rclad's blog View Details
Posted by rclad | Jul 09, 2020 @ 05:21 PM | 5,753 Views
Monty Python's Life of Brian ends with a happy tune: "Look at the bright side of life." There's even a cheery whistle. Now that I got my Black Magic pattern plane back in the air today, I can see the bright side of the tail damage done last week.

What made the recent grounding of my only pattern plane a bit gloomy is the upcoming contest next week. The only way I could continue practicing for the event was to fly my big 104" Extra 300. I had to set it up to respond very similarly to the pattern plane, so the transition back would not be hard. One of the items I changed was a new Flight Mode (FM3) to make the entry into the spin a bit easier. I could now make multiple changes to the control response with one switch. It worked great, but I forgot I had not copied the settings over to the pattern plane.

I got a big surprise today when I flipped to Mode 3 for the spin with my newly repaired pattern plane. There was no throttle control, no aileron, and the elevator went to 100% - full rate with little expo. I ended up snap rolling the plane into a spin. I regained control by switching back to Normal Mode.

I got the plane back on the runway and immediately found the error, then added the settings for the spin mode. The next flight went much smoother when I switched to the new Mode 3. No surprises!

Anyway, the new gear sets have been installed in the old Futaba S9650 servos that control both halves of the elevator. Although only one servo was damaged, I replaced the gears in both servos, since they were well worn. In the process of installing the refurbished servos I found one of the nylon brackets on a control horn had gotten worn and allowed too much free movement of the elevator. That also got replaced. Now, no more slop!

So, look at the bright side of life!
Posted by rclad | Jun 15, 2020 @ 11:17 PM | 5,630 Views
June 13-14, 2020
St. Marys, WV
CD: Mark Radcliff


My first Pattern contest is now in the books! The Flying Wing Nutz RC Club of St. Marys, West Virginia, hosted the event, with Mark Radcliff, AMA District III V.P., as the Contest Director. The club has one of the smoothest grass runways I have ever flown on. Very nice!

I had one week to prepare, since the old Black Magic pattern plane I bought recently had to be converted from glow to electric. That was completed and flown on Saturday, June 6. I got 17 flights on it before heading to the contest the following Friday. The canopy still needed paint, but at least it was flyable.

There were seven pilots, including me, flying in the Advanced class. There was some tough competition. Flying an average of 80% percentage of perfection might have gotten me a first place win in IMAC, but here I only managed to squeak in a Third place finish. Still, I was very happy with the performance of the plane, and I was happy to put in a solid effort without a single zeroed figure. I even managed a 10 for a slow roll and a perfect landing.

For contest scores click here.
Posted by rclad | Jun 06, 2020 @ 10:49 PM | 3,980 Views
Yesterday (actually early this morning) I finished the conversion of a used 2 meter Black Magic pattern plane to electric. Today was the big re-maiden.

I'm not sure who was more excited to see this old bird fly again: me, or the original owner, who was there to assist me with the flight and setting all the mixes to get it flying straight. It didn't take much. Just a bit of up elevator trim after take off on the first flight, then we checked CG - right on. Knife edge needed some aileron mix in same direction as rudder, and up elevator. High throttle needed some right rudder, and no throttle needed down elevator to keep it from pulling to the canopy on the down lines. By the fifth flight it was flying knife edge and vertical up and down lines straight as an arrow.

I still need to finish painting the canopy. And the biggest item overlooked in the rush to finish was adding an opening in the firewall and an exit hole in the bottom of the fuselage for airflow to cool the batteries. How I missed that, after all the past conversions and other electric planes I've put together, is beyond me. Must be getting old.

Anyway, the Black Magic is my first pattern plane. After years of flying scale aerobatic planes like the Extra, with their draggy airframes, it was amazing to experience a sleek thoroughbred again. (I got started in sailplanes, and there is nothing more clean, aerodynamically, than that.) The power to weight ratio, while similar to my 104" Extra, translates to...Continue Reading
Posted by rclad | May 29, 2020 @ 03:50 PM | 4,438 Views
I've been wanting to try Pattern for a long time, so I finally bought a used 2m Black Magic to get started. It was originally set up with a glow engine and tuned pipe. The original owner took that out and sold the plane with a Plettenberg Xtra 30-10 Evo brushless motor.

