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rab's blog
Posted by rab | Sep 24, 2009 @ 09:52 PM | 3,517 Views
So another dZee was built, it's been flown a few times. I'm happy with it.

It is made of EPP. You can see the skewers that damp out the wing flutter which happen on exit of a fast dive.

The flying weight is about 8oz with a 2s700mah lipo. The motor is a blue wonder 1300 with an 8060 GWS dd prop.

And credit where it is due - this plane is really only a very minor variation on GPW's Foam-EZ...Canard Sportif' the dimensions on this plane mostly match the dimensions on the Foam-EZ.

-Allen
Posted by rab | Sep 20, 2009 @ 08:41 PM | 3,365 Views
I am planning to start another Gee Bee QED build.

I've a couple of choices to make.
1) Material, EPP or EPS?
2) Wing airfoil, under-camber or symmetrical?

A few of the related parameters. I have and would both 3mm and 5mm sheets of either foam. The wing span will be about 30inches the flying weight should be 8 to 10 ounces. So I am not expecting a high wing loading. And I am not asking for a high speed. I'm planning to use a blue wonder motor and a 700mah lipo.

What would you choose for this project?

- Allen
Posted by rab | Sep 17, 2009 @ 09:36 PM | 3,415 Views
So a few more photos to post. The field shot is from a weekend this August before I got the HK450 back together.

And I do have the HK450 back together, I've been flying it as much as I can. Working on being able to be comfortable hovering side in. Progress is happening, but it feels slow. At my current rate I might be comfortable with a race track pattern by next year.

And a couple more photos if my DR1. The DR1 is sorted out now, I'm mostly flying it on some 2s 700mah lipos, pulling something like 300mah off the battery in about 10 minutes flying. I'm currently working on a pilot to put in the plane because it just looks wrong to me to see it cruising around without one.

- Allen
Posted by rab | Aug 02, 2009 @ 09:47 PM | 3,276 Views
So I decided to fix the HK450 by getting another one. Put the new one together and finished the set up yesterday. But I had pitch reversed, so right after lift off it drifted forward a little and when I pulled the stick back a little I nosed it right into the ground. The blades popped right off, the main rotor holder sheared off right where the flybar went through it. Today I did an inventory of parts from the first one and the second one and realized I had just enough good parts to put it back together. Then when I had it all back together I found that the main shaft had bent. So it will be a few more days till it is ready to go.

Balancing and the DR1, yes balancing the blade made a huge difference. I also adjusted the wheels so they don't wobble so bad too. I can fly it on 2S or 3S. At the moment 2S is what I'm preferring - the plane looks right going slow.

While I'm waiting for the heli shaft I think I'll go back and rebuild the d'Zee. I did not put that one together well, it is falling apart.

After that it'll be another QED. Although I've been looking at the Miles M20 too. We'll see, it'll be next week at the earliest before I will start that.

- Allen
Posted by rab | Jul 08, 2009 @ 10:13 PM | 3,414 Views
I totaled my heli this morning. I've been trying to get to fly my heli in a race track or even just back and forth. The HK450 is much more challenging than the CX2 since I can't ignore roll. So when I got behind and could not get reoriented in time I ended up driving it into the ground hard. I have a bent frame, ruined blades, and most of the upper part of the head is bent or broken. I could fix it and upgrade the broken bits. But it will cost less to buy another kit and turn what can be salvaged from the crashed frame into spare parts.

My DR1 is bugging me. The bad bearing in the rewound BW is getting worse and the vibrations are now definitely affecting performance. But I do have another BW on the work bench now for rewinding, hopefully this one will not develop a bad bearing.

And on the note of bad vibrations. I think I have to pay more attention to balancing props. I have two planes that have minor vibrations that I suspect are due to their props.

I've finally got some video of the Viggen, of course it is currently 450mb of .mov file for 3 minutes of flying so some editing will have to happen before I post it here.

