Topic: YS

Yoshioka Aladdin update

The wonderfully strange Yoshioka Aladdin 45L that I built in the autumn of 2012 has finally flown, after hanging on my wall for almost three years (That’s what family life can do to ones hobby). The first flight was highly successful. After some trimming, it flew hands off straight and level. The engine, an old but well looked after YS .63 FZ ran rich but did not stop. It has ample power, it’s not a rocket, but it pulls it along with enthusiasm. The sight of the sleek plane with the fourstroke sound was very strange. It looks like a pattern plane and sounds like a scale model.

The Aladdin has a very strange feature, an offset engine installation. It is explained in the poorly translated Japanese instructions that mounting the engine like this does not require any right thrust. It looks very odd, and gives the plane its trademark appearance. See here:
Offset! It’s mounted 90 degrees to the models centreline. The benefit, apart from the obvious fact that the engine and muffler are almost completely buried in the cowling and not hanging out the side, is that right thrust will vary with engine RPM, and this setup will not. I have just the one flight, but I could see no apparent problems in the air, it certainly flew straight enough. Perhaps it really does work? But if so, why haven’t others done the same? Comments?

Here are the build photos.

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

Laser R.I.P

It happened a few weeks ago but I’ve tried not to think to much about it- the Laser crashed and was totally destroyed during practice in rough winds. It was much better but sadly not flown as much as the Red Laser that preceded it. Intended as a backup model I originally fitted it with an O.S 200 FS engine. It was fitted with a pump and Hatori header that was later sold cheap after realising it had none of the power I wanted. I replaced it with a YS 1.60 which I discovered was badly broken before I had a chance to fly it. It then got a used YS 1.70 DZ which performed really well. After changing fuel from one type of Rapicon to another it stopped on takeoff, breaking one undercarriage leg. It took a while to get the leg I wanted from Germany and by the time it got mended, last years flying season was over and I was eagerly looking forward to receiving my new Integral. The Laser was in storage for a full year until my Integral broke and then it came out of hiding, dutifully performing its role as backup model. It flew very nicely and after three trim flights due to a change to 2,4 Ghz it performed well. It was very honest to fly with no bad habits. Although not being able to match the Integral in knife-edge performance it was a very decent F3A model, despite looking like an IMAC half-breed.

There was a lot of wind that fateful day. I don’t really mind wind as long as it blows straight down the field but this was the kind of day when your model must be bolted to the grass in order to not fly away on its own, the kind of windy day only an idiot flies. I was that idiot. After the second round of P11 I was about to turn onto base leg for landing, and with a tailwind best described as a tornado, the idiot move I made was to retard the throttle and pull a little elevator to turn. It stalled, simply flicked forward and was blown nose-first into the dirt in the blink of an eye.

Crash pictures

Video (With OS 200)

“There he goes. A high-powered mutant of some kind never even considered for mass production. Too weird to live, and too rare to die.”
– From Fear and Loathing in Las Vegas

Engines part four: Why won’t it run?

Everytime I go to the field someone has a “faulty” engine – one that won’t start, or that dies in flight or on takeoff for some reason. Or at least they think they do. Fact is, it’s hardly ever the engine. People say the wildest things: “The whole setup is gone” (meaning cylinder and piston) “the bearings are busted”, “this damned engine is just crap”, “I heard [any brand engine]s are just crap”, “the engine was full of metal shavings when I opened it up for inspection” yada yada yada…

Hear this:

  • 8 times out of 10 it’s the fuel. Too much, too little or just not the right kind
  • 1 time out of 10 it’s the plug. (Which means it’s not an O.S. plug, or it’s a very old and worn O.S. plug)
  • 1 time out of 10 it’s the pilot (That would be you)

That’s 10 out of 10. My guess is, about 1 time in a hundred, something in the engine itself might actually be broken. In 20+ years of glow engine flying, that’s happened to me just once.
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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.

Top Star 110 video

Laser with YS 170

Although it happened a little while ago now, here’s the status on the blue Laser. It’s been fitted with a used YS 170DZ/Hatori combo and thanks to my buddy Audun it ran very smooth. I had three great flights at Auduns field and I was very pleasantly surprised to experience the immense braking effect on downlines with such a powerful engine. Fuel consumption… not so impressed :-) I have enough for a schedule but no more so I need to be careful. I’m very happy with the choice to standardize on YS engines. That’s Auduns Oxalys in the picture, the plane used to belong to Ola Fremming. Audun was unfortunate and broke his belly pan during a forced landing. Pictures here

YS 160 damage

The YS 160 engine failed to run properly so we opened it up. The valve lifter was stuck, _really_ stuck and we found metal shavings had jammed the pump piston. We tried to fix it but never got so far as to test it, when we saw the busted conrod we thought all was lost. Read More »

YS for OS: Laser engine change

DSC00020The blue Laser has got a new engine, a YS 160. The Hatori 828 pipe has a much larger opening so the YS header does not fit. I fixed that with a silicone tube over the header which gave a very tight fit. The engine mount is new (Hyde mount from Central Hobbies) and I have redone the cowling fasteners which turned out lighter and easier to remove.

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.