Rebel Ready To Fly Again

The guys at Motion RC took care of me after my Rebel crash and provided me with $50 store credit to offset damages, which more than covered the cost of a new fuselage kit.

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Everything else was salvageable, so this was the only replacement part necessary for the plane itself.  For piece of mind, I will scrap the battery back from the crash since it appears a bit damaged. So in the end, my only out-of-pocket cost is under $30. Not bad.

Reassembly was easy. The fuselage kit comes complete with plastic for the nose gear, a new canopy, tail and nose cones, and even servo extension cables pre-installed, so this was mostly a bolt together job. The nose gear strut and the pushrod connecting the nose gear steering servo were both slightly bent, but easy to straighten.

After reconnecting the ESC to the fan, I wrapped the connections tightly with electrical tape. That should keep them together.

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Since I had everything out on the bench, I decided to replace the “T” style battery connecter with an EC3 (I don’t the way the “T” connectors spark when you mate them). The EC3 was tight fit through opening in the fuselage, but with a little coaxing, it squeezed through.

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Of course, this meant I had to pull back the pre-installed servo extensions to make room. I was a little concerned about getting the throttle connector and servo extensions back through this tiny hole, but using a length of nylon pushrod sleeving, it was easy to fish them through.

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Everything else then was just bolted/glued in place. Since there was a small crack in the original canopy, I decided to use the new one provided with the fuselage kit. Like last time, I carved a small bit of foam from the underside of the canopy to allow for battery clearance. The plane rebalanced with about 1.3 oz in the nose (like last time).

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For good measure, I will re-verify all my control throws, but there is no reason to expect anything has changed since the wing and tail were undamaged and no changes were made to the electronics. Here she is ready to re-maiden.

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Now I just need the weather to cooperate!

Crashed My Freewing Rebel Today :(

Well after a very successful maiden last week, I had a very unsuccessful third flight today. After about 2 minutes in the air this morning, the EDF quit in flight and I ended up “lawn-darting” her in.

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The battery had plenty of charge left so it wasn’t a brown out due to a low battery. I could still move the control surfaces, so I know it wasn’t due to loss of radio signal. I assumed either the motor fried or something went wrong with the ESC.

After getting her home and doing a bit of disassembly, I discovered that the motor to ESC wires had come loose!!! How does this happen in flight? They must have been loose from the factory.

Unfortunately, the connection is hidden when the fan unit is installed and I never thought to remove the fan to check the connections. After-all, I never had anything go wrong on bench tests before her first flight. It just never occurred to me to even think about checking the ESC connections.

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Well lesson learned! From now on, I will be double-checking all connections and mechanical joints on any ARF I happen to buy.

To make matters worse, I had a new 4S 3000 mAh pack (only used once before) in the plane that got a bit crunched too. The pack is deformed and feels a bit squishy (not like its puffed), so I think I am going to trash the pack. It’s not worth the $37 to risk fire with a physically damaged pack.

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I sent pictures and a description of what happened to Motion RC (where I bought the plane). Maybe they will take pity on me and help me out here. If not, I can pick up a new fuselage for $50 and get her back in the air without too much trouble.

Maidened My Freewing Rebel EDF Today

My wife bought me the Freewing Rebel EDF for Christmas this past year. I have been slowly building up the courage to get her into the air and finally took the plunge today. I had two great flights despite all my nerves and shaking hands – thank god for expo!

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She’s definitely faster than anything else I’ve flown, but really stable and well behaved. Take-offs were uneventful, except she feels a bit sluggish until it picks up speed, and needs a bit more take-off roll than any of my prop planes. In the air, she was very predictable and responsive on low rates. I didn’t do anything fancy, but never felt like I was out of control, and at full throttle, she was tearing up the sky! With half flaps, landings are a breeze, really no harder than my old T-28. I did not try full flaps. Flight times are a bit short, I am getting about 3-1/2 to 4 minutes with a 3000 mAh 4S battery, with ending capacity at about 20%.

