Topic: Integral

Integral electric conversion

MY ZN line Integral has been converted to electric. It has been flown just a few times this year, and although I love the simplicity of the 170 CDI, I needed to strip the whole plane down and re-paint parts of the nose where the paint had been eaten away by Nitro, and the home-made soft mount needed replacing. It was not a small job – a new Hydemount would have required a hefty spacer from the original firewall, and would have added much weight. The engine itself needed lots of spare parts and servicing. After stripping everything, I weighed the lot – it came out at almost 1.9 kilos, including tank, throttle servo, linkage, CDI box and fuel tubing. A YS setup is heavy!  It didn’t take a lot of thinking to decide on going electric with this one. It’s a beautiful machine and deserves to fly. It pays to have two planes with a similar setup, so I set off converting it.

Before: YS 170 CDI and Hatori header. Since the picture was taken, it was refitted with a 9650 servo inside the fuse for the throttle.

I made a new firewall and bolted the Plettenberg 30/10 to it. The battery fit nicely above the undercarriage, and a test of the CG proved it would be no problem fitting the battery there. The bellypan has MK magic box snap lock fasteners, so I can change the battery very easily. The only practical difference is that changing batteries on a plane that lack plug-in wings, is that I need to bring the stand with me every time I fly. The underside of the plane where the pipe used to be is not very sturdy – only the area around the undercarriage is. I wanted to strengthen it without adding too much weight, so I drilled through the undercarriage former and the original firewall, all the way through to the new former and glued in two 6 mm hollow carbon rods. They add no strength to the structure of the plane, but when the battery straps are slung around them, the carbon tubes bear the weight of the battery across four sturdy formers, in the event of a hard landing. (Picture)

After: The battery tray is essentially a plate to raise the battery above the screws that hold the undercarriage. I couldn’t rest the battery on the screw head for fear of damage. To remove the undercarriage, the battery tray comes of with four small screws. As mentioned, the straps go through the floor where the pipe used to be, and are slung around the carbon rods. One rod also serves to hold the controller, along with a small nomex plate. The controller is offset from centre so that I can access the motor bolts if it needs to be uninstalled for some reason, alter the thrust line etc.

Other modifications include removal of the 2000 mAh Schulze battery in favour of a small 700 mAh LiFe battery. I haven’t weighed the finished plane, but calculations indicate it weighs the same or less, compared to it’s YS CDI former self. The nose has been sanded and the paint touched up, and it’s ready to fly. Stay tuned for a flight report in a week or so.

More before/after pictures

Flying season 2010

Here’s an update about what’s going on in the 2010 season. The integral is pictured here with a new undercarriage which was violently torn off minutes after the picture was taken.

The Integral is the best flying plane I’ve seen. I just love how it presents itself in the air and the color scheme is brilliant. The CDI engine is really easy to operate and is very fuel efficient. It’s also one less thing to charge before I go flying since there’s no glow driver involved.. I typically charge about 600 mAh after four flights in the combined RX and ignition battery pack. At the annual Løten F3A cup I experimented with my own blend of fuel with 10% oil. That definitely did not work well, it overheated in both rounds and stopped. After a forced landing the undercarriage mount was badly damaged and is currently being repaired. I have changed to the taller ZN landing gear that is used in their electric models like the Xigris. It looks really nice and gives better prop clearance so that I can run 19 inch props if I want to. I have had some hysteresis problems with the throttle servo which gives an unreliable idle so I’m changing the throttle servo position and will be using the Futaba 9650 servo.

150 km/h into a wall of grass. Integral does not approve.

While the Integral is undergoing undercarriage surgery I have flown and trimmed the Lorenz Laser. It hasn’t flown since I broke an undercarriage leg last year and now has a stronger, lighter undercarriage and it’s converted to Futaba 2,4 ghz. Trimming it with the new radio and receiver should have been uneventful but it was rather terrifying when the elevator horn broke. Nothing raises your pulse like seeing your elevator flapping freely in an untrimmed plane. To top it off, a wheel fell just when I was touching down. I got some applause from rolling out perfectly with one wheel and one elevator. Every dog has it’s day! Upon inspection, the other elevator horn was fractured and broke off with a light twist. A light surgical procedure involving 5-minute epoxy later, the Laser flew two trim flights and one P-11 schedule successfully.

