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

The 2011 championships are over, and Christophe once again came out on top, with Onda as close as possible behind him (the semi-final scores settled it, as they won two final rounds each) and Andrew Jesky in third place. Ola Fremming, our top man became 21th, and Alex Heindel in 31th place. Also on the Norwegian team was Henning Jorkjend who took this picture, but could not fly because his plane was damaged by fire in the opening round.

The project really started in 1993, when I crashed my original Tiger 2, built from a Goldberg kit. I really liked the plane, so I kept the drawings all these years. In 2004 I came across a canopy in a hobby store in Bangkok (!) and after we moved to a new house last fall, the canopy appeared, irresistable. I found the plans, did a quick sorting through of all the odd bits and pieces that were stashed away and found out I had about 90% of all the hardware I would need to complete it. So I started, not knowing what lay ahead!

I had most of the wood I needed lying around, and as a result the structure was heavily modified to suit the sizes of wood available to me. For example, the ailerons are a built up, sheeted construction. They weighed 11 grams each before covering. It’s 99% balsa, and I aimed to keep weight down as I built. The finished plane weighed in at 1900 grams ready to fly! It turned out nose heavy, so I replaced the LiPo RX battery I planned on using with a heavy 5-cell NiCd, and that sorted things out. It weighs 2 kgs dry with that battery. The plane doesn’t seem to mind, and vertical performance is really something.

The Tiger was 95% finished before christmas 2010, but in early 2011 I started building the Xigris in order to get that ready to fly in the 2011 season so the Tiger was put on hold. It was intended as a winter plane, so I thought it could wait until next winter. Then I got the urge again, and a couple of days of assembly was all that was required to make it airworthy.

When it flew today it was utterly un-spectacular, it just did it’s thing like it was supposed to, it obviously needed some trim and the engine isn’t performing 100% yet, but it felt great to chuck this thing about the sky. It almost makes me want to build one more, with a .72 O.S FS-a. Maybe in another 20 years?

Pictures from the project are here.

I’ve experimented with Beli-Zell before, using a file to roughen the surface area of the hinges so that the Beli-Zell glue would adhere better. I used normal Beli-Zell, the green tube which is an expanding polyurethane glue. A lot of hingepins got glued stuck, but no hinges came off. Semi-successful at best.

Two types of Beli-Zell: The white one is perfect as a hinge glue

This time I’ve tested both the green (clear/yellow glue) and the orange (white glue) tube. The Beli-Zell white (20 min) tube is simply something completely different. Using Du-Bro pinned hinges, I glued one with each type of Beli-Zell to a balsa trailing edge. The next day, I tried to remove them. I was able to, using great force, to pull the clear Beli-Zell hinge out. Looking at the hinge, I saw the glue had only partially adhered to the surface. White Beli-Zell was another story. It was stuck, and no amount of force would remove it. I cut away the wood to inspect the hinge, only to find that it was totally merged with the wood. A blob of glue from each tube confirmed that the white Beli-Zell is in fact more elastic, In the picture, the white blob is still slightly rubbery, while the clear glue is stiff and brittle. And best of all – the white Beli-Zell does not expand into the hinge pin. It’s just a a tiny bit to thick, so it doesn’t come in contact with the pin at all. What’s more, the tip of the glue tube fits the hinge slot – two licks of glue in the slot, push the hinge in, and wait for it to set – done! No mess, and no working with old knife blades and epoxy. I just hinged the entire Xigris this way using white Beli-Zell, and it was all done in one evening. I’m never going back.

The plane weighs 4930 grams ready to fly without wheel pants. I left them off because my axles didn’t fit, but they will be added this weekend when the new axles as ready. I plan to add a carbon spinner and prop to save weight and move the CG a tad back, as it was a tiny bit nose heavy. The only mix I’m likely to need will be a little bit of down trim when diving, and one wing needs to be lowered slightly using the wing adjuster.

I’m very happy with it!

More: Maiden flight pictures, Build pictures, and background/details on the project

- Wings are almost done, just final sanding around the root now that the root ribs are installed. Covering is next.
- One central bolt will hold the wing, with the incidence adjuster as anti-rotation pin in the back and one pin in front.
- The kit comes together very smartly, part fit is excellent and apart from the wing root ribs I’ll end up using all of the included parts.

Here’s the gallery with all pictures to date:
http://www.flickr.com/photos/aerowold/sets/72157626024138550/

Equipment:
- Plettenberg Evo
- Kontronik Jive 100 HV
- Futaba FASST
- 9650 x 2 in stab
- 9154 x 2 ailerons
- BLS154 rudder

Follow the build here

I built and flew a Tiger 2 in 1994-1995 and I’ve always felt I had no closure with it, since it was shot down by an idiot heli-pilot on the same frequency while I was still getting to know the plane. No parts remain from the original but over the years I’ve kept the plans and collected bits and pieces. When I found a canopy in a Bangkok hobbystore 7 years ago the collection of parts was complete and I really had no more excuses not to build it again. And NOW, a mere 7 years after that I’ve actually started. It’s not hurry after all… An O.S. .55 AX will power the 2011-edition and it’ll use some bargain Hitec mini servos and leftover scraps that have collected in my parts drawer for years. UPDATE: Link to build pictures on Flickr

I’ve always had a soft spot for formula 1, and the 1970-80s brand cars in particular. Cigarettes and oil brands dominated in those days and are beautifully retro to look at now more than 30 years on. You remember Tyrell, Elf, Marlboro, Rothmans and the incredible all-black and gold striped John Player Special cars don’t you?

In honor of the early 1980s liveries that have stuck in my head since childhood I’ve decided to make a very special paint job for the Xigris. I’ve tried to emulate the look of the 1982 season Ligier Gitanes look. Gitanes is a French sigarette brand, quite appropriate for the French made and French-sounding Xigris, don’t you think? At least it will be quite original and eye catching. (The 3-view is not of a Xigris, but it’s close enough)