Willy Nillie's Shoestring micro racer powered by COX TeeDee010

Good work Andras

4.52 oz without the receiver? What size battery is in there?
Do you recall the empty weight of the built up frame?

Well done and enjoy your trip!

Cool project Andras!!!….. The clear finish is unique….Looks like a great match for the .010….Good luck with first flights!!!…. Looking forward to your report  

Thank you guys.

Brad the 128g is all up dry weight. I have a 1cell 370mAh Lipo battery and small step-up electronics set at 5V output voltage, and a Zepsus magnetic switch brazed to it, the total weight of the three is 20 grams. I decided to omit mechanical switch to save weight and room.

Engine 13 grams. Balloon tank 4 grams, 2 nano servos (elevator and ailerons)  4 grams each. The body of the empty plane  weighs 77 grams. Futaba Receiver - temporary- 6 grams. I saw a smaller one at Lindinger Austria that I will buy next week to save room inside plane. I will tank 15 ccm 50/30/20 all-castor fuel for a near 8min flight. The engine has never seen fuel, I will break it in before the maiden flight, maybe tomorrow.

All Natural Cool Andras! Safe travels.. catch you on the "flip-flop"

Andras you are very good to keep models lightweight, a kind of engineering

Very Nice Andres , I like the clear coat and nice decals , Look forward to the median report .

Thanks Eric, my attempt on a maiden failed because the sealing between the backplate and crankcase of this brand new old stock 010 was not tight..the mounting face of the crankcase is not fully plain, its corners where the backplate bolts are protrude a bit...strange, I have never met it before. I was thinking of sanding it plain but simply could not force myself to butcher the gold anodized case of this lil gem... instead  I cut a thin ring from a clear silicone tube whose diameter is a tad smaller than the backplate center that sinks into the crankcase, and after pulling the ring on this center part then slightly spanning the crankcase bolts the sealing is now perfect.

Levent Suberk wrote:Andras you are very good to keep models lightweight, a kind of engineering

Thank you Levent, I am only following the efforts of others like Robert and Brad...this model is advertised by Doug Hart  the owner if WilliNillies as weighing  around 150 grams, so my 128 grams is not bad, thanks to the lightweight battery and electronics that I brazed together..that Zepsus magnetic switch  https://www.mg-modellbau.de/main.php?desc=&anr=ZMS7A&action=articledetail&gid=&action3=setspeech&speech=2 is a real light piece of component, and all it takes is just swiping a strong magnet along the fuselage section behind which it hides, and it toggles on and off with every swipe. Mechanical switch is no longer needed.

Andras, I looked at Willy Nillies site and saw your Shoestring is advertised with a wing area of 70 sq in…. At 128 grams gives it a wing load of 1.82 g per sq in …. Just for comparison it’s right in between a couple of mine … Pageboy is 1.74 g-sq in…. Ace Littlest Stick is 1.93 g-sq in…..Power off glide is quick but manageable in this range

Thank you, Robert, compared to the few 010 powered planes I have built and flown (Roaring20, Pageboy, Sharkface, my own design Lil SpeeDee) I find the Shoestring really light. I hand launched it without the engine running just to make sure its initial visual trimming not to be surprising during the maiden flight, and I found it really glides well. Hope it will behave the same tame way during the maiden flight.

Sharp looking!

TD.010 Shoestring 150 maiden


@5 mins. in on the vid shows the Shoestring TD .010 flying




 

Thank you, Brad, that TeeDee010 in the video ran way below the sweetspot 27k rpm (I audiotached 22k-ish while in the air), so with the proper engine setting at 27k loaded, and >27k unloaded speed in the air, I expect a faster flight than what the pilot reached there.

roddie wrote:All Natural Cool Andras! Safe travels.. catch you on the "flip-flop"  

Thanks, Roddie,

were it not for my daughter, I would probably avoid driving to Benelux states...the company I still work for part time resides in Belgium, and the climate and cuisine of these countries are not that attractive, so except for their touristic sites like Amsterdam in the Netherlands, , they are not in the frontline of my favored destinations.

Andras, you sent me to Wikipedia. Doesn't happen very often.

The Benelux Union (Dutch: Benelux Unie; French: Union Benelux; Luxembourgish: Benelux-Unioun) or Benelux is a politico-economic union and formal international intergovernmental cooperation of three neighbouring states in Western Europe: Belgium, the Netherlands, and Luxembourg

BTW. I missed this thread. Beautiful job, and the clear finish.........beautiful and unique.

Bob

Thank you Bob,

yes, since the expansion of EU the Benelux countries as a collective name is used less and less frequently. I have never been to Luxemburg, but visited many times Belgium and the Netherlands - the former mainly on business, the latter on touristic and family reunion occasions -, some might find my rudimentary assessment  next to a blasphemy, but these 2 countries are geographically and meteorologically similar,  all the same, not too attractive to me, and the local food -except for the foreign cuisine - is good not for culinary pleasure but for a forced weight loss diet...just for curiosity, spent a few days in Japan on business in December last year, then April and May recently, and I had to eat more raw fish and seaweed than the shipwreck Tom Hanks in the film Outcast....the older I get, the more I am focused on my vegetative life than on the intellectual observation of foreign countries...(the US still remains one of my favourit culinary and touristic destinations   )

And thanks for your note on the Shoestring, I need to skip the maiden flight to sometime next week, but will report back on my experience.

Cribbs74 wrote:Sharp looking!

Thanks, Ron,I trust it will live up to its looks when flying!

Engine tuned, Prop tweaks, Hot fuel should really make it sing Andras…. Looking forward to your results

super super cool!

Wow, quite a featherweight! Well built model, getting 22g off the advertised weight is a lot in that weight class. That’s about 15% or so.

The problem with the back of the crankcase is strange, well spotted. The bulges are probably remnants of he thread making process. You probably know this already, but in many large-scale serial production systems, threads are not made by cutting, but with a tool that forces the shape in the material, especially when aluminium is used. The tool sort of displaces the material, instead of cutting. That can cause the surface to bulge around the hole. Just speculation, I don’t know how the threads were actually made.

I seem to remember that in Paul Gibeault’s Mouse engine prep instructions it was mentioned that the back of the crankcase should be checked for flatness, and lightly lapped on an oiled 1000grit paper if not completely flat. Or it could be one of our resident speed engine gurus that gave this tip. It wouldn’t hurt your engine, you would merely finish what was left unfinished by the factory

Beautiful model András!...congratulations!
Is the wing fixed - glued? Or is it attached somehow to the fuselage?

Thanks, Kari. I think the.lightweight electronics I packed combined with the COX TeeDee010 helped reduce the design weight substantially.

I worked in aviation in my prime as a young engineer and learnt that the thread of bolts in the wing and fuselage of airplanes is extruded instead if cut/tapped, in order to avoid micro-crevises in the material, leading to fatigue breaks. But the threads of our COX engines were most likely cut and tapped. The very light and thin wall of the 010 TeeDee crankcase may have got distorted under the stress of thread tapping, leading to the uneven, jutting out face near the bolt area. I remember reading the tip about sanding the face plain..I simply did not feel like butchering the nice gold anodized surface of this tiny jewel and, managed to restore sealing in a non-destructive way. 40-50 years ago, and in places when and where hobbyshops sold abundance of COX engines, such a home surgery would have been a common practice..