FRC Su35 MK2 NAMCV2 ready for paint... :)

Hi everyone -

I have been busy in the workshop for the last couple days, the Su35 MK2 NAMCV2 is ready for paint and then final installation of the ESC, Rx, servos, pushrods and it will be ready to fly... :)

I estimate with a 2200 3S battery I will be in the neighborhood of about 21.5 oz which is a bit heavier than my current Su35, but that one has no paint weight as I only did that with magic marker.  Funny how my ugliest "paint schemes" seem to last the longest...hmmmm... :/

With the cloudy skies of fall/winter rapidly approaching, I thought I would go with this inspiration for my paint scheme from http://www.mars.slupsk.pl/fort/sukhoi/  It was for an Uzbekistani Su27 from 2010, but I think it will show up well against the grey skies.  I had a similar paint scheme on my Israeli themed FRC F15 MK2 and that worked really well against any background.

So maybe another day or two for the paint job to be done, the rest of the gear installed and setup and hopefully it will fly this week... :)  Editing the build video will take a bit of time also, but hopefully that will be ready to go by the end of the week also.  I think it is going to look pretty cool when it is done... :)

Cheers,

Scott

FRC Su35 MK2 NAMCV2 update

Hi everyone -

Just wanted to let you know I was still alive and kicking!  The FRC Su35 MK2 NAMCV2 build is clipping along well now, should have the build finished up over the weekend and maybe even painted.  The bulk of the airframe is together now, then it will just be final finishing and sanding, installation of electronics and paint!

The build video is going to be fairly lengthy, but hopefully very thorough.  And the fast forward button was invented for a reason... :)  The video will be a step by step process, starting right from how I prep the plans before cutting out foam, how each piece goes together, some techniques I have discovered that make the whole process much easier as this will be the 9th FRC score and fold park jet I have built of this type that all have essentially the same build process, etc.

I have taken the opportunity throughout shooting each stage to also talk about some of the basic build techniques I use that can be used on any plane, so that accounts for some of the increased length as well as I often get asked about those, or at least I used to when I was still active on the RC Powers forum.  I have also shot a bit of intro to put the whole thing in context and to put out some caveats about the video and why I do things the way that I do, including a bit of "soap boxing" about my opinions of what I think is important to remember about scratch building park jets (ie, do your own thing, not what I do or the crowd does, follow your dreams and remember to have fun... :) ).

So if all goes well, should have the build video edited and published by this time next week I hope if not sooner.  Been a long gloomy week here weather wise, so if I do get some nice weather, I may have to go out and feed the flying addiction which might push the timeline above a bit to the right... :)

Cheers,

Scott

RCP Mig-35v2 NAMC Ready for Maiden

MIg-35v2 NAMC

RTMS (Roll Tide Mig Shop) division of NAMC has been quiet on the blog but hard at work in the shop.  After the NTM Prop Drive 2700 destroyed my Mig-35 it was time to build another.  All I have left is the Mig-29v4 with stock elevons and NAMC vertical rudders and inboard ailerons.

Approaching this build, I had several ideas and goals.  I continue to seek the Hloly Grail straight line knife edge.  I’ve accomplished the knife edge turn, but going straight continues to elude my pilot skills.  To help attain this goal, I felt like I needed more rudder authority.  As previously mentioned in a post, when in high alpha only the inboard rudder is truly generating yaw.  Additionally, I’ve wanted more yaw in rudder stall turns.  So for this build, I went supersize on the rudders.  Other goals include more scale like appearance and less frontal area to further decrease drag.

The larger vertical stabilizers that Scott designed gave me plenty of room to increase the size of the rudders.  I was initially concerned that the vertical stabilizer at the top front corner of the rudder would be a weak point.  However, with glassing the vertical stabilizer is very solid and I have no concern for structural weakness.  I gained a lot of authority on this set of rudders.  On my Mig-29v2 it has straight rudders the length of the vertical stabilizer, Scott has these on most current.  This style rudder is perfect for all desired yaw maneuvers except for knife edge.  So if you have no desire yet to knife edge, go with the simple straight full length rudders.  Here is the rudder drawing:

