provide correct information. You stand behind G Harry Stine's words, and I maintain that he's not a deity.

    Look, I'm not looking for an argument here, but I will not stand by while incorrect information is promulgated in public forum. I understand you've got a different background and may have a lot of experience with that background, but I'm here to tell you, you've got some incorrect information you're going to have to unlearn. It's the same as the classic argument that swing wings are heavy and unreliable. Well, yeah they're heavy and unreliable if you use the same crappy designs that have been out there for decades. I came up with a wire wing saddle and cut the weight of the entire airplane in half. And I've never once had one fail to work.

    Put in the time, tweak your product a little, and heck, I'll link to you on my page even if it costs me sales. But you have to prove it to be a safe system first. Frankly, mad props to you just for getting those HK linear servos to work. That's not an easy thing to do on a rocket.

    Oh, one other thing: Carbonette 19, airframe <20g, Parkzone receiver/servo/esc brick, 3g, battery, 3g. Total, <26 g. I have an airplane on the market with rudder/elevator control that weighs less than 1 oz, and I'm not even using the lightest wood available. The perception that such an airplane is necessarily heavy is simply false.

    Quote Originally Posted by XolveJohn View Post
    The rocket field has changed, there is actually not much interest in gliders these days.
    Uhm...no. Rocket gliders are a sideline for me, but I'm paying off my house with them. If you're not getting sales, you're marketing to the wrong crowd, especially with a $25 kit. Frankly, I can't turn enough of a profit at that price to justify selling them, so again, mad props to you.

  21. #21
    Join Date
    28th May 2015
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    36
    Just thought of one thing further regarding a link between sales and "jinking" on the elevator. You may very well be flat out marketing to the wrong crowd in that regard. Many of my sales are to people outside of the rocketry community. They're R/C folks who are familiar with the concept of flying an airplane. As such, the notion of flying the airplane really isn't a problem. For the rocketry crowd who are looking to get into R/C, it's a different issue entirely. They really need to buy a little R/C foamie and learn to fly that first, and you'll see that recommended often on this forum. R/C flying is a whole other ballgame, and even with rudder only, you've got to deal with orientation. The idea of a non-diy rocket glider in the R/C community is very, very attractive. Frankly, most of them perceive it as a black art. Anytime a kit comes along, if it's marketed well, people buy it. Unfortunately even with mine, there's significant work required to airfoil those wings. Hopefully someday I'll be able to offer milled wing panels like Hacker used to do with their hand launched gliders long ago.

  22. #22
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    22nd February 2017
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    264
    So why did AeroTek discontinue the Bob Parks glider? Not enough sales.

    If you are doing well, that is great. Gliders and kits is not my forte, it was just a lark.

    Note this glider is NOT my design, it came from Bob Singer in 1969, Model Rocketry mag. Thousands have been built.

    I have never seen one do a death dive. Stines explanation of the turbulence from wing giving a little up elevator must
    be true, because normal gliders that have the stab in line with the wing need a pinch of up elevator.

    I just thought it would be a neat project. In flying some new "high reliability" pop pods, I got frustrated due to failures, so went with the vector pod, virtually unknown here, but popular in europe. I am certain you will have bad things to say about that too.

    Jinking is just rapid adjustments of elevator. The old school E class RG's used in the internats were essentially neutrally stable, and had to be flown on the way up. The RBC avoids this, and I believe you when you say you have gliders that do it. It just involves boost trim, but if neutral stable, that is clearly impossible.

    Not concerned with lack of sales. Full time job in industrial robotics is super, Xolve keeps me happy on weekends, I will still fly RC gliders, but giving up on selling them. You have developed better techniques, keep at it, I will just stay in the background and watch.

  23. #23
    Join Date
    28th May 2015
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    36
    Now we're having a good discussion. Let's unpack some of this and see where it takes us.

