Libelle - Build Review Part 2

Shortly after Part 1, I received my new servos and completed the build of this little DLG.  Flying it simply got in the way of Part 2, but here it is...

Now that I've had a handful of flights, some much more exciting that others, I'll highlight the final build process and then share my impressions.

In Part 1, I mentioned issues with the recommended servos and in a separate post I detailed my experience with Hitec's HS-35HD servos.  I won't belabor the issue, but there was much frustration and I decided to order Dymond D47S servos for the wing and a slightly smaller Dymond Sky Arrow 3.7 Extreme servo for the Rudder and Elevator.  While this required some (minor) trimming, the effort was well worth it and provided an excellent result.

I'll note that since my purchase in mid 2014, Dream-Flight now offers a different servo package for the Libelle and it is reported to be problem free.  I personally am thrilled with the speed and accuracy of the Dymond Servos and would have no problem recommending them.

Setup of servo throws, Dual Rates, and CG were done exactly as described in the manual and it required very little adjustment or trim to fly properly.  I did order the steel weights offered by Dream-Flight and ~20g or 4 sections were needed to balance.  These fit nicely and securly on the side of the battery.

As I stated earlier, I've now had multiple flights with the Libelle and they have been incredible.  This is my first DLG so my only comparison is to various gliders and gas planes I've owned, as well as a few flights on my friends Blaster 3.  Overall the Libelle handles very nicely and has been a joy to fly.  Hopefully it's preparing me for a Blaster or Snipe in the very near future.

Some of the minor issues I've experienced may be more related to my launch style or lack there of.  I get a significant rotation to the left on launch.  I've added a touch of right rudder on my launch mode but it appears this is only partially beneficial and I think it's impacting my launch heights.  I also seem to be creating some bad habits in how I launch as I try to compensate for the left rotation.  I likely just need some more time and critique of my launch from someone who knows.

Early on, once I started to give my launches a little more punch, I noticed quite a bit of flex in the wing.  While I didn't want add a lot of weight, I did add a layer of clear packing tape down the center on both the top and bottom of the wing.  This made enough difference that I'd recommend it to others as part of the initial build process.

I have also had the rear wing bolt down (in the fuse) loosen up.  It appears this is from some harder than expected landings due to missing a catch.  Nothing a little CA couldn't fix.   In conjunction with some of these failed catches, I knocked off the rudder as well.  Again, nothing a little CA couldn't fix and I was back flying.  A bit of glass or carbon fiber patch on the tail boom (like most full size DLG's) would eliminate or minimize the chance of this happening again.  I just CA'd mine back into place and it hasn't been issue since.

The plane has proven to be quite durable.  I had a mid-air collision with my friends Blaster and we momentarily locked up and then both descended rather rapidly, sadly without enough altitude to properly recover.  Both DLG's sustained damage but were repairable.  The Libelle stripped a servo gear in one aileron, but obtaining replacement parts from Dymond was quick and easy.  Also, the leading edge of one wing was slightly compressed in a small area, but with some hot steam, I was able to get the foam to re-expand.

Overall, great little plane.  It does exactly what they advertise, it gets me out flying.

CC3D by OpenPilot

Background Story:

I started investigating quadcopters several years ago and came across a website and company by the name of FliteTest.com.  This group of guys is relatable, down to earth and appear to be creating what we call in the business world "disruptive innovation".  I love it and I hope they are successful in their endeavor.

Bat Bone
copyright flitetest.com

FliteTest did what they do best, and I became so enamored with their tricopter kit the Bat Bone that I just bought it with out doing a whole lot of planning.  I typically figure out the whole kit and and know every piece I'm planning to use in a build, but this time I just pulled the trigger.  Way to go FliteTest :).

During my brief addiction to all the FliteTest video's, I also did a significant amount of research on Flight controllers, GPS and OSD.  While I did come across OpenPilot's CC3D at that time, a clear contender in this market space was DJI.  To those who fly DJI equipment you can clearly attest to the quality and ease of use.  In fact I was so convinced that when my father needed to test the potential use of a quadcopter in his business, I immediately pointed him to the DJI Phantom 2 Vision Plus which at the time was their most current Phantom offering.

This proved to be a spot on recommendation (thankfully since it was $1400).  I graciously accepted the assignment of unboxing and maiden voyage.  You can see my review and first flights here.  I'll refrain from restating my initial post, but I was so thoroughly impressed by the ease of flight and quality of the software.  It truly was a product that someone without extensive programming or RC experience could use with a little practice.