On his latest build, Scott went with a longer tapered aileron.  When I did my initial flight testing of ailerons on Mig-29v3KNEx, they were straight.  With Scott’s extensive flight testing (a gazillion test flights :o!) and positive review of a tapered aileron, I went with that design on this plane.  I maintained the same surface area as my inboard ailerons on my last build, I just halved the width and doubled the length maintaining the same taper as stock.  I still believe these planes they fly better with less disturbance at the wing tip.  Every time I fly high alpha I turn my ailerons off and wing rock is comes on much later.  This is the easiest experiment you can do if you are non believer.  Program a mix with your dual rate to turn off your ailerons.  Try it, you’ll be amazed at how much more stable slow flight and high alpha is as well as high speed mowing the grass fly byes.  Here is the aileron drawing:

My last goal was to decrease the frontal area and drag along with a more scale like appearance.  The first thing I did was to take a 1/4 inch off of each end of the canopy.  I then tucked the sides under the end pieces.  Personally, I’m extremely happy with the improved look.  I pasted in the scale Mig blueprint plans as well as the SebArt Mig-29.  Look up the SebArt, it is an amazing thrust vectoring ducted fan plane.  I would own one but it falls into the “balsa” class of planes for me.  I’d never enjoy flying the plane for the fear of crashing it (something I’m quite proficient at).  No tears in my beer over another plane.  Been there done that, ain’t goin’ back.  And yes, I have a drawer full of t-shirts.  Anyway, back to the topic.  I studied the wing and fuselages of the the v4, scale and SebArt.  The v4 is too long and I have not figured out a good way to shorten it—that is a winter project.  The LERX and the leading edge of the v4 wing are larger than both the scale and SebArt.  The wing trailing edge distance to leading edge of the horizontal stabilizer is good.  So I scaled back the LERX and the wing leading edge.  This will decrease the lift, push back the center of lift as well, and increase the wing load.  Hopefully, this will result in faster and “sharper’ flying plane that flies more scale like as well.  I hope that high alpha will not be adversely affected.  The look though is winner.  Check out how the outer nacelle curves in.  Here are the drawings and the plane:

For the paint job, I had to copy Scott.  I tried to mimic the Azerbaijan Air Force camo scheme.  This is by far my favorite paint job.  For the stickers, I print them on regular paper and covered them with packing tape.  I cut them out and glued them on with Alene’s.  Why is the Canadian flag on the wing tip?  Of course it is to pay homage to my Canuck partner and

friend who was put the fun back into RC for me.  Figured it out yet?  We are always checking each other’s six—more military stuff.  The M3e3 is honoring the first NAMC prototype.  I better not ever crash this one!!

One last comment, I recycle all of the electronics and tested them all but the motor.  One of my servos from my last crash was bad.  I didn’t test the FP 2700, but I had to change it out.  It beeps then just stutters and moans.  Until Scott finds a new source, I’ll try the Turnigy and Grayson 2200s.

After I sort her out, I’ll put together a build video with some flight highlights at the end.

Build Highlights

Tapered cockpit

Narrowed LERX and wing leading edge

4mm carbon wing main and 3mm leading edge

True 40% KF4 with dollar store foam

Narrowed nacelle

Downsized tapered ailerons

NAMC Elevons

NAMC Vertical Stabilizer

NAMC Outboard servo placement

NAMC RTMS Inboard vertical rudders

16oz without battery

Blue skies to you,

Stephan

RC Powers F18 V3 1 yr anniversary... :)

Hi everyone -

I had my oldest and my newest planes at the field yesterday for some fun... :)

I am thinking of building another F18 in the coming weeks, so as I was looking through some of my old flight videos on my RCP F18 V3, I realized it was over a year ago that I maidened this reliable plane!  It has been a few months since I flew it as I have been busy with the Mig29 V4 in a few different variants, but decided it was time to take the old gal out for a spin and get right of some of the "hangar dust".

This particular plane has been a real turning point in my park jet career as it was one of the first planes where I really concentrated on building light.  This is probably one of the reasons it has lasted so long as it has suffered many gonks, hitting the ground, the fence, trees, my leg... :/ and other than a crack in the wing, a new nose and new left elevon, it has survived amazingly well.  As I saw how durable it was, it allowed me to push my flying skills harder as I wasn't as worried about writing the plane off completely and as a results, my confidence and skill levels improved exponentially.

It is also one of the first planes that I started using for testing.  Not so much control surfaces and setups like I do now in partnership with Stephan, but testing different motors and power setups.  It is what got me started with testing different options on park jets and along with Stephan's ideas got me thinking "outside the box" a lot more in my approach to building and flying.  This has also opened up a lot of fun interesting building and flying that all started with the F18 V3.