    Quote Originally Posted by XolveJohn View Post
    So why did AeroTek discontinue the Bob Parks glider? Not enough sales.
    Aerotek is a huge company. A specialty product like that takes away from their bottom line and is waaaay out of their typical wheelhouse. If it's the Phoenix you're talking about, you need to consider the challenges associated with a rocket fuel company that works far outside mere hobby activities having to set aside resources to cut foam wing cores, something that is not required by a single other product of theirs. Why hold on to that product when you can make more from just doing the same stuff and getting a few more contracts?

    Besides, Aerotech has no reach outside the rocketry industry. I market to rocketry, free flight, and R/C communities. I suspect a reasonably priced Phoenix in that context would be very successful as it's a great airplane. Personally hot wire cutting isn't something I wish to spend my time doing at a production level, but there are lots of folks who are very, very successful at it.

    For what it's worth, Estes has retained the Eagle for quite a while, and Apogee, Semroc, etc, seem to be getting excellent sales. Is QCR still around?

    Quote Originally Posted by XolveJohn View Post
    Note this glider is NOT my design, it came from Bob Singer in 1969, Model Rocketry mag. Thousands have been built.

    I have never seen one do a death dive. Stines explanation of the turbulence from wing giving a little up elevator must
    be true, because normal gliders that have the stab in line with the wing need a pinch of up elevator.
    I read the article. Again. No one in the free flight world trims like that. My twelve year old self tried. And failed. For every one you've seen succeed, I've seen one fail. Not of the Bumblebee per se, but countless other aircraft designed in the same manner. If you talk to guy like Stan Buddenbohm, Lee Hines, Curt Stevens, etc., from whom Stine got the wing-stab gap in the first place, you'll find that it has nothing to do with trying to provide downwash on the stab for glide stability.

    Quote Originally Posted by XolveJohn View Post
    Jinking is just rapid adjustments of elevator. The old school E class RG's used in the internats were essentially neutrally stable, and had to be flown on the way up. The RBC avoids this, and I believe you when you say you have gliders that do it. It just involves boost trim, but if neutral stable, that is clearly impossible.
    Frankly, that's poor design. Neutral stability on a thermal ship is bad regardless of flight regime. But I suspect they weren't. On the other hand, flight modes did not exist back then, so you had to hold in down elevator on the way up to prevent looping. That's an entirely different matter now.

    Quote Originally Posted by XolveJohn View Post
    I will still fly RC gliders, but giving up on selling them. You have developed better techniques, keep at it, I will just stay in the background and watch.
    Why? I've already said I want you to keep selling them. All I want is to see the stability concerns addressed. Me keeping at it is stagnation and helps no one, including me.

    If you're having trouble with sales, get it out there on social media. Post some flight videos on youtube. Heck, send some kits to key people to review and see what happens when their reviews get posted.

  24. #24
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    22nd February 2017
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    Don't know who QCR is. I did not install the "downwash stab", it was there. But I began to wonder why the Bumble Bee did not need "decalage" like many front eng gliders, and ran into Stines ref. I know you don't like it, but it seems to work, that bird ALWAYS transitions well, settles into a nice glide, if the cg is in the right place, and NEVER dives sporadically, even in wind. Yes an elevator would help, but my beginners rc bird is not meant for high wind anyway, and I did not want them to have to fool with an extra channel at first.

    Note Tom Beach, ed of Sport Rocketry, built an RBC and flew it successfully at a couple large launches. He specifically said it generated little interest, but people recognized it from the article.

    I am saddened by the lack of interest, but it does not really matter, I am busy enough with other activities. Maybe things will change, who knows. Am a bit shocked by your larger sales, but you may have learned the right places to tap into. The NAR does not seem to be one of them. In the old days, we did study and copy some HLG techniques. That is where I saw the first vector pod used, on a well finished HLG by a pro, he won B RG at NARAM 13 with it.

