Turbo Timber 2M SWS – Part Six – Flying!

Turbo Timber 2M SWS – Part Six

With the Turbo Timber ready to fly I made an exception to my usual standard for maiden flying weather and  headed to the field on an exceptionally warm (72F in early March in Indiana) and rather windy day with solid 10-15mph winds with occasional gusts to probably 20-25.

I put in two flights, with each flight lasting around 7 minutes of actual wheels up air time.  I was very happy to see that both flights ended with batteries at above 60%!  Both flights were using my SMC 5900 HV packs.  I used a mix of throttle settings and manuevers with a fair amount of IMAC inspired aerobatics.  Only one real full throttle pull straight up and a couple of hover/prop hangs just to see how it handled it.  The plane did fine but my reflexes were a bit rusty with the gusty winds making things a bit more challenging.

My first impressions is that she is fairly fast.  The plane looks and feels very slick.  She picks up speed quickly and seems most comfortable to fly at a slightly higher pace than just your average trainer/high wing STOL in my experience.  She will slow down quite nicely with some flaps applied.  I’ll get a better feel for that when I can fly minus the winds at some future point.  Maintaining a comfortable speed at around 60% throttle seems to be a very economical cruise mode from what I can see in telemetry… drawing 10-30A which would result in 10 minute plus flight times if maintained!   This speed doesn’t look “slow”, nor does the plane feel sluggish if your just maintaining level flight and making standard turns.  I will add my GPS module soon and get some speed readings. She fairly jumps when you hit the throttle and is quite quick to all appearances.  Pulling straight up and rolling in throttle results in a nice steady vertical line if that is what you want.

After the first 7 minute flight, I was amazed to see my meter report a bit over 60% of capacity still in the batteries.  My timer was set for 5:30 but I flew past it, expecting the battery to end up closer to 25-30% but now I will push it up to 6:30 and try my 5300mah HV packs to see where the charge state ends on those.  Telemetry reported peak draws at 70 amps for one flight and 75 on the other while in flight so the ESC should be capable of handling that with ease. On the ground, restrained you can hit 90 or a bit more. That’s running a Xoar 15×8 E Prop which is extremely similar in shape to the supplied wood prop.  I wouldn’t be suprised if the supplied is also made by Xoar, as I understand they are a huge manufacturer in the field.

With those peak currents the ESC is reporting as high as 1400 watts and over 9000 rpm. Considering the motor is spec’d for 900W max, I wouldn’t want to hold that for a long period, but the climb rate is quite impressive so not sure why you would need to.  I see one near vertical climb I made which netted 290ft of vertical climb in 9 seconds…  so holding that for another 20 seconds is going to put you at 1000 feet and the airplane is going to be looking pretty small!  With any moderation at all, I don’t think the motor or ESC is going to have any heating issues… but we’ll see when the temps move from 72F or so to 90F here in a few months!

The receiver reported voltage stayed between 7.5 and 7.32 through both flights with the BEC temp running from 85-130F so I am happy to report that the BEC isn’t showing any strain in spite of a lack of any airflow in the area where the ESC is mounted.  I may eventually add some exit area just to encourage some modicum of air passing the ESC and maybe I’ll remount the ESC so the heat sink won’t be wrapped in hook and loop material.  I don’t understand wrapping a blanket around that to hold it when it has mounting tabs built in! 

With only 35 or so frame losses during the flying portions of each flight, the receiver seems to be getting good signal… though it occurs to me I have an extra remote or two laying around I might add just so when I do some glider tows to extreme altitude later on, I have have confidence in my control of the airplane.  Though there are two antennas, the 8360 is just one receiver so having a remote receiver I can mount elsewhere in the plane seems like cheap insurance.

Mental notes from the first flight include:

  • Possibly adding a bit more down elevator to the flap mix.
  • Bringing down the Elevator rates.  Mid rate had enough throw to cause a snap… something I normally reserve for a high rate setting.
  • Adding a remote receiver for “signal insurance”
  • Adding a GPS module (which I already own) to get some readouts on speed

That’s what I can report for now. So far she is flying well and I am enjoying it. Lots more fun and experimentation with crow, full span flaps, reverse thrust braking etc… coming during future flights!

Turbo Timber 2M SWS Part Five – Final Tweaks

Turbo Timber 2M SWS – Part Five

Having run through the majority of my checklist, I had a just a couple items left to consider. 

Originally, I had thought about making some servo/linkage covers for the TT, but on reflection I didn’t really think that was really necessary in this case.  With it being a high wing and keeping the wings somewhat cushioned from handling issues by storing them in wing bags, I am not really concerned about handling or field damage (on a low wing, sometimes the linkages would touch the ground during a less than optimal landing but not on this bird!).  Also, with the TT, I’m not expecting a lot of high speed flying so wind resistance or aerodynamic considerations are not really a factor so we will just check that box off and move on.

The next item was to add a glider tow release to the airplane.  I’ve had something similar on several planes and have a good handle on the proper placement and functionality needed.  The tow release is actually not the way you want to detach the glider from the tow plane, its simply an extra safety measure allowing the tow pilot another option in the case that the glider causes issues… release failure, erratic flight, or whatever…  and there is a need to quickly remove the connection between the two craft.

Placing the release toward the trailing edge of the wing is typically a good compromise.  Close enough to the CG of the plane to minimize the effect of the tow on the flight of the tow plane with plenty of avaialble structure to mount to and a clear path for the tow line to avoid any likely entanglement since the towed plane is typically above and behind the tow plane.  I had a nice tow release I pulled from another aircraft when I sold it, so all I had to do was create a mounting plate and assign a switch with appropriate endpoints and I was pretty much in business.  As I’ve done on other aircraft, I notched the trailing edge at the center of the wing to fit around the release.  Here are some pics of the installation.

I built the whole release mechanism out on a board cut to size to fit the bulkhead top to bottom brace dimensions and then glued and screwed it in…  Here is a shot of that installation.