So I set my sights on a DJI Naza M flight controller and accessories.  It was priced higher than what I had wanted to spend initially, but I was so very impressed with my first DJI encounter that I just wanted to have the best.  Then I read the fine print...It will do just about anything BUT it doesn't support tricopters.  Even though I was sitting alone, I verbally exclaimed "What!!!"  That just didn't make sense to me and I probably spent the next 2 hours scouring the web for someone who just may have found a way to make it work.  I couldn't believe I had just been talked out of a purchase by reading the manual.  Okay that sounds a bit silly but I really thought this thing could walk on water so to speak.

This is where my friends will say "just get a quad and forget about that tri".  Well I REALLY like the look of the Bat Bone and I'm sort of cheap skate.  Now that I owned the kit, I didn't want to just let it sit on the shelf waiting for some tender loving.

Several months have now passed...

My dad received a new plane for fathers day and it was fully loaded with a flight controller that my brother said would make him the best pilot ever.  This got me thinking that there was bound to be an inexpensive "fixed wing" flight controller out there and I started the hunt again.  This time with a budget in mind and some different criteria.

Enter the OpenPilot CC3D

Having been a supporter of Open Source for some time now with my day job (tidbitsofit.com),  I've kept my eye on the OpenPilot hardware.  The CC3D has been of interest and now that it appears to have "fixed wing" capability and the fact that the price is at a point I can justify a, buy-to-try, I ordered one last week.  At $18.00, including a hard case, I figured it was pretty hard to go wrong and I really still need to build that Bat Bone tricopter if the fixed wing solution is a bust.

CC3D
copyright OpenPilot.org

The CC3D arrived and it is just as pictured.  Okay not exactly, mine was white but really just the same.  The Ground Control Station (GCS) worked as designed.  The documentation was well organized and I had a POC up and running quite quickly.  My first attempt was simply to see if I could get it programmed and to take a stab at learning some new terms and technology. I still have much to learn but thanks to youtube and the excellent documentation, I figure it won't be long before I'm quite comfortable with the setup.

My first goal is to retrofit a GWS Slow Stick.  Since it's cheap, I won't be afraid to experiment and it gives me a reason to cut in some ailerons like I've wanted from day one.  Silly, I know, to mod a Slow Stick of all the planes but most everything else I have is considerably less stable as it is, or fly much faster.  When it comes right down to it, this just seemed like a good option to cut my teeth on.

More to come...

DJI Phantom 2 Vision Plus

The DJI Phantom 2 Vision Plus arrived this past weekend after 3 weeks of anticipation.  Amazon had indicated that it would be available on April 25th but that date came and went with no new updates until May 13th when they announced a new delivery date of the 16th.

Unboxing the DJI Phantom 2 Plus

As you can see by the picture, the packaging was very well done and somewhat reminiscent of Apple products.  The quad is basically ready for flight other than charging some batteries and attaching propellers.

Total setup time was about 1 hour but this was due to reading the manual, downloading and configuring the iPhone application and setting up the wireless.

My biggest hurdle was the compass calibration and after my 5th try I was finally able to get it to complete the process successfully.  What I learned was that I wasn't able to hold the quad stable enough, by hand, to complete the calibration.  The unit needs to stay on a smooth flat surface with slow deliberate motion while completing the various rotations required.  After reviewing the manual, this will make more sense.

I had initially planned to remove the camera before my first flights but after it arrived I discovered that it was all but integrated into the quad.  I'm sure it can be removed but it requires removing the plastic clips on the gimbal which are not reusable.  In the end I decided to do a very brief hover test and then determine if removal would be necessary.

Charging took 40 minutes to complete on the flight battery.  I also had a second battery that I began charging immediately there after.  Both arrived with about 50% charge which is a typical practice when storing lipoly batteries.  The Wireless Range Extender required about 2 hours to complete its charge, but this could have been due to the usb charger that I was using.

Essentially, 2 hours from unpacking, the Phantom 2 was ready for flight.  The madden voyage was simply amazing.  I've been an RC pilot for 20 years and have never experienced a maiden flight quite like this before.  The DJI flight controller lived up to all the hype.  It was extremely stable and hovered easily and consistently while I gained some experience with the controls and movement.  Within a few minutes I was transversing between my neighbors yards and up the street a 1/2 block.

Snap Shot from the Phantom 2 Vision Plus (~100ft)

I then took it up to approximately 100 feet and shot some beautiful video footage of the neighborhood and surrounding area.  Since this was video footage and not still photo's, I took a few screen shots to share.  The video quality is superb and the the DJI gimbal provided excellent stability through out the flight.

