Some thoughts about flying in cooler weather

Hi everyone -

Frost on the field, temperature -2 C/28 F...check

Two Russian park jets ready to rip up the skies...check

Fire lit in the clubhouse wood stove so pilot can get warm...check

So you might be wondering why someone would be crazy enough to fly when the temperature is below freezing... :/?  Well, sometimes I ask myself that, but this time of year where I live it can be some of the best flying weather we have as the winds are calm and the nice cool, dense air helps give good lift and great air for the prop to bite into.

Like very hot weather that some folks are experiencing in the southern hemisphere now and which I wrote a few thoughts on here http://migsrus.blogspot.ca/2014/07/motoresc-performance-in-hot-weather.html , colder weather can also present it's challenges to park jet flying.  I have found that when temperatures are between 5 C/40 F and 25 C/77 F, I don't worry too much about things getting too cool or too hot, but once the temperatures get outside that range, experience has taught me to adjust my flying accordingly.

Now cooler weather flying is probably a bit more of a challenge as not only does the plane have to be treated with care, but the pilot is normally affected more by cold than heat as well... :/

Obviously we don't need to worry too much about ESCs or motors getting too warm, but batteries are another story in my experience.  What I have found is that as the temperature drops below 5C/40F, batteries tend to discharge a little faster and if they are a bit older can have a tendency to discharge more unevenly.  My personal rule of thumb is to not run my batteries down below 3.7 volts per cell.  So to be on the safe side, I shorten my flight times by about 30 seconds to help extend the life of my batteries.

I also try to keep my batteries warm by keeping them in my pocket inside my coat until I am ready to use them or if I have a bunch, I leave them in the little clubhouse where they can stay warmer after I get the fire lit in the wood stove.  Then when I expend them, I also keep them warm so that they don't get too cold as I am continuing to fly, again I am lucky to have a warm clubhouse in which to leave them.  Then when I get them home, I ensure they have warmed up to about room temperature before I put them on the charger.  By following these rules of thumb, I have had good experience now going into my third winter of flying.

Another area to keep an eye on is servos.  I store my planes in the garage, so they are "cold soaked" when I put them in my car and don't get warmed up much on the short drive to the field.  Anytime I have ever stripped a nylon gear servo, it has been cold and I have been too aggressive too soon.  I find that by taking it a bit easy during the first part of the first flight with a plane allows some current to run though the servo and get things warmed up and worked in so that gears, etc are not so brittle and less likely to break/strip.

I think it is also a good idea to give the plane a quick inspection as well, especially if it has been stored in the cold for awhile to ensure all the glue joints are good.  I have found that Foam Tac is a bit more resilient to cold than hot glue.  Sometimes hot glue will pull away from the foam as it gets really cold (ask me how I know this... :/), so it is a good idea just to check all the important joints are still in good shape before flying.  

So what about the pilot?  Well obviously dressing for conditions is important, I find that with all the standing around while flying, my feet can be most susceptible to get cold, so I have good winter boots with thick duffle sock liners that keep my feet toasty.

Hands (ie thumbs) are another story, I guess some of it depends on a person's tolerance to cold and the conditions.  Fortunately when I was flying yesterday, the sun was out and that helped keep my hands warm enough that I had pretty good dexterity for my flights, and then I just put gloves on in between to keep my hands warm. 

 There are lots of options.  I have seen other guys use one of these radio muffs at my field, but since we hand launch our park jets, it might be tough to get your hand back in there quickly enough.  Or even tougher to find someone to come stand in the cold and launch your planes for you... :/

I am a "thumb" flier as opposed to being a "pinch" flier, so having good feel between my thumb and the end of the transmitter sticks is important to me.  I have found using different sticks on my radio has been helpful in the past although the ones I use now have pretty good "sharp" points on the top, so I continue to get good feel even as my thumbs get a little cold. http://hobbyking.com/hobbyking/store/__23762__Alloy_Anti_Slip_TX_Control_Sticks_Short_Futaba_TX_Red_.html

I have also used these big "Turbo Thumb" http://hobbyking.com/hobbyking/store/__12996__TurboThumbs_Super_Big_Futaba_Rocker_1pair_Red.html sticks in cold weather with good success, but don't find them quite as precise a feel as the ones above, but then they have "Turbo" in the name, so they do have that going for them... ;)

In conditions when the sun isn't out and my hands do get cold a little faster, I have flown using military issue flying gloves that I was lucky enough to be able to keep after I retired from the Air Force.