Here is what it looks like with the wings notched to fit around the release.  I’ll clean up the notches a bit… maybe harden them with some glue on the exposed wood and then paint white or cover…

Another couple of items on my list are items for another day.  Having a camera mount would be nice to grab some video, but I’m still debating location(s) and how to attach the mount(s).  I may work on a design to use the glider tow release as one mounting point…  just don’t drop it by mistake!  Another option is in cockpit but the windscreen is curved and not perfectly transparent so likely I’ll look at something underneath instead… probably attached to the landing gear in some way.  But, I’m not in a big hurry for that.  Likewise, I’d like to put floats on the TT, but I have some time for that and I haven’t decided if I can adapt some floats I have or if I’ll dole out for the standard option available from E-Flite.  Likewise, I want to paint a prop with some matching colors to the scheme on the airplane but for now, my standard Xoar 15×8 is looking pretty nice so that can wait for another day as well.

Just as I thought I was going to concede that I was ready to fly this bird, I ran into a minor issue.  I was having trouble getting the prop nut tight enough to feel safe that the prop and spinner were going to stay attached… especially if I employ reverse thrust… without the prop spinning against the spinner backplate.  With a cowled installation like this, there just isn’t access to the motor to get another gripping point.  After some discussion online, I was reminded of an old trick I had employed before and had forgotten.  Taking some sandpaper and cutting out a couple discs and then gluing them back to back I created a very high friction washer.  Sandwiching this between the prop and backplate stopped the slippage and  allowed for a nice snug connection.

Of course, this was NOT the end of the story.  As soon as I had the prop and spinner properly attached, I ran up the motor and immediately noticed that the tip of the spinner had a very small “wobble”.  I verified that the motor shaft was running true so it had to be something in the spinner itself.  I have no idea where this went wrong… maybe in trying to tighten and hold the spinner, I damaged it/warped the backplate… maybe in manufaturing… whatever.  I found an appropriate location for the spinner… (I have several trashcans in my shop) and started looking for a replacement. 

I had considered replacing the spinner early on with a slotted spinner in order to increase airflow over the motor and so this was just an opportunity to check off that item.  I quickly found a couple of vendors out there for a nice spinner that promotes air flow and in a few days I had a nice spinner from Gator RC in my hands.  That spinner (57mm/2.25″ diameter) turned out to be a perfect fit, with the metal backplate fitting the motor shaft perfectly as well as eliminating the slipping issue AND no more wobble!

All that is left at this point is to check balance and throws and get a good day to get in the first flight or two.  Eventually, I would like to consolidate my various rate switches (I always start out with Ail/Elev/Rudder throws and expo settings on individual switches) but for now I want the flexibility to switch each individually and see what setting best matches the way I want the airplane to fly.  I’ll try to post some pics and report on how that goes but I have every reason to expect it is going to be a great flying airplane.  Here’s to a successful maiden flight!

Turbo Timber 2M SWS Part Four – Radio setup, modifications and repairs??

Turbo Timber 2M SWS – Part Four

There were a few things I felt I just needed to change right out of the box with the new Turbo Timber SWS.

My first thought was that I wanted to take advantage of the electronics provided in this newest iteration of the Turbo Timber.  To that end, I started down a long list of adjustments I wanted to make.

First, I did a bit of programming on my radio.  Starting with a template I created from the program I had based on the Grand Tundra, I checked all the settings were adjusted per the manual.  Using the template gave me the voice prompts and standard switch locations I would normally use without having to manually reenter them.

 I always like to have my ailerons on separate channels when I have the channels available but in this case I also wanted to do it to allow for a bit of crow mixing.  To allow for this, I adjusted my wing type  to 2 aileron, 1 flap.  I didn’t bother to split the flaps as they are not hinged to deflect upwards anyway so there is not much to gain.  One accomplished, I removed thy Y harness and wired the ailerons each to their own channel making sure to get the correct aileron in the appropriately labeled channel.

Next up, I wanted to enable the reversing function of the ESC.  I attempted to enable this using the ESC telemetry programming screen that normally is available as the last telemetry screen you will find if you scroll through all the Telemetry screen with the airplane and radio powered up… but to no avail.  The screen just wasn’t there!  After some troubleshooting, including rebinding, upgrading my radio to the latest software, etc… I realized that the ESC was loaded with very old code.  I was a bit iritated with this, as that particular function has been out for a very long time and I would have thought by now, Horizon would have made sure all the shipping product had that code already loaded.  But apparently not.

I then pulled out my trusty ESC programmer and connected with my laptop and updated to the latest version.  Following a power cycle, “bingo” the programming screen was now available!  I adjusted the braking method to allow reverse with the laptop and programming box but inevitably realized after disconnecting and packing it away… that there was another setting or two I wanted to adjust!  For one, I wanted to move the reversing function to a higher channel to eliminate conflicts with other radio functions I might want to program on the lower channels.

No problem, I simply went in with the radio and scrolled across to the ESC programming screen and entered the menu via the indicated stick motions… or maybe not.  After a couple of attempts, I recalled that you need full channel output to get this to work so I adjuted my switches to max throw and again, things were looking up.

As I was scrolling through the options, I realized there were a few other things I wanted to adjust.  So while I was in the screen I adjusted the brake/reversing function to channel 10 as planned,  but also disabled the auto cell count function and disabled the voltage cutoff feature.  If you think that’s a bit unusual, let me give you the brief logic.  First, I like to run the new HV Lipo batteries from SMC and I have seen ESCs that will mistake an HV 6S for a 7S and if the cutoff feature is enabled, this can lead to a cutoff occuring very early in the flight.  This can be dangerous, especially to the airplane’s health!  Throttle being cut just after takeoff is not ideal. 

Second, if I have to make a choice between damaging my batteries due to overdischarging them but managing to eek out enough power to get my airplane down safely… or having the ESC protect my $90 battery at the expense of trashing my $800 airplane… I think you can guess what I pick.

I also set the BEC output to 7.4V instead of the default 6.0V.  The servos in this bird are high voltage and the vast majority of Spektrum receivers (including the 8360T provided) are capable of working with a wide range of voltage inputs.  With this equipment I would always favor a higher voltage setup.  For reference, volts times amps equal watts (which measures power).  So you can provide the same amount of power supplying a higher voltage with less current draw and high current often exposes any flaws in the electrical system.  For instance, many connectors can easily handle a higher voltage than we require but when they have to pass higher current they begin to heat up and the excess heat causes failures.  So as strange as it might sound, if the electronics are designed for it, I believe using higher voltage is easier on the system.  High current causes problems that an appropriately high voltage does not.  Also pulling less current to do the same work means longer flight times, assuming the extra battery weight to get the higher voltage isn’t prohibitive.