Flying it alongside my latest variation of the Mig29 V4 was also a real testament to how far my building style has improved in the last year as well.  I know it is comparing two different planes, but the extra care I took with sanding and shaping the Mig's leading and trailing edges and modifying the control surfaces make a huge difference in how the plane feels in the air.  The Mig seems so smooth and fluid in the air where the F18 with limited sanding, shaping and the old "chisel" leading edge on the wing and elevons feels more sluggish and abrupt.  

But hey, I had to start somewhere and I owe the F18 V3 a huge amount in what it taught me about building, flying and testing.  Besides, I still have a huge smile on my face whenever I fly it, and this hobby is supposed to be fun, right?!

So my next build after I finish up my current FRC Su35 MK2 will be another F18.  I was initially thinking of some crazy "morphed" version of the V3 and the V4, but decided after flying this V3 again to keep it a bit simpler.  I will essentially build an F18 V4 with a few changes.

I will build a standard wing without the leading edge slat that the stock V4 has and I will use smaller elevons with the horizontal stab and elevon setup similar to the Mig29 V4.  I might also move the motor mount back a little bit, and essentially the rest will be stock with a fairly "retro" (at least for my style of building) and simple paint scheme.  More to follow in other posts as I get ready for that build, but sometimes simple is the best approach... :)

I shot some flight video to commemorate the 1 yr anniversary of this plane.

Will it still be around for a 2 yr anniversary?  Well, only time will tell, I think I will still take her out for a spin on a nice day like you would with an old classic car, it is just so much fun to fly and nice to have a change of pace once in awhile... :)

Cheers,

Scott

RCP Mig29 V4 Center of Gravity findings

Hi everyone -

If you have been following this blog for a little while, you know that Stephan and I have been busy this summer building, modding, flying and testing the wings off our Mig29 V4s in stock and modified variants.

Here is a picture of my three Mig29 V4s... :)

Since I'm retired and a bit of a "park jet bum", I have managed to rack up 437 total flights between all three of these planes over the summer and early fall.  I don't mention this number to brag or impress, but rather hope it will lend a little credibility to what I have discovered about the center of gravity (CG) of this plane in all the variants I have built and flown.  I know the details of the CG of all my Mig29 V4s is scattered around the blog, but I wanted to consolidate my findings in one post to be of the most use for anyone considering this plane as a future build.

I guess you could say I am a bit anal/OCD when it comes to getting the CG dialed in just right with my planes, I just find the extra attention to detail and taking the time to get them dialed in makes a huge difference in the long run for how my planes fly and handle.  I wrote this post on how I like to dial in my planes...it is a bit detailed, but this process has certainly helped me over several different planes http://migsrus.blogspot.ca/2014/07/some-thoughts-about-dialing-in-plane.html

Essentially, I try to get the plane balanced with zero trim in all axes if I can so that when I take my hands off the controls it will stay straight and level on it's own without climbing, descending, rolling or yawing.

On all three variants of this plane I have built, I have found that the CG has ended up forward of the stock CG (the one that is marked on the RC Powers plans, available for purchase at http://www.rcpowers.com/community/pages/home/ )  I have flown all three variants of this plane in pretty much every possible wind condition from dead calm to 15+ mph winds, so I'm very confident I have all three of them dialed in properly for all flight conditions.

Here is what I have found with each plane individually.  I won't discuss the complete details of the mods I made on the NAMCV1 and NAMCV2 planes other than those that might impact where the CG ended up.  If you have more questions on these, you can read through the blog or post a question anywhere on the blog and we will try to help out.

All the variants have the same power setup, same number of servos and control setup other than different size or shaped control surfaces.  All have KF4 airfoils, although the modded variants have slighter different size KFs.

Stock Mig29 V4

The stock build Mig29 V4 is the tan/grey/green camo plane in the middle of the picture above.  I now have 221 flights on this plane.  It is the heaviest of the three, now weighing 21.8 oz/618 gr with a 2200 battery.  It has gained a little "repair weight" after a few "gonks" here and there, but still flies amazing.  

My CG on this plane where it flies the best in all flight envelopes is 5/8" ahead of the stock CG, this is with no trim in the pitch.  It is the only plane of the three where to keep it level in the roll, I have my battery all the way to the right side of the electronics bay and still need two clicks of right trim.  Because of how I built it with my servos spread along the airframe, my 2200 battery is about 1/2" from the bulkhead, so if I want to fly it with a lighter battery like a 1600, I have to put in some down trim to keep the nose down.