This was my first Freewing plane, and overall, I am very impressed with the quality. I did end up fussing with the elevator a bit. The stock setup had two pushrods, one for each elevator side inserted into a single hole in the servo arm. While I am sure that this would work fine, I was having a hard time getting both sides of the elevator to travel identically and could only het about 10mm total travel (vs the 16mm recommended).

To address this, I made up a new custom pushrod set by silver soldering two wires together and replacing the clevis links with Du-BRO micro links . I also slightly trimmed the foam ahead of the servo to provide clearance for the pushrods. Most of the control surfaces on this plane use low friction nylon hinges, but the elevator is a standard foam hinge, and felt a bit stiff. So, for peace of mind, I replaced the stock servo with Hitec metal gear servo. Finally, I used a slightly longer servo arm to get a bit more travel. All together, these small changes got the elevator travel up to the full 16mm, aligned, and moving smoothly.

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The battery compartment is a very tight fit. The receiver and wires fit, just barely, behind the battery cavity. I needed to trim a small amount of foam from the front in order to fit the pack without mashing the battery wires.

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With the 3000 mAh battery, the plane needed about 1-1/2 oz of weight in the nose to balance. Before gluing on the nose cone, I cut a small hole in the nose, then mixed some lead shot into a bit of 30 minute epoxy and “pouring” it into the hole.

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The only other fussing required was getting the aileron throws set properly. The right aileron had about 3-4mm more travel than the left. Since there are no empty spots on the 6 channel receiver, there is no choice but to join the servos on a “Y” connector. There is no way to trim one servo separately from the other. I’m not sure if the problem is with the servo, or (more likely) with the position of the control horns relative to the hinge line, but to fix the issue, I simply moved the right aileron pushrod to the outer hole on the control horn, and left the left in the middle hole. Travel is now aligned to within 1-2mm.

I probably am fussing a bit more than needed, but fussing is what I do!

I also got in a bunch of flights with my trusty ParkZone F4F today. This continues to be my no-fuss, no-muss plane. Like their tagline says “Just Fly”.

On the other end of the spectrum is my E-flite Hurricane. This is my “repair after every flight” plane. I had one fairly good flight with her today, but landed a bit hard and pulled the right landing gear mount out of the foam (again). No damage to the foam and, in truth, this is working the way it is supposed to (easier to glue the mount back into the foam than it is to repair a broken wing!).

Lots of Flying Last Week!

Well I took a couple of days off last week to extend the Fourth of July holiday and I was able to get in several more trips to the field. I did have a few more minor mishaps but also a few successes, so all in all, a great couple of days!

I got my F4F back up in the air after repairing the tail feathers that got damaged when she blew off the bench on the 4th. The first flight was a bit hairy as as it took a LOT of up elevator trim to get her flying right. She was porpoising all over the place while I was trying to get my thumbs in the right place to click the trim. I have not had to click trim settings in flight for a while, so I would pull up elevator, let go to click the trim, but before I could get my thumb there, she was nosing down.

After a few tense minutes, I got her sorted and she was flying great again. After landing, you could see that the left elevator was deformed a bit more than I thought causing the trim problem.

I took her back up again and had a great flight, but on landing, managed to crack the cowl! Fortunately, replacement cowls are still available even though the plane has been discontinued.

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Next, I decided to try the Hurricane again. This time, I took off from the paved portion of the runway, and I got her in the air with no incident. Once again, I had a bit of a battle with the trim and again had to dial in a bunch of up elevator! As this was only the second flight for this plane (and I was shaking so bad with the first flight that I never got to trimming!) this was not really surprising (although the amount of trim required did surprise me a bit). I got two conservative flights in with acceptable (if not pretty) landings and called it a day.

I got back out to the field again the next day (without the F4F), but did bring out my FT Viggen. I’m still amazed at how well this cheap Dollar Tree foam board plane flies. While I can keep it under control, it definitely has potential to go beyond my (current) abilities. After the first flight of around 5 min length, the battery (a 4S 3700 mAh) was down to only 14% charge with one cell down to 3.69 volts! Way to low. I reset my flight timer to three and half minutes for future flights.

