Category Archives: General Post

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Final Tweaks To H9 Cub ARF

Well I planned to spend an hour or so with the final tweaks to the H9 Cub ARF this weekend, but it turned into quite a bit more work than I thought. I started by checking the balance with my Vanessa balancing rig. If you have never used a Vanessa rig, it is a simple tool for finding the center of gravity for any plane (I’ll post a bit more about my setup and its use in the future).

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I turns out that I needed to shift the battery pack as far forward as possible to get close to balance. This shouldn’t have been a surprise since the motor and ESC combined together are lighter than the glow engine this plane was designed for. The battery more than makes up for this, but in the location I originally placed it, much of that mass was behind the firewall.

No problem, since there is plenty of room in the cowl to slide the pack forward, EXCEPT… I now need to turn the pack around and face the wires towards the back as there is no way to reach the plug inside the cowl. No problem, EXCEPT… the battery wires from the ESC don’t quite reach far enough to connect with the battery. So, now everything has to come apart so that I can add about 1-1/2 inches to the ESC battery wires.

I do realize that is typically never a good idea to lengthen the battery to ESC wires, but 1-1/2 inches should not be much of a problem and the total wire length from ESC solder point to battery connection at the pack is still only about 8-1/2 inches (anything over 12 inches typically requires additional capacitors to be added).

Everything back together and I try the balance again. It is much better, but still about 5/16 behind the ideal location.  Note: The forward mark in the photo below is the ideal location at 3-1/4 inches behind the leading edge. The mark behind it represents where the plumb bob should point to mark that spot (compensating for the fact that it is offset by 1/2 of the dowel thickness that the plumb bob string is hanging from).

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It will take about 5 oz or so of additional weight to get the balance on the money. But since the plane is already coming in overweight by about 11 oz, I think I will call this close enough. Note, I was a bit surprised by how much overweight the plane is until I discovered that the combined weight of the battery, motor, ESC are about 8 oz heavier than a glow engine sized for this plane (although I would have that at least some of that would have been offset by eliminating the fuel tank, the receiver battery, and the throttle servo though).

So, after the better part of a Saturday afternoon (and a bit of Sunday morning), the balance is finally done. Now just a few minutes to set the control throws. The elevator goes quick enough, as does the rudder (although it is not possible to get the full travel called for without hitting the elevator, reconfirming that this older ARF is not at all up to today’s standards).

The ailerons however are another story. The ailerons must be set with a differential throw to prevent severe adverse yaw tendency inherent to both full size as well as model Cubs, with a greater down aileron throw vs up. No problem, I installed the servo arms at an offset angle (as called for in the manual) which will build in the differential. In addition, I am using a 6 channel receiver with a separate channel for each aileron, allowing me to fine tune the travel for each. EXCEPT… at full down aileron throw, the pushrods are binding against the mounting hatch (did I mention that the quality of this ARF).

This turned into another lengthy trial and error project of trimming the aileron hatch, adjusting the initial angle of the servo arms, and adjusting the travel limits separately for up and down motion for each aileron. Nothing extraordinary complicated, but time time consuming. You can see in the photo below the notch that needed to be cut in the hatch to allow full pushrod travel without binding.

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At this point, I am calling it done! I’ll give here a good once over to make sure everything is secure and all fasteners are tightened up before taking here out for a maiden, but I am definitely getting tired of fussing with this ARF (I guess I got what I paid for!).

Hanger 9 80” Cub ARF

Several years back, I picked up and older Hanger 9 80” Cub ARF. It was unassembled, and all the parts were there, but in truth, it could best be called fair condition. The covering was badly wrinkled, the plastic windscreen was a bit dented, and the fiberglass cowl had a crack in the bottom. But the price was right, so I thought I’d give it go.

Compared to newer ARFs, this was quite crude. The control surface needed to be hinged, the wing mounting dowels and bolts needed to be drilled, and all the clear parts cut out, trimmed, and installed. The dummy engine bits were just white vacuum formed plastic and they too needed to be cut, trimmed, glued to the cowl, and painted. Pushrods needed to be assembled from balsa dowels and piano wire, and even the tailwheel wire needed to be bent to shape from straight stock piano wire.

