T3chDad's blog archive for August, 2007 - RC Groups
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Archive for August, 2007
Posted by T3chDad | Aug 16, 2007 @ 12:36 PM | 6,150 Views
While flying this morning, my friend Vicarious was good enough to play videographer and photographer for me. I took the clips, some music and threw it all together. This video is a nice showcase for Grayson Hobby's GH2212-06 Motor.

I hope you enjoy it!

Posted by T3chDad | Aug 13, 2007 @ 09:10 AM | 6,349 Views
I've been wanting to do a clear canopy and humorous pilot modification for my SU-27 for some time. I found the time and got it done. Here's the pictorial on how I did it.

Note, the vacu-forming was a failure (I kept getting folds in the plastic as I pushed it down over the mold onto the vacuum box. Next time, I'll make a wood box and put the whole thing in the oven and simply turn on the vacuum after the plastic is ready.

Edit: Due to a couple of inquiries about purchasing my canopy, I added five more detail pictures that show the flaws...mainly, lop-sided to the left side of the aircraft....Continue Reading
Posted by T3chDad | Aug 07, 2007 @ 07:39 PM | 5,454 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 @ 02:34 PM | 5,496 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 @ 10:08 AM | 5,083 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.