On a related note; I am always torn between using separate flight pack batteries (usually a 2S LiPo) or letting the ESC provide the power on 6S powered aircraft.  At the typical size/weight range of a 6S bird, you are approaching airplanes that can typically handle the excess weight of a separate battery pack to provide power to the servos and radio gear without noticable effect on wing loading.   Also, separating this function relieves some of the load on the ESC as well as providing a level of fault tolerance if the ESC should fail or the main fligsht pack gets disconnected, etc…  That’s the positives of using separate receiver packs.  On the downside, it adds weight to the airplane, adds expense to the setup (additional packs, switches, etc…) and adds a bit of complication which weighs in against reliability.  Complicated things just fail more often.  When I move up to higher cell counts I default to a seperate power pack (or two) but 6S is right on the border for this setup, in my mind anyway.  For the TT SWS I do not plan on a separate pack, so setting the ESC to high voltage is what I believe is the best option.

Once finished, I moved on to wiring up my multi-connectors to make the wings easier to attach and detach along with cleaning up a bit of wiring.  This presented a bit more of a problem than I anticipated.  First, I made the connections between the three servo wires exiting the bottom of the wing and then wired up the other side of the multi-connector to the receiver.  Doing a trial fit I realized that there is a bulkhead that touches the bottom of the wing in between the wire for the lighting and the wires for the servos.  I thought about notching the bulkhead but I didn’t like that idea so I went to plan B and pulled the lighting wire back up to the flap servo hatch and then fished it down along side the servo wires to make them all emerge at the same exit.  Here’s a couple of pics of the process.

Here’s the original routing with my multiconnect already plugged into the flap and aiileron wires.

 

I used a wire to snag the lighting wire from the front portion of the wing back into the flap servo pocket.  I then pulled the servo connector end of the wire back to this point.

Following that I looped the wire through large nut (a convenient heavy weight to help with the process) and lowered and shook the wing to get the wire to drop down to where I could snag it and bring it out to the wing root.

 

At this point I removed the nut and fed the wire through the same hole in the bottom of the wing that the servo wires emerge from.  Problem solved.

Once I got those connectors in place, I remembered a problem I had with the smaller Tundra’s and which will be amplified by the size in this case.  That is, when assembling the wings and plugging in the wiring, you must hold the wing up out of the way and even with only two connections to make, this can be a bit tedious… especially if there is wind trying to grab that big wing and throw it on the ground!  I’d seen a few approaches to fix the problem and I liked the idea of attaching the connectors inside the airplane so that I could connect each connector with one hand.  After a few measurements, I created a bracket that holds the connectors in place in the airplane and can be disassembled if needed for any sort of repair.  I used my trusty 3D printer to create this bracket and used some canopy glue (which can be removed in a pinch but holds plenty tight for my purposes) to help hold it in place.  Here’s a pic of the installation.

At this point, I recalled that I wanted to have a way to switch the landing lights (these are located in the cowl) off and on.  I had this on my Grand Tundra, and enjoyed it.  So I moved on to connecting up a small in-line switch (the PERS v2 from Hansen Hobbies) to allow me to switch that output.  After inserting the PERS, I noticed the landing lights were flickering and soon one and then the other winked out.

To me that seemed… to use a technical term… BAD!  I pulled the PERS back out and connected back to the standard wiring… no go.  I then got a separate battery… nope.  OK, so what the heck… then I recalled that ESC voltage setting… 7.4V… instead of 6… hmmm.  I guess the LED circuit wasn’t designed for the higher voltage… even though every other component of the airplane is!  Even though every other LED seems fine!  Yes, Horizon Hobby didn’t tell me to do that… or that I even could.  But, I still think they could have done better on this one.   

It was a bit of a job to replace the LEDs… They were glued in very well.  I ended up crushing them with pliers to break them up and then drilled out the remains before gluing in replacements.  With an appropriate resistor in line with each to limit current appropriately at the higher voltage, things brightened up nicely and putting the switch in line was easily accomplished without issue.

At this point, I was getting pretty close to finishing up with all of my setup for the TT SWS.  Next time, I’ll try to wrap up this series with my final few items before she has to sit in corner and wait for some nice weather.

Turbo Timber 2M SWS – Part Two (Inspection and Possible Modifications)

Turbo Timber 2M SWS – Part 2

As I was ordering, unboxing and just enjoying looking over the new addition to the fleet, I was reading and thinking and starting to make lists of possible updates, upgrades, modifications and accessories that I wanted/needed for the new airframe.

Its pretty cold and windy here in Indiana in the wintertime (Jan-Feb) so my available hobby time was in the shop or attending swap meets when possible.  Often I was going to the swap meets and selling stuff to pay for the TT SWS!

While I was doing all that I started compiling a list of things to consider changing/adding as I assembled the airplane.  Some came from reading about it on line, some from my experience with similar airplanes and what I knew about this new one and some came up during my unpacking, inspection and assembly.  So here is my list, in no particular order along with a few notes.

