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Archive for May, 2016
Posted by KristofferR | May 31, 2016 @ 05:02 AM | 5,972 Views
The weather continues to be hopeless; at least from a RC flying point of view. Otherwise it's an awesome 28 deg but the strong NE wind is not matched by any slope. In my last blog post I tried the cliff of a nearby island but this time I went to the trusted Sandsjöbacka slope, knowing that the skewed wind meant slope lift would be almost absent but the sun and wind might make great thermals.

It worked; I floated around reasonably well and had to use the motor a few times but the I rode a thermal higher and higher until it was too high and too easy and dove out, did three, the first quite wing-bending, loops and generally enjoyed myself. I tried the same bubble again but managed to find only sink and minor bumps. In the end, five motor runs of about 7-8 seconds each resulted in over 40 minutes of flying.

Endnote: I've been considering a "proper" model as I gradually get more proficient when it comes to rough slope landing but this time I misjudged the landing spot by three meters short (well last time I overshot, check the video from my last post) and ended in the burned heather which turned out much more evil than it appeared; so bumps and scratches as well as black "crayon marks" everywhere. Well well....
Posted by KristofferR | May 25, 2016 @ 10:27 AM | 6,027 Views
Spontaneous slope visit: The wind was strong but from the "worst" direction when it comes to sloping, northeast. I had already planned a walk/hike and brought the glider as this cliff looked promising. The actual slope is narrow and too round to be really good and the steep drop to the sea on both sides means electric is a almost a necessity or a mistake will cost a plane. The gull company, a (possible) marsh harrier and two good thermal lifts made my day though! The landing is not fun though and I doubt I will try the site again.

Phoenix 1600 slope soaring Amundön (3 min 29 sec)


Spec: HK Phoenix 1600 ARF (lanyu, volantex, modster) with 2mm incidence change on stab.
Motor: HK Turnigy 2830 1020kV 3mm (overstressed with prop)
Prop: Stock, folding 10x6
ESC: Jeti ECO 25 with HK 3,5mm bullet connectors
Battery: Multiplex Li-Batt 3s 2000
Servos: Four HXT900 (Rud Ele Ail Ail /Spoilers) no flaps installed)
TX RX: Multiplex Cockpit RX-5 light

Location: Amundön, Gothenburg, Sweden
Flying, camera, editing, production, music: Kristoffer
Song Titles: Edge of the Sea, Drone Charge
https://open.spotify.com/artist/3bBEDJhsg6Lbtpv3b6V0CK
Posted by KristofferR | May 24, 2016 @ 09:27 AM | 4,803 Views
The wind and calendar has not matched for slope flying. I shouldered the glider bag and walked off to the nearby soccer field to try some thermalling. During the last weeks I watched a lot of youtube and googled up threads on thermal soaring to learn. I put the 950mAh up front to lighten the plane and was eager to test my new knowledge.

During my approach (on foot) I watched flags & birds and tried to imagine where the lift would be. After launch, I set upon an upwind search pattern. The day was very warm and evening thunderstorms were predicted; it should be good. Huge clouds were forming inland already.

I soon saw the characteristic "jump" of a lift zone and tried to dial the "cylinder". A bit later the plane almost flipped over. I kept up a lot longer than usual before but did not really nail the circling. Good!

I kept on searching the whole area, upwind and downwind and I noticed that birds immediately showed up where I got lift. Not watching me but probably insects. I observed flags, birds, sounds, clouds and the wind passing by.

I've read that some people let the plane fly itself and use the trim buttons to circle while others go hard bank in the turn. Some say you need to be patient and avoid sink. Both things worked well and both things also went wrong. The very cautious approach did work but the half-cautious was quite useless. After a while I decided to be more aggressive - or rather try to turn like I do on the slope, tight...Continue Reading
Posted by KristofferR | May 23, 2016 @ 01:05 PM | 3,908 Views
The Teton keeps rolling on. So far, it has been utterly reliable despite relentless bashing.

A >2m (~7ft) landing to flat tarmac due to a missed jump in the skate park broke a suspension arm and the brushed motor stopped working twice; once because it was flooded with muddy water and once some gravel got inside and it got stuck. The ESC has a built in protection and flashed red to indicate a fault.

It was easy and intuitive to replace the suspension arm and remove the motor to get the gravel out. I used a straw to blow and very gently rotated the motor axis until it ran free.

Once we accidentally reprogrammed the ESC from NiMH to LiPo which stopped the car early. Typically, the two 1200 & 1500mAh NiMH provide about 40-45 minutes of runtime which has always been "enough".

Here is a clip from last outing. Driving by my daughter, filming and music by me.

LaTrax Teton "playground and woods" (1 min 44 sec)

Posted by KristofferR | May 20, 2016 @ 03:55 AM | 4,594 Views
When trimming the Phoenix 1600 I moved the battery back and forth. It is secured by a velcro band but as I went outside the designated slot for the band and therefore stuck some velcro on the wooden battery support.

As usual, the stick-on velcro grip, from Multiplex "Model Service Box" was stronger than the adhesive so I used some CA glue to fix it. Then after a dozen battery removals I first pulled out a screw and then the wood broke ...! The velcro is just too strong. The quality and workmanship of the Phoenix is perhaps not all the way but for €42 it's very hard to complain and for the record, I went outside the design specification!

