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Old Sep 28, 2011, 02:01 AM
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Originally Posted by Jurgen Heilig View Post
Hi Steve,

That's quite a bit of extra weight you've got here. I wonder whether your UHU was made from denser (i.e. heavier) foam?

I find it a bit strange that you reinforced the wing saddle rather than the sleek nose section.

Jürgen
Hi Jurgen,

I had exactly the same thought about the density of the foam! Unfortunately I didn't weigh the individual components prior to assembly so I can't be certain. However, I can't think of another explanation for the extra 50 + grams.

The only extra weight I added over stock was the CF reinforcements which in total come to 6g. I did indeed reinforce the nose too. There is a 210mm CF rod set in on the underside and covered with reinforced tape.

Steve.

Edit update:
I checked the weight of the canopy - 17.8g which is 5g more than you quoted at the start of the thread.
My wings complete including speed carbon spar, 400speed motor + prop assembly = 248g.
Assuming the motor/prop combo + spar to be in the region of 110g then the wing would be 138g which is 20+ grams over your stated 116g.
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Old Sep 28, 2011, 07:02 PM
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Elektro Uhu diet

I put my Elektro Uhu on a diet, by swapping out my Align 400SF for a much lighter ADH300S 2400kv micro outrunner, even though I also changed the APC 5.5x4.5 to a slightly heavier folding 6x3, overall, my E Uhu now weighs only 445 grams, with a 2100 mah 2S lipo.


new motor for Uhu:

http://www.hobbyking.com/hobbyking/s...dProduct=11882
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Old Sep 29, 2011, 05:37 AM
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UHU maidened !

It wasn't exactly perfect conditions with little erratic gusts of wind but I decided to give it a go anyway.

Short version: I came home with the plane still in one piece!

Longer version: A few test glides indicated that there was too much weight in the nose as she wanted to dive in and I needed to apply up elevator.
Removed 5g from the nose; test glide seemed much flatter so I decided to power up into the blue yonder.

Climb rate steady even on full power with no need for down elevator to compensate. Up to reasonable height, into the wind and power off. I needed to apply up elevator to maintain a steady glide. Power on again and a few circuits to get used to the handling.

By now the gusts of wind were becoming stronger and more erratic. Thus, it was difficult to truly ascertain how well trimmed the model was. Therefore, I thought it best to call it a day and land before disaster had an opportunity to strike.

I think I'm going to need a dead calm day to get both the CofG and trim sorted out properly. However, despite weighing 500g the Uhu still indicated great floaty flying characteristics which I'm sure I will enjoy once everything is sorted out.

Steve.
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Old Sep 30, 2011, 06:10 AM
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Yes Yes Yes !!!

Dead calm this morning at 9.00 am so I went to the field for more test/trimming flights.

After checking the manual again I saw it recommended 1mm up elevator trim for a CofG at 70-80mm. As I set 80mm I dialed in the 1mm and did the first test flight. Flew a combination of motor on/motor off and found it necessary to add more up trim to maintain a good power off glide.

Landed and noted that I had about 2mm up trim so I removed some weight from the nose and reduced the trim to 1mm. Up and away again and it proved to be much better. Climb rate and angle of ascent improved and overall feel of the model in the air was much better and I was becoming more used to its handling. After a few more tweaks I finally had the model dialed in to my liking. So, I landed and put in a fresh lipo.

I set the timer on my Tx to 20min and launched into the clear blue sky. The Uhu was now slowly cruising around at level flight with the mimimum of throttle and gliding to my liking. After the 20 min I managed to land the model gently at my side.

Back home and charged the lipos. My 20 min flight only consumed 577 mah from my 1800 mah lipo so 40 min flights should be easily possible with something left over as a safety margin.

I am one very happy Uhu owner. Now the model is dialed in, it performs exactly as I hoped it would. And to think what it cost me ( virtually zero ) what more can I say?

......Apart from.......now yearning more than ever to get myself a relaxing 2m soarer....!!!

Steve.
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Old Sep 30, 2011, 10:02 AM
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Awesome flight report Steve!!!
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Old Oct 01, 2011, 05:50 AM
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Cheers Doubletap.

I did 2 more 25min flights early this morning.

