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Posted by wingloada | Nov 09, 2014 @ 06:58 PM | 3,426 Views
Since I am learning the art of foam core cutting and composite construction, I thought I'd turn my hand to making a second wing for my Allegro Lite. This one will be a bagged composite wing that, I hope, might even be lighter than my built up wing. I'm generally following the Allegro (pre-Allegro Lite) design by Dr. Drela available at the Charles River site.

Last weekend I made the templates by printing the airfoils in Profili and then gluing them to 1/32" ply with CA. Today I cut the blanks from 2" Foamular and cut the cores. I am still very much a beginner with this -- evidence: I cut two right side mid panels rather than a left and right) and the power supply I am using is inadequate so the wire drags in the middle too much. I did get a (nearly) complete set of cores cut and later, when I am less emotionally connected to the work, I'll evaluate them to see if I should make a better set before continuing onward.

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Posted by wingloada | Aug 09, 2014 @ 06:40 PM | 4,670 Views
I built this Allegro Lite electric about two years ago. It's a very nice flyer but to get the stubby nose to balance the tail, I have to add quite a bit of weight. There's little to no room up front for that in the pod as designed by Dr. Drela so this weekend I took on the project of building a new fuselage that has a pod with a longer nose moment and a bit more internal space. My preliminary calculations show that this should save 3-4 oz. on the AUW. If I make new tails and keep them to a total of 1.5 oz together, I can shave another 3 oz. off the AUW bringing it to only 1 oz. over Dr. Drela's build-to weight on the plans....Continue Reading
Posted by wingloada | May 30, 2014 @ 08:32 PM | 5,204 Views
Since I had some time over the long holiday weekend, I decided to take on a quick build of the Mimi 1M DLG with built-up wing option. I had gathered the plans and parts beforehand so the build only took about three days....Continue Reading
Posted by wingloada | Mar 29, 2014 @ 10:19 AM | 5,767 Views

I'm building an electric fuselage for the Vivace 126 using the (larger) pod drawings I made to fit a 38-42 outrunner motor using the lost foam plug. I can see where this technique might give way to learning to mold with composites.

Given the weight of the motor, battery, and esc, all in the nose, I have calculated that I should install the rudder and stab servos in the tail rather than in the pod. If I enlarge the thickness of the base of the fin, I can sink the two servos into it and drive the controls with short rods from there. The servo wiring will run inside the boom from the receiver to the tail servos....Continue Reading
Posted by wingloada | Mar 23, 2014 @ 11:27 PM | 5,175 Views
:-)
Posted by wingloada | Mar 20, 2014 @ 02:58 PM | 6,224 Views
Last year at this time I posted a photo of the four planes I had built after decades of being away from the hobby. The building continued this year so here's the update photo. I built a glider fuselage for the Vivace 100 but used the same wing as the electric version I had completed earlier last winter. That accounts for the 0.5 in the total number.

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Posted by wingloada | Feb 13, 2014 @ 11:52 AM | 6,279 Views
I have created a model of the Viking 74 e-glider for X-Plane.

http://wkleinsasser.net/download/Viking_74.zip

This plane has an electric motor but it can also be towed as a glider. Here's a link to a file that explains how to fly these in x-plane:
http://wkleinsasser.net/download/x-p...directions.pdf
Posted by wingloada | Jan 28, 2014 @ 10:14 AM | 8,212 Views
In 2012 I brought home my very old Carl Goldberg 1/2 Viking model from my parent's house. I had originally built the plane in 1974. I have posted about that plane here and there's a photo of my rebuild-electric conversion from 2012 earlier in the blog.

This January, I decided to build a larger 74" modification of the plane for RES + throttle. I drew up the plans and started building. The fuselage is lengthened, the fin/rudder enlarged, and the stab modified to be full flying. The classic Viking pylon and pod are slightly modified for a longer nose moment and enough room for the motor, battery and other electronics. The wing will use the original planform for the outer panels with an added flat center section to bring the span to 74". The airfoil I decided to use is S3021 rather than Goldberg's original undercambered airfoil. I'm hoping for an AUW around 22 oz. [it turned out to be 26.5 oz.)

Here're some photos....Continue Reading
Posted by wingloada | Jan 05, 2014 @ 10:07 AM | 6,760 Views
I have updated the model of the Vivace 126 glider for X-Plane.

http://wkleinsasser.net/download/Vivace_126_Xplane.zip

Here's a link to a file that explains how to fly these in x-plane:
http://wkleinsasser.net/download/x-p...directions.pdf
Posted by wingloada | Dec 08, 2013 @ 06:41 PM | 15,025 Views
I have taken the plunge into composite construction with work on a Drela SuperGee II DLG.

I tried my hand at bagging the two tail pieces a few weeks ago using a large Ziplock bag and a hand vacuum pump. It worked pretty well but I could see the advantages of an electric vacuum pump and better bagging materials.