After several flights, I installed the software on an iPad and allowed my children and neighbors to experience FPV flight.  To say they were impressed is an understatement.  If it weren't for the steep sticker price (not to say it isn't worth it), I likely could have sold several on the spot.  It was very addicting and I ended up flying right up to dusk and maybe a hair later.

The following day I was able to test the "return home" function.  Obviously nervous about simply turning off the transmitter and "seeing" what happens, I found a large unoccupied area and performed the test.  I first flew out 30 feet from my starting location and positioned the quad 2 feet off the ground.  I then initiated the return home function by turning off power on the transmitter.  The iPhone app quickly responded stating that connection from the transmitter to the quad had been lost, and then a few seconds later it reported "returning home".  The quad then smoothly raised to about 35-40 feet AGL and proceeded back to the starting point.  Once returning it continued to hover at altitude for approximately 30 seconds and then descended to the ground and shutdown completely.

This test was repeated several times along with the steps to recover control mid way, which worked just as the manual described.  During these tests, the GPS was accurate to within 2-4 feet each time.  I had read about this feature, but seeing is believing.  Simply amazing!

I have a greater appreciation for the craftsmanship and expertise that has gone into the flight controller and design of the Phantom 2.  I would give it 2 thumbs up without hesitation and I highly recommend the vision plus version due to the outstanding picture quality and ease of use.  The iphone/ipad application was top notch in my opinion and deserves more than the 2 stars the app store had it rated at.

Battery life is the only minor draw back.  I typically saw 18-20 minutes of flight.  DJI reports 25 minute flight times but this must be indoors, zero wind and hovering.  Regardless, 20 minutes is still very reasonable.

I'm now anxiously awaiting the firmware release that allows the use of their Ground Station (GS) software, as it provides another unique view and control of the system via way points.

Dymond D47S "Fast" Servo

My current project is the Libelle DLG by Dream-Flight, which was built with the Hitec HS-35HD servos in mind.  However, there have been recent issues with the quality control of these servos making them more difficult to locate.  (Review can be found here.)  Hitec is working to resolve this issue but due to timing, I sought an alternate solution and in the process found a terrific little gem or "Dymond" shall we say.

While there are many micro servos in the market place, finding one with a thickness less than or equal to that of the 35HD was difficult.  The driver behind this size is not only to limit weight, but the Libelle wing is only 12mm thick.  The other factor was finding one with sufficient torque.  Based on my research and several recommendations, I settled on the Dymond D47S series.

Dymond D47S

Dymond D47S

The Dymond D47S is considered the "Fast" version of the original D47.  It measures 17x8x22 (mm) in size which is very very small.  The pictures don't do it justice, but help to depict just how small they really are.  Even at this size, they are able to deliver 16 oz-in of torque. And to top it off, they are also  a high voltage servo meaning they can handle up to 8.4 volts. To those flying with 2S Lipoly packs, this is a welcome feature.

My initial perspective prior to receiving them, was that they appeared slightly odd and boxy compared to other servos.  This is just another one of those opportunities to be reminded not to judge a book by it's cover, because once I had them in hand, my opinion quickly changed.  They are extremely light weight and the thin nature of the mounting lugs are a nice feature.  Looking back I'm not sure why the design didn't initially appeal to me because they are quite impressive.

 

Dymond D47S (left) Dymond D37 Extreme

Additional nugget...the D37 Extreme is another offering from Dymond.  I purchased a couple for review and will post on that model shortly.

















Here are a few additional pictures for comparison purposes of the Hitec HS-335HD & Dymond D47S.

Libelle - Build Review Part 1

Stock Photo dream-flight.com 

My Libelle arrived a mere 4 days after placing my order.  The model was well packaged and thankfully so as it appears USPS gave it a good thorough testing (read - they beat the living tar out of the box).  Regardless, the contents were in good working order.

While I didn't have the time to assemble it on the day it arrived, I did spend about an hour admiring the kit and reviewing the instruction manual in preparation for assembly.  I would highly recommend taking the time to review the material.  Nothing about the assembly is necessarily difficult, but I did find that it re-inforced some key aspects that could be "gotcha's" for some who may not have assembled many planes. Overall I found the instructions to be very thorough and accurate.

Kit Review:

The foam parts are well molded with no imperfections noticeable.  For those looking to eliminate any additional amount of drag, the trailing edges require just the slightest amount of sanding with very fine paper.  I also removed the sharp edge on the black plastic portion of the fuselage.  While very minor, this helped clean up the look and eliminated any sharp edges that will be encountered if hand catching.

The canopy is secured with multiple earth magnets and is also keyed for a perfect alignment.  I know some have suggested using tape due to losing the canopy when launching aggressively.  My guess (I'll find out soon enough) is that this was due to improperly securing the battery pack as the magnets appear to hold it very securely.