  1. How to attach the landing gear “spats” to the aluminum gear.  – I’ve already seen videos where they fell off on the first flight or landing or both.  I don’t think glue is going to handle this by itself.
  2. Install a light switch? – I had one in line with the landing lights on my Grand Tundra and it was nice to be able to switch those off and on separate from all the other lights.
  3. Crow?  – If I separate the two ailerons onto individual channels I could have full span flaps and crow if I wanted them… there’s some other mixes this enables as well.  Of course this plane doesn’t need any of that… but I could.
  4. Replace the ugly yellow wing bolts. – The yellow bolts just stick out like a sore thumb against the pristine white covering.  Black would look more in keeping with the color scheme as it exists so if I don’t have some whiter nylon bolts available I can go that way.
  5. The wood prop that it comes with is labeled 15×8 and looks remarkable like, other than being a tad shorter and not as shiny a finish, a Xoar E prop.  I happen to have a Xoar 15×8 in the drawer brand new so I could swap and maybe paint the stock prop to look nicer.
  6. Replace the wheels/tires.  – I’ve seen complaints on the tires being to hard but I’m not a fan of the inflatable types on this size/type of plane because they are hugely heavier than these.  If I have any other options laying around or if the new tires are really hard I can look around for a good light replacement.
  7. Servo Covers  – I’ve had a plane or two that had little 1/4 of an egg shaped covers or cowlings that shield the servo arm/linkage.  They look nice and are nicely aerodynamic.  I also like the protection they give the linkage/servo when the plane is in transit…
  8. Floats – I’v sure the TT makes a great float plane.  I love flying on floats and I have 3 or 4 sets around the house in dusty crannies… If I can find some that are a good fit I might adapt those.  Could always spring for new ones too…
  9. Add lights (interior).  – I would like to light this thing up internally to make it easier to fly at dusk and beyond.  
  10. Multi-connectors for the wings.  – I have some hanging around already and have the ability to tools to make more.  I know how much easier it is to connect/diconnect the wings when you only have one or two keyed connectors to plug in.
  11.  Spinner  – I had another plane recently that used a slotted spinner to increase airflow to the motor and love the idea of keeping the motor as cool as possible for long life and good performance.  Need to see where I can get one and at what price.
  12. Wing bags  – There are no wing bags with the airplane and a good set is really needed to keep things looking and functioning like new for a long period.  I need to see what I have around and if not, will probably order something.
  13. Identification  – Just a reminder to make sure I add my FAA registration as well as my AMA number.  Don’t want to run afoul of any regulations that will keep me from focusing on having fun when I’m out to fly.
  14. Personalization  – I pretty much always do something to separate my bird from the flock and this one will be no different.  Intially I’m thinking of stripping anything that is an actual decal and then add some stripes/pin striping or something similar made from vinyl or RC covering rather than water slides.
  15. Camera Mount  – Sooner or later I will want to put a GoPro or two on the plane and get some video so need to start planning location and method of attachment.
  16. Clean and Wax  – I have found that, especially on foamies but on covered aircraft a well, if you give the plane a good coat of wax… something like a good map on floor wax… less dirt clings to the airplane and it is easier to keep clean.
  17. Glider Tow  – Towing gliders is great fun and this plane looks like it would server very well for this.  I just need to figure out a mounting plate I can put near the trailing edge of the wing (top) and get that in place and controllable from a switch.

There are bound to be other things that pop up as I walk through the assembly so I’ll be back in the next part to talk about my assembly process as it proceeds and also comment on the above items as I address them or decide not to… as well as resolving any of those discovered issues.

 

 

Turbo Timber 2M SWS – Part One (Buying and Unboxing)

Turbo Timber 2M SWS – P1

I have long been a fan of versatility in an airplane.  I love aircraft that have a wide flight envelope, can fly for a good while if you keep out of the throttle, can tow a glider, haul a payload, fly off grass, snow and/or water, and look pretty good doing it!  For that reason, I have had many planes that to some extent fit that description.  I had my Telemaster 40 rigged with a bomb drop, glider tow release, floats, etc… over the course of serveral years and had several of the Timber line of aircraft, as well as the Grand Tundra and some others…  The Grand Tundra was my everyday airplane filling that role for a good while, but it was never a partiuclarly attractive aircraft and it is foam… I know a lot of folks thing that is great, claim they are easier to repair, etc… but I am in the opposite camp.  I would always prefer to work on a wood airplane.  Once its broken/bent/scraped and battered, I find it much harder to get a foam plane back in shape.  I know partly that is because I hate the sanding and finishing work it takes to make a foam plane look good.  Without a huge amount of work, a foam plane just looks like… well… foam… and once you compress it and tear it… lots of work involved to get it back looking decent… flying maybe but no exactly straight or pretty without a lot more work than I want to do.

So, when E-Flite dropped the Turbo Timber 2.0 SWS it caught my attention.  It is almost the perfect plane, on paper. 

I prefer Electric power to anything else these days (check).  I love anything that uses 3S, 6S, 8S or 12S as I have the appropriate batteries for most of these already in hand.  6S aircraft in particular often fall into a sweet spot of large enough to fly well, easy to haul and inexpensive to operate with high quality 6S batteries being easy to get at good prices these day.

I have been using more and more of the Spektrum electronics in my planes.  The ESCs have all the features I want, including some useful telemetry when combined with the Spektrum receivers I’m already choosing.  They also have some good servo lines and what seem to be good motors and this has all of that as part of the package.

Wood construction covered in good quality iron on covering with a nicely visible scheme.  This means the airplane just looks better than most foamies ever will.  Plus a wood airplane is often just stiffer with less material involved so ends up holding its shape better under G loads… at least that is what I believe.

Thus began my determination to get one…  Several planes went up for sale, along with assundry other items laying about the shop… bye-bye Grand Tundra and hello TT SWS

First of all, I know some folks are going to say… “The price is to high!”  and I get that.  But, my feeling is… aside from I’m getting old and everything seems high to me… the price actually seems very fair.  Especially when you buy the ARF like I did.  The electronics that they chose in this airplane seem to be pretty high end.  The Spektrum line of ESCs, Servos and Motors all seem to be good quality.  My experience so far with their ESCs has been nothing but positive and I have several.  I especially enjoy the programmability right from my transmitter and the available telemetry is something I consider to be a must in an electric aircraft.  You have to combine them with the compatible receivers to get all of this but I would have bought that or a very similar receiver anyway!   I will point out that I do not have, nor want the Spektrum batteries and chargers and don’t see the value to justify the cost of that part of the Spektrum product line.  I have done a lot of study on LiPo batteries and I have a couple of favorite brands I purchase from at a much lower price and better performance than anything Spektrum has produced so I don’t expect that to change anytime soon.  The servos have great specs for the price and while I’ve only had a few, so far so good.  I don’t think I’ve owned any of their motors yet, but they appear to be well built and I’ve not seen anything that would give me pause… so the ARF comes with equipment I would likely chose for myself so all in all the bundle makes sense to me financially.

So a few days ago I figured out how to get a 10% off coupon which aligned well with the balance in my “RC fund” as a result of some sales at a couple of swap meets and Facebook marketplace adds and the order was placed.  I also got lucky and caught it in stock for what I understand was about a one day window on Tower Hobbies web site.  I think this was the second shipment they received and the ARFs didn’t last long!  I settled in to wait the predicted 2 weeks or so for free shipping and started looking for any discussion groups or video reviews that I hadn’t already read.  That lasted for about a day when suddenly I got an update saying it was shipped via Fedex!  Being only 100 or so miles from Champaign, IL where Tower is based has some advantages and the predicted arrival was 1 day!  It got confusing for a bit as Fedex seemed to decide it hadn’t shipped after all then changed the expected arrival day two or three times until finally it actually showed up after only 2 work days!  Yahoo!

