Tuesday, November 30, 2010

Home made ball link pliers

After buy few different ball link pliers that was not working at all on my gliders (for tailplanes), I decided to build my own. I use it to plug or remove the ball link on the tailplane. It works like a charm.



To build your own ball link pliers, you just need a low price flat nose pliers, and with a mini drill, you grid a slot in one of the nose:

Then shorten the other nose by 5 mm.

Monday, November 29, 2010

2.4 Ghz: The judgment day is approaching …

When 2.4 Ghz appeared few year ago, lots of people were wishing a convergence of the systems in order to be able to mix brands together like we can still do with PPM radio.

But this dream is, from my point of view, flying away with what we see currently on the market, and worse than that, large manufacturers are suppressing PPM transmitter from their catalogue to offer only 2.4 native transmitters.

Today, it is impossible to find a Futaba T10FG. Graupner is selling out the MX12s and MX16s. When you open big shop catalogue or website, you don’t see anymore PPM radio.

Another example with Multiplex who is protecting their transmitter by supressing the PPM signal on the Royal Pro. When you send a Royal Evo for maintenance, it comes back with the firmware of the Royal Pro !! too bad ...

This prevents the end customer to buy a PPM transmitter, then install any 2.4 HF module of his choice. All alternative brands, with affordable prices, are in danger in a near future. I think this explains why Jeti will release a transmitter beginning of 2011.

We are clearly in the middle of the 2.4 war, and this war will not stop before some players die. We are of course hostage of this situation. As soon as we choose a system, we are prisoner of this brand.

What to do ? Any idea ?

Servormance max torque versus blocking torque

Following my post about the test results of the DS6125, I received several mails asking me about the difference between the max torque measured by Servormances and the max torque indicated by MKS. More generally the question is the same for all other servos tested with Servormances. So I think it was necessary to come back on that topic and give more information in order to avoid any confusion.

As we say in french, we can not compare apples with oranges, and this is a little bit the case here, so let me develop further:

On the manufacturer specifications the max torque mentionned is the blocking torque, that is to say the torque at which the servos cannot rotate anymore. The servormances team took another approach. Servormances max torque is very restrictive as the value published respects the following criteria:


  • Precision is within a range up to 1.5°
  • Speed is better that 0.8s for 60° of travel
  • Power Consummation is under 80% of the max consummation measured


Taking the DS6125 under 6v as an example, it means that, according to Servormances, this servos is working under normal conditions at 2.6 Kg/cm. In other words, you won't notice any degradation. Then the blocking torque can be much higher. Just to give you an idea, 2.6 kg represent twice the ballast the Ambrosia can carry. not bad !!!

This comment is valid for any servos. In fact, what is the most representative for us, the pilots, is the "usable" torque, and the objective of Servomances is to test servos in the very same conditions in order to be able to compare them.

To finish, I let you enjoy the demonstration of the blocking torque on the DS6125 with this video from the manufacturer. Pretty impressive !



Ambrosia F3X ready for maiden

I finished the Ambrosia this week-end. I found in a DIY shop a square steel tube with the right dimension, 14x14mm, and some wood for the spacers.


I made slugs length in order to have 2 slugs per compartiment, that is to say 4 slugs per wing. What is interesting is that compartiments are located on each side of the joiner which garanties that the CG will not move too much when ballasting.


Each slug is about 160 g.

And the total ballast weight is about 1300g, which is perfect


I also did the CG balance of the plane and moulded the lead for the nose. I needed around 150g of lead which is not too much considering the fin and tailplane which is usually heavier than a V-tail.

The total weight is 2250g. The Ambrosia F3X is ready for maiden :) !!!

First flight next week-end if the weather is cooperative. We had snow falls the last days ...



Stay tuned !

Tuesday, November 23, 2010

Ambrosia F3X assembly "Part 3"

Assembly continued with the wing servos and pushrods installation. The Ambrosia F3X comes with the brass ring-screws. You'll need 8 clevises (M2), some threaded rod and also aluminium tube with an internal diameter of 3 mm. First of all, I grinded 4 clevises (that will be on servos side) in order to use the servos arm hole the closest to the axis.


Then, the servos being in place in the wings, I cutted the threaded rod at the right length, glue with some rapid epoxy the clevis on the ailerons/flaps side. Once dry,  I glued the clevis at the other end, and inserted a 3mm aluminium tube to make the control rod more robust and stiff. The reason I fix the clevises with rapid epoxy glue to to suppress any possible slope on the command. You will also notice that the ring screws are not glued in place. It will be done at the very end because once in place, the clevises cannot be removed anymore.