While I put that together I've been practicing the Advanced pattern sequence. I finally have the sequence memorized and flew it correctly without a caller yesterday. My 104" Extra has a similar thrust to weight ratio and wing cube loading as the Black Magic, so it's a decent substitute, for now. At least to get the sequence down.
Posted by rclad | May 06, 2020 @ 05:35 PM | 6,378 Views
...the more they stay the same. I found the comment below, from the first issue of Model Aviation to be a fascinating peak into the early years of the hobby. The talk of geared motors (rubber powered, apparently) caught my attention, as my current giant scale project uses Aeroplayin's StinGR with a 3:1 gear ratio.

As much as we need to follow sound scientific principles when designing something new, especially when a poor design could pose a risk to person or property and involves a large investment of time and money, in the end it's a hobby. We do it for pleasure, whether that's the thrill of competing with a high performance machine, or just the satisfaction of completing a long and complicated build, then watch as it takes flight.
Posted by rclad | Apr 29, 2020 @ 05:16 PM | 7,698 Views
After a couple months in the shop for an Extreme Makeover, my Extreme Flight 104" Extra 300 EV2 took flight again on Monday, April 27. We had beautiful blue skies in Hebron, Kentucky, and temperatures in the mid-sixties, but the air was a bit choppy and gusting to 13 mph with a cross wind close to 90 degrees at times.

Engineering an electric plane of this size is not easy, especially when it is designed for competition. The goal was to carry enough battery capacity to complete two Advanced IMAC sequences (see PDF below), while keeping the weight below 29 pounds. I managed to achieve the weight goal, even with all the bells and whistles I added: electric canopy locks with LED indicator lights, electric arming switch, and a battery tray that automates all the connections to the ESC and telemetry.

The goal for flight time was 9.5 minutes at a 40% power average. The plane is very close to reaching that. The first flight was an easy warm up at a 33% power average and lasted 9.28 minutes and used only 65% of the available battery capacity. That was with brand new, never flown or cycled, 6S 65C Dinogy V2 10Ah LiPo packs in a 12S configuration. The second flight was at 43.5% power average and lasted 8.45 minutes and used 81% of the battery capacity. That was with packs that had flown a couple times already at partial throttle. The last flight was another easy one with the new packs that lasted 7.23 minutes.

The second flight pushed the batteries hard. There...Continue Reading
Posted by rclad | Apr 14, 2020 @ 10:29 PM | 6,997 Views
Some people never learn. I must be one of them. Eleven months after the first incident of a mid-flight pack ejection I lost another set of batteries while practicing the 2020 Advanced IMAC sequence with my Extreme Flight 95" Extra 330. Details here.
Posted by rclad | Apr 14, 2020 @ 12:44 PM | 7,627 Views
When I finally set up a rig several weeks ago to get an accurate measurement of the final all-up weight of my new EF 104" Extra 300, I was surprised at the results. I had carefully weighed each component that went into the plane and expected the final weight to be around 29 pounds. The scale measured 29.53 pounds (fuse RTF minus wings: 393 oz + wings: 86 oz - rod and cord used to hold fuse: 6.5 oz = 472.5 oz = 29.53 lbs). This plane will be competing in the Advanced class in IMAC, so I need it to be as light as possible. It not only has to perform well in all the Advanced aerobatics, as an electric powered plane it has to be able to retain enough power to complete two sequences, or a total of twenty aerobatic figures with multiple elements in each figure. My goal was to keep the weight at or below 29 lbs, so some weight reduction was in order.

To accomplish that goal the Extra went back into my shop for an overhaul, after just two flights! Below is a list of changes and weight savings currently underway:
  • Replace 1/4-20 x 2.5" steel motor mounting bolts with 1/4-20 7075 T6 aluminum - 46g
  • Replace 60T gear in the StinGR gear reduction unit with one that has machined holes - 77g
  • Replace EF spinner backplate with Falcon backplate - 24g
  • Replace EF fiberglass wheel pants with Precision Aerobatics CF wheel pants - 112g
  • Move rudder servo from tail to cockpit to maintain CG - 28g

Total weight savings = 46+77+24+112+28 = 287g = 10.12 oz = 0.63 lbs
New AUW = 29.53-0....Continue Reading
Posted by rclad | Mar 12, 2020 @ 08:12 PM | 7,276 Views
Like full-scale pilots we could benefit from the use of checklists to make sure nothing gets missed prior to a flight, especially a maiden flight. The larger and more expensive the plane the more critical it becomes to use a checklist to avoid a costly mistake, and possibly injury or worse. Below is a checklist I made for the maiden flight of my first giant scale plane, an electric one, a few years ago.