These gloves fit pretty snug and still allow me decent dexterity.  I have also seen folks with cheap wool gloves cut just an inch off the end of the thumb and index finger of the glove so they can still have good dexterity to fly and work switches with bare thumb and finger tip.  I have also seen folks use the glove/mitten combo below, that way you can just flip the mitten part back over your fingers and thumbs between flights to warm them back up.

Of course I am pretty blessed to be able to go into a nice warm clubhouse and warm up every few flights or so if I need to.  Many folks in the northern hemisphere are finished flying (other than those who can fly something indoors) for the year right now and focusing on building, but like I said if you can, it is normally a great time to get out and sneak in a few flights if you take care of your gear and yourself... :)  I always feel a bit more motivated to build something after I have been out on a cool, crisp day ripping up the skies with my plane... :)

Cheers,

Scott

Motor spreadsheet and component weight table link

Hi everyone -

I have been trying to educate myself on Google Drive, so I created a folder accessible through this link https://drive.google.com/folderview?id=0B7TFxGixs_w3a1Z2R2RkUnliVkE&usp=sharing

It contains the spread sheet with the most up to date test data I have compiled on park jet motors and a document that indicates the weights of all the components I used in building my park jets.  On both the spread sheet and the weight document I have included links to all the items should you want to research them more or want to purchase them.

Hope this might be of help to you.  As I am still figuring this all out, if you have problems accessing it, please let me know either by leaving a comment on the blog or sending me an e-mail at migsrus@outlook.com ... :)

Cheers,

Scott

RCP Mig29 V4 NAMCV3 high alpha gone wild...literally!

Hi everyone -

Had just a beautiful day at the field today, tried my hand at some high alpha with my NAMCV3 Mig.  Hopefully you can see when I concentrated on flying rather than yakking or wasn't distracted by the deer that showed up, it flies some pretty amazing high alpha I think... :)

A little extra entertainment when the deer showed up on the runway at 3:15, then I tried my hand at the fancy "behind the back" pass at 3:35, then almost hit myself in the head at 4:44 along with a couple close calls with the ground scattered through the video.  All in all a very fun day, I feel very blessed to live where I do and get a chance to see wildlife in such a beautiful setting and have such great fun with my park jets!  Please enjoy the video... :)

Cheers,

Scott

RCP Mig29 V4 NAMCV2 elevons only

Hi everyone -

Great day of flying at the field today with two awesome planes... :)

I also had a little company towards the end of my flying, a deer family, the doe is giving me the evil eye as the buck walks away keeping a close eye on the fawn which unfortunately is hard to see in the dead grass.  I was probably about 50 ft from them when I took this picture as they walked along the edge of the runway.  Awesome to see, all very healthy and in good shape... :)

Before discussing the NAMCV2 on elevons only, I also reached some pretty neat milestones today -

• 50 total flights now on the NAMCV3;
• 100 flights (102 and counting) on the NAMCV2; and
• 500 total flights (505 and counting) with all my RCP Mig29 V4 variants in total.

So the other day I was at the field and there were a couple of new folks there flying trainer type planes, one had an E-Flite Apprentice S http://www.e-fliterc.com/Products/Default.aspx?ProdID=EFL3100 the other fellow had a Flyzone Sensei http://www.flyzoneplanes.com/airplanes/flza3010/

So in between flights we spent some time shooting the breeze and checking out each other's airplanes as RC pilots will do when one of the guys asked me if a relatively new pilot could fly one of the Migs.  I said yes, a very simple setup with elevons only is a great way to start.  Then I realized, I had never flown any of my NAMC Migs elevons only to see how the smaller elevons managed.

So when I went to the field today, I turned off the rudders and ailerons on my NAMCV2 (the all blue one in the picture above), cranked the aileron input up to 100% in my elevon mix and off I went.  I wanted to fly the Mig elevons only from a standpoint of how it would handle if I was a beginner (which I still feel like depending on the day... :/)

I flew seven full flights with elevons only and was very impressed with how it handled.  It turns very easily and without hesitation, not as much control input actually required as with other elevons only planes I have flown because the surfaces are more efficient and cause less drag and turbulence when deflected than larger stock surfaces.  Rolls were a bit more lethargic than I am used to with elevons and ailerons working together, but still very good rates for where a beginner would want to be.