Finally, I had another mishap with the Hurricane. It started with a fantastic flight. I started really getting comfortable with her and felt like she was dialed in just about right. On landing, I was not too happy with the final approach (I was afraid she was drifting too close to the tall grass off the runway) and when she was just about to touch down, I decided to go around. Well, I was way too late and as soon as I applied power, the left wing tip stalled, dropped and hit the ground. Of course, she ground looped. I thought she was a goner, but the only real permanent damage was another broken prop. Other damage consisted of the right gear strut pulling out of the retract unit, the right simulated exhaust manifold popping off, and some scrapes and dings in the foam. Truth be told, it was cheap learning opportunity,

I hit the LHS on my home from the field and picked up a new cowl for the F4F. They also had a new-old-stock stabilizer assembly for the F4F (no longer available from Horizon), so I grabbed that too (just in case). I also picked up a couple of props for the Hurricane.

Today I got around to getting the Hurricane back together again. The gear strut bolted right back in, and with a few minutes of minor tweaking and adjusting the gear was operating smoothly again. A few drops of hot glue got the exhaust manifold reattached and the new prop bolted right on. She was ready to go again, except …

Earlier (before my last flight), I had noticed the seam on the right rear side of the fuselage seemed to have opened up a little. This was definitely there before my ground loop incident, but was something I had just ignored. I decided to wick in some thin foam-safe CA today while doing my other minor repairs. You can’t really tell from this picture, but I ended up making a bit of mess with CA running everywhere but where I wanted it to go. Oh well, no real harm and no one will ever call this bird a hangar queen!

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Multiple Mishaps Today

Spent the morning at the field today. It was a bit crowded, and although the weather started out beautiful, the wind started gusting a bit by mid-day, so I did no get quite as much flying time in as I had hoped. I got in a a few flights with my Park Zone P51 and F4F, but then ended up with a couple of minor mishaps.

First up was a gust of wind that blew my F4F off the bench when my back was turned. It landed up side down and end up putting a small break in the rudder and elevator. Easy to fix, but ended the F4F’s flying for the day.

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Next up was an attempted flight with my e-Flite Hurricane. This would have been my first flight for this plane this season and only my second flight ever for this particular plane. I decided to fly off the grass instead of the paved portion of the runway. I just started my take off roll and was getting up to speed, but I hit a bit of rough patch and the plane took a few strange bounces and end up nosing down and breaking the prop. No other damage, but I did not have a spare with me, so a second plane ended up out of commission.

I thought about putting up my PZ P51 again, but given the wind gusts and the way my luck was running I decided that it would be better off calling it quits for the day. Still better than a day at the office though!

Hog Bipe–Cowl Design

I haven’t posted any progress on the Hog Bipe in quite some time, but I have been picking away at it and I am almost ready to start final assembly. I’ll try to catch up and post some of the key build steps.

The biggest deviation from the stock kit was the creation of a custom cowl. A while back, I posted a Sketchup model of the Cobra 4130 motor to be used in this plane. I then went ahead and built a Sktechup model of the nose of the Bipe including my new cowl.

I started by scanning front section of the plans to use as a guide to the fuselage shape. I then modeled the fuselage for the first few inches back from the firewall and placed the model of the motor in place with the prop plane at the stock location.

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Next step was to try different section shapes and use the Curviloft Sketchup extension to generate the final form of the cowl. This was a bit of a trial and error process until I came up with a pleasing shape that blended to the fuselage and cleared the motor.

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Once again, I ran into the basic limitations of Sketchup where tiny computational rounding errors would add up and cause small gaps and imperfections in the generated surfaces. I had to blow up the cowl to 10x size to work with the design, then shrink it back down once I was done. While this helped quite a bit, I still had to do a lot of fussing and tweaking to stich surfaces together and close up gaps.

Here is the final shape.

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Next step was to design the structure of the cowl itself. I decided to use standard formers and sheeting for the back half of the cowl, but with all of the compound curves, I decided to carve the front half from balsa rings stacked together like a wedding cake.