As useful as these checklists are, they leave out something that is just as important, if not more, than getting a plane ready to fly. That is getting ourselves ready! We have to prepare, too, both physically and mentally. The physical part is relatively easy. Get some sleep! How many times have you stayed up late the night before a maiden to finish up a plane or all the settings/programs that are now available to help us in flight? I'm guilty! Lack of sleep can have the same effect as alcohol, slowing down our reaction time. We need to be mentally sharp and focused to fly well. I nearly lost a plane flying the day after pulling an all-nighter.

Beyond getting rest we also need to be mentally prepared. Again, the bigger the plane and the more time we have put into the build, the more that will play with our nerves. This may not be an issue, if you're maidening your umpteenth giant scale plane and your hobby budget is unlimited, but for the rest of us it can be a big deal. It is for me, anyway.

My most recent build (EF 104" Extra 300 EV2) took over a...Continue Reading
Posted by rclad | Mar 12, 2020 @ 07:07 PM | 7,050 Views
There is a reason we have a building season and a flying season in the latitudes far from the equator. It's not only too uncomfortable flying in extremely cold weather, electric planes dependent on LiPo batteries need warmer temperatures to perform well. I had recently heard that 50F (10C) is the lower limit for adequate LiPo performance. The maiden and second flight of my new 104" electric Extra have both been in temps below 50F, and while the plane had plenty of power, it didn't quite have the punch I was looking for.

Here is an article that graphically shows the drop off in performance under various temperatures:

https://batteryuniversity.com/learn/...w_temperatures

You can see that below 10C the capacity (and thus the maximum discharge rate) drops off dramatically. Notice also, that the capacity continues to increase with temperature as high as 40C (104F). At that temperature, however, the battery life (expected number of charge/discharge cycles) drops by 40%! So, for a good compromise between performance and service life, it appears the best operating temperature is between 20C (68F) and 30C (86F).

A good solution to cold weather flying is to pre-warm the batteries before the flight. On the drive to the field keep the batteries in an insulated container with something to warm them up, like a chemical packet skiers use to warm hands and feet. If you charge batteries at the field, as I do, they will accept a higher charge (more capacity) if they have been warmed up first. If it's really cold out, openings in the cowl can be taped to keep batteries warm in flight. If the batteries will be pushed hard with aerobatic maneuvers, this may not be necessary.

Here's to warmer weather and long flights. Cheers!
Posted by rclad | Feb 25, 2020 @ 01:56 PM | 6,327 Views
After more than a year (off and on construction) I finally finished the build, and conversion to electric, of the new Extreme Flight 104" Extra 300 V2. I'm calling it the EV2. IMAC contests and practice took a lot of my time during the flying season last year, so the build itself took less time than the calendar dates indicate, and even less time than just planning and researching the best options for an electric version.

Major revisions to the airframe:
  1. Modified wings and ailerons to accept a single servo (Futaba A700), rather than two per aileron, and buried the servo in the wing to reduce drag and align the servo arm with the movement of the aileron control horn.
  2. Modified rudder servo compartment in the tail to bury the servo (Futaba A700) in the fuse to reduce drag and align servo arm with the movement of the rudder control horn.
  3. Modified motor box structure to accept a battery tray that self aligns on insertion, is pinned in place to avoid bolts, and automatically connects to the ESC and voltage sensors.
  4. Modified canopy with pins and CF reinforcement to tie both sides of the motor box together where part of the original fuse structure was removed.
  5. Automated canopy locking using a DPDT switch and Actuonix linear servos to reduce time removing and replacing the canopy to reload fresh batteries.
  6. Automated ESC arming using a DPDT switch, an Actuonix linear servo, and a Jeti Anti Spark Connector

Adding these custom options required time to design, test and...Continue Reading
Posted by rclad | Feb 04, 2020 @ 12:58 PM | 5,832 Views
The build of my 104" Extreme Flight Extra 300 V2 ARF has taken more than a year(!), but the finish line is finally in sight. This is a conversion to electric power with a battery tray that makes the power and balance lead connections upon insertion. The last hurdle was soldering a wiring harness for the two micro servos that lock the canopy. I was excited to see it actually work, so I had to skip ahead in my posts to show the video of the circuit in action. Link is below.