First, zero to very gentle breeze from the West........ lovely!

Second, the wind blew up a bit and changed direction by 180 degrees. From the East it gets quite turbulent as it passes over many obstacles (blocks of flats, trees, etc) and it can catch you unawares at times.

Compared to my Terry S, the Uhu is more relaxing (slower) to fly which is what I was after. I would say that the Terry is "smoother" though, albeit it has to be flown faster. I guess a few more flights on the Uhu is needed before I feel truly comfortable with its character.

Steve.
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Old Oct 02, 2011, 09:55 AM
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After a couple more flights this morning I think I now have the optimum flight set up for my kind of flying.

I have reduced the nose weight yet again and now have only 2.5g up front. I tried removing it altogether but even that tiny amount made a difference to the C of G and flight characteristics as the nose of the Uhu is quite long.

My AUW is now 488g.

Weather here looks very promising for some relaxing "glide arounds" later this afternoon.

Steve.
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Old Jan 20, 2012, 03:02 PM
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Just found this tread and wanted to share a small flight of my E-uhu with you guys... (ps don't pay attention to that weird dude holding the transmitter, that's just little old me...)
http://s302.photobucket.com/albums/n...t=100_1202.flv

Also a quick question... some of you guys have painted your models, but what kind of paint can be used for this? just some spray paint out of a rattle can, or will this destroy the solidpor?

Gr,
Sjaak
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Old Jan 20, 2012, 04:53 PM
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Quote:
Originally Posted by Black Cloud View Post
Just found this tread and wanted to share a small flight of my E-uhu with you guys... (ps don't pay attention to that weird dude holding the transmitter, that's just little old me...)
http://s302.photobucket.com/albums/n...t=100_1202.flv

Also a quick question... some of you guys have painted your models, but what kind of paint can be used for this? just some spray paint out of a rattle can, or will this destroy the solidpor?

Gr,
Sjaak
I use regular spray can enamel such as found at your home improvement stores, just make sure to use light coats to get the desired color depth. Never had a problem with "rattle can" paint with Solidpor, Elapor, EPO, PP, Arcel, etc.
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Old Jan 21, 2012, 02:11 AM
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I think most "Craft" type waterbased (acrylic) paints are fine on Elapor, Solipor, etc.

However, I will add one caveat. Some "rattle cans" use a solvent as a propellent so best to test before using.

For very simple colour schemes permanent marker pens are ok along with coloured packing tape.

I flew my UHU for the first time in months last Sunday. Nice and relaxing after recently transitioning to aileron models. But, I now feel that the rudder needs enlarging for slow speed flight as it just doesn't seem to have any bite on the air and the delay in control is unnerving at times.

Still, a lovely model for relaxed cruising and gliding.

Steve.
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Old Jan 21, 2012, 03:42 PM
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Thanks for the replies guys, once the weather over here gets a bit warmer i'll try to put a more visable colour scheme on my uhu.

Sjaak
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Old Jun 14, 2012, 06:48 AM
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Had a little spare time today, so popped my E-Uhu in de back of my car and went for a little bit of flying... The GF was smart enough to bring a camera.
So here are a few pics including new color scheme:










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Old Jun 14, 2012, 10:30 AM
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Great pics Black Cloud.

I recently redecorated my UHU for better visibility. At the same time I increased the size of the rudder too because it didn't have enough to turn the model at very low speed.

I'm now really happy with it and it's one of my light wind, easy going, relaxing models to fly when I'm in that sort of mood.

Steve.
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Old Jun 14, 2012, 01:41 PM
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I'm glad to see that others are still flying their Elektro Uhu despite that there are newer and shinier models on the market, but the Elektro Uhu is still a wonderful soaring sailplane for light air conditions, it is still one of my favorites.
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Old Jun 14, 2012, 04:14 PM
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I'm glad to see that others are still flying their Elektro Uhu despite that there are newer and shinier models on the market, but the Elektro Uhu is still a wonderful soaring sailplane for light air conditions, it is still one of my favorites.
Couldn't agree more Doubletap.

Once dialed in the UHU will float around beautifully and is perfect for those balmy evening flights. After a hard or stressful day when all you want is some relaxing down there's nothing better than the UHU.

Steve.
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