    Again, this design has no stability problems. The boost is not perfect, probably due to the rc pod hanging down below, but once it gets the small cg shift when the engine leaves, it is on its own in the world of gliding. It NEVER does weird $#!T.
    I like this pod because it is small and light, even with the critical tuning of the tilt angle. The option is a very long pop pod like others use, for massive cg shift, but that adds weight that reduces boost alt. Pop pods sometimes fail, too, unless some superduper NASA type design, usually complex. Geo Gassaway came up with some, I made a pod that pivots off, others have too. With the vector, if the engine blows, you are good.

    The scaled up D version also flies well on a D-12, no diving, even in wind. It is possible your derating of the "stine effect" is premature. Perhaps you should fly one! Thanks for the offer of help, but I am concentrating on the Lithium Fire Box, and scads of beeper locators. My website is not fancy because I do it now, stripped out all the obsolete and not competitive altimeters. Not a PC jock. Hang in there.

  25. #25
    Join Date
    28th May 2015
    Posts
    36
    Quote Originally Posted by XolveJohn View Post
    I did not install the "downwash stab", it was there. But I began to wonder why the Bumble Bee did not need "decalage" like many front eng gliders, and ran into Stines ref. I know you don't like it, but it seems to work, that bird ALWAYS transitions well, settles into a nice glide, if the cg is in the right place, and NEVER dives sporadically, even in wind.
    1. Yes you did install it. The article shows the stab on top of the fuse.
    2. Let's take this to an actual test. I've got the plans, I'll build one, and we'll do a video on stability.
    3. We'll then have an interesting data point to compare to my Aleda design, which does have a great deal of decalage.

  26. #26
    Join Date
    22nd February 2017
    Posts
    264
    The stab is on the bottom of the fuse, the wing is on the top.

    NEWS FLASH: The FAI is considering allowing single channel A eng. rc BG! Wow, I am a pioneer.

    Actually, since an A eng glider will glide about 2 min max, if really good, the idea is about as good as....

    The Dilbert Underwater Barbacue.

  27. #27
    Join Date
    19th January 2009
    Location
    Georgetown, Texas
    Posts
    651
    Quote Originally Posted by XolveJohn View Post
    NEWS FLASH: The FAI is considering allowing single channel A eng. rc BG!
    Actually the FAI is about to allow single channel A engine RG*, again.

    The guy who won the event in 2000 used a single channel system set up for yaw control. The rules were immediately changed to disallow the practice. There's a copy of "Sport Rocketry" from the era that shows a photo of the winner with his model.

    James

    *The 2000 event was flown at B impulse, and allowed boost gliders. The current event is limited to rocket gliders, and is flown at A impulse. If the proposed rule change is successful it will be implemented during the 2019 FAI contest year.
    ____________________

    James Duffy
    www.spacemonkeymodels.com

  28. #28
    Join Date
    22nd February 2017
    Posts
    264
    Interesting. This is what I have.

    FAI is considering allowing single channel RC for A rocket glider!

    Begin forwarded message:

    From: "fulldec2001@yahoo.com [NAR_FAI_Spacemodeling]" <NAR_FAI_Spacemodeling@yahoogroups.com>

    Subject: [NAR_FAI_Spacemodeling] New Glider rules proposed

    Date: March 5, 2018 at 12:18:53 PM EST

    To: <NAR_FAI_Spacemodeling@yahoogroups.com>

    Reply-To: NAR_FAI_Spacemodeling@yahoogroups.com



    Nice to see proposals adding an S8D/P event and another allowing a single RC channel for rudder or dethermalizer in S4. I support both of those changes.
    Don





    More on single channel A RG.

    Begin forwarded message:

    From: "Marc McReynolds marcmcreynolds@gmail.com [NAR_FAI_Spacemodeling]" <NAR_FAI_Spacemodeling@yahoogroups.com>

    Subject: Re: [NAR_FAI_Spacemodeling] New Glider rules proposed

    Date: March 5, 2018 at 1:27:14 PM EST

    To: NAR_FAI_Spacemodeling@yahoogroups.com

    Reply-To: NAR_FAI_Spacemodeling@yahoogroups.com




    Long ago, before RC equipment got really light, I flew a single-servo A RG with the motor underneath the wing (like an Aerotech Phoenix) which had proportional control of the elevator so that I could fly a lifting boost, and then switched to proportional rudder when I bunted the elevator full-down at apogee. At that point the elevator was pulled by elastic to a hard-stop glide-trim position, though for getting out of a thermal down-elevator could still be accessed via full rudder in one direction. Depending on the final form of the rule if it passes, a setup like that might be an option.




