Ben-Erik Ness

I have scratch built quite a few indoor models, from large 2m airliners to smaller more traditional models. I buy no less than 10 sub micro servos at the time, since I frequently experience that these servos fail on me... So, what kind of 1,5-2g servos do you prefer in your indoor creations?

Maiden flight video 🙂

After some cg adjustments I had 4 great flights last night! Video to come soon!

I'm slowly getting there... Wings done with servos and retracts. The legs on the undercarriage has to be shorten to give it the right look low on the ground. Still have some work to do, but hope to fly it at our annual Xmas indoor show on the 28th. But first family and Christmas! Happy holidays 🎅🎅🎅

Id like to share some of my experiences with flying really big models indoor... My first and largest airliner, my Boeing 777-200 has a wingspan of 2 meters, and weighs in at approx 585 grams. The big question is: How not to hit the wall??? During my research, differential thrust was essential. And in the video below you can se how it goes when differential thrust is not activated... I use two channels for throttle, and have two mixes with the rudder. When I apply full left rudder, the thrust increases on the right engine with 25% and the left engine reduces it's throttle with 15%. This really get things moving around - but you have to know how to use the rudder!!! So if you are doing a twin indoor - this might be of help to you! Enjoy the video, including the crash into the wall 🤣

I have had several questions regarding if there are formers or longitudinal stringers in the fuselage. There are bulkheads in the fuselage (3mm and 6mm depron), and they are glued in with only a small hole in the middle. When they are in place they are all cut back to a minimum. Bulkheads are in the front just ahead of the cockpit window, then there are half bulkheads where the nose gear is to be glued in. Next bulkhead is just in front of the circular fuselage. just ahead of the wings. This one is strictly not needed, but helps med when the forward part is going to be glued in place. It started with a full "plate" and glued in place. Afterwards it is cut back to only a few mm. The two most important bulkheads are over the wings, to these the two wingboxes are secured. As with the others, these are also cut down to a minimum to save weight. In addition there is one just in front of the horizontal stab, to ensure that the fuse keeps it shape in this area. The added photo is taken from the very rear of the fuse (I need access to install the elevator servos)

Fuselage meets wings for the first time... 291 grams. Slightly on the heavy side, but manageable Next is electronics, servos, flight surfaces, nacelles with motors and retracts...

A little while since last update. However I'm working on it, and as all scratch builders know, there is no instructions, and sometimes it takes time to figure out how to do things. Just installing servo wiring in the wings takes a lot of time Both wings are now sheeted, and the process has been as follows (in case someone wants to know how its done for inspiration) On my first airliner I sheeted the wings with the two depron sheets meeting at the leaning edge. That had to be secured with tape. The result was not as round as I wanted to, but it worked quite well. On my 747-200 i first sheeted the underside from tailing edge to the forward spar. Then I glued the top sheet on the underside and folded it round the leaning edge, over the formers to meet the bottom sheeting at the tailing edge. I was happy with that approach. On the 74 the leaning edge is more or less straight, on the 737-200 it bends just where the engine is mounted. It makes a difference, so I had to come up with another way of getting the same result. The bottom part is done the same way, bun now I sheeted the top of the wing, starting from the tailing edge. I used 3 days to figure out how to do it with the first left wing, scared by the fact that using uhu-por only gives me one chance to get it right. During the weekend I just manned myself up to the task and followed my new plan, and and after some fiddeling the result came out ok. Today I did the last wing, and took some photos in the process - and the whole operation took less than an hour 😁😁😁 Wing weight is approx 70 grams... So the RTF weight target of 400g is within reach. Next step is electronics....

Wing-sceleton is now done, and I just had to let the "wings" meet it's fuselage. I can see that my vision of a 737-200 is coming to life. My target flying weight of 400 grams is still within reach 🙂

Just want to share a video on how I cut my 1mm depron sheets 🙂

My version of the Pratt & Whitney JT8D in 1,2 mm depron... The Emax 1106 4500kv is mounted in a thrust pipe, and with the 5 blade prop I'd delivers 200 grams of thrust on 2S Wings next!

Indoor season is here, and I'm at it again... I have now managed to produce 1mm depron sheets with consistent thickness after have made a feeder system for 3mm depron sheets, that are fed towards a stationary hot wire, resulting in slicing the 3mm sheet into two equal parts. This gives me more or less unlimited quantities of thin depron, very suitable for building indoor planes. This seasons subject is the Boeing 737-200. The building method is a combination of following the scaled up paper-model route combined with traditional built up wing structure. So far the fuselage sections are built, and temporarily taped together - since I need access to the mid section when building the wing connecting system. Adding a few pictures 🙂

Got to fly her again 🙂 Nacelles are in progress, so hopefully in the next video they will be on...

