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Posted by phil alvirez | Jun 20, 2013 @ 12:10 PM | 4,657 Views
i have been using the quanum systematically (2 sets) to keep track of the charge available in the airplane in several of my sailplanes, and these are the conclusions i have reached:
1 of them ran uneventfully for some time. no problems. after initial binding, every time just plugged the tx in the plane's charging plug of the pack (no pushing the bind button), then turned the screen on and away she went. i got readings of all the cells, and the alarms went off as scheduled.
but lately i need to press and hold the bind button on the rx before i plug it to the pack, and also to press both buttons of the screen at start, otherwise does not connect to the tx. otherwise all is ok.
with the 2nd 1 i began to get warnings of 'no signal' and the screen went blank for several seconds, then the figures reappeared. i was using the small antenna, and replaced it with the stock, keep the cell fully charged, and this has not happened so far. with this set i have to bind it every time i use it, just as i detailed in the previous paragraph. i don't know if this is happening only to my 2 sets, or also to some other modelers. i would like to hear from any1 who purchased 1 and is using it how is he doing.
in my opinion, it is a remarkable system, that provides a safeguard against packs going too low and then crashing or loosing the model, for a reasonable price and ease of operation-even with the drawbacks mentioned before. installing and using it requires no previous knowledge and the...Continue Reading
Posted by phil alvirez | Jun 02, 2013 @ 05:42 AM | 4,696 Views
i am of germanic descend, from the germanic tribes that settled at the northwest of spain-therefore my appearance and name.
in mexico i married a woman of spanish/mexican descend and raised a family.
we migrated to canada with our children.
our daughter married a guy from chile and raised a family.
our youngest son married an italian girl and adopted a chinese girl.

a typical north american family.
Posted by phil alvirez | Jun 01, 2013 @ 03:17 PM | 4,622 Views
ok guys, from all that i read here, 2 cells are better for the 9xr, as there is less heath to dissipate, and as i have some 2x1000's and some parts, i decided to give it a try. these are the details:
i happened to have some connectors (the white plastic pieces) for 2 and 3 cells connectors that match the 1s at the 9xr, so i removed the 3 pins from the 2 cells battery and plugged them in the receptacle of a 3 cells connector, so now it fits into the radio. the black wire goes to the bottom, the blue to the 2nd, the 3rd is blank, and the 4th takes the red. that's the way i understand it should go. i don't remember where i got the parts, but there is an option: removing the pins from a 3 cells battery and using the receptacle to plug in the 3 pins from the 2 cells.
it may be other ways to do this, but this was the easiest for me.
i hope we hear comments from those who have done this.
still, you have to use a large capacity pack to stay charged long enough.
i tried a 1000 but does not last very long before the alarm goes off.
Posted by phil alvirez | May 27, 2013 @ 08:26 AM | 6,376 Views
although my experience has been only using the basic readings of volts, and this with quanum, i think that it could be of some use for some.
1st of all, what is the good thing of quanum? well, it is independent from your radio, so you can use with any radio. no electronic link, no programmimg the radio. the only connection it has is with the pack that goes into the plane, as it takes power from it, from the other end that is used for charging.
so, what is it? the 16 grams basic unit (that goes into the plane) is a transmitter with a built-in voltmeter. that's it. (you may add an amps/temperature probe too). what it does it senses the volts on your pack and sends readings of all and every cell it to the receiver (screen), that can be mounted on your radio (transmitter) or on your wrist, like a watch. there you see what's going on in your plane. it helps to avoid draining your pack below limits so you don't reduce the pack's life or, more important, to run out of power while in flight.
this is the product: http://www.hobbyking.com/hobbyking/s...dproduct=10343
1.-once you get it, unwrap it from its nice package that has instructions for binding-but no more, and charge the screen (receiver) by plugging the usb cable to your computer, or with the adapter to your cigarette lighter in your car. it will show full charge at the icon on the lower left corner, that is like the 1 on your cellular.