The wing and supporting components glued up quickly and were well described in the instructions.  The most challenging step I encountered was the alignment of the tail surfaces. While not difficult, I think the use of quick setting glue and knowing the importance of getting it aligned, created self imposed stress.

I opted to order the steel weights they offer due to the price and the fact that they were made to fit.  I would have ordered their battery pack as well, but I already had an order of NiMH batteries on their way that included 1/3 AA size cells.  Anything larger will be a very tight fit and require considerable trimming.

In Part 2 I'll report on the servo installation and setup.  I had a bit of trouble locating the recommended Hitec HS-35HD servos.  My review of this servo can be found here, along with a post from Hitec regarding its status.  I'm still anxiously awaiting the arrival of an alternate servo, the Dymond D47S sold by DymondUSA.com.  Several other Libelle owners have suggested this as well as Dream-Flight themselves.

Component List:

Libelle
Steel Weight Set
Dymond D47s (4)
Servo Extensions
4.8V NiMH Battery Pack (1/3AA size)
Taranis FrSky Transmitter
Taranis D4R-II 4ch Receiver

Hitec HS-35HD Ultra Nano Servo

Hitec HS-35HD (front), Hextronik HXT500 (middle), Futaba S5102 (rear)

The Hitec HS-35HD Servo is truly an "Ultra Nano" servo just as they describe.  However, BUYER BEWARE!

I have been a supporter of Hitec products for many years.  In fact, I'm still using a Prism7 PCM/PPM radio on occasion for some older gliders.  Unfortunately, there has been quite a bit of discussion and concern regarding the quality control of this little servo which leads to this post and warning.

I recently purchased the Libelle DLG from Dream-Flight.com.  A phenomenal little DLG which was designed to use the HS-35HD servos.  Sadly the reviews and blogs I read have been filled with frustrations regarding this little piece of hardware.  I opted to give Hitec the benefit of the doubt and tracked down several of these little giants, but they happened to be out of state @ SparkFun Electronics.  As chance would have it, a fellow pilot and friend of mine was headed that way on business and offered to stop in and pick them up in person.

Prior to sending my friend, I called the shop and asked that they test the servos.  They indicated that they typically don't offer that service but they have a great RMA system.  I really wasn't crazy about buying out of state, sending a friend to pick them up and then play the RMA game.  So it was decided that we'd send a transmitter and receiver to test the servos at the time of purchase.

Of the the first 4 tested, 2 were immediately deemed inoperable.  Two more were brought out and one of those was found to be defective.  This went on and on until all their stock had been tested and 4 were deemed "good".  In the end there was a >50% failure rate!!

At $25.00, these aren't considered inexpensive in my book.  I've purchased a good 20+ "blue" micro servos for small gliders, foam projects and Slow Sticks and have only had 1 DOA.  While Hitec has offered to replace or repair (depending on how long you've owned them) this just isn't acceptable and they have yet to admit there is a problem.

So here I sit with 4 really small and quite frankly cool looking servos (love the clear case).  Can I trust that they will stay functional and put them in my brand new bird?  My plan is to test, test and test some more before my maiden voyage but that still doesn't give me a warm fuzzy.  In the end, I fear I'll be testing the Hitec warranty service.

Hitec Update (5/9/2014):  I began testing the 4 (believed to be good) servos in preparation for installation.  These were simply pulled from the box, and connected on the work bench to a receiver and 4 cell NiMH battery back.  Within 2 minutes, 2 began to show signs of jittering and unintended movement.  Centering became problematic and it was apparent these were exhibiting the same signs as the others that were tested previously.  The other two, while less pronounced, began to twitch within a few more minutes.

Not believing this was plausible, other servos (Futaba & JR) were attached and they worked perfectly.  A different battery and receiver were also used to simply complete the testing process.

Once again, trying to give Hitec the benefit of the doubt, I opted to call their service center in California.  I wanted to see what information they could provide and if they would facilitate a timely replacement.  Sadly I experienced just the opposite.  To protect the service technician, I'll refrain from using his name here but I did not receive what one would call good customer service.

Upon reaching customer service, I explained what I had experienced with the servo(s) and the process followed to test, prior to purchase.  I also referenced the blog posts and forums where they had been discussing the failures and frustrations.  Almost immediately before I could complete my sentence, I was told they were "unaware" of any major issues with this servo.  I was then told I must have installed it incorrectly.  I quickly interjected (restated what I had already explained) that I hadn't installed the servos, they had simply been taken out of the box and connected to a receiver.  He then proceeded to explain that I should squeeze the case to see if that resolves the issue...seriously.