So as I was flying, I tried to remember back to my first park jet, an elevons only RCP F35 V2.  Not the best picture in the world, but hopefully you can see that those elevons are pretty huge... :/  One of the first things Stephan and I both wanted to look at with our park jets when we got together was how scaling down the control surfaces, primarily ailerons and elevons would help with our plane's handling as we both found that the "control surface creep" that was happening in a few park jets was impacting how they flew.

So back to when I first started flying this F35.  I remember often getting into trouble being too slow in a turn, cranking on too much control (something I think almost all beginners do at some point) and my plane would just park itself in the air as those big elevons acted like air brakes, made the plane stall, do funky things, all of which caused me to try and over control even further, leading to...well not the best of situations.

So I got looking at the trainer planes these two fellows were flying as they are good basic trainers for learning how to fly.  Granted they are a scale high wing type plane, but their control surfaces are not huge, rather more in line with what they would be on a real version of a plane.  Enough that a person can fly them around fairly gently, or have some fun with basic aerobatics as skills progress, something any beginner plane should have I think.  So why would we not use the same thing on park jets?  Smaller, more scale size elevons for elevons only that allow for precise control without as much tendency to TV stall makes a lot of sense to me.  

I remember many a time having my heart race when I watched planes park themselves in the air because of very large control surfaces that suddenly acted as "un-control surfaces" making my life very difficult and often leading to my day being shortened due to a crash.

Obviously Stephan and I are big fans of downsized, more scale like elevons and ailerons, we like our rudders big, but prefer smaller more efficient elevons and ailerons as they are more efficient and allow for more precise control of our planes.  We both are huge fans of the fixed horizontal stabilizer and hinged elevons on the Mig29 V4 which is also on the RCP trainer the Su34 V4.  I am very happy to see this on the trainer.  I think this fixed horizontal stabilizer setup is the biggest breakthrough yet on the two of the V4 planes.  I have also tried it on an FRC Su35 MK2 and will use it on every plane I build from now on.  The stability it adds coupled with how it reduces the size of the moving surface thereby reducing drag and turbulence associated with the moving surface is a simple yet amazing improvement in the world of park jets.

So yes, we do push our planes hard and are not beginners, but I think the philosophy of having enough control so that you don't over control is very beneficial when learning.  I think smaller, more scale size elevons on an elevons only plane is a very good way to go.  Just my humble opinion backed up by what I saw today with the best elevons only flying experience I have had.

So I guess my message is, stop "control surface creep", like everything in life, moderation is a good thing and bigger is not always better when it comes to control surfaces... :)

Cheers,

Scott

RCP Mig29 V4 NAMCV3 Dialed in

Hi everyone -

Another great day of testing and "dialing in" at the field yesterday.

I had my oldest plane, the RCP F18 V3 out to field test another motor, the YUSHOP66 2212/6 2700 Kv motor from a vendor on eBay http://www.ebay.com/itm/321227178111  You can read more about this motor and the test results both at the field and on the bench here http://migsrus.blogspot.ca/2014/11/yushop66-a22126s-2700-kv-park-jet-motor.html

It was a good day to do some final "dialing in" on my RCP Mig29 V4 NAMCV3 (which I will call the V3 for the rest of this post for simplicity's sake).  I had a myriad of conditions from dead calm to the odd bit of swirling wind up to about 10 mph.

This plane handles amazing in the wind.  Of course it is about 15% heavier than the other Migs that I fly which does help, but the wind had almost no impact whatsoever on it's handling and stability.  I was very impressed, no wobbles, tail wagging, just solid and true tracking through the wind, especially in turns.

I managed as well to better assess it's slow speed handling and high alpha performance.  Normally I have had real challenges getting planes with the NTM Prop Drive setup to stay consistently stable in high alpha.  The bigger heavier motor and extra torque roll affect of this setup can make high alpha a bit more of a challenge for me than with lighter setups.  This plane is very stable in high alpha, although it is more susceptible to wanting to pull left due to prop wash and torque roll.  There is some very detailed information in this post http://migsrus.blogspot.ca/2014/08/mig29-v4m3e3-hi-alpha-testing.html about prop wash, prop torque and P factor and their impact on a plane's high alpha performance.