I started picking away at it as a fill in project, and (of course) converted it to electric power, using a Turnigy G46.

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There are some scale details I have yet to add (like non-functional wing struts), but she is finally about ready to fly. Not too much to look at, but I am hoping she will be a good flyer.

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Looking forward to some warmer (and drier) weather to try her out!

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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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.

Happy New Year!

2015 is upon us and it will be a bright an prosperous year! I look forward to new opportunities and plenty of fun in the new year.

I recently posted a comment on the MAN site about the Future of RC in response to the question: “What’s in store for RC aircraft in 2015?” While reflecting on the question posed (and my reply), it occurred to me that we are at a dawn of a Golden Age for the RC hobby and the Unmanned Aerial Vehicle industry. Yes, things are changing rapidly, and some of that change may be uncomfortable, but all in all, we have more options, better technology, and lower barriers to entry than at any time before the RC hobby.

The commercialization of drones and unmanned aerial vehicles IS going to happen (despite the FAAs bungling of the rule making process) and that will pour millions of dollars into technology and innovation that will cross over into the hobby market. Hobbyists will find new and innovative ways to adapt this technology and this will feed back into the commercial market. This cycle is unstoppable and will continue just like it has with every disruptive technology since the wheel.

Yes, there are growing pains that will need to be sorted through. The lower entry barriers means that irresponsible actors (both private and commercial) will end up causing problems that will likely lead to new regulations. But while those regulations may end up restricting certain elements of our hobby (and some will feel disenfranchised as a result), the core of the hobby/industry will thrive.

I don’t know what the future will bring, but I am sure it will be bright. We need to keep an open mind about the future and the AMA and our clubs need to continue to adapt and evolve with the hobby and with the industry it will spawn.

Be safe and have fun!!!

Site Moved To New Host

In addition to trashing my site with no warning, I recently discovered that sites hosted with the free hosting service 000webhost are blocked by many ISPs. Well, I guess you get what you pay for.

I decided to move my site to Host Metro, taking advantage of their $1.84 per month promotion. It took a bit of wrangling to get the site set up, but I think I have everything moved over now. Initial impressions are OK. Customer service seems to be helpful with rapid responses from their live chat support. The website itself seems a little slow though, but it is only been one day, so I will give it a bit of time before making a final judgment.

Site Problems

My site went down recently and had to be rebuilt. I am not sure what happened. I use 000webhost.com  to host my site. This is a free hosting site that has, up until now, been flawless. I was really impressed with how much functionality provided by a free site (but in the end, I guess you get what you pay for). I am not sure what went wrong, but noticed on the site forum that a few others also had the same problem. Fortunately, I had a backup from August and was able to recover with only two lost posts (and after a bit of head scratching, I was able to recover these from local Live Writer files).

I don’t mind paying a (reasonable) fee for hosting and was considering upgrading to a paid account at 000webhost, but I want to make certain that everything is stable there first. In the meantime, I’ll be sure to capture a new backup now.

Falling Into A Pattern

Well just like previous years, it looks like I got a way from posting as the summer went on last year, and now I am starting up again as we head towards spring. I don’t lose interest in RC planes or flying, but between work, holidays, and family activities, I find little time left for posting in the fall and winter. I have been putting time in here or there working on various RC project and will post more details (with pictures) soon. For now, I just wanted to at least get one post up to ensure that my site is still working!

Welcome to My New Home!

It’s been a some time since I have posted. While I’ve been busy with my builds, I have also been busy moving to my blog into its new home. While I was very happy with the free WordPress.com  site that had been hosting my blog, I wanted my site to have its own domain name http://alsrcsite.com. WordPress.com charges you an annual fee if you have your own domain name, so I moved onto a free hosting site hosted by www.000webhost.com. So far, I have been quite impressed with the features and performance of this free site, more than adequate for personal use like this. I guess you can get something for nothing!