In the end, the only options I was provided, were to return the servos to the place of purchase, or send them in for repair.  When I asked if they would send me advanced replacements, I was told they didn't have any stock and that they didn't expect shipment until the end of the month.

What is truly unfortunate in all of this, is that all Hitec had to do to keep me as a customer was to put on their "big boy pants" and admit they have a problem.  Stated another way,  simply take accountability, apologize for the the inconvenience and then provide a reasonable remedy.  We have so many options now days and the Internet just makes it that much easier to find a replacement.  For companies like Hitec to survive, I believe they must differentiate themselves and I for one expect not only a quality product but reasonable customer service.

SparkFun Electronics Update (5/9/2014):  After an extremely frustrating discussion with Hitec, I contacted SparkFun to determine how best to proceed.  To say this was a night and day experience is not an exaggeration.  I asked to speak with Bobby who I had dealt with previously in the technical support department.  He was attentive, apologetic and EXTREMELY helpful.  It is amazing how different the experience was between the two companies especially when you consider that neither have a true solution for me.

Knowing that it was typical to get store credit instead of a refund, I braced myself for the inevitable news.  But once again, to my surprise they offered to provide a refund (due to the circumstances).  And to top it off, they have already provided a UPS shipping label and pick up for the products.  Truth be told, I fully expected to pay the shipping charges.  Not that I'm complaining as I think this just indicates they are a mature, customer focused company.

Sparkfun, my hat's off to you.  I'll be back again guaranteed.  In fact I've already told 3 other potential customers how great my service was and what a fantastic selection of techno goods you offer.  Well done!  Oh and Bobby deserves a raise or at least employee of the month.

Dream-Flight Update (5/12/2014):  I also reached out to the creators of the Libelle to determine what information they might have as well as a suggested alternative if necessary.  George kindly took the time to respond and with his permission I'll post a portion of his comments for everyone's benefit.

"We have concluded testing/evaluating our own digital 4.3 gram offering that we hope to have available in June.

We will offer them as singles...in bundles of 4 and as a flight pack with the servo extensions and Rx battery.

Until then...with a little foam removal and a different length extension...we know from many that the D47 are working well. In the UK the guys have been flying the genning servos from T9 Hobbysport."

Note: While George was gracious enough to allow me to quote him he noted that most news and updates can be found on their website and Facebook page.

Hitec Update (5/12/2014): - Please see Mike's (Hitec) response in the comments section below.  He does explain the rationale behind "squeezing" the case and provides some much appreciated information on the state of the servo and their efforts to resolve the problem.  This is more in-line with what I've experienced from Hitec in the past.   Hopefully they can put the QC issues behind them quickly, so that we can get back to loving this little servo. 

The Libelle DLG by Dream-Flight - "Say hello to my little friend"

A friend of mine recently introduced me to DLG planes and while I haven't had an opportunity to fly one yet, they've certainly caught my attention and I've now watched many hours of YouTube video's and read my fair share of blog posts & reviews.  Sadly there is only a small following in my neck of the woods and local information is at a minimum.

My friend jumped in with both feet and purchased a nearly new Blaster 3.5, truly a work of art.  This was no small investment and soon enough it was determined that while his Spektrum DX6i is a great little radio it just didn't provide the flexibility and mixing to really do right by the Blaster.  This led to more research, a quick trip to a semi local DLG event for an experts opinion, and finally a new radio, the Taranis X9D.

After seeing the Taranis, it only took an hour for me to be convinced that I too needed one.  Mine is currently on a truck somewhere in the Mid West headed my way. I hope to be configuring it by the weeks end.  Now it just needs a new little DLG to fly, which brings me to the Libelle by Dream-Flight.

A little background first..backing up one week, we find my friend at the local park ready and anxious to fly his new bird.  I wasn't present at the time but I have received all the gory details...we've all experienced the walk of shame (caring the pieces back to the car, head hung low).  The plane is likely repairable but due to the hollow carbon wing, it will be challenging.

While the situation was a rare freak circumstance (he is a very talented pilot) it caused me to question my plan to plunk down 6-800 on a new plane, or at least not right away.  So the hunt was on for a less expensive option that would still give me some experience learning to discus launch.  Enter the Libelle ($120).  From what I've read, this should be a very good inexpensive entry into DLG.  While it won't compete with the big boys, it will give me the courage to get out and fly, and hopefully often.

I expect there is a Blaster, Neos or Snipe on the horizon for me but hopefully some time with the Libelle will lessen the learning curve.

More to come, as I'm still watching and waiting for USPS to deliver my new toy.

Build Review - Part 1