I have swapped the lovely little T8 Futaba radio for it’s bigger brother, the T12FG. It offers more programming ease with it’s larger screen and also has logical switches which I find very helpful for switching flight mode from normal to snap roll using stick positions. I also have a flight mode called “IGN ON” which powers on the ignition. It’s a non-standard flight mode which means the radio gives and alarm if switched on when the ignition switch is on. I have installed a 2800 mAh Robbe Li-Ion battery and updated it to firmware 2.1. It’s a superb radio but sadly it lacks the trim position reset feature and the superior ergonomics of the T8. And I really miss the backlit display, it’s almost impossible to see the screen in poor lighting conditions. It’s always nice to have an excuse to upgrade your radio if something better comes along…

Vingtor Cup 2010

24 pilots came to do battle in the second Norwegian cup contest of the 2010 season. With the unexpected high turnout we could only manage three rounds for all three classes (F3A, Nordic 09 and Sport 07) but we had a great contest with sunny warm weather and a great social event on saturday.

Particularly positive was the fact that we had a lot of debutants this year, in all classes. In Nordic and sport in particular, many were either first timers in contests or had advanced from last year. Former Vingtor boss Audun Thinn has done a great job coaching juniors for many years and his protege Kristoffer Rosmo from Vingtor flew convincingly and came third in Sport.

It was my first ever contest in the F3A class and I came in 13 place (out of 14), barely managing to hold a fellow F3A debutant behind me on the scoreboard but hey – I’m flying F3A in contests! To be able to say that means I have finally reached the goal I set for myself more than 20 years ago. How about that. Fear not though, if you are a rookie, don’t fly at home like I did all those years. Come to a contest to see how it’s done and you could be in F3A in just a couple of years.

Here are pictures from the event and a small video I’ve stitched together.

Integral flies!

Finally! The Integral test flights went well. Although there was a lot of wind today I could tell right away this is an exceptional plane. It’s very responsive and smooth. I had my usual brain seizure while setting it up, programming the exponential the wrong way – I had 40% positive expo so the first flight was kinda squirrely if you know what I mean…

The engine starts very easily and runs reliably. I had two trim flights and then one run through P-11. On the fourth flight the pipe came off – the Nishioka mount had fallen off, leaving the pipe hanging inside the belly pan. I landed OK but I slammed the tail in hard, bending the tail gear. The tail gear needs to be changed anyway, with the very low ZN main gear it proved difficult to get off the ground on a rough surface so I need to find away to lower the tail. Perhaps just a small skid will do it. And a new Nishioka mount.

Integral CDi conversion

The Integral is finally ready. The YS 170 is converted to CDi and as soon as the weather is warmer I will run and tune the engine so it’s ready for the next season of P-11. I’m now using Futaba FASST 2.4 GHz to avoid ignition noise so hopefully I’m immune to radio interference. Ignition is controlled using a Turnigy transmitter operated switch which seems very safe and easy to operate.
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YS 170 CDi conversion

I’m rebuilding the YS 170 in the new Integral with the CDi and low-oil conversion kit. The CDi consists of a new backplate, ignition box, wiring and cable protectors, head and plug. Low oil parts are just the new crank and cam gear, all other parts will be reused. Getting the engine apart was not really that much work, putting it back together is. The crank ring in particular is very delicate.

New plane: Integral

New plane in da house! I’ve bought a brand new, ready built ZN Line Integral. Masterly built and painted by Rune Gjelsnes who is now well on his way to financing the switch to electric F3A. It has a used Ys 170 for power but will be rebuilt with CDi conversion kit before I fly it. It has an anhedral stab and removeable canalizer. More pictures here

Mid-season status update

I have been quiet here on the blog but very actively practicing and tuning models. Here’s a quick update on how me and my planes are doing.

The red Laser (OS 160) is performing extremely well. A better manifold (thank you Just Engines) and shorter pipe lenght has produced more power and it now pulls the 18×10 APC at a steady 8300. The idle RPM is comfortable at 1500 but possible to get down to 1300 (!). That said, I have made a decision to sell it and make the switch to YS fourstrokes entirely, because…

The blue Laser (OS 200 FS) is not performing like I had hoped, reaching only 7500 rpm on an 18×10 and being sluggish in the air. I have decided to sell the engine and swap it for a used YS 160 that a friend of mine sold me. So now that I’m a proud and slightly apprehensive YS owner, having never owned or operated one before I have made another bold move…:

I have made a deal to purchase a ZN line Integral complete with YS 170 from an F3A pilot who’s switching to electrics. The plane is just ready built and complete but not yet flown. Sometimes you just have to jump on a chance to get a professionally built plane like this. I’m hoping to get some flights on it at the end of this season when I get in in a month or so and that it’ll be my new primary model.