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To generate the “layers” I created sections in Sketchup and then projected them forward. In order to minimize end grain in the final cowl, instead of cutting each layer out of a single sheet, the base form of the layer would be made by gluing  together square strips arranged with as much of the grain running lengthwise around the perimeter as possible. A horizontal and vertical line is used to align the layers.

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I then exported the final design to DXF and used a free DXF CAD editor to create a “blueprint” for each layer.

On to actual assembly. Each layer was built up from balsa stock. The outer edge was cut to the final shape using a scroll saw using the printed out layers.

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Here are the layers ready for assembly. Note that I did not yet cut out the center of the last layer, which is cut from a a single sheet  of 1/8” thick balsa, as I was afraid it would be a bit too flimsy. It will be cut out as the last step in shaping the cowl.

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The rear section was then built and sheeted using stringers and formers.

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Then each layer of the “wedding cake” is assembled using the horizontal and vertical tick marks for alignment.

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Then with a bit of carving and sanding, the final shape emerges.

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Using a Dremel with a sanding drum, I smoothed out the interior. I was afraid to get too aggressive with this step and sand through the wall. Note, I forgot to snap a picture of the cowl inside until right before I was ready to assemble it to the back section of the cowl.

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Here is the cowl assembled to the fuselage, ready for final sanding. I use three 1/4” dia rare earth magnets to hold the cowl to the fuselage along with a pair of 1/8” dowels as locating pins.

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A Beautiful Day at the Field

A beautiful day at the field today! Sunny with an occasional light breeze to cool things off. There was lots of activity at the field including a giant tow plane pulling aloft some absolutely gorgeous sailplanes. This was the first time I have seen that in action and it was quite impressive.

I got in a bunch of flights on my P-51. By the 4th or 5th flight, I finally started to get my head on right and feel a bit settled in. For me, I know I am at that point when I am thinking more about what I want the plane to do than what my thumbs are doing!

first flight of 2016 Season

I got out to the field for the first time this season with my PZ P-51. It was bit windy with some pretty strong gusts up in the 25 mph range. I really had a hard time settling in, so I gave up after two flights. I’m glad I went out and definitely now have the itch to get back to the field again, hopefully with a bit less wind though …

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Airplane Storage Rack

One of my projects this summer was to put together a new storage rack for my RC planes. My original storage rack was made with PVC pipe, but it really wasn’t big enough or sturdy enough to hold my growing collection. I put together my new rack using three 2×3 studs mounted to one wall of my basement. Each stud has a series of holes bored into the wide end to accept 3/4″ PVC pipe. This lets me configure the rack to handle a variety of different planes in a safe and sturdy manner.

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One problem I encountered is that the OD of 3/4″ PVC pipe is just under 1-1/16″ dia, but 1-1/16″ dia drill bits are not commonly available. To solve this problem, I ground down an inexpensive 1-1/8″ spade bit to 1-1/16″. Problem solved.

The rack is secured to the concrete wall using a powder actuated nail gun. Given the potential value of the planes hanging on the rack, I wanted a little extra insurance, so I screwed a couple of steel straps to secure the top of the rack to the exposed floor joists above … a lot of extra security for a very small amount of effort.

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Finally, I repurposed many of the PVC “tees” and “elbows” from my original rack to create a new wing panel storage stand. The bottom of the stand is made from some scrap plywood. I added a layer of Dollar Tree store foam board to the base in order to create a soft surface to stack the panels on. I also cut a second foam board lengthwise to use as a “cushion” between the wing panels.

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This weekend project really helped me got my storage organized and was well worth the effort.

Hello Again

I can’t believe it’s been 9 months since my last post. Of course, this blog is really intended to be my own personal journal of my RC experiences, so for it to be meaningful, I guess I will need  to step up my activity :)

It has been a crazy busy year this, with lot’s of things going on both at work and at home, not leaving as much time for hobbies as I would like. I did find time to keep a several projects moving along (mostly RC related, but I have also started dabbling around with model ship building). I also have managed to get in a bit flying this summer, almost exclusively with my foamy ARFs. More on all of these topics soon.

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