Mig29 V4 NAMCV1

The NAMCV1 is the mostly blue Mig on the right in the picture above.  I now have 136 flights on this plane.  This was the first modified variant I built of the Mig29 V4.  It is a little lighter than the stock Mig29 at 21.5 oz/609 gr with a 2200 battery.  For comparison purposes with the stock Mig29 V4, I put all the servos, the ESC and Rx in the same spot to have the same weight distribution to reduce the number of variables in evaluating the handling and performance differences.

As part of the modifications Stephan and I discussed and decided upon, I extended the KF airfoil back about 1/4" to make it approximately 40% of the wing chord.  We have found this to work very well on Migs we have modified in the past, so kept it as part of the winning combination.  I understand that this small increase in KF chord would probably impact the center of lift (CL) and CG, the CG on this plane is 1" ahead of stock now.  This requires that I fly with my 2200 battery directly against the bulkhead to maintain proper balance with no trim in the pitch.

I cannot fly this plane with a 1600 battery without inputting down trim in the pitch to keep the nose down.  It flies amazingly well, but I don't really have the flexibility to fly it with a lighter battery without inducing more drag by adding trim in the pitch.

Mig29 V4 NAMCV2

The NAMCV2 is the blue camo plane on the left in the picture above.  I now have 80 flights on this plane.  This is the lightest of my 3 builds as I really focused on trying to keep it light.  It weighs 20.8 oz/590 grams with a 2200 battery.  After having seen what was happening with the CG on the first two Migs I built, I purposely shifted some weight forward in my build, moving my elevon and aileron servos and my Rx 1 and 3/4" further forward than my other two Migs.  This variant also has the extended KF like the NAMCV1.

On this plane, the CG is 5/8" ahead of stock to have it balance in the pitch with no trim.  Thankfully because I planned for it in the build and moved weight forward, I do have the option of flying this one with a lighter 1600 battery, it goes all the way up against the bulkhead still, but no down trim is required to keep it balanced.

So I am not sure if things just happened this way for me, but to have the same trend with the CG on three planes, I tend to think it is not a coincidence.

My power system is not that much heavier than what RC Powers recommends on their master parts list http://www.rcpowers.com/community/threads/master-parts-list-official.8300/ ., so I don't think that is making it more tail heavy than a plane that might be built with stock recommended setup.  From my own data collection, the motor I use, the Focal Price 2700 with a 6x3 EMP prop is actually 2 grams lighter than the Turnigy D2826/6 motor with a 6x4 APC prop.  The only real difference is that I use a 40A ESC instead of a 30A ESC which is 7 grams heavier, so when the dust settles, there is only a 5 gram increase in weight in the power system.

Perhaps even with my stock Mig using the full KF4 affects the CG somewhat, when I look at the promotional pictures from RC Powers of the plane they built http://www.rcpowers.com/community/threads/mig-29-v4-%E2%80%9Cspeedmaster%E2%80%9D.16826/, it does not show the top KF extended all the way along the LERX, so I'm not sure if that makes a difference, if the CG was determined without the extended KF along the LERX.  When the plans were released, it had the top KF extending forward, I'm not sure if the CG needed to be adjusted, but it could have made a slight difference in why I have found the CG to be ahead of the stock CG.  Perhaps that is why, I'm not sure.

Again, perhaps this is just an anomaly, but as I mentioned, to find that happen on all three planes including the stock built Mig29 V4, I tend to think it is a solid trend.  After accumulating as many flights as I have and evaluating these planes over such a large body of flying, I am fairly confident in my findings/observations.

So why is it important to mention these findings?  Well, I'm not sure what others have been finding or reporting as I don't follow the RC Powers forum any longer, but it might impact how you build your Mig29 V4 depending on what flexibility you want regarding batteries, power system, etc.

As I mentioned in the posts I wrote during the build and post flight of the NAMCV2, I purposely put weight forward as I knew I wanted the flexibility to use lighter batteries without having to add trim or extra weight to get the plane to balance.  Perhaps this might not be an issue if you are building simple, no KFs, elevons only or a less complex setup than mine, I'm not sure, but it might be something to keep in mind if you decide to build this plane in any configuration.  

Hopefully this is helpful if you are thinking of building an RC Powers Mig29 V4, it is an amazing plane in any configuration, it is without doubt the best stock built plane I have ever flown.  The mods discussed throughout our blog were to improve on some things Stephan and I saw to tweak the plane to fly to better suit our flying styles.