I have been at it again... For the last 16 months I have had this project in my hangar, working on and off. Now all the time, calculations, recalculations, guesstimates and an endless amount of (quality time) hours has paid off. CG was spot on, throws and setup worked great and it flew well too. Not too much power on 4S, but I got off the ground (ice to be more precise) fairly easy and when it was airborne it was as on rails... Enjoy!

The plans are obtainable from www.scale-parkflyer.de - I guess you have to talk to them 🙂

Back in 2010 I was waiting for the Windrider 737 to arrive, and since it took some time I started another build. The McDonnel Douglas MD-83 was based on drawings from scale-parkflyer.de. Back then I got it nearly finished (95%) and then the 737 showed up - and the project has been stored ever since. The 737 is long gone, so it was time to finish the MD-83 project and fly it! Plans where from www.scale-parkflyer.de (now also availible with a precut depron piece set) and the specs are as follows: Wingspan: 1300 mm (51") Fuse length: 1670 mm (65") RTF weight: 1250 grams (39oz) Power: Two55 mm brushless EDFs Here are a cople of shots from the first meeting in the season (yes, it is a frozen lake!) The development within the field of EDF has come a long way over the last 12 years, but I opted for keeping the old fans - and it actually works, not too much power, but enoug to get of the ground (ice) and do well in the air. It need some speed, the wings are not big at all! Enjoy video and pictures! Drone video of the maiden flight: Video of the second flight:

Time for some reflections after yesterdays maiden flight: CG was spot on at 150mm from the leaning edge at root The re-hinging, from bottom to top hinge on the second set of flaps gave me full authority over the aircraft The setup of butterfly for braking up before landing was also spot on. If flew very nicely, no bad habits on the first flight (20 minutes) The second flight had to be abandoned, due to the clevis attached to one of the main flaps snapped loose out of it's rudder horn. In the future I will bring spares. They are easy to replace and I have plenty. making a stronger horn will make repairing much worse and expensive It looks good in the air. Penetrates quite well. Keeps speed quite well too. Next is dummy engine pods with spinners! Looking forward to the next flight for this one

Successful maiden yesterday! Full report later! Full video soon! ??? VID_20210622_204915.mp4

Snow has left us and flying season is here! Decals are on as well ? In order to get the Dash-7 flight ready, I decided to cut lose the mid flaps, remove the lover hinge and top hinge them in stead. This will give both flap movement and better aileron control. CG has been set at 150mm from the leaning edge, and I had to add 850g of ballast in the nose to acheive that... Not too happy with that, but can't blaim anyone else than the designer. She ends up a tad over 5Kg ready to fly - so I will need more than a light brezze to fly her. This weekend I should of course have been at the Grat Orme, and one day this bird just might fly there! Fabolous pictures. Next weekend we have a slope meet coming up, and for the first time I had to check if thefuse fits in the car. I'm a lucky man ? The weather forcast gives us flying wind, bun not too optimistic about maiden, I don't think it will be enough wind at these slopes for this kind of plane. Time will show! Thanks for all input so far!

Thanks for all input on CG. I may have done a major f-up... And it messes with my CG. I have 2 degrees positiv eincidence on the main wing... Why? I because I have that on a powered plane of slightly smaller size, and i flies great. I have consulted a few "experts", both knowlegable modellers and professional glider designers, and they all end up with roughly the same calgulation (incdence calculated into the equation. So my CG ends up at 15omm from the leaning edge at the root. I feel calmed and confident that it will work. As you know nose heavy planes are a pain to fly, a tail heavy plane only flies once... I'm waiting for stickers for livery and windows, and two new servos that I have to change, one of the Futaba 3150 actually burned during a test - without load... My favourite slope where maiden will find place is still covered in snow, and the weather the last tree days has not helped ?

Calculations.... Maybe I shouldn't have started this discussion with myself ?... eCalc says: between 19,7 - 20,6 cm from leaning edge Aircraft Center of Gravity Calculator: 18.8 cm from leaning edge When measuring the root at the wing and listening to my gut feeling i'm more at 16 ish centimeters from the LE at the root. I'm considering various options: Make a chuck glider and see how it flies, maybe find a gentle slope and try the plane somewhere else than the grand big slope... Any input will be appreciated!

Okay, here goes again, and now the map is in sync with the terrain! Thanks to the trained eye of Gary Binnie who spotted my errors! Ben-Erik

I think you read my mind.... ? The "distance to the tip leaning edge is 15cm and the equivalent distace from the tailing edge is 10cm. The corde at the tip is approx 17cm (rounded curve) Again, very well observed! The floor is nice too... Ben-Erik

Very well observed, I think I have to go back and meassure on the wing and not the drawings. I have so many versions of drawings, and I think I might have used the wrong edition here... Back later this afternoon with updated and dependable meassurements.... Ben-Erik

Thanks for your input! There is some washout built into the wing yes, and I will mix ailerons up when landing, like a traditional butterfly setting we use on the 3m F3F gliders. I don't care too much about scale, that's why I don't have any undercarrage ?