I was a bit concerned when I saw the box had a corner torn out…

It turned out the outer corrugated box had done its job and protected the contents and even the inner box with all the pretty graphics was in like new condition! 

Work got in the way and it took me the better part of 2 days to unpack the box and another to unwrap all the parts and lay them out on the bench.  It may have taken a few hours just to clean the bench and make room to do this but much of that was done while I attended to some conference calls with my headset on.  Having a new airplane all layed out on the table right behind you can be distracting but I managed to at least do my cleaning chores and some unwrapping while paying sufficient attention so a few business calls!

Here’s some pics of that process to give you some idea how well the packaging worked out… Everything seems intact with nothing beyond a scuff or two… that’s about as good as can be expected for a shipment from (I presume) China all the way to the midwest US.

Just taking off the lid…

Wings out and down to the tail sections… everything taped down to minimize shifting/scuffing.

Tires, LG, all the hardware… bags in bags to keep things separated.

Notice the wings have guards over the servo linkages to keep those from digging into anything else… nice.

Front and back of fuse are embedded in foam to keep it away from box sides…

With tail pieces removed we find the cowl (fiberglass) nicely protected/wrapped and secured in place.

After removing the cowl and body… down to the bototm of the box where we find the prop and wing tube.  Prop looks like a copy of a Xoar (or maybe made by them??)  Finish on the prop is not quite up to Xoar standards and the length of the blades is a few mm short of my actual Xoar but the basic shape and profile is very close.

All the parts on the table… awaiting unwrapping.

Now free of all the plastic wrap… not a lot of parts.  If I was in a rush maybe a 2-4 hours and I could have it done??  But I am being meticulous on this one so it will take much longer.

I’ll break this up at this point and start on my next steps with the following disclaimer:

I’ve seen enough on the lists and video reviews and such that I am confident in saying that you could easily (if you have much experience at all) just go through the directions provided in a few hours and come out the other side with a perfectly serviceable and good flying, completely stock, Timber 2.0 SWS…. but that is just not how I roll!  I’m not big on doing modifications just to do them, but I like to do what I think will result in the airplane having a long life… no silly crashes because someone didn’t tighten a bolt… and I want it to be just a little distinct from every other similar airplane at the field.  I also want to do what I can to make it run efficiently with adequate power and flight time, and as easy to transport and assemble as I can without to much effort.  So next up will be an inspection and a list of what I see that I might check/change or modify to make this airplane uniquely mine and to help make it last (I hope).  Some other setup/changes will be to suit my intended purpose(s) without getting to drastic.  And I’ll be picky and try to fix anything I see that jumps out at me as being “not to my standard”.

1.2M P47… The latest addition

E-Flite has been updating a number of their existing warbirds in this size class to include the latest round of upgraded electronics, including 3 and 4S capable power systems, upgraded digital servos and often a livery change and/or some tweeks in response to past user feedback.

It was inevitable that they would eventually get around to one that I could not resist and of course the the P47 is the one for me.  I consider it the ultimate WWII aircraft.  Showcasing all that allowed America to come out on top in that epic struggle, it was powerful, fast, tough and reliable, heavily armed and armored and we made a bunch of them!  (15,000+ I believe)  Many were assisted down the assembly line by my Grandfather in Evansville, Indiana!  How can I not love the Thunderbolt?

P-47 Razorback 1.2m BNF Basic with AS3X & SAFE Select

So, as soon as they started rolling out the newest version, I put one on order with my local hobby store.

After about 10 flights with mine.  Here is my list of what I really like and dislike about the new bird.

Good:

The new electronics are great.

Upgrading to a 4 cell power setup gives the bird the power it needs to perform like a warbird

The new SMART ESC and AS3X receiver allows for plenty of data to keep an eye on battery usage, temperature, etc… to insure she continues to fly well. 

The servo upgrades seem to work with precision and the plane just overall flys nicely as a result.

Weight.

The plane is actually pretty light, especially considering the available power, even when you load all the armarments on board.  It keeps the airplane relatively light on the wing which results in easier takeoffs and landings.

Livery.

I’m sure there are some who were hoping for somethin different but the Kansas Tornado is a reasonably easy to see and, at least to my eye, attractive scheme.

Prop.

It seems to be almost imposssible to fit a large enough 4 blade prop on a model P47 to look really scale but at least we got a 4 blade with a somewhat appropriate shape!

Bad:

Retracts.

I do not understand why E-Flite wouldn’t have put a few dollars into the retracts to give them working Oleo struts.  As light as the bird is, they would not have had to take much abuse but it sure would be nice to have something to take a little of the shock in the case of a poor landing.

Tires.

Combine the lack of functional struts with these rock hard tires and you have zero shock absorption in the landing gear.  Are decent foam tires with “any” give whatsoever so hard to source?  Add to that the pressed in diamond pattern on the tread which looks just silly…  OK, maybe I’m being overly dramatic, but it seems so easy to have done it right!

Prop.

While I like the general idea of a 4 blade and I get that properly sizing one for scale looks is difficult, I don’t trust any airplane where they claim you can run 3 or 4 cells without a prop change.  I mess with prop changes frequently on my aircraft to get the performance I want so I’m very aware that adding 33% more input voltage to the same prop means you have made huge sacrifices somewhere.  Likely its just a compromise that is mediocre for either.  It would have been nice to get 2 props with the aircraft… each actually matched to a 3S or 4S setup.  My observation so far is the prop is probably overloading the 4S setup a touch and pulling more current than it needs to and likely underloading the 3S setup and therefore not getting as much power out of the system as would be possible with a correctly sized unit.

Fuel Tank.

I like the removable rockets and bombs, but why is the centerline fuel tank fixed?  I took care of that issue, but my solution is a bit more permanent… involving some side cuts.  The plane flys even better without any of the extra drag and that is how I fly it most often.

Overall I am enjoying the P-47 very much and I am already keeping an eye out for some replacement struts and/or tires… even if I have to turn to my 3D printer to solve the latter.  She flys very nicely and with the AS3X in the background, is especially stable even with some adverse meteorological conditions.

