Electric Schwing Development

Schwing electric is sleek but not made for just E soaring! 

Milling on the Schwing electric is about to start but I just couldn’t help sharing the development that’s gone into this project so far.

The electric fuse will be fully interchangeable with the glider version which meant quite a design challenge to keep within the wing root spacing and still have a decent power set up.

In the end we managed up to 6s capability using 28mm diameter motors. So this will cover 500w with a 28mm outrunner on 3s or up to around 2.5kw on 6s!

Design specification was for up to 6s! Here we configure 3 x 3s packs to check the spacings. 

Following on from power train tests we have been doing for F3B electric we’ve been looking into the motors too using a geared 28mm diameter in runner to give high efficiency up to around 1.3kw and lower. They are 64mm long and a bit bigger than most geared motors you can find. These will run with more power and cooler. It’s just simple physics, the bigger the motor the bigger the magnets and the bigger the stators and more efficiently it will run at the same power level. One of these with the right KV, gearbox and prop will give bursts well over 2kw on 6s, which should be quite an outrageous hotliner with the sleek, clean Schwing airframe!  

Cone design with integral battery tray 

Fuse has air exits moulded in  

Skinny electric gliders can now run efficiently on 800w+ on 3s ,4s, 5s and 6s using 16-17’’ props using 28mm diameter motors. Of course you can get to these power levels with shorter motors but you’ll find the power out is much less and you’ll find they get hot very quickly!      

Bigger makes all the difference- stock Hacker geared B40L, 58mm long motor and our test with a 64mm long can using a Reisenauer gear box

Prototypes to be made at the Sloperacer workshops and just can't wait to fly one of these! 

Schwing pictures

We have at long last completely up date the Schwing section main site. Here are some extra pictures of the Schwing. Many thanks to Pierre Rondel for some of his wonderful shots included in this collection.

New Air One Electric Video

Airone-14102012 from Jonathan Wells on Vimeo.

This is from the week end too. Very little wind despite the noise from the camera, actually 5-8mph slightly crossed.
It's just amazing what a 1kw can do. Look out for the rolling loop!

No wind!

E gliders have their place but with a distinct lack of any wind and still you need that slope fix we have been playing with our go to light wind machine.

Point nose down and keep a fair speed on

3.5m, light and fast enough to be entertaining but thermals away given any sniff of bouyant air.

Here's some pictures from the weekends flying using the Vulture F3J on the slope. Purists will be heartened we didn't stick an electric fuse on but pitted against nature making use of light lift and thermals. We did plenty of that too but sometimes as a slope nut you just need the right machine and flying can resume. Of course this makes a great UK style F3J/F5J machine for the flat and many competition flyers do just that but for sports flying on the slope it can be kept moving and just seems to find lift a lot easier than an F3F/B type 3m. A different type of flying but sometimes it's all you need. A bonus is that there's no foamies to get in the way but just watch out for the slower built up thermal soarers hanging in your path!

Hurricane maiden

Since all the modifications were done it’s been an age when conditions and opportunity have coincided to test this new model. During which time I even threw on a bit of paint to help visibility on this prototype ‘white ghost’(all our prototypes are just moulded white for simplicity).

Massive joiner from the Schwing and of course massive spars to go with it!

Maiden flight in westerlies 10mph gusting to 25mph

Stuff of dreams straight out, no drama!

Here probably see one of the mods clearly, it has an extended nose to make radio install a bit less of a squeeze.

It tracks like the proverbial rails! 

Muggy day and glad I splashed on some paint.

Doddle to land with big throws on the brakes

Young Jonathan Wells flew the maiden, yes he did rolling loops!

Can't deny it I was very happy indeed!

Well we had our chance last weekend and weighing in at 1.8kg + 3 slugs of ballast (approx another 250g) it was flung off a local westerly slope in good to moderate conditions with wind speed varying between 10-25mph. The all moving tail had been set to 0-0 with the wing using an incidence meter and proved just perfect. It was twitchy in the roll though, way too much aileron and some expo dialed in during flight. Jonathan Wells, local kid supremo, did the first flight. A few fast passes and soon it was rolling circles and even rolling loops!! CG at 98mm was just about spot on. Dives from height pointing straight down with rolls on the decent and inverted fast passes and it was a struggle to get the Hurricane back off him! The tracking and smoothness of the flight is the first impression. It really grooves but eventually it was wrenched back and I flew it for the most part for the rest of the day. A session practicing EM style turns just catching the turn with a bit of rudder to fly through the exit and it became seriously entertaining. The tranny was passed round and whether it was the super stiffer wing with outsized joiner or not it certainly was a maiden that could not have been any better. It’s a very precise machine and it’s roll rate can be a blink of an eye. For a first mouldy it can be tamed to just carve beautiful shapes in the air. The tracking a joy to watch. Set up as it was it was incredibly acrobatic and a bit too much for one of the older pilots! But hey it’s easy to reduce besides rolling loops are really not in most planes repertoire and this one did it again and again! The prototype as you might expect is a bit on the heavy side but the improved strength and structural changes will be carried through. There doesn’t seem to be anything else we can tinker with.   

I think we are ready to go to production on this!!!   

Weekend of test flying!

We had a busy weekend of playing, I mean working!!- We test flew two planes; the New Air One Electric under power and the prototype of the Hurricane, our new 2m sports plane. More about this one later.