Probably due to the volume of air and the aggressive bite inherent with the 6x4 APC prop compared to the 6x3 EMP prop, in order to fly in a straight line with a high AOA (angle of attack), constant right rudder input is required, otherwise the nose will just continue to drift left.

I also found that because the center of mass on this plane is so much closer to the center of gravity and it is a larger quantity of mass (3.2 oz more than most of my Migs), rudder response is much greater, so I softened up the rudder with more expo and also really focussed on keeping rudder input as smooth as possible.

So again, this was very interesting to me as normal rule of thumb from previous experience was that for good high alpha stability on most planes, the largest percentage of mass (the battery) needed to be fairly far forward of CG for good stability in high alpha.  This plane with it's centers of mass, gravity and thrust all being much closer together seems to go against that theory.

Granted, the battery is ahead of the CG, but when I compare it to my F18 V3 with which I have flown considerable high alpha, the battery on this Mig is much closer to the CG than on the F18 and remains very stable.  I won't get into another round of measurements as I have in previous posts, suffice to say that other than the increased effects of prop wash and more sensitive rudder, this plane does high alpha very well even with a heavy, higher torque motor like the NTM Prop Drive.

As I have written in a previous post when I did a fly off between the NAMCV2 and V3 http://migsrus.blogspot.ca/2014/10/rcp-mig29-v4-namcv2-and-v3-flyoff.html, the V3 requires less control input to generate the same rate of roll, pitch and yaw.

So now that I have 41 flights on the V3 and have it dialed in where I like it, I got out the ruler and did some comparison.  I will only compare the throws on the ailerons and elevons, I keep the throws at 100% on the rudders on all my planes just because due to phenomena discussed in the link above about high alpha testing, I like to have maximum throws on my rudders.

I will express my settings in inches of travel rather than percentage of throws for the ailerons and elevons as your servos and transmitter are probably different than mine.  I have also posted the travel for my NAMCV2 Mig for comparison purposes.  I should caveat that I prefer to fly my planes a bit more scale, so keep my throws fairly low as I don't need my planes to tumble loop or do rifle bullet type rolls.  I do however like to have a bit of extra "emergency throw" in the elevator to help avoid sudden impact with immovable objects... :/

NAMCV2

Elevator travel -  2.5" in each direction for a total of 5" travel.

 Aileron travel - 5/8" in each direction for a total of 1 and 1/4" travel.

Spoileron deflection for high alpha - 5/8".

NAMCV3

Elevator travel - 2" in each direction for a total of 4" travel.

Aileron travel - 1/2" in each direction for a total of 1" travel.

Spoileron deflection for high alpha - 1/2".

So I am very pleased with these settings and the results when compared to the V2.  By having much better balance with the V3 and the centers of mass, thrust and gravity so much closer together, I get the same handling performance with 25% less control surface travel.  So why is this important to me?  Well as I have said many times throughout all of the experiments that Stephan and I have done in downsizing control surfaces from stock, smaller surfaces travelling less distance make for a much smoother flying and more stable and precise plane.  

With the laws of physics working much harder in our favor, it means the surfaces don't have to work as hard.  Anytime I can have less deflection on a control surface to do the same job I will take it as it means less drag and therefore less turbulence.  This makes the control surfaces perform more efficiently and makes for a smoother and "quieter" flying plane from a standpoint of stability.

So I continue to be very excited by how well this latest NAMC version of the Mig flies.  Stephan hopefully should have his built and flying shortly, so I'm very excited to hear what he thinks and what his findings are.  It is through repeatable results and thorough, consistent testing that we have found the best information and validation of our modifications.

In a previous post I mentioned I was thinking of going back to the lighter Focal Price setup on this plane, but I have decided to "man up" and keep this big motor in this plane as it pushes my skills a little harder than the lighter setup.  Instead I will build another Mig (big surprise there...hello, my name is Scott and I am a Migaholic... :/) with a lighter setup, less reinforcement, etc.  I will probably wait until after Stephan has built and tested his in the event there might be other mods we could test/try, but I have a feeling that although the work is never done, this V3 is the culmination of a lot of great ideas and testing that we have worked towards over the last six months since this plane was released, so I'm not sure what else could be done.

Cheers,

Scott

RCP Mig29 V4 NAMCV3 Speed fun... :)

Hi everyone -

Back out at the field yesterday with my two favorite Russian park jets.