I have been flying more and more on my 4S 2800 LiHV packs and with proper throttle management, nice 6 minute flights are the norm.  I’m just getting comfortable enough to be working on nice scale takeoff and landings as well as experimenting with making the manuevers more scale like as well.  She can certainly fly like a sport plane if desired so making scale manuevers is something you have to be intentional about.

As I get more flights on it and make any modifications, I’ll be back to report but overall I expect this bird will remain in my fleet for some time to come.

New Freewing JAS-39 Gripen… Good, but not my cup of tea.

I recently aquired a Freewing JAS-39 Gripen. 

Up until recently, I have never been particularly interested in flying EDF aircraft but with the latest updates in battery technology allowing for more and more energy per ounce of battery and the shift toward more and more of these type of aircraft being available in ARF or RTF foam bodied airplanes I have begun to consider having one or two in the fleet.  I did some research into available A10s and didn’t find one that really met my personal requirements.  Same for a couple other models.  In the end it came down to an impulse buy from another club member at a nearby swap meet.  He had an airplane that had always interested me and it was essentially new and at a good price.  Not least of all, there is going to be an EDF only event at the field this summer so I wanted to have something nice for the event!

As with most warbirds that I purchase, I did some research on both the real airplane and the model.  First, about the real airplane.

The Gripen is a swedish multi-role fighter that is largely considered to be one of the top two most capable fighters in the world (the late model F-16 is the other and they stack up very well against each other) if you exclude stealth aircraft.  By most accounts it is one of the best gen 4 jets ever built and it continues to be upgraded.  Its distinctive canard design and power to weight ratio make it a very capable dog fighter and the advanced electronics packages and flexibility of weapons payloads make it an extremely dangerous opponent in BVM (Beyond Visual Range) combat.  The F16 is also a very nimble and highly powered platform with similar capabilities… it just gets there by having more thrust to offset its heavier and larger chassis.

As far as the model goes, research says this airplane has a lot of capability depending on how you set it up and fly it.  There seem to be three common complaints from those who own the airplane.

  1.  It is rather large as compared to other aircraft running a similar power system which leads to complaints that this results in it being a bit heavy for this system and therefore not as high a thrust to weight ratio as some would like.
  2. Using the recommended battery size and capacity results in an aircraft that is nose heavy compared to the recommended, which results in an inability to perform certain manuevers.  A select few who seem to be well respected say even the recommended balance point leaves the plane significantly nose heavy.
  3. Using the recommended battery also results in short flight times… perhaps even compared to most EDFs which are somewhat notorious for short flight times to start with.

I’m not as concerned about the first issue as I haven’t done much EDF flying and am not all that fond of high speed so while I wouldn’t mind to have some extra punch available to me, I’m not looking for a lot more speed than is necessary to make the airplane fly well… and it seems to be capable enough by that measure.

Items 2 and 3 are somewhat of a concern and are of course intertwined.  In most electric aircraft, you have the option to add a bit of battery capacity if want to extend flight time, but with this airplane, adding a larger capacity and therefore heavier battery will just exacerbate the nose heavy condition as the battery is in front of the balance point and can not practically be moved rearward to compensate.  I don’t like extremely short flight times and I would like to explore some high alpha flight which requires a proper balance point to perform.  In addition, since the airplane is already a bit on the heavy end of things, I don’t really want to add dead weight to the tail to force the balance rearward.  There was no apparent solution…  Welcome to the world of EDFs and aircraft design I guess… Everything is a compromise.

Further research along with some fortuitous timing led me to what I hoped would be some improvements.  I won’t go into a lot of long winded discussion… maybe another post… but the answer seemed to be to use a battery that housed a bit more energy with minimal weight penalty.  The best thing available looked to be the SMC LiHv packs so I ordered a couple 6S 5300s.  They are no heavier than many other 4500-5000mah packs and pack a bit more punch than standard LiPos due to the HV cells.  Best I can tell, they are the bomb!

I flew the Gripen for just 2 flights.  It took off beautifully from our Geotex runway and tracked nicely in the air as long as you kept a good amount of power on it.  You could slow down pretty well and the plane would continue to fly but it starts doing a bit of rocking which indicates you are approaching stall.  That is a good thing compared to many jets who (as I understand it) just drop a wingtip and stall with less warning.  Credit to the aerodynamics of that big delta wing I suppose.  Visibility leaves a lot to be desired between the gray and the arrowhead body shape, there isn’t much to keep me oriented aside from keeping it close.  I added some extra markings between flights 1 and 2 which helped but to get much better I’d really have to do some thing drastic.

And then I had to land it.  I probably carried more speed than I had to but again the big delta wing makes itself known during the flare as you can really get into a fairly nose high attitude as you land which results in smooth landings with little load on the gear.  Both flights the landings were really pretty.

I didn’t really get a chance to do much trimming or playing with rates and mixes as the flights were by necessity short as the power system is typical from what I understand… which is to say inefficient and power hungry!  The good news is it apparently needed little to no trim so I didn’t need much trim time!  By the time I got a bit comfortable with it I was on approach.

I flew the first time for 3.5 minutes before landing with a decent battery margin and the second time with a bit more crosswind and holding a bit more speed during the flight for only 3 minutes.  The first time I had a decent margin of capacity left but not a ton and the second it was a bit lower than where I normally like to land.  This is just far to short for me.  I couldn’t get the plane up and comfortable with enough time to actually explore much of the flight envelope and I also didn’t like how fast it has to fly in order to fly well.  That also left me no time to try out different mixes, play with high alpha manuevers etc…

Maybe I could adjust to it eventually… but I don’t think I’d ever be really happy with flying it.  Having a fast flight regime is great, but I also want to be able to fly slow and gentle.  I have planes that can do both but I don’t this is ever going to get there.  I’m also concerned that if I try to push it to do what I want it to do I’ll find the hard edge of control one to many times and crash the plane.  There are just to many other planes I would rather fly and/or want to own to hold on to this one.  This one flys to much like its scale counterpart… fast, powerful and heavy.  I don’t think EDF fighters are for me.  For those who like these type of airplanes, I suspect there will be some folks who will love it.  Just not me.

Maybe an A10 or L39 someday…  In the meantime, anyone interested in a low mileage fighter?