After I went back and forth over several options, Curtis Suter helped me find a great deal on a used oil-less diaphragm vacuum pump online and linked me to places to get the hardware I needed for a rudimentary constant-run pump setup. With this all in place I started in on the wing.

I had bought cores from Bob M. (rcbobcat55) a few months ago. I bought the fabrics over the summer bit by bit as I had spare dollars so it was just a matter of making templates, mylars, and cutting all the wing pieces from 1 oz. Aramid. Having Aramid scissors is essential, I found.

I put the left wing panel into the bag yesterday afternoon. I got up this morning after shutting off the pump at around midnight (8 hours on with West slow-cure epoxy). I had the wing half weighed down in the core shucks overnight. I pulled out the wing panel from the bag, carefully removed the mylars (I had used FreKote release) and they came right off. For a first time, I was very happy with the result!

The panel is a bit heavy -- 59 grams without the center joiner. I used a little too much epoxy (I mixed about 40 grams for the left wing panel). I did cover the wet-out top and bottom...Continue Reading
Posted by wingloada | Nov 24, 2013 @ 05:51 PM | 7,303 Views
For my Allegro Lite electric, i have been using a very small LiPo for power and radio. It's a NanoTech 350 mAh 3S battery with a 60-120C rating. It's the largest LiPo I have found that will fit in the pod aft of the motor and in front of the 25A ESC along with the necessary balancing nose weight.

I have run the calculations for this power system using Drive Calculator software and anticipated available power for WOT for about 60 seconds.

I was curious about a real-world test of the performance of the battery, especially the voltage available to the servos while the motor was running at full throttle.

Here are the specs:
Motor
Mystery 2830 1300 brushless outrunner motor
Max Power: 206 Watt
Continuous 30A, Burst 40A up to 10 Secs.

ESC
Castle Creations Phoenix 25 w/BEC 5V 2A

Battery
NanoTech 350 mAh 3S 60-120C

Prop
Aeronaut CAM 9.5x5
WOT Current with this setup 20 Amp (measured)

The battery will power the motor at full throttle for two 30-sec runs with a bit left over.

What I wanted to find out:

1. While the motor is running at full throttle, what is the voltage available to the Rx and servos and are there any brown outs?

2. If I run the power (static) for two 30-sec runs with about a minute between, how many minutes of control of the servos will I still have?

I set up a test rig with the plane connected to a fully charged battery running through a Watt meter and with a basic voltage gauge connected to an open channel on the receiver. The receiver...Continue Reading
Posted by wingloada | Jun 29, 2013 @ 01:50 PM | 9,105 Views
Over the last month, I decided to change my radio programming for my e-gliders, including the Allegro e-Lite I built last summer and have been trimming and flying this spring.

Instead of using the throttle stick to control the motor, I put it on a switch on the top left of my Tx and used an adjacent rotary pot controller for variable throttle. This way the throttle stick is used just to adjust spoiler or flaps depending on the plane. My idea was that for the e-glider, I just need motor on-off and when I need more control, I can use the rotary pot. The pot is also used as a safety when the plane is on the ground, turned all the way off until I am ready to launch.

So far so good.

I had flown RC powered planes from 1985-1990 (albeit followed by a long break until last year) and in all that flying, I used the throttle stick to control the motor. Can you see where this is going? :-)

Today I took out the Allegro Lite, which I had dialed in pretty well during my last few flights with it about a month ago -- before the throttle control reprogramming. Before launching, I checked the CG, control surfaces and the controls but I forgot to check the rudder dual rate switch, which was on low rate by accident.

First lesson remembered: double check the position of every switch and knob before every launch.

I flipped the throttle switch, waited a second while the motor wound up to full throttle and then threw the plane into its launch. Immediately, it was clear that I didn'...Continue Reading
Posted by wingloada | May 31, 2013 @ 02:27 PM | 9,868 Views
Work continues on the Vivace 126" wing. Main and outer panel spar and rib construction is built and ready for rounding and Aramid tow wrapping. I have started a build thread available here:

http://www.rcgroups.com/forums/showthread.php?t=1894426

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Posted by wingloada | May 13, 2013 @ 10:39 PM | 12,422 Views
I modeled my Houston Hawk in X-Plane tonight. Here is the file if you wish to download it.

Updated 1-5-14 -- Improved CG and balance settings.

http://wkleinsasser.net/download/Hou...awk_Xplane.zip

Here's a link to a file that explains how to fly these in x-plane:
http://wkleinsasser.net/download/x-p...directions.pdf
Posted by wingloada | May 12, 2013 @ 01:31 AM | 12,369 Views
For fun, I modeled the Vivace 100" plane today in X-Plane. The airfoil is not accurate, but close enough for the model to fly. All controls are modeled (no motor) and winch launching in X-Plane is interesting--quickly the plane is too small to fly. Pretty realistic, maybe.