Then, I drilled the wing plug housing at the root of the wing. The housing is at the perfect dimension for the green MPX style plug. 


The servos are screwed on their frame, and the command pushrod put in place. The ring screw is glued with epoxy at that time.


Same for the flaps. The only difference is the servo arm neutral position with is different in order to obtain more travel down for the airbrakes:



The servo covers are cut, following the moulding mark. They fit perfectly:



I prepared a small ON/OFF switch on an epoxy plate which is then screwed on the servo tray. The switch is small enough to let the space for the receiver.


The battery has been soldered. Cells are hot glued together. A transparent shrink tube allows a nice finish.



To complete the assembly, I just need to install the receiver and program the servo travels and neutrals, do the balance lead to obtain the right CG, then build some ballast. The ballast tube square section is 14x14 mm . I found a steel tube of this size and I will melt some lead in it.

Stay tuned !

Friday, November 19, 2010

Some aerial pictures

The weather was beautiful today, so I decided, during the lunchbreak, to do some aerial pictures of the mountains around.



Thursday, November 18, 2010

Ambrosia F3X assembly "part 2"

I continued the assembly with the servos installation, in the fuselage and in the wings. In the fuselage, the DS6125-H are simply screwed with the woodscrews provided.



Pushrods are made from metal tube with a external diameter of 2mm. First, I cut them at the right length before to fix a M2 treaded coupler at the end. I used MPJet couplers made from brass because they are execellent quality.



Usually, I glued, then pinched the M2 treaded coupler on the pushrod. Prior to that, I inserted 5cm of 1 mm pianowire in the tube in order to not crush the tube when pinching the coupler.



I started also to have a look on the battery to use. This is straigth forward: 4 eneloop cells mounted in 2+2 format will take place easily in the nose.



They enter without any problem by the canopy, once servos are in place. This is a good point because the canopy is not that big.



On the wing side, I prepared the servo holes to receive the wood frames. Once positioned, I glued the frame with rapid expoxy (10 mn R&G epoxy), put the servo in place with a very thin plastic film in between, ajust the position of the frame & servo in order to have the servo horn well aligne with the control horn.


I put a ballast on top of the servo and let everything to dry smoothly all night long.



This morning I checked the result, and all is perfect. The DS6125 fit perfectly in its wood frame which is well glue




The result is clean and ready to receive the control rods which is the next step of the assembly.

Stay tuned !

Tuesday, November 16, 2010

Aerial Pictures: Grenoble and Belledonne

Taken last saturday using an EasyGlider equiped with a Sony cybershot DSC-W350. It was already late in the afternoon, and the shadow created by the sunset and the mountain was not ideal. The picture is above the south of the grenoble valley, where are located some chemical plants.



If you look carefully on this second picture, you will see a small part of the Mont-Blanc, behind the mountain range the highest summit in Europe with 4807m


The mountain range is Belledone: Belledonne (French: La chaine de Belledonne) is a mountain range (French: massif) in the Dauphiné Alps (part of the French Alps) in southeast France. The Belledonne range is approximately 60 km (37 mi) long by between 10 km (6.2 mi) wide. There is no road that cuts across Belldonne (source Wikipedia).

Monday, November 15, 2010

Sad news: Hans Graupner passed away

One of the legend of the aeromodelling died during the afternoon of the 11th of november, only 2 weeks after his retirement has been announced officially during a press conference in Friedrichshafen. Hans was 81 years old.

This sad news has been announced here: http://www.vth.de/news/hans-graupner...html?tx_ttnews

This is a big lost for our hobby.

Sunday, November 14, 2010

Raviole Soaring episode #1

Raviole Soaring is unformal regional winter league competition in order to be busy and have some practice during the winter. We selected small slopes, not high in order to not have snow, or at least a low probability. The name "Raviole Soaring" has been chosen because of th food speciality of the area: This regional speciality of the Dauphiné perfectly suits our ways of modern consumption: easy to prepare and quick to cook - only 1 minute!

More information can be found here

Let's come back to the contest. 12 pilots from the area met around 10 am this morning and completed 4 round before the lunch in a strong wind (about 40 to 50 km) with some dust reaching 60 km/h. The slope is a grass field, with slow angle slope.

Then we had a lunch break of 1 hour to cook and eat some ravioles and other great specialities :) ! Then we started again for 4 additional rounds until 4 pm.

Yves Tirand won the competition with his Vampire. I got the fastest time with 41,72s. I thing this slope can go under 40s which is unbelivable when you see the angle of the slope. We were able at soem occasion to do some energy management turns. The slope was however most of the time very turbulent.