Since making the repair on the motor mount on the Mig, I also took a look through my motor bin and found an NTM with smoother bearings than the first motor and also put on a brand new balanced prop, so I wanted to do another round of speed trials on both 3S and 4S.

So here is some video footage of it.

Oops, sorry, wrong video...but thought that would get you in the mood for some speed... ;)

Here is the real video, first part is on 3S, second on 4S.  I apologize that due to the speed, the fact it needs a lot more room in which to fly because it is so fast and the bright sky that it washes out occasionally, but hopefully you get a sense of darn fast this little beauty is... :)

So with a good solid motor mount, smoother running motor and brand new balanced prop, I actually squeezed some more speed out of it... :) 

On 3S, I managed 4 good speed runs of 99/97/96 and 93 mph, about a 2 mph improvement in top speed over the first set of trials I did.

On 4S, I managed 4 speed runs of 117/111/105 and 102 mph, again about a 2 mph improvement in top speed over the first set of trials I did.

I am really so pleased with how well this plane flies, I haven't flown a plane with that much speed before, so it does take some serious concentration as you might see on the very last speed run on 4S, I twitched the stick just a bit to the left before making the right turn and it was headed for the trees at a rather rapid rate of knots!

Awhile back, Stephan and I had talked about building a plane light but strong that would still be able to take the NTM Prop Drive motor, but also fly well with the Focal Price motor.  I think that even though I increased the weight with more carbon reinforcement and one set of metal gear servos over how I normally build, because I reduced the size of the plane, the two balanced out.  That and experimenting with thinning my paint down helped me keep the weight of the paint job down.  

So this makes this plane pretty flexible being able to swap power systems and have the airframe easily handle either without sacrificing overall performance.  In all honesty I will probably go back to the lighter FP setup as I am so used to that, it is a bit more relaxing flying.  But it is nice to know that if I am really feeling feisty I can do a 10 minute motor and ESC change and really tear up the sky... :)

So next up is another FRC Su35 MK2 with a fairly ambitious modification plan, then we shall see where we go from there.  Maybe I'll do something different and build another Mig... :/

Cheers,

Scott

YUSHOP66 A2212/6S 2700 Kv Park Jet motor updated with new results 10 Nov

Hi everyone -

A couple months ago when I was searching around for alternatives to the Focal Price 2700 Kv motor http://www.focalprice.com/YO090X/A2212_2200KV_Outrunner_Brushless_Motor_for_Airplane.html which at the writing of this post is still out of stock (been that way for about three months now), Rob Davis one of our followers told me about this motor from an ebay vendor in China http://www.ebay.com/itm/321227178111

Here is a picture of it with the bullet connectors, X motor mount and prop installed.

The dimensions and weight of this motor are exactly the same as the Focal Price and Deal Extreme 2700 Kv motors I have already tested.  It weighs 66 gr/2.3 oz with all connectors and prop installed.

Just like the FP and DX motors, you need to provide your own bullet connectors and a prop collet, the one that comes with it is the same quality as the one that comes with the Focal Price motor so I replaced it with a better one.  Shipping with this vendor is free, but it was slower than with Deal Extreme, the package was shipped 08 Oct 2014 and I received it 07 Nov 2014 on the west coast of Canada.  It may very well take longer depending on where you live.

At $10.99 it is a bit cheaper ($1.30 cheaper) than the FP or DX motors, but if you buy 3 motors from DX, the price is the same per unit $10.99 per motor.  I think this vendor buys up 25-30 motors at a time from somewhere and then resells them.

After a break in period, I retested the motor and received more realistic results, updated on 10 Nov.

This test was done with a 6x3 EMP prop, Turnigy plush 40A ESC, 2200 3S 40C discharge battery.

At 50% throttle, the motor drew 12.7 amps and produced 150.1 watts and 517 gr/18.2 oz of thrust.

At 100% throttle, the motor drew 35.7 amps and produced 421.8 watts and 1033 gr/36.4 oz of thrust.

So definitely a 40A ESC is needed with this motor like it is with the FP and DX motors.  Here is a video of some field testing I did with this motor in my RCP F18 V3

Thanks again to Rob Davis for finding the motor for us, it is definitely the same motor as the Focal Price and Deal Extreme 2212/6 2700 Kv motors and another source to purchase from depending on availability.

Cheers,

Scott