Integral #3

[Xavier]

Since I want to be fully ready for the next team trial in September, I plan to have more than one pattern plane ready to go at anytime for the 2010 season. In addition to my 2 years old Integral and the one I got last year, I got a third one late last fall from Chad Northeast who has been the best Canadian at the world chmapionnship for a few years.

This plane will be my primary plane until I finish building the Xigris (http://www.wimac.ca/forum/showthread.php?t=2825) and then will become the #1 backup.

Today, I assembled it and installed the tail servos. I will order servos for the ailerons as well as a switch-regulator. The motor will come from my Integral #1.

Xavier

[Dwight Macdonald]

Xavier, what is the overall cost of a typical 2M span electric pattern plane ... new and used in good condition?

[Xavier]

The Integral is a very good airplane sold by Composite ARF and it's a good deal at about 1100$. If you add the most expensive components, like Plettenberg motor, Shulze ESC, ThunderPower 10S batteries, digital JR/Futaba servos (5 servos required) & receiver, it will cost about 3500$ total.

There are some wood kits availables that are less expensives but also ARF from Oxai that are a lot more expensive (5000$ just for the plane). The 2m airplane are really only required for serious competitors. There are some '120 class' airplanes available for a lot less money that fly almost as well on 8S.

There is also now the possibilty to use motor, ESC & batteries from Hobbicity and you cut the price a lot. I plan to get one setup like this to try in my oldest Integral. For servos, Hitec has some very good ones that are a lot less expensive than the JR/Futaba . In the end, a completed Integral could be almost half the price.

There are some used airplanes available from time to time and price will vary. Obviously, the electric keep there good shape longer because of the cleanless and the low vibration level. So it could be a good deal.

Compared to other top of the line type of airplanes or helicopter, it's not that expensive and it flies so well.

Xavier

[Dwight Macdonald]

Hmm ... half of $3500 would be not much more than a DA 100 with cans and prop ...

[Xavier]

And you have to think about the 32 servos :-)

[JimmyG]

And you have to think about the 32 servos :-)

Wow 32 servos! Is there at least 1 dedicated to the pilot feeding himself pea nuts during the flight?

[Xavier]

There is also one moving the finger showing the other pilots there are #1 ... :-)

note: Ok maybe 32 was an exageration. It's probably closer to 24 :-)

[Xavier]

The plane re-flew for the first time last Saturday. Even if I have done many first flights, I was still nervous until it was back on the ground. As they usually say in reviews, it only needed 2 click of up trim :-) In that case it's true anyway. I only had one flight and will verify everything before the next session. It flies well but felt a little too soft so I will recheck the throws and compare them with my older one.

If anyone is interested, I know someone with one like this missing only the batteries and the receiver and he is asking 2200$. Includes Hacker motor, Jeti controler, Futabe servos, additional landing gear, canopie, wings. A good deal I think. Too bad I already have a few.

Xavier

[beto9]

Xavier... 32, 24 servos???? Is that a joke?

How many really? What functions? Not even Mike puts 24 servos in his planes...

[Xavier]

There are only 5 in this one. 1 per elevator, 1 per aileron & 1 for the rudder.

The 32/24 servos was a joke about the big Imac planes :-)

Xavier

[Xavier]

23 flights up to now and it's getting trimmed to my taste. The latest mod was to add some right trust and it made a huge difference everywere in the flight. I should fly this one now. My oldest one has now over 500 flights. I just got an E-logger that show me current, voltage, trottle position on graphs after the flights. Once I managed to make the GPS work (gives 3D image of the flight, 2D over google map, speed), and connect the RPM, I will have nice tools to fine tune my flying. I am also having fun with that :-)

Xavier

[Dwight Macdonald]

It will be interesting to hear how the GPS works out for tuning your pattern flying.

[beto9]

What is the resolution of a commercial GPS? Just trying to understand how precise it will plot your flying.
You are starting to fly an UAV!

[Xavier]

I don't understand all the info below but it seems to be very precise. Only real tests will say for sure.

GPS Expander Specifications (subject to change)
· Update Rate: 10Hz
· Cable Length: 11” (28cm)
· Antenna: Built-In patch
· WAAS and EGNOS support
· Built-in battery backup for fast fix reacquisition
· Time to Fix: 1 second hot, 36 second cold (typ)
· Speed Accuracy approx 0.1 m/s
· Current draw: less than 40 mA when tracking
· Dimensions: approx 1.4” x 0.9” x 0.3” (35x20x8mm)
· Weighs approx 0.4 oz (11g)
· Position accuracy approx 8.2 ft (2.5m) CEP with WAAS/EGNOS
· Sensitivity: approx -165dBm
· Datum: WGS84

http://www.eagletreesystems.com/Support/Manuals/GPS%20Expander%20Manual.pdf

[Flying73]

WAAS supporting GPS........... You can fly an approach to a select few REAL airports that now have this system, if you had the necessary software. Wow.

[Jeremy Cartlidge]

As Dwight said, it will be interesting to see how useful it is to fine tune a pattern sequence. GPS accuracy is a very complex subject influenced by many variables and you will have no way of knowing how accurate the logged data really is.

Unless you paid megabucks for it, you will have a module that is mass produced for consumer products and is not intended for tracking 3-D motions. It is likely a GlobalTop PA6B with a MediaTek MT3329 chip. There is no vertical accuracy data provided for this chip by the manufacturer. The vertical accuracy will be less than in the horizontal plane, typically 2 or 3 times worse. You may need to add a barometric altimeter, but then you must allow for response lag and sync the GPS 2-D position. The max update rate is 10Hz and this may not be achieved if the processor cannot keep up. With WAAS enabled there is more for the processor to do, and so you may get better results with WAAS disabled since you only need relative not absolute positional accuracy. The default update rate of the chip is 1 Hz, configurable by firmware. At 1 Hz there will be a maximum of one data point logged per second. Is this enough to get a good record of the aerobatic sequence?

It will be a valuable and interesting tool for recording flights that may give you an edge over the competition. Dwight will want one. Keep us updated.

[Dwight Macdonald]

It would be interesting to see how high we go and how far away in a typical pattern. Also how close we are flying to the neighbors for noise concerns.

[Xavier]

I am curious to see it too. One thing that could be done is plot the airplane track over a Google map image. That will be interesting to see how close or how fare we fly as Dwight said. For 60$, I am not expecting too much but it will be fun. I am more interested in the speed of the aircraft and idealy be able to compare speed of horizontal and vertical lines. I should be able to try it this weekend. I am also curious to use the RPM reader and compare it to trottle position vs current vs change in altitude. But I also have to practice so I may not be able to do everything as quickly as I want.

[Xavier]

Here some images from onboard the Integral last week. This was with old batteries so the power is not very high. I have seen 3000W on other flights. The GPS tracking seems to be affected by the rolls, snaps and other maneuvers. Only the take of and landing circuit are looking about right. I am surprised by the speed. I run the GPS in parrallele with the GPS in the car and the speed and heading were the same so I have to assume that what is on the graph is true. There might be some effect from altitude change. I will have to do a flight with only straight lines to be sure.

[Xavier]

The plane has almost 30 flights now. I still have a few twiking to do but it's flying well.

Xavier

[Dwight Macdonald]

What are the speed units? Km/hr or Mi/hr?

[Xavier]

Km/h. It's fast enough :-)

[Dwight Macdonald]

How fast is it on straight and level?

[Xavier]

I am not sure as I was doing a sequence and I am having trouble defining what is what. That's why I need to do a flight just for that. Straight lines in all orientation. I'll post what I found but it maybe in a few weeks.

Xavier