Here are the results


The planes:


  1. Yves : Vampire
  2. Pierre : Alliaj HM
  3. Laurent : Ceres F3F / Dynella
  4. Arthur : Dingo
  5. Olivier : Dingo
  6. Serge : Dingo / Martinet
  7. Thomas : Big Snip
  8. Fabien : Freestyler 3
  9. Stéphane : Sniper
  10. Paul : Dingo
  11. Joël : Caldera
  12. Etienne : Ascot

A big thanks for the co-organizers for the food, the logistics, the pylon judges. We have a very friendly and breathy day !










More pictures can be found also here.

Saturday, November 13, 2010

Ambrosia F3X assembly started

I started the assembly of the Ambrosia F3X. First I prepared the wing servos wire and te equivalent in the fuselage. I use DIY plugs because you can make the exact length you need, and also because it is much cheaper. Ambrosia F3X has MPX green plugs housing already moulded.




With a mini drill, I prepared the housing on the fuselage ad let a lip all around in order to glue the plug in place.


The plug is fixed in place with cyanoacrylate glue. The result is perfect and clean


The Fuselage will be equiped with the MKS DS6125-H. The servos tray is cutted for futaba S3150, I guess, but not problem for the MKS servos.


In the wing, I will use 4 DS6125 equiped with their laser cut wood frames:


The servo hole is not that big, but the frame can enter with some exercice :) !



Stay tuned !

Thursday, November 11, 2010

MKS DS6125-mini and DS6125-H: 2 new kids on the block

The glider servo family manfactured by MKS is expanding with 2 new versions of the already presented DS6125 wing servos.


The MKS DS6125-mini is a shorter version of the DS6125, still with impressive specs with its aluminium case and chrome gears: Torque is a little bit lower than the DS6125 but delivers plenty of power for glider application:
  • Dead band:0.001ms (Default)
  • Control System:+Pulse Width Control
  • Working frequence:1520μs / 333hz
  • (RX) Required Pulse:3.0~5.0 Volt Peak to Peak Square Wave
  • Operating Voltage:4.8~6.0 V DC Volts
  • Operating Temperature Range:-10 to + 60 Degree C
  • Operating Speed (4.8V): 0.12 sec/60° degrees at no load
  • Operating Speed (6V): 0.1 sec/60° dagrees at no load
  • Stall Torque (4.8V): 4.8 kg-cm ( 66.65oz/in)
  • Stall Torque (6V): 5.8 kg-cm (81.0 oz/in)
  • Motor Type: DC Motor
  • Potentiometer Drive: Direct Drive
  • Driver Type: FET
  • Bearing Type: Dual Ball Bearings
  • Gear Type: Chrome gear
  • Programmable: NO
  • Connector Wire Length: 15.0 cm (5.9 in)
  • Dimensions: 30x10x29.9 mm (1.1811X0.39X1.17 in)
  • Weight: 25.26g (0.89oz)


The MKS DS6125-H if the vertical mounting version of the DS6125 Mini, with the same specs expected the case shape.


So which servos for what glider application ?

The DS6125-H will be perfect as elevator servos. It will fit in the slimmest F3X fuselage, and if the servormances tests results are identical to its brother (excellent accuracy, positionning and low bending), will provide a crisp and solid control without any slope of the elevators. 

The DS6125-mini will be prefered for ailerons where the DS6125 will be used for flaps or for large ailerons when needed. For example on a 4 m large sailplane, the DS6125 will be perfect.

MKS is well known in the helicopter world for the quality of their servos. I bet that it will be soon the same in the glider world !!!!

DS6125, DS6125-mini and DS6125-H servos are my choice for my next planes.




Monday, November 8, 2010

GPS book software

With the introduction of the 2.4Ghz and onboard GPS modules, a software to load and read the GPS traces become a must have. A friend of mine developped a freeware called GPSBook that does it very well.


The development is not totally completed but the software is already usable.


