#8 We have Homologation for First Class Competitions!

#8 We have Homologation for First Class Competitions!

We are happy to announce that today Sep 20th we have received Homologation Letter from FAI officials to support GliderKeeper model 309 in conjunction with Fw_F1.22 to be used in official FAI First Class competitions.

We want to thank FAI officials all their time, suggestions and effort to evaluate our device.

We, GliderKeeper team, also want to thank all our F5J community friends for the interest, help, suggestions, critics and encouraging words that have been paramount for the development of this new AMRT.

We are sure that with this new boy in town F5J formula will earn many followers and the biggest diffusion in aeromodelism.

FAI_S Firmware Homologation and FAI web page updating will follow in the next days.

https://gliderkeeper.com/

#7 Keeper Conf. Explanation

#7 Keeper Conf. Explanation

We have written here a detailed explanation of GliderKeeper behavior upon the different settings of “Keeper Conf.” menu as several users have requested. This Shows how easy is to configure this AMRT in Field.

Starting from version 1.22 you will be able to see your Fw and UI standard in the blue ribbon of all GliderKeeper pages.

Depending of the Fw type you will have more or less access to these settings.

Competition Settings. -These settings allow you to configure how GliderKeeper will control your throttle.

Training/Esc Setup. – You have the throttle control ALL THE TIME. Use this “competition setting” for calibrating your ESC. Or in the very first flights of you model.

FAI Mode. – This behavior is according the rules of FAI “ F5J – RC ELECTRIC POWERED THERMAL DURATION GLIDERS”

Para 5.5.11.1.3.h)  “ii) To restrict the operation of the motor by the competitor to a single continuous run not exceeding 30 seconds. “

That is, you have control of your throttle during the first 30 seconds of flight, or until you retract the power setting below the threshold. After the first of these two events your throttle is controlled by GliderKeeper to the value stored when powered up.

Altitude Shut.GliderKeeper will shut the throttle upon reaching the Stored Altitude Level, 30 seconds or a lever retract below the threshold, whichever occurs first and will be maintained to the value stored when powered up. When this Competition is selected you can change the Altitude Level for this shutting operation this altitude target is set in metres.

Time Shut.GliderKeeper will shut the throttle upon reaching the number of Stored Seconds in or a lever retract below the threshold, whichever occurs first and will be maintained to the value stored when powered up. When this Competition is selected you can change the Motor Seconds for this shutting operation.

F5J Height Calculation. -All above settings will allow for an F5J height calculation which is certainly meaningful when is FAI mode, but can be very useful for training and other competitions.

Enable Emergency Motor.- This setting is applicable to FAI, Altitude and Time modes. If enabled, Gliderkeeper will return throttle control to the pilot after 30 seconds of motor shut. The use of  motor in Emergency during flight will delete the result of a previously calculated F5J height of this flight and will show “—.-“ meaning this flights is to receive a Zero score. But maybe save a hull.

IMPORTANT NOTE: In strict compliance of FAI rules this flight cancellation may happen despite the landing time and a Flight Duration has been calculated, if throttle lever advanced. So pilots in competition should take care or their throttle lever both for safety and for their score.

Show Flight Time on Display. If muted, the flight time will not be displayed in OLED screen.

Logging settings. Mainly to save storage memory, it shows when the data logging will start. Always means it will be started on device initialization (important to track the “altimeter Zero”). On motor means that logging will start after motor is started. And On Altitude Logging will start after the desired trigger altitude is exceeded, this trigger altitude can be changed if On Altitude is selected.

GliderKeeper Orientation. Select Flat if GliderKeeper is installed in the canopy or the bottom of the fuselage. Deselect it if mounted lateral to the fuselage. Remember the long dimension of GliderKeeper must be parallel to flight direction either wire to the front or to the rear.

Always click or tap “save” for the changes take place next time GliderKeeper is powered up.

FW Types.

Fw STD is loaded in GliderKeeper. Al above Options are available

Fw FAI_F (First class competitions Fw), will only allow for Show Flight Time on Display and Gliderkeeper Orientation. The rest of the setting will be ignored and assigned to: FAI mode. Emergency Motor DISABLED. Logging Always

Fw FAI_S (Second class competitions Fw), will only allow for. Emergency Motor, Show Flight Time on Display and Gliderkeeper Orientation. The rest of the setting will be ignored and assigned to: FAI mode. Logging Always

If rules would change or some other developments would recommend it, new firmware type may be published.

We wish you found useful these descriptions and they help to take better profit of your GliderKeeper and have the happiest landings!

#6 A timekeeper_less F5J competition

#6 A timekeeper_less F5J competition

Last Thursday, eight brave men met to demonstrate that a F5J competition is possible with no need for timekeeper duties. All of us were equiped with one GliderKeeper inside our models.

We are all getting used to this new device so for the first times it is worth to take some minutes so everyone understands how to use it.

Very soon you will get comfortable with it, once you have used it a couple of times.

After reviewing the configuration of each of the devices we simply went into a single group eight in a row six flights competition.

This video is the demonstration that this is possible! It took us only two hours to do all the flights.