2.- now remove that sticker from the screen. at least,...Continue Reading
Posted by phil alvirez | May 07, 2013 @ 04:32 PM | 8,031 Views
akropolitan (from greek=inhabitant of the heights) is a hybrid that uses the fuse/tail/avionics of a fox 2.35 meters ws: http://www.bananahobby.com/4-ch-fms-fox-arf.html and a wing that i designed for thermaling, so it has the looks that i like, and flies more to my liking.
i enlarged the wing to 100" with undercambered, thin airfoil, 10" chord, 960 sqin; 2 pieces wing with gull dihedral to lower the center of gravity, and raised tips. 1/8x1/4 over/under spruce main spars with 1/64 webs, and 2 sets of 1/8 sq over/under spruce spars. 1/16 v trailing edge, 1/8 cf tubing leading edge. 1/4" dural join bar plugged in cf tubings. covering is hangar9 HANU950 transparent red, and solarfilm SLF125 tr yellow tips. auw is 1100 gr (about 39 oz) with a 3x1300 pack. i also enlarged the tail by adding 1" to the chord of the elevator and rudder. balance is at 33%, and the pack sits at the back of the canopy. after further tests i added 1" more to the rudder, as it was sluggish. i added quanum telemetry (16 gr). elevator is very sensitive anyway. although not intended for it, recently i flew it in extremely windy and gusty weather. it handles it well but there is wing flutter when climbing on full power. but on calm to moderate wind it is ok.
Posted by phil alvirez | Apr 22, 2013 @ 05:29 AM | 10,041 Views
i have been flying my planes for many years, but it has been in warm weather...until now.
in those years, i got into thermals regularly, and grew under the impression that it had to be warm weather in order to climb with the help of hot air (the so called 'thermals'). but recently i have been flying near freezing, and have witnessed my planes climbing and staying up there for a long time. some say that is the differential temperature that makes air go up. that is, if there is air at, let's say, -20c, and surrounding air is -10c, that mass of air will go up. so if in freezing air, and then we encounter not-so-freezing air, that makes planes go (or stay-up) there, why call them 'thermals'? shouldn't be more correct to call them something like 'rising air'? or 'risers'?
the original word comes from greek: therme=heat. see:
i found this in etymologies:
from Greek therme "heat," from PIE *ghwerm-/*ghworm- "warm" (cf. Latin fornax "an oven, kiln," formus "warm," Old English wearm; see warm). Sense of "having to do with heat" is first recorded 1837. The noun meaning "rising current of relatively warm air" is recorded from 1933.

and the last 1 brings the key word (relative), as i mentioned when i said that it is the differential temperature. 'relatively warm air' means that what matters is that some mass of air is warmer than the surroundings.
there is some interesting data about their shape here: http://www....Continue Reading
Posted by phil alvirez | Apr 12, 2013 @ 02:50 PM | 4,633 Views
at the beginning, sailplanes flew from slopes, like at elmira, new york, where an upward draft kept them airborne. no need to go anywhere, just stay into the upward wind. like the planes at slopes do, so a shorter wing was better for smaller diameter turns.
then they began to get into thermals, and as they gained altitude could go somewhere else and get into another thermal. so distance was the goal, and then wings began to get longer and thinner-the trend that we see today. but models that copy the shape of full size narrow wings find themselves into trouble, as they tip stall easily. the problem is due to the air density, that makes the smaller wings less efficient the smaller they get (that Reynolds number thing).
and if we look at birds, sure those that stay around, like buzzards, haws, and eagles, have short wings, and those who go places, like albatross, have long, narrow wings. and the chord of all is almost the same all through the wing. no taper nothing. just the tips. so they may know better, after millions of years of evolution. and they use turbulators too. just think about it.
