phil alvirez's blog - Page 5 - RC Groups
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Posted by phil alvirez | Nov 20, 2015 @ 08:23 AM | 7,582 Views
at least we at the northern hemisphere are facing the season when it is too cold and windy to fly our planes, and it will not improve until maybe the end of april, so we have to aim at something to do with our time. so, maybe posting some anecdotes will entertain the other viewers, for instance? i have been doing so for some time, so why not you too?
Posted by phil alvirez | Nov 11, 2015 @ 06:07 AM | 7,691 Views
i have been compiling opinions on the subject:
1.-"All sailplanes are gliders, but not all gliders are sailplanes.
2.-A glider is any airplane without an engine.
3.-A sailplane is a glider that is aerodynamic enough that sustained flight is possible by using rising air currents to maintain altitude, or even to climb.
4.-A glider that is not a sailplane is not expected to maintain altitude or travel very far. During world War II the US, Britain, and Germany all used large troop carrying gliders. These could in no way be called sailplanes.
5.-The words are virtually interchangeable but generally a sailplane is a high performance glider. Some gliders have engines to allow them to takeoff or stay aloft longer but they are referred to as motor gliders. Usually a glider has a glide ratio of less than 20:1. 20 feet forward for every foot down. Some sailplanes have glide ratios of more than 50:1 but there is no clear cut definition of the glide ratio when a glider becomes a sailplane.
6.-They're interchangeable. It's only a matter of semantics.
7.-From a certification point of view, a sailplane really doesn't exist.
8.-The license in your pocket will say glider on it.
9.-A glider is designed to descend in a controlled manner, whereas a sailplane is designed or intended to be able to climb in lift."

in our case with models, as powering a glider/sailplane to get to altitude, mostly with an electric motor, we call them ' electric sailplanes (or electric gliders').
i myself call my planes 'sailplanes' because they can get into thermals. and the 1 i agree most is #9.
anyway, i think that we can call ours whatever we find more to our liking. as long as we understand what kind of planes we are talking about.
above all, enjoy them.
Posted by phil alvirez | Nov 06, 2015 @ 08:11 AM | 7,684 Views
i started with thermals when my 1st plane (free flight) got into 1 and went up and away. from then i began to use a fuse for dethermalizing and was able to get back my planes most of the time. then came radio and got into sailplanes, with which i was able to hunt for thermals. climb to about 45 to 60 degrees and watch the plane for jumping up and turning until got it. when drifted too far brought it back and search for another. no more than 10 minutes. fun!
then recently got a vario and a new dimension, as i am able to 'see' the thermal-or whatever makes my plane stay there or climb. but then i faced another situation, as now i could stay longer, so got devices to warn me of low voltage. ended up having 1 that sends vibrations, and another that shows volts of each cell, and sends beeps when reaching the voltage that i decided to be the lowest safest. the smaller (vibrator) fits my planes with reduced space, and the other the larger 1s.
but once on a long flight i didn't feel the vibrations and lost a plane. am not sure if the device failed or its battery went down or i just didn't pay attention to it, but now am trying to take measures to avoid this to happen again, like bringing the plane down at a higher voltage warning, and above all, not staying up for so long.
and will keep enjoying the most enjoyable (to me) experience.
these are the alarms:

have fun.
Posted by phil alvirez | Nov 02, 2015 @ 07:20 AM | 7,564 Views
this what i have learned about the rad's duration:
there are several ways it could reach the end of its serviceable life:
1.- wearing out the brushes of the motors, be the 1 that powers the plane, or those at the servos;
2.-the resistive ink on the PCB wears out as the wiper slides through it.
the symptoms for the motors may be: for the main motor, it may just get weak, or runs uneven, even sometimes refuses to re-start in flight;
for the servo motors, the servos may run uneven or sometimes don't re-start in the middle of the flight.
and is practically impossible to check them unless having specialized equipment and may be removing or disconnecting them.
for the track on the pcb you have to remove the servo, which is sort of delicate task and also have to remove the brick.
(this is what happened to 1 of my rads, so maybe this part is the 1 that wears out before the others).
so, whenever your plane starts to behave erratical, or any of the servos stop functioning (and this may happen in the middle of the flight), it is time to get a new brick-or a new plane.
these are not complaints. to me this plane is the most wonderful i even flew, and intend to keep using it despite these facts.
just to any1 to consider this in case it happens to you.
Posted by phil alvirez | Oct 15, 2015 @ 03:31 PM | 8,015 Views
waves are spaces where lift is found. their shape is similar to a sea wave. i have been flying in waves long enough to understand their behaviour at this field. it is in a flat area all over, some 5 km north of lake erie, and the prevailing wind blows from the lake too.
and the great thing is that i have the vario that sends tones and switching i can get height too, so it is as if they were colored clouds. no guess work. with this i have been able to learn:
1.-they are found on a line across the wind;
2.-climbing to 200 meters is where i find them;
3.-at this height they don't move. are stationary for a long time;
4.-if i climb to 300 meters i find thermals that drift with the wind:
5.-this happens even in clear sky, but not all the time;
6.-and sometimes i get them even if the wind is blowing from the north (away from the lake);
7.-usually waves are located around a slope or mountain range but as i see, also at flat surfaces;
8.-so this means that even if waves are stationary, thermals can drift above them.
9.-this does not happen in many places; it takes some sort of special situation like the 1 i find at this specific place;
10.-but as i said, it is necessary to have a vario like mine that tells height and sends tones that tell if the plane is climbing (and how fast depending of the pitch and frecuency of the tones) to pinpoint their location.
11.-even if they are stationary waves, are linked to fronts: they depend on the front that pushes the air inland.
anyway, a most...Continue Reading
Posted by phil alvirez | Oct 14, 2015 @ 06:10 AM | 9,073 Views
slow start
1 trick that i have learned with the umx rad is to have a slow start. launch and run it at low throttle for 10 seconds, then accelerate at whatever speed you want. before i learned that, i have experienced unexpected cut-offs at about 5 seconds after launch, with the consequent dive and crash. i guess somehow the esc can't handle the surge. this happens only at the 1st flight after plugging-in a cell. now doing this it does not happen anymore.
Posted by phil alvirez | Oct 12, 2015 @ 07:14 AM | 8,207 Views
well, after the most enjoyable time when i catched great thermals, i found my plane again into another situation where it drifted through a wave for some time and then decided to stay at the point where the lift was strongest. it drifted with the wind so brought it back and catched another thermal and drifted again. started at 200 meters and climbed to 330, so decided it was enough and began a return and descent. all seemed ok, but when it was near the field at 180 meters high it stopped sending signals from the vario. it was not beyond the range, but didn't know what that could mean at the time. as i was lying flat on my back through all this time i decided to stand up for the approach and landing, so i stood up and when i looked back at the plane it was nowhere to be seen. it was about 10 seconds. gone. in clear sky. i think it dove vertical, as when you turn off the radio by mistake. the vario is supposed to send a warning of low batteries, but i didn't hear it. not only that, it also had a low volt warning that vibrates, and it saved my plane last time, but i didn't feel it this time. later realized it had been in the air for 45 minutes. the other day when i almost lost it, it did 35 minutes.
>>>>An update: nov 14, 2016: after reading the manual again, i noticed this:
it really tells when the battery in the plane-or the battery in the receiver-is low by saying this:
“Battery Low”
Radio control receiver voltage is critically low, land...Continue Reading
Posted by phil alvirez | Oct 06, 2015 @ 10:52 PM | 7,944 Views