I removed the wooden tray, weighed it at 15g, considered removing it completely but ended up repairing it, smearing white wooden glue on it to prevent cracks, putting the screws in properly and to, my wifes amusement, sewing and CA:ing a velcro band from IKEA. No beauty points for that solution and I kind of rushed it but it turned out very functional.
Posted by KristofferR | May 19, 2016 @ 12:15 PM | 4,980 Views
A few days ago, about a year after building the Magnum, I got around to finish the carbon supports for the floppy fin. Took all of ten minutes. Just stuck them into the EPP with mix of CA and UHU Por to secure a good fit. It did help quite a bit, a more distinct rudder response and visible improvement in the air how the rudder moves quickly and crisply (well that last thing is relative).

The three packs I use now are two 2s 500-ish and a 3s 500-ish and while the 3s lets me hotrod vertical and long for the aileron acro wing, the Magnum and I like it best crawling along with the 2s on 1/3 throttle. The evening sun even provided a little thermal action, enough to "park" the plane in the air for a few minutes.

The Magnum is perfect for a short evening flight, it cruises around slowly and with the Hacker motor and the ESC inside it is very silent too and doesn't disturb the neighbors.
Posted by KristofferR | May 11, 2016 @ 06:31 AM | 3,236 Views
Today the forecast said northeast to eastern wind and strength starting at 5-7 m/s. Flags were flying so I took a chance at Sandsjöbacka. After launching the wind felt weak and there was almost no lift at the leftmost "bend" of the slope.

I had no luck with thermals either - the wind was constant - and after 20 minutes of more sink than glide and just getting one very small thermal I gave up and landed and walked to try a different spot but by then the wind turned more towards northeast.

Phoenix 1600 slope soaring in low lift (2 min 50 sec)


Still: Awesome nature, nice hike, the Phoenix performed well, I landed with control, and I got to try out my Turnigy glider backpack (more to come on that in a future post).
Posted by KristofferR | May 09, 2016 @ 03:02 PM | 4,121 Views
I felt there was more performance in the Phoenix 1600. After testing CG I decided to shim the front side of the stab to change the incidence. Turned a good plane into a great one.

Phoenix 1600, trimming flight part 2 (5 min 40 sec)

Posted by KristofferR | May 08, 2016 @ 02:07 AM | 4,161 Views
The weather has changed into summer. It's nice to fly without gloves again. Here is some video from a few flights with the Phoenix 1600 as I was testing different CG and batteries as well as looking for lift - thermalling is not in the video though because the plane becomes too small in the finished video.

Phoenix 1600 trimming flights (3 min 10 sec)

Posted by KristofferR | May 06, 2016 @ 10:51 AM | 4,916 Views
I was not completely happy with the tuning of my Phoenix on the slope. I had the CG at the recommended 65mm - as marked in the foam. I had pushed the battery back in increments but sort of felt that it was "too much" and questioned myself. Today I had great weather and decided to try it properly and risk running rear-heavy; something I don't want to do on the slope! Instead of a 2000mAh I put a 950mAh battery upfront. Well that was good. It flew like I wanted it to, became floaty and indicated lift really well. I had a bit of luck but I picked the first thermal less than a minute after launching. It also became a bit more lively.

The AUW ended at exactly 1000g with the lighter battery instead of 1065g. I then put the 2000mAh in as my previous "standard" and then as far back as it would go (there is space but I ran out of velcro reach) and also ran the 950 again to match that so I could compare same CG with different weights.

Back at home I measured my CG to 77-78mm from the leading edge. With this setting it curves just slightly up in the dive test. So now I added more velcro to the battery tray to permit the 2000mAh to go further back and the 950mAh to sit more secure up front.

The smaller LiPo is my definite choice for thermalling, those 65g makes a noticeable difference.

Dive test: http://www.charlesriverrc.org/articl...ee/cg_trim.pdf
Posted by KristofferR | May 04, 2016 @ 11:21 AM | 3,570 Views
Todays visit at the slope was the first with the Phoenix. There was lift but the wind direction was off and so was the wind strength. Still, I got to fly the Phoenix at eye level and enjoy watching it and it flew absolutely great. I tried my smoothest turns and tried hard but gravity beat lift and all left to do was to kick the power on and see it blast up against a gorgeous sea backdrop. Landing did not yield any beauty points but bringing a model home without a scratch is an achievement on these slopes. My fb Dan let his non-motor gliders rest and we talked about planes, music and life. Animals spotted included a deer, a pair of foxes and a pair of grass snakes (Natrix).
Posted by KristofferR | May 01, 2016 @ 05:57 AM | 5,182 Views
Today I had superb weather; 10 deg C, almost clear skies and 2-3 m/s winds.

A friend of mine competes with sailboats and that is one competitive sport. He once showed me how he taped every mount and wire fitting on his boat to decrease drag. I sanded and taped over everything on my Phoenix 1600 and was excited to see any difference. I know it's just a foamie but why not ....

I went through my checklist and all was good except after launching I realized the ESCbrake was off so that's a new thing to add. I landed as tail-down as I could with a spinning prop and moved the jumper to the right spot.

The followed thermal searching. I'm not very experienced or good at thermalling but I've gotten a taste for it and want to be good. A 1kg heavy 1,6 m glider is hardly the recipe for a good thermal ship but it's quite fast so I zapped around, trying to be super smooth and pay attention to wind, clouds and flags. After about 20 minutes and 5-6 motor ascents I felt the wind die out and was in the right place, found a good updraft. I did not manage to center it but went in and out and slowly picked up altitude, that is such a nice feeling to see it high up! Maybe I need a thermal ship too?

The orange-black livery I did after digging up some old threads and it works really well, particularly against a blue sky as the sun lights the orange through the wing. The black stripes near the fuse gets obstructed by the fuse and helps with orientation in certain angles. Under clouds...Continue Reading