Posted by phil alvirez | Mar 30, 2013 @ 05:49 PM | 5,205 Views
radios with nicads or similar.
i came back in 2006, just at the time when 2.4 was released. i got a DX6 and soon realized that the battery in the tx (8 nicad cells) didn't last long. then some1 released a 3 cells lipo for txs and have used it for 6 years, and since i have had no problems-with that radio.
last year i got 1 DX6i, that comes with 4 nicads, and used it with them. last season began to experience power failures. i had several planes crashing. i began exchanging rxs, then escs, replaced connectors for larger, also larger packs. nothing helped. then began to suspect the towers nearby were the cause. or the windmills that were installed not far away (they operate with microwaves). then 1 day when i landed, walked to my plane and at the moment i was going to switch the tx off i noticed that the screen was blank-and the switch still was on. i thought that my tx was history.
but at home i decided to check, starting with the easiest thing. and when pressing the cells i noticed that the screen came back to life: it was a false contact! i decided to install a 2 cells lipo (the largest that fits is the 2x610-and i had it), so i did the mod similar to the way of the orange tx http://www.hobbyking.com/hobbyking/s...y_Mode_2_.html . (see last picture on the right). melted a rectangular hole and fitted a male connector, and adapted the pack to match. as i have a lipo charger that charges and balances at the same time, and am familiar with lipos, i didn't have to get anything else. now the radio operates flawlessly. i strongly recommend to do this to all radios that use batteries of single cells, as are prone to have false contacts unexpectedly, as happened to me.
Posted by phil alvirez | Mar 30, 2013 @ 12:20 PM | 7,090 Views
Lynx was developed to find out if a sailplane with 1.5 meters wingspan and same weight and wing area than a 2 meters (like the Rex) can get into smaller diameter thermals.
the 460 sq in wing that sits on top of the fuselage and is held in place with 1 nylon bolt, has an undercambered airfoil with 8" constant chord and tips tapered to 5", 4 polyhedral panels. over/under 1/8x1/4 spruce spars with 1/64 ply webs, 1/16 'v' shaped trailing edge, 1/8 carbon fiber tubing leading edge and 3-1/16x1/8 spruce turbulators. covering is ultracote transparent orange; the auw is 510 grams with a 2x1000 pack.
the fuselage is made from the foam remainders of the 1st fuselage from the Thermal Rex, that was replaced with a spare that i was lucky to get when i got the asw28.
the nose section was badly damaged, but from the wing trailing edge aft was in good shape, so i adapted a balsa and ply front section that runs from the trailing edge of the wing to the nose, using a foam insert between the trailing edge and leading edge so that section is solid foam. the sides and bottom are 1/8 balsa with 1/64 plywood, and i added a plastic canopy from sig mfg. motor/prop/spinner/esc/pack are the same as the Rex. when checking the elevator pushrod i learned that there was too much drag, due to the 's' shape trajectory, so i replaced it with a servo near the top of the fin. now i get a smooth, precise response.
i still have to have good weather to compare both, but from the preliminary short tests they are stable and perform well. it is going to be an interesting evaluation in thermals.
Posted by phil alvirez | Mar 27, 2013 @ 06:23 PM | 4,478 Views
when i was doing indoor free flight i met some of the greatest folks ever. and got advice from the best. besides the technical, some gave me a point of view that is worth considering. Steve Brown, world champ, once asked me: are you having fun? i said 'yes', and he said 'good'. that was all.
another of the greats, Walt Van Gorder, when advising me about a plane said : 'it ain't easy. if it were, it wouldn't be fun'.
so there you have it. all about this hobby is making it fun, having fun doing whatever. nothing is easy or difficult: it's fun.