yesterday i went to our field at noon. it was overcast, and the windmills in the way were still. when arrived, there were clouds all over and almost no wind, so i launched my Maverick 3 (a 2 meter electric sailplane) that has vario, and climbed to 200 meters (440 ft), which is the height that makes easy to catch thermals for this size of airplane, and immediately began to get beeps that tell that there is lift, so swept the area. lift was at a corridor across the field from where the breeze was coming, a so-called wake, that i have experienced here some times before. then. after some time, i began to turn at the point where there was the strongest lift (the highest tones) and in short time i reached 351 meters (1,168 ft)! i could not believe my eyes (or should say: my ears, as it was the vario that told me the height). i never had an airplane so high. and still i could see the plane and what it was doing. but was so tiny! the good thing of having a vario is that now i know how high it is at any time. before, without it, my estimate of height was out of reality. anyway, now i began to worry at loosing the plane and trimmed it to go down, but still kept getting the tones that it wanted to climb. had to give it 'down' signal until i watched it increasing its speed, but was careful that it was not too fast as it could loose its wings. it was quite a fight, but eventually i managed to bring it down to 200 meters. and then the low voltage alarm went off! i had to hurry it down and land. then at home i checked the battery: it was down to 9%! i barely made it.
the flight was 35 minutes, but could stay there for a long time. it was good that i decided to bring it down to 200 meters, otherwise i would loose it due to low battery.
some say that flying is an adventure: you never know what may come. sometimes is the agony and the ecstasy.
still, i was lucky to have such experience and having a happy ending.
Posted by phil alvirez | Sep 25, 2015 @ 12:50 PM | 7,035 Views
umx radian:
for those of you fans of the lil rad am starting a thread where am bringing the posts i have placed in my blog, that are scattered all over the several pages, so you don't have to search.
Posted by phil alvirez | Sep 23, 2015 @ 08:42 AM | 6,336 Views
the only way i knew of going up without motor was with thermals.
(of course there is a way of staying up at a slope, but that is not the subject of this thread).
the purpose here is to seek for means to climb at a relatively flat field.
until recently i was of the idea that thermals were the only mean to do so, but when i moved to a new field, and got a vario that tells with beeps when the plane is climbing, i could search for lift and practically 'see' it as if it were painted in bright color. and then 1 day with clear sky my plane began to find lift in a long rectangular area across the field. there was a light breeze but lift was across it, not a circular pattern. i used it for as long as i wanted. it didn't move. it was an exhilarating experience. i couldn't believe my eyes-and my ears! i had to trim the plane down and drift far from the area to get out of it.
then i began to post at several forums and learned that it was a wave. there are several threads where i got answers.
eventually i moved them to my blog but now am starting this again here to see if there are more contributions and add data as i get it.will talk about my experience, but 1st will tell how is the place where i moved recently and am experiencing this: it is all flat farm land around, located at about 5 km (3 mi) at the north of a large lake, from where the wind blows most of the time. the 1st time i just explained it before, and for several days it didn't happen, until now again in clear sky, but this time stronger wind blowing from the north. and there were several waves that moved with the wind so i had to drift with them. altitude in both cases was about 200 meters (450 ft).
will bring more data as i find more experiences like this, but all polite, positive and to the point contributions are welcome.
Posted by phil alvirez | Sep 08, 2015 @ 08:23 AM | 6,549 Views
i have been an enthusiast about flying on thermals, since my days of free flight, and now more with sailplanes, radio and vario at my hand am having the time of my life.
i have been compiling data on the subject, and as i said, with the aid of the vario am learning still more about them.
as far as i knew, thermals form from the ground and rise to the condensation level and become clouds. their shape could be bubbles or a column.
but now on clear sky am getting some lift that i find in areas like waves that run across, like some clouds that are lines that run parallel. this i 'see' because am using a vario that sends beeps when the plane climbs.
has any1 experienced this?
is there any link about this?
for more details i started a thread here:
and if you have any info please bring it here.
Posted by phil alvirez | Sep 08, 2015 @ 08:07 AM | 6,215 Views
for all that i have seen (in text and real life), thermals develop as bubbles or columns that rise to the condensation level, where become clouds.
but recently in clear air i have detected updrafts in the shape of waves that run across the wind, very much like sea waves. or should i say "sort of currents that keep the plane up there"?
is there any data on this?
please bring only links or positive, polite comments to the point.

