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T3chDad's blog
Posted by T3chDad | Aug 07, 2007 @ 06:39 PM | 4,253 Views
After work, I took my trusty Creative ZEN Vision: M 30GB media player with me to the field. I got recordings of 4 WOT passes to get Doppler speed from. I kept it paused in my shirt pocket and I'd un-pause before I did the fly-by then pause it again until the next one. Here are the results.

Ultrafly SU-27 Flanker (25oz AUW)
Grayson 2212-06 motor with an APC 6x4E
Grayson 30A ESC
Align 3S 2100mAh 20C

Pass 1: 82.63mph
Pass 2: 74.29mph
Pass 3: 86.76mph
Pass 4: 79.53mph


Posted by T3chDad | Aug 04, 2007 @ 01:34 PM | 4,334 Views
It's been over 125 flights. She had gotten a little grungy. It was time for a re-fit!

1) Repaired and sanded the entire model...lots of old epoxy marks to clean up!
2) Finished Painting/re-painted.
3) New markings
4) Several coats of Minwax semi-gloss Polycrylic (spray).
5) Additional CF spars for the wingtips...maybe they'll stop breaking off now.

I'm now running (last 25 flights or so) Grayson Hobby's 2212-06 park jet motor with a 6x4E prop. Incredible!

Now she's ready for another 125 flights...

Update: No, the wingtips still break-off. I think this might be more a reflection of my piloting and not the strength of the aircraft.
Posted by T3chDad | Aug 01, 2007 @ 09:08 AM | 3,949 Views
From the Stingray thread in the scratchbuilt forum.

I loved the lines on this plane. I wanted something with much lighter wing loading than my previous project and this seemed to fit the bill. Start to finish, this was a four-hour build...very easy. This time, I used CA hinges (I HATE TAPE) and hot glue where ever I could.

She's a great low/slow/close-in plane. I have a problem with wing rigidity though. On maiden last night I lost control three times...all in high speed glide dives.

1) Pulled-out of it and regained control 3 feet off the deck.
2) It did crash...but barely. Slightly dented corner on nose.
3) Coming straight for me from 200ft, no control, pulling back on the stick...as it gets closer, I am just about to jump aside as it plows into the ground where I'm standing...I see the wings oscillating horribly...like a bird on coffee flapping its wings. Just before it hits the ground, it lost enough speed for the oscillation to stop and she responded and pulled up at the last second.

Time to add two more CF spars along the leading edges to make a huge triangle. That should help.

Update: I added a KFm airfoil to the bottom of the wing surface with spars behind. This solved all my oscillation/rigidity issues.
Posted by T3chDad | Jul 29, 2007 @ 09:10 AM | 4,001 Views
Lost orientation...too far away. Oh well, I guess I was looking for an excuse to start version 2.
Posted by T3chDad | Jul 27, 2007 @ 06:12 PM | 4,936 Views
The entire modification took about two hours. The whole landing gear setup weights 1.75oz. It cost me about $20. It only takes two minutes to install or uninstall it via the 5 nylon bolts. It's a blast to taxi this thing around ("here kitty, kitty") as well as do touch-and-go's over and over and over.

As expected, the gear has degraded flight performance. She'll still roll like crazy, but I can hardly get her to loop. She needs a moderate (about 50') take off roll and she rotates and climbs...not just lift off the ground. She's still very stable in flight slow and fast high or low. You do have to fly her in for the most part.

All in all, I'm glad I did this mod...I just think I need a little more power now.
Posted by T3chDad | Jul 25, 2007 @ 09:58 AM | 3,769 Views
…The SUPER Cat!

I started with modifying a picture I found on page three of the 24" House Cat thread. I used this for inspiration. Then I grabbed the 24” version of the plans for the House Cat. Once I had the plans printed out, I started modifying them based on my inspiration image. Several hours later, I had the airframe complete. When cutting-out all the pieces, I was mindful where all the writing was on the back side of the blucore so I wouldn’t have all the black logos and writing showing. I masked the stripes with blue painters tape and brushed on $.50 craft paint. After all the painting and sanding was done, I sprayed on many coats of Minwax water-based polycrylic (can is in pictures).

She flies like a dream. Very stable flight both slow and fast, high and low. The canards had much more effect on flight than I thought. I have about +1* incidence added to the canards. I love flying around the field 1'-2' off the deck...punching the throttle and going vertical several hundred feet...killing the throttle and letting her dive and glide past silently. She will hover very easily in a moderate head-wind. Also, the canards make this plane quite forgiving IMO.

I am currently contemplating a detachable landing gear platform with tricycle gear so I can taxi her around and do touch-and-go's when I'm in that kind of a mood.

Some modification highlights:
1. Vertical stabs are two pieces of blucore laminated together
2. Full fuse for battery, ESC, Rx, and …. Looks!
3. Static Canards
4. Magnetically attached canopy.
5. Extended wingspan (2.5” each side)
6. More horizontal stab area

Stats:
28” Wingspan
28” Length
9.5” Canard span
14oz AUW (5.5oz is the battery)
Powerplant: EMax CF2212 motor, APC 7x5 E Prop, 3S 2100mAh 20C
3x ESky 8g sub micro servos
Waypoint 25A ESC
AR6100 Rx
DX7 Tx
Posted by T3chDad | May 24, 2007 @ 09:57 PM | 3,568 Views
The first 50 flights were great!

51st flight. Throttle-up, threw it, felt a "hit" on the tip of my index finger. Ooops. I had a feeling. As soon as I leveled off, I looked down, and saw that it was definitely time to land.

There was a 3D flier out there at the same time, and we had a small audience. Funny, after this happened and and they saw the blood, the dad was saying "c'mon guys, let's watch the rest from the car..." to his two small boys. My wife, son and one of his friends were also there. They were kind enough to take me to the ER after the three Doc-in-the-box we drove by were already closed (only 7:30).

Three stitches later...Sorry, I don't have any pictures. Thankfully, it only took one hour at the ER.

I'll be back out there first thing in the morning getting some of the hair of the dog that bit me!
Posted by T3chDad | May 23, 2007 @ 01:00 PM | 3,315 Views
First blog entry huh...?

After a 27 year hiatus, I'm back R/C flying again. I originally flew with my dad back in '79-'80. I flew a 60" wingspan ugly stick with a 5ch Kraft single-stick radio. I crashed too much and being in 7th/8th grade, I didn't have the money to continue.

Now I'm back with a vengeance...and the funds to sustain this new obsession.

My new setup is:
Ultrafly SU-27 pusher jet (modified with rudders)
Ultrafly D/13/32 3200Kv brushless motor geared 2.38:1
APC 7x6 prop
Waypoint 25A ESC
Futaba 6EXAS TX
Futaba micro RX
Futaba s3114 servos x3
E-sky micro servo x1 (rudder)

I'm currently experimenting with various power setups:
EMax CF2212 direct drive outrunner with a 7x5 seems to be working well too.
...but...I've since gone back to the stock brushless with a 7x6 prop due to heat concerns and possible over-driving the EMax motor.

I could be a spokesman for Ultrafly. I LOVE THIS PLANE! See this thread for more info and pictures.