Posted by phil alvirez | Mar 27, 2013 @ 12:21 AM | 4,692 Views
the idea started when i was considering getting a fuselage of a sailplane similar to the ask 21 that i like very much, and design a wing/tail for thermaling, even if this means not looking scale-like. i just like the shape of modern sailplanes fuselages. so this means engineering the whole thing to match the fuselage, and it is not an easy task. after shopping for a suitable fuselage, i ended up buying first a 2 mt ask 21 from hobby king, and later an asw 28 from same source. then i decided to give them a try as they are, before discarding the wings and tayloring new sets for thermaling, with larger area and higher lift airfoils. the result was that both planes crashed several times due to strong tendency to tip stall. i tried improving them by adding dihedral to the '28, and then enlarging their wing area, but even if showed some improvement, still they were not pleasurable to fly, to say it mildly.
i have been able to work on the '28 wing. the new wing, that has more area, also uses a naca 6409 high lift airfoil that i have used extensively through the years, and polyhedral, and the results were a great improvement, and no more tip stall tendency. with this i even managed to get rid of the ailerons, so now i am able to do all that i need with only rudder and elevator.
see my blog. i will add more as i finish-and fly test-them.
Posted by phil alvirez | Mar 09, 2013 @ 10:08 AM | 4,644 Views
Maverick started with the availability at the time, of the fuselage/canopy/prop/spinner of the Dynamic-s, a hotliner with v-tail
i used the prop/spinner that come with it, and found a motor that looks close enough to the stock.
but the main difference is that i designed it for thermaling, with a larger wing, and t-tail instead of the v-tail.
as the v-tail comes with a wide base that works well for a t-tail, and the wiring for the servos, it made my life easier. mounting the wing on top, too.
the tail instal is similar to the Thermalis, except that there are no belcranks, and the elevator servo sits up near the stabilizer, with a direct-and short-pushrod that provides precise commands. the rudder servo sits at the bottom.
the wing is 8" chord and 5" tips, undercambered airfoil, and uses an over/under spar of 1/8x1/4 spruce with 1/64 ply webs, and 3 turbulators; the leading edge is 1/8 cf tubing with 1/8x1/4 balsa, and the trailing edge is 3/16x3/4 balsa. ribs are 1/16 hard balsa, has 1 center section flat, and is held in place with 2 nylon screws that fit into the stock mounts in the fuselage. the covering on top is transparent orange solarfilm and transparent red ultracote lite tips, the bottom is clear microlite.
i found the motor 35-36/910 kv, that weighs 117 grams, the closest to the stock, and it works fine. it delivers an enormous amount of power.
with 600 sq in and 690 grams auw, the wing loading is similar to the Thermalis, and the glide is good for...Continue Reading
Posted by phil alvirez | Feb 18, 2013 @ 09:03 PM | 5,319 Views
those were the days, my friend...
chapter 1.-in 1 of my many lives (my son calls me 'the cat', as i have lived-and survived-many adventures), i had a hobby shop at a mall, where i gave free building and flying lessons to my customers, most of them children from 8 years up. i had a building board and benches where they sat, and customers passing by were amazed at the sight-and some became members of the free club. when they finished their planes they took them to the field and i taught them to fly, be control line or radio. at the time i had my 1st Elf, a high wing trainer with a single channel radio, that was so stable that could fly free flight, and everybody wanted to fly it.
you can see pics of it somewhere here (i think is page 5-this is getting out of hand!)
2.- soon i learned that i had to arrive at dawn to be able to fly it, and even then they learned that and i had to do something else to have a chance to fly it. so i decided to sell kits, and later ready to fly planes, with free flying lessons included. this way at least i had the chance to fly mine now and then.