Full 3D Printed Airplane – Chapter 1 (Printing)

I’ve had a 3D printer now for a couple years and printing some add on accessories for my RC aircraft was the main reason I purchased it.  Cockpit details, air scoops, replacement plastic parts for broken scale details like antennas and the like have all been projects I have tackled successfully using my 3D printer.

My particular printer is an Ender 3 with the only functional modifications being a v4.2.7 motherboard, a glass build plate and some updated build plate springs.  The base unit can be bought several places and I recommend it as a beginner hobbyist platform.  From what I have seen, it is widely accepted as a great device in this role.  Here is my link to purchasing the current version of this printer from the Creality Store via Amazon.

At the time I purchased it, I was not particularly interested in or really aware there were very many options for printing a full RC airplane.  What I had seen were overweight, ugly airplanes that seemed to just barely fly.  After a time I heard about a new material that made it more feasible to print something that might actually approach a reasonable level of functionality… something called Light Weight PLA.  Here is a link to what I purchased.  There are other brands out there but eSun seems to be a well accepted as a quality product and I don’t have enough experience to accept the challenge of sorting out more factors than I needed to when I was embarking on a new adventure so I went with what seems to be a premium material.  Here’s a link to that:


So of course I purchased a roll of filament and quickly decided it was going to be to complicated to set up my printer to work with it.  Also my printer had such a small print surface that I surely couldn’t print anything of any size… so the filament went up on shelf to gather dust.  The reality was somewhat different, but I wasn’t wrong that with my level of knowledge at the time, I probably wouldn’t have had good results.  

Fast forward a year (or maybe 2??) and I happened on a YouTube video showing a really nice looking airplane that was 3D printed!  This got me thinking, maybe it was time to revisit the idea.  I had learned a bit more about 3D printing and felt I was ready to take the plunge.

So for a week or so, most of my recreational video watching was of 3D printed airplanes and fair amount of web research turned up some interesting information.  There were quite a few sites that espoused particular parameters and setups to get successful prints for LW-PLA and there were a number of free designs around.  What finally made me open the box was when I came across a free download from Eclipson

The 3D printed aircraft designs on their site are exceptionally nice looking… rivalying the available ARFs on the market from even the top tier companies using more traditional techniques.  They do charge for these files, but the prices seem very reasonable for the level of quality they appear to represent.  Their website is very well built and presents their product very nicely with lots of pictures and available information. 

Time out for a rant… feel free to skip to the next paragraph.  The only thing I wish for, and I may be completely alone here, is a nice manual to help me build.  They do a one page sheet that has a lot of information packed into it that is very helpful, and there is a good build video but for me personally, I hate build videos.  Especially videos with no narration or discussion like this one.  This one is as good as any I’ve seen, but I would much prefer a well illustrated and written step by step assembly book.  I’d even pay for one in addition to what is available if it was well done.  I find it hard to keep stopping  and starting a video… finding a way to backup and find that one part I’m looking for… stopping at just the right point to see what I want to see… Its all just a PITA for me.  I know some folks would rather have the video… I’m NOT one of those.  OK, rant ended.

Best of all, by all reports, the Eclipson aircraft fly very well.  What really got me out of the starting blocks was that they even provided ready made Gcode for their models, preset to work on my exact printer!  Its like just feeding in the files and hit print and out pops an airplane!  Ok, well maybe not quite that easy but it does get you around having to learn all the parameters necessary to print good quality aircraft parts using this material.  Certainly tweeking their settings a bit could make the parts even a bit better, but what I found was using their exact settings produced parts good enough to actually function.  Or at least it appears so to me.  I don’t mind learning about all the parameters and figuring out how to dial in my printer to produce my own good LW-PLA parts, but I like it even better if I can do that while another perfecty usable part is being produced!  Icing on the cake, they have one airplane you can get the files for simply by signing up!  This airplane is the Wolf.  This RC design is based on a german glider design first produced in 1935 and motorized for RC use.  So I signed up and downloaded the files.

I began printing parts from the supplied Gcode and occaisionally I’d tinker with my profile and try printing my own part just so I’d have that ability in the future and because in one or two cases I realized I could print the part just a bit better if I tuned the settings for my particular printer and material.  For instance, my eSun White PLA (that I used to print a few parts that needed more strength… per the instructions) happens to print better at 5 or 10c higher temp than the supplied Gcode is setup for.  So I pulled up the STL file provided and used my profiles I generally use for PLA+ and printed out those few parts with my own Gcode.  I suprised myself with how well those parts printed out.

Here’s some obligatory “parts being printed” photos..  All of these are using the eSun LW-PLA+.

First section of the port side aileron getting underway…

Here’s another section of the aileron

And this is obviously the vertical fin.  An exceptionally nice print if I do say so myself.

Up to this point, I had only printed some of the smaller parts of the airplane.  But if I want to have an airplane I have to tackle the big parts next and in my experience, big parts take a lot of time to 3D print.

I’m not typically impatient when building an airplane.  I don’t mind if a project is sitting on my bench for a while waiting for some necessary parts to ship in or whatever.  I can always find another project or a different aspect of this project to keep me busy.  I will admit however that I was a bit troubled by the thought of how long it was going to take to print all these parts.  I have done some moderatly large parts on my printer before that took 14 hours or more!  Looking at the airplane I was afraid weeks of printing overnight would be involved.  Luckily, once I tried it, nothing could be further from the truth.  I quickly realized that because of the way you print these, there is very little or no supports needed/desired and not much infill either.  This results in parts printing much faster that I expected.  I printed the first dozen or so small parts over a weekend and I think I got all of the LW-PLA pieces (by far the largest part of the airplane) done during a single week of just part time printing while working on other things.  Honestly think I could print all the parts in 3 days now if I really tried.

The final piece or two I needed to print, was the tire and hinges.  These pieces need to be printed  from something a bit more flexible and in the 3D hobbyist world that means TPU.  TPU is about the closest thing to rubber that we can print on a 3D printer and it demands yet another totally different set of printer settings.  After reading a bit on the proper settings, different brands and types of TPU available, etc… I decided to give it a try.  I had gained a little confidence through the process of printing the LW-PLA so I made the leap.  Another order to Amazon and the very next day I had a fresh role of eSun TPU95A in gloss black.