    THIS SOUNDS HARD, switching one servo from elevator to rudder. If that is what he did.











  29. #29
    Join Date
    28th May 2015
    Posts
    36
    Quote Originally Posted by XolveJohn View Post
    The stab is on the bottom of the fuse, the wing is on the top.
    This is what I keep getting at: you're claiming that someone else did that and that you just built per the plans, but that is simply not correct. Pages 26-29 of this article, which you posted, clearly show the stab on top:
    http://www.ninfinger.org/rockets/Mod...2n03_12-69.pdf

    The one credit I can give to that article is that it shows flat bottomed wing and a symmetrical stab airfoil, so there's a slim chance that the model will have stable pitch trim if the fuse is exactly straight. If it bends down at all from humidity or internal stresses in the wood, it's all over. I don't care where you put the stab, that truth remains.


    Quote Originally Posted by XolveJohn View Post
    NEWS FLASH: The FAI is considering allowing single channel A eng. rc BG! Wow, I am a pioneer.
    As James said, not an entirely new idea, but definitely another example in CIAM's endless doodling with the rulebook. Not that I dislike the idea, but I do dislike endlessly changing the rules. The Switchblade was too light, then it was legal, now it's being rendered uncompetitive. Not that I was ever seriously pushing it as an S4A design, but this situation is getting a bit silly.

    The proposal to ban piston launchers because some people cheat, now that one's just plain stupid.


    Quote Originally Posted by XolveJohn View Post
    Actually, since an A eng glider will glide about 2 min max, if really good, the idea is about as good as....
    My gut instinct is that a purpose built free flight S4A could do considerably more. I get around a minute from my 1/4A Switchblade off a piston. An interesting comparison, IMO. Obviously that's not an R/C model. I do think 2 minutes from an R/C S4A is going to be really, really challenging without thermals unless we go really crazy with super tiny batteries, cut down servo frames, and those ultra tiny receivers that weigh .3g. My Swingflop, which admittedly is optimized for larger motors, gets about 20 seconds off an A8-3 and no piston. I was getting 30-40 seconds, off a piston, on the old Switchblade XP. Not sure where that leaves us...

  30. #30
    Join Date
    19th January 2009
    Location
    Georgetown, Texas
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    651
    Quote Originally Posted by Maxout View Post
    As James said, not an entirely new idea, but definitely another example in CIAM's endless doodling with the rulebook. Not that I dislike the idea, but I do dislike endlessly changing the rules.
    I'm going to gently push back on this statement. I've been close to the center of the FAI whirlwind for almost two decades now, and I can even see my fingerprints on a couple of individual rules. With the exception of the elimination of RC from the S4 event back following the 2000 championships, the Internats community and CIAM never move quickly on a major rule change.

    Take the Scale Altitude event, for instance. It was tweaked following 2000 to favor larger boosters that would, theoretically, achieve lower maximum altitudes. That led to a full decade of 50mm minimum-diameter models, with the Bumper WAC dominating both Euro and World Championships. Conversations about changes to widen the scope of competitive prototypes began around 2004, but it was 2015 before any change was effected.

    The changes in S4 were deliberate, changing from boost glider to rocket glider, followed by a tweak (the minimum mass rule). We're approaching a decade of this, I believe. During that decade RC technology has had several generations of significant change, making the addition of RC a valid talking point.

    Change happens in the FAI world, yes. It doesn't happen quickly, though, and never happens without a great deal of discussion and thought.

    James

    ____________________

    James Duffy
    www.spacemonkeymodels.com

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