3.- there were visitors that became fascinated with the plane once they had the chance to fly it. 1 of them was a lady that walking by the mall became interested in giving her husband a plane so he could get into the hobby. she even went to the field and wanted to try it, so i handled her the transmitter and gave her some instructions and there she was, having a ball. once the engine stopped, the plane...Continue Reading
Posted by phil alvirez | Jan 24, 2013 @ 12:49 AM | 5,620 Views
when you get into 3d, 1st you want to learn to fly without crashing too often. of course, using epp will cut your training time considerably. once you don't crash too often, and your crashes are not catastrophic anymore, then you can think of improving your plane's performance. you read or hear from other guys talking about lighter planes performing better. sometimes you even watch them flying and speculating about it. then you know that you would like to build light so your plane helps you to do things easier. but how far can you go? when are you passing the boundaries of building light and getting into building fragile? and if you fly at a place where other guys fly at the same time and some are sort of kamikaze hunting for targets, you don't want to build fragile, even if you don't hit hard anymore. so, 1st you decide if you are going to fly only when there is no danger of midairs and build light, or to fly whenever and build strong. then, you begin building planes each 1 lighter than the 1 before. but you have to decide when to stop. that is, if you still have ideas on how to save a few grams without the plane disintegrating in mid air. but it is lots of fun. for instance: when i began building 'compact' 3d (24" ws, 100 gr auw), and using 6mm epp, my 1st plane ended up at 100 gr auw with a 2x300 pack (lipo). with the motor developing 140 grams of thrust on 2 cells, its power-to-weight ratio was enough to do 3d comfortably. then i went further and built a 2nd 1 that weighed 85 grams. what a difference! it flies slower, that gives me more time to think what am doing, so it's easier to do anything. when this happens, you don't want to go back to the heavier 1, that you can fly when the place is crowded and you don't care much if something happens, and also because it can take more punishment. but that creates 2 separate categories. so maybe it's good to keep both to fly depending of circumstances.
Posted by phil alvirez | Jan 19, 2013 @ 02:43 PM | 4,725 Views
i have shown before some plastic models from my son. now he has released a post here http://www.track-link.com/forums/new...ral/43435/flat. where you can see them. they are around the middle of the post, and he will be showing 1 by 1, with historic details and the camouflage he used on each 1.
i hope this will be of some use (or entertainment) to you all. some drawings (the 1s framed) are by me. he started doing plastic models in the 80's, when i owned a hobby shop in vancouver, and he had free access to materials and models. now you see how that evolved.
Posted by phil alvirez | Jan 12, 2013 @ 02:12 PM | 5,531 Views
Phil's Thermal Rex, or Phil's Rex for short, is a hybrid from a fuselage of the scale ASW 28 sold by hobby king. see
and the full size: http://www.easternsailplane.com/east...hleicher/ASW28
the reason why i choose this fuselage is because the looks are like science-fiction but it is very much like the full size. although i did not use the wing shape (especially the wing tips).
(i will be adding data at the bottom of this thread)
the new balsa wing it is a 2mt wingspan, 460 sqin, 543 gr auw w/2x1300 lipos; naca 6409 airfoil.
i used the foam fuselage and tail, and avionics, and designed a woody wing with larger area and an undercamberer airfoil for slower flights.
i got the whole plane and decided to try it as is, before discarding the wing. and boy, was i for a surprise! it falls into a stall and a spin unexpectedly, and i crashed it several times, breaking the nose and reinforcing it, until i throwed away the wing and started my own. fortunately with it the plane is now stable and predictable. originally it comes without dihedral, contrary to the full size, that has some. as the stock was too unstable and prone to snap roll, i added dihedral as per the full size and this helped a little bit; then increased the chord, adding area to the trailing edge, which helped more-but still was a handful. then it was when went into the balsa wing. it has a planked leading edge, polyhedral, and is covered with...Continue Reading
Posted by phil alvirez | Dec 16, 2012 @ 06:57 AM | 5,343 Views
t tail
aerodynamically keeps the horizontal tail clear of the wing wake, and this means no turbulence (and only 2 corners), so it is the cleanest of all, and there is a better reaction and sensibility. based on my experience, as i have 3 planes with it, i can confirm this. full size planes, especially sailplanes, use it extensively, and passenger planes like de havilland dash 7 and 8 too, so must be a strong reason for that. another thing is that it can be placed with the leading edge slightly ahead of the fin's leading edge, getting a cleaner entry-and improving even more its efficiency. an example is the ask 21. see http://www.alexander-schleicher.de/p...k21_main_e.htm
installing it, the cleanest way is placing the servo at the fin. or you can use a cable, but this means some drag to the servo. to eliminate drag you can install a linkage with 2 belcranks, but it is more complicated.