With my very first try, aided by the suggested settings from eSun and a small tweak or two based on articles and videos on line, I had my very first TPU print… a test piece based on a video from a youtuber named CHEP.  It looked great and did point out one small wall adhesion issue so I tweaked one more setting and tried printing my tire.  It worked well enough on the very first try.

As I went through and “post processed” the prints, removing some skirt material and sanding a couple of spots, etc… I did manage to damage a part or two and had to reprint a couple as a result.  The parts aren’t perfect and I have some ideas about what I might try to do differently if I do another airplane down the road, but I think it might actually fly some day! 

After assembling the needed RC gear and a few other necessary supplies (more on that in a follow on article) I had this pile of parts sitting on my bench… time for assembly!

3D printing add-ons for the Freewing JAS-39 Gripen

I recently acquired a Freewing JAS-39 Gripen (Griffin for us English speakers).  I’ve never had much interest in EDFs but why I have it and what possessed me to buy it is a topic for another post.  For my purposes here, it is enough to say I have one and I wanted to make it look a bit more formidable by adding some weaponry, help out with balance with a little added weight to the aft of the balance point and just add some scale touches at least for display purposes.

Luckily, there are some readily available STL files.  STL files are the output of a CAD program and are what you need to input to the slicer software which produces the G-code files.  The slicer software parses through the STL file to decide what instructions to send to the 3D printer to create the shape and creates a list of those commands which is your G-code file.  So, having the STL files means the hardest part of 3D printing what I want (the actual CAD design work) is done for me!

I printed a couple of Iris-T missiles first using some white eSun brand PLA+ filament.  The Iris-T is the European equivalent to the US Sidewinder missiles.  Both are extremely smart, relatively short range heat seeking air to air missiles.  The Gripen can carry either but I decided to start with the more “native” weaponry.   These are almost always carried on the wingtip hard points on the Gripen and since the wing tip hard points are already in place on the model, it made sense to start with something for those stations.  They came out pretty well with only a little bit of stringing and just one or two very slight imperfections.  I was pretty happy.   There are keyhole slots in the end of the rails on the wingtips of the Gripen and there are mounting rail STLs available so I printed a few of those as well.  The missiles have a flat spot designed in where you can easily glue these to the missile.  Once that was done, with only a little sanding/carving/cleanup I was able to slide the missiles onto the wingtips.  Here is a pic of the IRIS-T on the wingtip of the plane pretty much fresh off the printer with just some minor gluing and sanding.  These are 1/9th scale just like the airplane.

There are a couple of nice things about having these on the plane.  First, they add some needed tail weight.  The Gripen has a very swept back Delta wing so the wingtips are far back from the desired CG so while not the ideal place for extra weight, its not a terrible spot either. Second, they cover up the sort of ugly wingtip “rails” with some nice eye candy.  And third, I’m thinking there may be some wingtip strikes with the landing gear being fairly narrow as they are on many jets, so they can act as wing tip protection to some extent.  I can print another missile or fin or whatever, but the wingtips of the airplane would be much harder to reproduce and replace if they get beat up or broken.

Next I tackled some Meteor missiles.  These are long range, radar guided air to air missiles.  In real life these things are around 13 feet long, so scale they are around 16″ long.  These are massive and carry a big warhead.  Imagine a telephone pole coming at you with a big bomb on the front… at multi-mach speeds!  Used properly they are on par with the best such weaponry out there.  With the right launch parameters and guidance these can be fired from 100+ miles away!

These are generally carried on under wing pylons on the Gripen but the model doesn’t have any built in hard points for those so I had to print out the keyholes/hardpoints and the pylons themselves and get those mounted on the plane.  It took some carving in the wing, careful alignment and slowly digging a bit deeper until I had what I wanted then glued the hardpoints in.  With those in place I could slide the pylons on and lock them in place then slide the missiles in place under the pylons and lock them in and bingo, we are in business.  Below are some snapshots of that process and the results.

 

 

 

 

 

 

 

This is the outline of the mounting socket as I’m starting to remove just the skin/paint in preparation to route out maybe an 1/8 inch or so of foam so I can glue it in..

This is the socket in place.

 

 

 

 

 

 

 

 

 

 

 

 

The tape attached to the pylon is adding some pressure after the glue is in place and just starting to setup nicely.  It looked a little off so needed some pressure to get it to sit level in the wing.

Here’s the whole thing after I hung a meteor on it… starting to look pretty good! 

After I got this far I was down to needing sanding and painting so I started doing a bit of research and found a variety of paint schemes available and went to work.  The meteors especially varied a lot, so I took a bit more license with those and stayed with the white scheme but the IRIS-T is almost uniformly and almost completely gray so I decided to reprint those so I wouldn’t have to do so much painting (I hate to paint!).  Then I took advantage of where some of the color bands are to cover up some of the glue joints with pin stripe or color bands on both missiles.

Meteors (on left) and Iris-Ts (on right)

I’m sure for the true scale guys these are nothing special but I think they add a lot to the look of the airplane and the effort was not huge.  For me, having the 3D printer (and the efforts of the guys who first did the design) made it possible to really upgrade the look of the airplane with minimal effort.  And no one has anything that looks like these!

Of course, it doesn’t end here.  I have engine inlet and outlet covers printed as well and I’m eyeing some fuel tank designs I’ve seen…

So if you are wondering if you need a 3D printer to add a little extra something to your hobby… the answer is of course, NO.  But I recommend it.  There’s a lot you an do that will add that little something extra to your favorite bird.  I expect to do a bunch more of this in the future.

Couple of new “to me” motor vendors… specs

Electric motor specs available

I recently was involved in a conversation that started out bemoaning the fact that Horizon hobby often doesn’t supply much in the way of specifications on many of their electric motors, when someone referenced a couple of sites that provided a plethora of information about that particular electric motor vendor products.

I have used ecalc to help me predict power system performance for years but that doesn’t get you around a lack of decent information and for those who for whatever reason don’t have access to that tool or have trouble understanding how to use it correctly, information from the vendor like those below has a very high value.

I haven’t tried out these motors for myself but I applaud the disclosure of specifications along with predicted (maybe tested) test results with a variety of propellers.  This really allows you to pick a setup that does what you want to do without a lot of trial and error as well as allowing us to get the most out of the motor, again without a lot of trial and error.

So here are the links to these manufacturers sites.  With this sort of available information I may have to give them a try.

Leopard Motor Data Chart

Badass Motor Data Chart