for more details, i started a thread here:
Posted by phil alvirez | Sep 08, 2015 @ 08:00 AM | 5,721 Views
clear sky thermals
i have had my planes into thermals many times, be free flight towline gliders or rubber or engine powered, or r/c sailplanes.
so far i am under the impression that thermals rise from the ground in the shape of bubbles, although i could buy the idea that there are also columns. these bubbles or columns reach the level of condensation and form clouds. i have seen my planes reaching a cloud and being swallowed, so i believe this.
but what about a plane climbing into clear air? no clouds in sight?
this happens to me some times.
is there a source where we can learn about this?
meteorological data?
please bring any info here.
there has been some input at a thread here:
Posted by phil alvirez | Sep 08, 2015 @ 07:59 AM | 5,641 Views
vario to detect thermals
am trying to learn from you guys who use a vario what is your experience on detecting thermals; what shapes have you detected;
their size, strenght, how they evolve as they rise, how they change their shape.
recently am beginning to use 1 and am trying to learn more about them. i consider that with a vario we have the way to learn more based on hard data. there are so many theories about them that i think this is the only way to clarify that.

any input based on your experience is welcome.
please comments polite, positive and to the point.

guys who use a vario.
for more details, i started a thread here:
Posted by phil alvirez | Aug 15, 2015 @ 12:46 PM | 5,880 Views
am so happy that i want to tell you that today i went to the field and flew 4 of my sailplanes as long as i wanted as i was by myself and all flew well and landed nicely and got some thermals and there was almost no wind and came back without damage. this was the way it used to be for a long time. that is the idea of flying model airplanes, isn't it?
i have been through a series of radio failures and crashed many times several of my planes, and was not until changed field-and put 1 radio to rest-that things are going the way they were supposed to be, and had been for a long time. not even the moskitos got me!
so it feels good to just go fly and enjoy it.
and summer stil is not over.

so, i wish you all the same.

enjoy while you still can.
Posted by phil alvirez | Jun 28, 2015 @ 09:36 AM | 6,089 Views
i remember the days before i had access to the internet. whenever i needed some data or product, i had to write a letter, mail it, and wait for the answer or the shipment. it took at least 2 weeks.
then i got a computer and now i just click a few words asking for something, or search for it and i get it right there of after a few hours or days. or order something and pay paypal and is shipped to me and i get in a couple or weeks. it has accelerated my learning astronomically. no long waiting times. the only problem is getting the data in a clear way. so there are several possibilities: sometimes there is no data; others the manuals are written in chinglish. then could be that even in good english, it is not easy to understand, and then sometimes is clear. and no matter what, if in doubt, we may enter whatever forum and request some explanation, and most times we get it in short time.
wonderful times of change.
Posted by phil alvirez | Jun 26, 2015 @ 09:35 AM | 4,707 Views
just to remember that children listen, even when asleep, comes this funny episode:
i was talking to my daughter in law at the kitchen table, and my grandaughter was there too, apparently reading a book, when the conversation drifted towards cats, as they were considering bringing a cat for their daughter (which they eventually did), so i was explaining to my daughter in law about the retractable claws, and i said that also lyons and tigers had them, when my grandaughter snapped: 'lyons and tigers and bears, oh my!' as Dorothy in 'the wizard of oz' said. so she was listening all while reading. we laughed for a long time. she was so sharp!
Posted by phil alvirez | Apr 10, 2015 @ 07:25 AM | 6,541 Views
1 of the main reasons why i keep so many planes, and all in good shape, is that i don't take chances. if windy, i don't risk them. that is, until now. recently it seemed not so windy, but when i arrived at the field it was blowing strong and turbulent. but still i decided to give it a go. and this was a 30 inches wingspan light plane. i never flew it in such conditions-not even close. and flew she did. bouncing and jumping, but landed safely, with almost zero forward speed. not comfortable flying, but controllable.
how could i do this? how could i dare to do this?
well, i happen to have 1 of the new stabilizers, that i tested before in several planes in moderate wind and were so convincing that this time i decided to try it to its limit.
so now am able to fly small planes in windy weather, in small fields near home, and see them flying like way larger planes-although i don't think will try this windy again.
the device includes the receiver, and weighs only 8 grams, so the plane barely feels the extra weight. full range, adjustable response, great instructions and support.
and a forum:
Posted by phil alvirez | Apr 03, 2015 @ 11:19 PM | 7,025 Views
back at the nearby park, no snow, neither ice at the lake. better still, the 2 swans are back, although not on the water. perhaps it still is too cold for staying in it.
and some ducks on the water too.
means they are back because it is the time of the year to return, but still colder than what should be?
anyway, it was great to have little wind, so i could try my wings again.
for the past few years the swans have settled for the good weather. it is a great view.
like a post card. and all of them seem to feel comfortable when my planes fly by (maybe because all are electric).
this time i was anxious to try several things. 1 of them a stabilizer, that lets my small planes handle wind like bigger planes.
the other a vario, that i am exploring to detect thermals when it sounds tones.
both worked fine, but takes time to program them to my satisfaction, so am progressing on it. amazing technology at the reach of our hand!
Posted by phil alvirez | Mar 17, 2015 @ 02:03 PM | 7,265 Views
yesterday was not so windy and above freezing so went to the park nearby.
the pond was still frozen but there was almost no snow on the grass.
a pleasant time i had.
and even more when in 1 flight, 2 'v' shaped geese formations flew near my plane.
they maneuvered to avoid my plane, otherwise just honking happily.
it was a pleasure to see them again. although not expected so soon.
maybe as the climate is going weirder every year they are disoriented about when to come back i guess.
they usually land on the pond but, as i said, it still is frozen.