also, it is heavier than conventional, as the fin has to be built stronger. but that could be very little if you do a good job engineering it.
and is more prone to damage if you fly competition and do those landings (crashes) to get to the spot-or if your landings are not smooth.
i have a 2 mt sailplane radian that has conventional tail (really it is a low 'x' tail) and it also behaves great, so at the end of the day it depends of what you like best.
i like better t tail for the aerodynamics reasons, and now i do smooth landings, but i must admit that you can live with any way that provides you good results, as long as you do a good installation with as little drag as possible and land smooth.
Posted by phil alvirez | Dec 01, 2012 @ 06:39 AM | 5,335 Views
from the beginning of time, man has dreamed of flying. the wildest of all dreams. and for those who are into this, flying is an adventure. the final frontier. just being able to fly an airplane is all that it is. and for models there are several ways to do it: starting from the easiest, to get an rtf (ready to fly) plane, to an arf (almost ready to fly), to build it from a kit, to build it from plans, or to design your own, the goal is the same: to be able to fly. to experience that thrill of controlling it if it is radio or control-line, or to watch it flying, if it is free flight. of course, having total control in 3 axis that radio control gives us is the ultimate experience of fully controlling it (that is, if-or-when you are able to do so). but even if you are not having total control of it due to being learning, is still a wonderful feeling. i know, sometimes things may go wrong, but that is another thing that adds to the fun. if you could count that everything is going to go right for sure, it wouldn't be the same. the unexpected is the key factor that adds to the feeling of adventure.

but, oh what a glorious feeling, don't you think?
Posted by phil alvirez | Nov 20, 2012 @ 03:04 PM | 5,723 Views
Thermalis is an idea of an electric sailplane for soaring in calm to moderate wind. it has 80" wingspan and 10" chord almost to the tip, and 764 sq in; weighs 926 grams (32.5 oz) with a 3x1400 mah pack. i just started evaluating it and will provide comments whenever i get enough flights, but so far am flying in cold weather with no thermals. am also playing with cg and trim.
nov 21-the concept: a simple sailplane for rudder and elevator-no ailerons, for relaxed flying and getting into thermals (hence the name), in moderate wind conditions. the wing is 1 piece polyhedral and the fuselage is box type, 1/8" solid balsa, like the horizontal tail and rudder. still, as i wanted to try spoilers and flaps for the 1st time, i decided to add them. the flaps are of the split type (similar to the 1s used on the full size douglas dc-3). another feature that i added was the t tail, that is not as simple as conventional tail, i must admit (i will comment on this later).
>>>will be adding details. check at the bottom.
testing the Thermalis‏
i started with the cg a little bit forward from the point for which i designed it. the launching went fine, with a strong climb at half throttle. the motor is very powerful and with the 10/6 folder it has lots of power. the climb is at about 70-80 degrees without tendency to tip stall, that was haunting me with the other sailplanes before. the glide is the best i have got compared with the other...Continue Reading
Posted by phil alvirez | Nov 14, 2012 @ 11:19 PM | 5,550 Views
at the beginning i posted a link to an article where it stated that thermals are like horizontal donuts that climb, with the wind going up at the center and down at the edges.
we all believed that article (it was back in the 60's), but recently i found another approach. http://www.xcmag.com/2007/07/thermal...rt-1-thermals/ where he brings an explanation that comes very close to how cumulus nimbus grow, including the same shape, so am beginning to lean towards this idea.
so this way thermals don't turn left or right, just wind goes up inside and down outside-and this matches with the other theory in that sense, so you turn any way you find is better to stay put.
and the idea of trimming the planes to glide to the left from those days could be to balance the torque of the motor, be rubber bands or engine-and somehow it became customary and we did gliders that way too. just a guess.