I tried to follow the Keep It Simple S_____ rule, but this one got complicated. So no KISS for me!

The video of the canopy lock circuit and description of the design can be seen here.
Posted by rclad | Jan 07, 2020 @ 01:17 AM | 6,773 Views
The commanding officer of the Navy S-3 squadron I flew in decades ago had one quirk: he expected his junior officers to recite a poem on special occasions. That included the day a number of us arrived on base after graduating from flight training. We didn't know this beforehand. That evening, after getting squared away, all of us headed to a local bar and grill. With only minutes to prepare something original, we had to stand in front of the CO and seasoned pilots, one by one, and recite our poem. I suppose his goal was to get us to think fast on the spot. It must have worked, because we all survived our tour of duty.

I love flying aerobatic planes. It inspires me. When I'm not flying I enjoy thinking about flight and what it means to be in the air, above all the craziness down below. I still write poetry, and a number of my poems are about flying. I try to write from a perspective that both an RC and full scale pilot can relate to. Some of the poems that follow have been published in the IMAC newsletter. One of them, a pantoum, took first place in a poetry contest.

I'll start off this collection with the only poem that survived from my tour in the Navy. Enjoy!
Posted by rclad | Jan 01, 2020 @ 12:26 AM | 4,434 Views
I began 2019 with plans to build a new IMAC plane, a 35% scale Extra 300. I thought it might give me a wee advantage over my 30% Extra 330, allowing me to climb to new heights in scale aerobatics. Well, as the Scotts say about best laid plans ("The best laid schemes o' Mice an' Men, / Gang aft agley"), things did not turn out the way I expected.

In retrospect I can't complain. I realized a dream I hadn't dared to voice out loud.

At the end of the season in 2018 I moved up from Sportsman to Intermediate class in IMAC. The most I had hoped for in 2019 was to learn the skills needed to be a competent pilot in this new class. The step up to Intermediate was a challenge. I had to learn how to do negative snaps, combination rolls, and get comfortable pushing to inverted from a long dive with multiple roll elements. I had to learn how to do a roller, turning the plane 90 degrees while completing a full roll, from upright and inverted, without climbing or descending. As much as I needed the new plane, once competition began I wanted to be out flying. Being stuck in my basement making sawdust was lower on my list of priorities. The catch was that I would have to be that much better of a pilot in order to remain competitive in the new class.

As anyone who has followed this blog knows, I accomplished that and more. I did my first 360 degree roller in June, from upright and inverted. I flew my "little" electric Extra against 43% scale, piston...Continue Reading
Posted by rclad | Oct 06, 2019 @ 09:33 AM | 3,780 Views
Aeroplayin posted a more comprehensive review of the math used in electric powered planes. This is a good read for anyone interested in designing the best power setup for their next electric plane. Check it out here!
Posted by rclad | Sep 17, 2019 @ 01:52 PM | 4,604 Views
The North Central Regional IMAC Championship this past weekend was the last contest of the year and had one of the tightest races I have ever seen. I felt like the little engine that could, competing against gas giants with my little electric plane. See pic below. More pics to come. Read more about the competition here.
Posted by rclad | Aug 27, 2019 @ 12:56 PM | 4,830 Views
Another contest with great weather made for an enjoyable weekend, but what a squeaker! Read more about it here.
Posted by rclad | Aug 26, 2019 @ 12:31 PM | 4,966 Views
Aeroplayin wrote an excellent post in the Power Thread on the relationship between Amps, Torque, HP, Watts, Voltage and Kv. Good information, if you fly electric!
Posted by rclad | Aug 16, 2019 @ 12:52 AM | 4,111 Views
We finally had beautiful weather for an IMAC contest last weekend, my fifth one of the year. Read more on the Cincinnati IMAC Burnit Challenge, and the results, here.

Below is Ben Batts flying freestyle after the contest on Sunday, August 11, with one eye closed!

Cincinnati IMAC Burnit Challenge Freestyle Show 20190811 (3 min 57 sec)


Cincinnati IMAC Burnit Challenge Freestyle Show Part 2 20190811 (1 min 52 sec)
...Continue Reading