It allows to:

  • Load and save GPS traces in various format
  • Apply filters into GPS data loaded
  • Edit tracks, routes, point of interest
  • Display information into graphs, table or maps in 2D and 3D

GPSBook is an open source software, free and able to run on Linux, MacOS X and Windows.
More information at the following URL:  http://gpsbook-team.blogspot.com/

French 2011 F3F league calendar

Here is the calendar for the french F3F league 2011, plus 2 FAI and the national championship:

  • La Madeleine (south west / Basque Country): 2 - 3 of April
  • Laurac (VKR slopes): 16 - 17 of April
  • TOA (Ardéche) : 7 - 8 of May
  • Notre Dame De Vaulx (French Alps near Grenoble): 4 - 5 of June
  • Vosges (East of France)- National championship: 11, 12 and 13 of June
  • La Banne (Auvergne / Center of France): 25 - 26 of June
  • Caussols (Cote d'azur)- FAI/Eurotour: 15,16 - 17 of July
  • Briançon (French Alps): 30 - 31 of July 
  • FU-Menée (French Alps): 20 - 21 of August
  • Col du Glandon (French Alps): 3 - 4 of September
  • Vosges(East of France): 17 - 18 of september
  • Laurac (VKR slopes)- FAI/Eurotour: 30 of September, 1 - 2 of October
  • Caussols (Cote d'azur): 15 - 16 of October
  • Laurac (VKR slopes): 22 - 23 of October


Friday, November 5, 2010

The Ambrosia F3X has landed !

I received 2 days ago my Ambrosia F3X from Miro Model. This F3F model with a wingspan of 2.95m doesn't look like other plane with its crosstail, and a very original and nice planform. The section is a DP 8.3/1.66 at the root, with an evolution to a thinner section with less camber at the tip. Another particularity is the canopy that is located at the bottom of the fuselage, servos being upside down.





Characteristics are:
  • wingspan: 2950 mm
  • Lenght 1450 mm
  • Area: 56.4 dm2
  • Root chord: 250 mm
  • section: DP 8.3/1.66
Moulding quality is absolutely superb, one of the best I have seen. The finish and fitting is just perfect. To illustrate it, just assemble the 2 wings on the fuselage with the joiner to see that there is no need to force. I will not have to sand the joiner, even a little. The fit at the root is perfect.

My Ambrosia is a glass version, the fuselage is made from kevlar carbon. The servo tray is already installed, like the control command to the tail and rudder. a small pocket with the wing servos covers and brass control horn is provided.

Ballast take place in the wing on both side of the joiner, which is good to keep the balance right, while loading the plane. The square ballast tubes accept up to 1400g of ballast (brass ballast).

Weight per element is as follow:
  • Fuselage: 322g
  • Right tailplane + joiner: 29g
  • Left tailplane: 25g
  • Left Wing: 627g
  • Right wing: 637g
  • Joiner: 92g
  • Total: 1732g
I can expect a flying weight around 2100 to 2150 gr

As I said at the beginning, the Ambrosia F3X is manufactured by Miro Model, located in Slovakia. There is no website yet, but you can contact them at the following address: p.polonec(at)zoznam.sk (replace the (at) by the @ to obtain a valid email address).

More to come with the building, so stay tuned !

Aerial pictures above Maupertuis garden

Today, during the lunck break, I flew my Gaui and did some aerial pictures in the parc close to my office in Meylan. Meylan is a commune in the Isère department in south-eastern France, a suburd of Grenoble.



Wednesday, November 3, 2010

Aerial Picture of the day

Picture of Grenoble taken at midday from an EasyGlider equiped with a Sony Cybershot W350. Grenoble is a city in southeastern France, situated at the foot of the French Alps. Mountain sports are an important tourist attraction for the city, both in summer and in winter. Twenty large and small ski stations surround the city. In the background you can see the Vercors.



More information can be found on Wikipedia

Monday, November 1, 2010

A new fresh and beautiful video from Jean-Claude Gonnin

Jean-Claude is very good to share with us the beauty of Spain. This time is no exception with this new onboard video taken above Peñiscola.

Enjoy !



2 new amazing videos from Team Black Sheep

You have probably seen their film series called "Living FPV". I propose you today 2 new amazing videos. The first one is "just" the immersion world record with 47 km !!!! they use a flying wing for that:


Very long range from RiSCyD : TeamBlackSheep on Vimeo.




I personnaly prefer the second one which is absolutely superb. An immersion flight in patrol with a 8.4 m ASH31 sailplane !!! Using the Go Pro I can tell you that the flying wing is very very close to the sailplane !


Glider Formation FPV from RiSCyD : TeamBlackSheep on Vimeo.


RCRCM Typhoon Full Review (In French)

Full review in French of the Typhoon from RCRCM. The Typhoon is a 2m slope allrounder: Read the article.

Review in English is here.





Opale Paramodels Spiral 1.2 Full Review (in French)

Full review (in french) of the RC Paraglider from Opale Paramodels: Read the article






Mistral Soaring - Rognac

Yesterday we had a good friendly winter contest in Rognac, between Aix en Provence and Marseille. I left Grenoble aroudn 7am under the sn...