- Allen
Posted by rab | Jun 04, 2009 @ 08:59 PM | 3,501 Views
So I could not get the dZee canard to turn. As happens the issue was mostly not were I first thought. These two changes fixed it:
1 - moved the CG slightly forward
2 - took all the reflex off the main wing

- Allen
Posted by rab | May 31, 2009 @ 10:21 PM | 3,455 Views
You can see the Viggen's nose is all fixed, it's been flying very well. In front you can see my new toy. The heli seems to be working pretty well, but it is going to be some time before I can fly it very well.

- Allen
Posted by rab | May 04, 2009 @ 09:43 PM | 3,939 Views
The Viggen's shattered nose back has been put back together, there were not too many pieces. There was one fragment missing, I patched in a new bit of depron there. Then since the lower side of the nose was getting abraded by landings I put some light weight fiber glass cloth on the nose with thinned white glue.

- Allen
Posted by rab | May 03, 2009 @ 01:36 PM | 3,280 Views
So on the dZee I put fins on the end of the main wing, turns out that is too much of a good thing. I could not get it to turn. I had enough differential in the ailerons that it should have turned. I found I could put a little bend in one fin or the other and get the plane to make a flat turn in one direction or the other depending on the bend. Since I really don't want to put a fourth servo on this plane I am going to move the fin inboard were it was on previous instances of this plane.

The nose of the Viggen has glued back together easy enough, it was only missing one smallish fragment. I think I am going to put some light weight fg on the bottom of the nose for abrasion resistance. The pink foam nose cone was more abraded then I thought. Paint matching will be challenging if not impossible.

I've been researching heli basics as I have the parts for my HK450 on the way.

- Allen
Posted by rab | Apr 26, 2009 @ 10:56 PM | 3,184 Views
I've pranged the DR1 again, entered a spin unexpectedly. I've been happy with the power system, a rewound blue wonder pulls about 16 ounces of thrust and uses about 250ma in 10 minutes. But I've not been happy with the amount of noise this plane generates. Somehow at the best flying speeds the plane gets an unpleasant growl going. I might try to address that when I rebuild this. I also thought it would slow down better than it does.

I flew a rebuilt dZee today, rebuilt in EPP this time. Flew nice and slow. But I tried to just use a single spar at about 25% of the cord, that resulted in a rather large flutter when the plane reached about 80% throttle. I'll add a spar as far to the rear as practical and another at the leading edge. If that does not seem to work then I may replace the main wing with some blue core.

I've been somewhat frustrated with my blade cx2. Saturday I figured out that I've made the cg too far forward. I'll have to rework how the gear is mounted to pull the cg back. I would like to figure out how to make a boom mount so that I can replace the stock body tail. That way if I move the gyro to the rear I could easily access the gyro's to pots. I'll have to pay close attention to the bottom rotor drive too, it seems like the bottom rotor spins a little slower that the upper rotor.

I now have ordered the last parts I should need to finish the HC450 I bought back in January.

- Allen
Posted by rab | Mar 29, 2009 @ 10:35 PM | 2,952 Views
My last two weekend's flying have generated some repair work. Two weeks ago snapped my DR1 in half and rearranged the interior of my dZee, this weekend I made my Viggen need a nose job.

The DR1 was victim of a bad solder joint I made on a battery connector (it take over a year to fail). Lost power at fifty feet or so then made a graceless cartwheel landing. The fuse snapped in two just behind the wings. The repair was easy and finished the same evening. I've added some paint. I am planning to make a pilot and guns for this one.

The dZee was again my fault - it is too symmetrical- I could not tell if it was right side up or what, in the end I made a one point landing. The battery and motor both migrated forward through the interior structures. I should get to fixing it this week. I'll add a canopy which should fix the visual symmetry issue.

The nose on the viggen was messed up because I did not keep the battery warm, so it hit low voltage cutoff on launch and I was not able to restart it before it nosed in. I am not sure if I will attempt to repair or replace the nose. Either is possible.

- Allen
Posted by rab | Mar 21, 2009 @ 10:44 AM | 2,430 Views
I put this together in four days. I had hoped to fly it at an indoor event, but a friends new baby trumps a new airplane! So no it has not flown yet.

Yes it is a biplane canard, and yes the biplane wings are probably too close together, but I thought it looked good on paper, well QCAD actually but you get the idea. It might be quirky in the air but it should be slow enough that it tolerable anyway.