As with my non-virtual first flights, the CG location and airspeed make all the difference. Using the virtual plane, I was able to practice the CG dive test and really get a feel for how decalage and CG relate. I was also able to better understand the idea of using inverted flight to test CG location. I'm not sure these are really true-to-life but X-Plane is pretty sophisticated so it seemed to model flight characteristics pretty well.

The 7 outer panel dihedral as modeled seemed a good compromise. With enough airspeed, the plane was solidly stable and held turns well. I was able to model mixing rudder to the aileron control and find when spiraling occurred in thermal turns (quickly when mixed in). I was also able to play with flap-elevator mixing for level flight transitions. Again, I don't think these will transfer to real model trim and mix, but it was interesting to play with it.

If anyone is interested, here is the X-plane aircraft file.

http://wkleinsasser.net/download/Vivace_100_xplane.zip

If you are interested you can download a free demo of X-Plane and take the plane up on the winch launch.

http://www.x-plane.com/downloads/x-plane_10_demo/

Here's a link to a file that explains how to fly these in x-plane:
http://wkleinsasser.net/download/x-p...directions.pdf

Now I need to find wind tunnel data for the AG35 airfoil to import its likeness into the X-Plane model.

UPDATE: I have entered the Reynolds number, thickness percent, lift coefficient and drag coefficient for AG35 into the wing's airfoil definitions in X-Plane. I don't notice any real difference.

UPDATE 1-5-14 -- Improved CG and balance settings.
Posted by wingloada | May 07, 2013 @ 10:30 PM | 12,490 Views
Today I received the box of laser cut parts and wood from National Balsa to build the larger 126" wing for the Vivace. The plan is in a post on April 26th below. This wing will increase area and also increase the percentage of chord allocated to the flaps and ailerons.

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Posted by wingloada | May 03, 2013 @ 08:18 PM | 10,354 Views
PART 1: The electric version

UPDATE 4: Today I flight tested the glider version of the Vivace 100 and it was pretty clear that the issues with the electric fuselage version (same wing) were caused by the CG being too far back (tail heavy).

UPDATE 3: Tim Schuh took the time to run some calculations on the design. Thanks Tim. His suggestion is that the plane was probably slightly tail heavy on these first flights. Here's what he offered:
"These results are with an AG35 airfoil and no washout.

Glide speed is right around 24mph - 28mph depending on CG. I'd be
willing to bet that a prime factor is the relatively high aspect ratio.

2.0deg decalage (horizontal stab parallel to flat surface of the wing)
the CG range is around 2.875" - 3.125"
1.5deg decalage the CG range moves to 2.5"-2.875"

This CG range seems to agree with your flight test which suggests that
with CG at 3.25" you're a bit tail heavy but controllable. Its also
interesting to note how much the CG changes with a half degree change in
decalage. That change doesn't affect glide speed as much as it does
sink rate.

In that range for AoA at the zero moment point is about 2 degrees. You
can make a fairly linear guestimate for 1 degree per 1/8" change in CG."
So I have three possibilities: I was at the correct CG but flew badly, I was nose heavy and stalling the horiz. stab, and I was tail heavy and the plane was less than controllable because of it.

I am going to go with...Continue Reading
Posted by wingloada | Apr 26, 2013 @ 12:14 PM | 10,277 Views
I have been fooling around with wing options for the Vivace. Here are pdf drawings of a 126" version and a clipped-wing 100" version with a higher wing area than the original elliptical wing.

Modified 5-31-13 -- fixed some mistakenly drawn ribs. Finer line weight on pdf.

Modified 6-23-13 -- Added enlarged tail section proportional to wing increase from original 100" design.

126" wing

Modified 6-23-13 -- Added enlarged tail section proportional to wing increase from original 100" design.
Modified 7-5-13 -- Corrections to the drawings.
Modified 7-15-13 -- Simplified stab construction, added lost foam fuselage for electric version.
Modified 7-16-13 -- Clarified parts for built up stab and fin-rudder.
Modified 7-28-13 -- Minor corrections as prototype build progresses.
Modified 7-28-13 -- Specifications added and outer panel aileron spar dimensions added.
Modified 8-10-13 -- FIxed some mistakes in the electric lost foam fuselage drawing.
Modified 8-14-13 -- Added a lost foam pod with wing pylon fuselage drawing.
Modified 9-12-13 -- Added tow hook details to lost-foam pod.
Modified 9-17-13 -- Some details fixed and added during the build.
Modified 9-20-13 -- Corrected stab airfoil and construction drawings.
Modified 10-7-13 -- Stab construction and flap-aileron drawings updated.
Modified 10-13-13 -- Stab deflections added and dihedral adjusted.
Modified 1-4-14 -- Increased accuracy of the scale measure
Modified 1-8-14 -- Scaled and separated...Continue Reading