Print your boarding passes at home and the only thing you will need to bring to the airfield is the loudspeaker box with the speech manager. We call it GliderTimer. We will be talking of it in the next months.

Obviously, it was not a top level competition, and the more important the competition is the bigger the number of persons that must be hired for organisation. We want GliderKeeper to help reduce this overhead.

This was humble but serious competition, you can see results here: https://fam.gliderlink.net/comps/results/56

And there were awards for the podium. Since we were in Valencia the prize was a kilo of paella rice!

Thank you for reading our post and we hope you liked it!

Comments and questions are welcome at support@gliderkeeper.com.

#5 Altimeter reading deviations on flight

#5 Altimeter reading deviations on flight

We all have seen in our traces that the altitude plot features some non-expected peaks and snags when we shut motor or in the landing moment.

I have identified the following effects that will cause our altimeter, which is a device that measures just pressure, reads an altitude not in line with expected.

We want to measue the undisturbed static pressure at the location our airplane is, but certainly the only presence of the model slightly disturbs the rearing. Note that what we want is to measure the pressure, say a few meters away the model but we are measuring the pressure “somewhere inside the fuselage” of the model.

The motor and propeller flow do change as well this pressure inside the fuselage.

Kinetic Energy.

Main effect here is kinetic energy. When you are climbing like a rocket at the end of your climb your airplane is likely to be running at speeds around 12-15 m/s (43-54 km/hr) or even more this doubles its cruise speed which is around 6 m/s (24 km/hr). No matter the model is absolutely horizontal: a trimmed model will just float up to its cruise speed is achieved by exchanging its kinetic energy in potential energy that is increasing its altitude.

The only and last formula here is:

Delta(h)= ½ (V12-V22)/g

where Delta(h) is meters and V in meters per second and g, gravity 9,8m/s2, for the numbers above (15 m/s and 6 m/s) this Delta(h), increment of altitude due kinetic energy, is around 10 meters, which very much what you see if you are not very careful in your top of climb. and the prressure distribution will be similar

If you wanted to maintain exactly the altitude when you shut the motor you should push the elevator such the altitude is constant while the speed decreases. I made a simulation for a glider 4m span, 0,4 m/s descend speed at cruise, 1,4 kg mass and an aspect ratio of 18. It will take around 6,5 seconds to dissipate all above kinetic energy down its cruise speed. Ahh this where the famous 10 seconds of F5J altitude calculation comes…

Fuselage Shape 

In figure you can see that the pressure in the skin of a Dreamliner (source https://leehamnews.com/2015/04/28/fundamentals-of-airliner-performance-part-7-the-wing/ )Airliners are not that different than our models…

Yellow and red areas are where the static pressure is higher than atmospheric pressure (ram effect), pink areas are those where that pressure is more or less equal to atmospheric and GREY areas are where the static pressure is LOWER than atmospheric: there is more or less where the canopy of your model is.

This is a static motor On excursion

This means that when your model is flying at airspeed, the leaks in the canopy area will make your altimeter reads HIGHER altitude than real altitude. This effect is around 4m when motor is on.

This is an example   Where you can see this effect and also the kinetik energy recovery of height

 

 

 

 

This same Fuselage Shape effect can be seen during landing  , the airspeed changes from 6 to 0 m/s in an instant   so the effect should be around ¼ of the propeller effect around 1 meter..

This is an explanation why you see in your gliderkeeper traces the landing moment is “a bit high” also take in account that depending on the landing manoeuvre  the altimeter “may” be a little higher than the nose touching the terrain and triggering the landing time.

 

 

 

 

Another interesting effect I have seen in a couple of instances is a dynamic effect during this landing. See picture it is clearly dynamic effect and as you can see this is around -2,5m which would mysteriously match to a hammershock effect of a fuselage pod column of air of 1,5m long braking at 2g in a very hermetic fuselage cabin… or it is just inertial forces in pressure sensor (difficult to believe). That fuselage does not show much Fuselage Shape effect so it is likely to be very tight sealing canopy.

Please note all above effects are depending and may vary in your peculiar installation, Fuselage shape and as well the way you pilot your  plane.For further details please contact us in support@gliderkeeper.com.

We all wish now you have a little more confidence in the readings of your favourite AMRT and this helps you to have the happiest landings.

#4 GliderKeeper Installation

#4 GliderKeeper Installation

During our tests supporting our design we have made made quite a few installation trials and subsequent functional tests to ensure the response of the unit was insensible to the different possibilities. But certainly we have not covered everything at all. There is a general recommendation to fix GliderKeeper to your model canopy but really only two rules apply:

1.- The long dimension of gliderkeeper must  be parallel to flight direction.

2.- It has to be fixed as stiff as possible to fuselage body…

In this picture you can see a very neat lateral  installation in a Plus X fuselage body. I challenge our users and fans to share their installation pictures either by sending us a picture and the relevant comments and tips to our e-mail (support@gliderkeeper.com) and we will update this post with them or to just leave a comment with the picture in our Facebook wall!

And this is the last day´s flight with GliderKeeper as passenger.