It is based on/inspired by GPW's FoamEz, a really great flier. It was aimed at (and hit) a wing loading of 3oz/sq ft. The wing span is 24in. I do still have the weight budget to put a canopy and some paint. But I'll do that after I see how it flies, in the mean time I'll go put some paint on that DR1.

- Allen
Posted by rab | Mar 15, 2009 @ 12:31 PM | 2,384 Views
So the DR1 is ready and waiting for it's first flight. But it is a wet drizzly day.

-- There was a break at the end of the day I took a risk with the long drive to the field and was able to fly the plane twice. On my second landing the wheel retainers popped off. The wires that link the ailerons have a very annoying rattle. Otherwise the plane flew around like I wanted it to. --

I've been planning how to paint the DR1. These thumbnails are my two favorite ideas so far.

- Allen
Posted by rab | Mar 10, 2009 @ 08:39 PM | 2,533 Views
Today finished de-kitting a bw motor I had turned into a kit with an unbalanced spinner some months ago. Put 15 turns of 26awg wire, I left the sixteen magnets it came with alone. On the bench with a GWS 9x5dd on 3s it made 16oz thrust for 7.8a and 84w. It is sufficient.

The DR1 is coming along, seems like it will be ready to maiden this weekend. So far it is on target to be under 12 oz auw, giving a wing loading just under 4oz per sq.ft. Between the light wing loading and the undercamber airfoil I am hoping for a very low stall speed.

- Allen
Posted by rab | Mar 08, 2009 @ 10:00 PM | 2,246 Views
Here is something that was put together in a week. It flies. The roll yaw coupling is amazing, a hard quick roll can also send you in the opposite direction. I'll fly it for a while until I think of something else to try.

- Allen
Posted by rab | Jan 30, 2009 @ 09:26 PM | 2,358 Views
Working on an Fokker Dr1 adapted from Jetset44's plans that I scaled to 80%. I am currently puzzling over what material to make the various struts with. The plan calls for lite ply and I suppose that is mostly what I'll use, but it sure seems to me that I could think of something lighter. I've laminated balsa and tyvek before, I might try that again. Here is a construction photo.

- Allen
Posted by rab | Dec 26, 2008 @ 08:44 AM | 2,670 Views


- Allen
Posted by rab | Oct 25, 2008 @ 05:34 PM | 2,528 Views
I went out an bought a used Blade CX, learning to fly it has been enjoyable. Some days I take it with me to the big field. That is actually more difficult than flying in my back yard. I've bounced it off the house a few times, run into a few trees. Replaced more than 8 rotor blades. I did not have any blade strike incidents until I put in a heavier battery. Since then I have had a few blade strikes.

I've revisited the Saab Viggen. This version still uses the GWS 55, now with a Hyperion P1913 6 turn 2.3 mm 4 magnet. This motor seems like a much better match to the GWS55 fan. The fan now generates about 15 oz static thrust for 18amps. I used 3mm depron and 1/4 inch blue core for the airframe, increased it's size by more than 15% and came out a few ounces lighter so the wing loading should be lighter (better). The plane is not painted and a number of details are not done, but it is ready for the first test flight. Hopefully that will happen tomorrow morning.

- Allen


The new Viggen flew very well! Plus a little fun with EPP Pete .
Posted by rab | Mar 05, 2008 @ 03:18 PM | 4,652 Views
Time has come to rebuild my Infineon. I got nearly year of service out of the first one. It had several major misshaps. In the end the carbon fiber I used was warping (pine is carbon fiber, no?) - Allen
Posted by rab | Apr 19, 2007 @ 08:27 PM | 2,684 Views
Since last Saturday we have had some very windy weather. Saturday I met Anatoly we both flew three planes, we both had Infineons. His is lighter than mine. At this point mine is porked up to 14oz flying weight. I decided to put a BP21 up front and then make use of the four 1200 mah 3s batteries I have. Stall speed is up but OK for the local baseball field. Moderate breezes are not an issue now, and the vertical performance is good. Anyway here is a photo from this morning, Infineon and Tiger moth.

- Allen