First the electric powered New Air One. This project was specifically aimed at F3B electric which as a quick recap meant it needs to be a slippery largish 3m airframe and light for duration but enough power in the electric set up to haul up 4kg + when fully ballasted. The original motor, Hacker FAI was taken out and replaced with a Hacker B50 12s geared running a 16x13 but still with a Castle Creations 100 lite and 4s TP 1800mah 65c. This saved 50g but reduced the static power to around 1.2kw. AUW is now 2.45kg without ballast. Current thinking is that around 700w is the minimum required but will require a longer motor run. I wanted a fast climb and short motor runs to allow smaller lighter lipos and besides it’s more fun this way! The numbers look good with the new set up, the original 1.7kw+ set up was a bit too close for comfort for the esc and lipos especially as I wanted to use a Ubec to power the radio gear saving the weight of a separate RX battery: static tests now showed 93a.

Remotored with B50 12s geared running 16x13 with CC100 lite and 2+2s TP 65c 1800mah

The first reflight was on the slope. Power on and it went scolding away with a short speed up whilst the delayed start up kicked in and the motor and prop began to bite. The thrust line was set up with 3.5 degrees down thrust which meant it didn’t automatically climb on power. A small dab of up and after only a few seconds it was very high above the slope. Power off and the brake worked a treat with props folding back immediately. Of course with all that height it was pointed down and screamed across the slope with some F3F practice pulling some very high speed turns- what a laugh!

To be fair the conditions were good and needed ballast so the New Air One was light but the power was nonetheless impressive.

Later we down loaded the logged data and saw around 1.1kw dropping to 1kw after a few climbs. Current at this power was around the 80a+. Not silly but very safe for all the components.

The next day with very little wind we tested the New Air One on the flat. The conditions were thermic and variable wind directions but predominately from the S/E. A straight throw and power on after release saw the plane speed up and with a dab of up point 70-80 degrees. It needed less than 5s to get to 250-300m and power off saw the New Air One continue on it’s trajectory gaining even more height. Vertical climbs are effortless and the longest logged power run was just over 6s. The high pitch prop gives good speed so much that we did one power run at around 20 degrees and pulled to vertical at the end after power was off gaining nearly as much height as all the other climbs! At over 200w per lb- it’s definitely hotliner territory! It makes me think about my other hotliners of the past which had more power but considerably more weight too, perhaps they did climb faster but this is no slouch and obviously a very efficient use of power for such short motor runs being required. It doesn't make that contorted bark of cavitating props though! It just pulls without fuss and very little noise. Of course a loud prop isn't efficient but it does sound great and very scary! Thing is though doubling the power doesn't give double the performance when dealing at these levels. Which isn't the case at lower power levels say 500w to 1000w as the difference is huge but 1kw to 2kw is much less than you might think and even less from 2kw to 4kw.
1kw for this plane as we have found is very nice indeed.

The New Air One Electric felt very buoyant and cruise speed could be slowed down due no doubt to it’s low weight. It was thermalled away several times and even once when coming in for a landing when it hit a bit of low level active air- very satisfying! We drained 3 packs with about 20 climb outs but cautiously only using about 500mah per pack. There is definitely an opportunity to reduce the pack size to 1300mah saving another 50g or so. For F3B Electric you only need one climb, may be 2 per flight if a relaunch is necessary so 10-15s motor run time is ample, with 1800mah there is 60s available if you dare consume 1500mah, leaving 300mah for the radio.  

All in a very promising model and set up. As a do everything 3m electric sports model if your thing is the gliding and not tearing around under power then it’s pretty much optimized for about 10 climb outs per flight. Top up climbs when already up will get you more. Then you can tear around gliding and have quite a thrilling time doing it!

Now 2.45kg, approx 200w+ per lb in old money! That's real hotliner territory. 

We’ll have to see what it can do in F3B but what we can say definitely is that it makes a good practice model without the fuss of a winch to haul around.

New Air One Electric maiden

Well today was one of immense satisfaction! The New Air One  Electric was maidened. Surprisingly a large number of us ignored the rain forecast and and gathered at a local easterly slope, Harrop Edge between Leeds and Manchester.

The foamy brigade respectfully gave way to us to launch  the New Air One Electric with 1/2kg of ballast (AUW 3kg) in 20mph winds for the first flight flown by Jonathan Wells. Pretty much from the off it was put into F3F racing style turns with 3/4 circuit rolling circles, well he was nervous not being his plane! What was surprising was the energy retention in the glide and you'd be hard pressed to say the folded prop made much difference in slowing it down. It really is a slippery conversion. At 3kg it felt very bouyant and Jonathan said it could have taken a lot more. There is provision in the wing and joiner for a further 1kg! The CG was a little forward but it looked very quick and more importantly it didn't bleed the speed which was what I was looking for.

There was no real need for the power train, the objective was to trim the plane. That will be another day but a quick spurt of power caused the motor to cut out after a few seconds. The ESC set up still had the current limiter engaged as a precaution so I guess we'll try again with that off and disable the Ubec and run the radio gear with a small lipo. MKS servos can now use tiny individual Sbecs to regulate input voltage which will allow use of a 2s lipo. The power set up is a bit more than I had planned and bench tests showed 1.75kw at 128a. For F3B electric I was aiming for 1kw which we'll fine tune later but for now, it will be fun to see what  it's like at this power and that will be for the next time now we have a trimmed out airframe.

Updated classic by Brian James (AKA Yellow Blue). Bagged foam core wings using PU glue and glass fibre 1/64 laminating sheet with co ordinates provide by Dr James Hammond using the Schwing section.

So all in all big grins from me and yes I flew too today, 2nd flight with my new Vampire F3F. Even more so to catch up with local fliers and one in particular, Brian James- He maidened a 'new' plane too. Its says Ridge Racer on it and older readers will remember this slope nut classic, only Brian got foam cores CNC hotwired using the Schwing section and bagged his own set of wings. Now at this size and bigger fuse it brings the design bang up todate. Looks like a prototype for the type of slope model we should bring into our range...Hmm!