Cheers,

Scott

RCP Mig29 V4 Stock build and NAMCV2 slow flight comparison

Hi everyone -

Great day for evaluating some slow flying characteristics at the field today... :)

It has been a big source of frustration for me over the last few weeks/months to be able to do a valid "slow flight" fly off between a stock and modified plane of the same type that were of almost the same weight with the same power system.  Either I had the wrong planes with the right wind conditions or I had the right planes with the wrong wind conditions... :/  Anyway, the "park jet planets" aligned today and I was finally able to get some good slow flight testing and evaluation done today, right planes, right conditions... :).

The gist of this post is not so much about comparing two different Migs, but proving to myself that smaller elevons and ailerons do not negatively impact slow flight handling.

I was so happy today to finally have two planes with pretty much identical setups other than the size of their control surfaces to prove to myself once and for all that what I had always known would be proven true.  

So I decided to fly some maneuvers that were easily repeatable, I essentially flew a zig zag/slalom from one end of the field to the other, alternating 90 degree left and right turns followed by a 180 degree turn at the end to fly back the other way and repeat the same.  I found that about 35-40% throttle was about as slow as I could go without the planes falling out of the sky.  It was just mostly a matter of feel I guess, you get to the point where it feels like you might start losing control and then just add a little power til it flies properly.

I was essentially looking for a couple things, how crisp and solid did my control inputs feel and how well did the plane maintain energy through multiple maneuvers?

So here is what I found starting with the stock Mig29 V4.  The first turn or two were OK, but after that without an increase in power, the plane had a tendency to want to not only tip stall, but just stall in general as it lost speed and energy quickly.  It also felt sluggish and almost a bit sloppy as I went through repeated turns.

With the NAMCV2 with smaller elevons and ailerons, control was much crisper, more direct in fact and only when the speed bled off after about the fourth consecutive turn did it feel sloppy and need more power to get the speed back up.  The V2 held it's energy much better and longer and tendency to tip stall was almost non-existent until it got to complete stall speed.  

In the discussions I have read against smaller elevons and ailerons,  the argument presented was that larger surfaces moving less were better for slow speed flying and handling than smaller surfaces moving more.  My experience not only today but throughout all the testing and flying I have done with planes with smaller elevons and ailerons says this is not the case, at least for how I like to fly and what I expect and observe of my planes.  

So did I need more stick movement with smaller surfaces over the larger stock surfaces?  Not really, the plane just responded quickly and with less slop and drag with the same stick movements as used with the stock plane.

I'm sure someone smarter than me (perhaps my friend Stephan who often stays at the Holiday Inn Express and has read the "Big Book of Aerodynamics" might know... ;) ) can tell me if putting a large surface at less deflection causes more or less drag than a smaller surface moving more.  I have written and reported "ad nausea" that I find smaller elevons and ailerons to be more crisp, precise and efficient than larger elevons and ailerons, often needing the same or even less deflection to get my plane to fly how I want it to.

So a smaller surface moving the same or less than a larger surface is always going to cause less turbulence and drag, therefore allowing for crisper handling and better energy maintenance as my plane goes through the air, at least in my experience.

So please don't think I am trying to tell you that if you build and fly a plane with large or stock control surfaces you are going to be disappointed, build your planes and fly them to suit your flying style and enjoyment.  Just know that if your plane is not meeting your expectations, there are plenty of other options out there.  As both Stephan and I have said before, don't let fear and what the "everyone else" is doing hold you back if you want to try something different, foam is cheap, hack up an old plane if need be, follow and explore what you think will work, no matter what I or anyone else says.  The worst thing that can happen if try something else, it cost you a bit of foam and glue and you learned something in the meantime... :)  

There is no better way to prove or disprove a theory whether it is yours or someone else's than to try it out and see what happens as your plane flies around.  Like I have said, you might be amazed at the reward for the risk of a sheet or two of foam and some glue... :)

Anyway, a very fun day at the field and a very therapeutic way to finally get rid of some "park jet frustration"... :)

Cheers,

Scott

RCP Mig29 V4 NAMCV2 dialed in for high alpha... :)

Hi everyone -

Another great day at the field with a couple of my Mig 29 V4s... :)

I was blessed this morning with a couple hours of dead still air, so took full advantage it to get my NAMCV2 (the blue camo one in the picture) dialed in for high alpha.

I will caveat this post by saying my high alpha skills are a work in progress and if a plane doesn't necessarily do high alpha well, I don't consider the plane a failure, not all planes were ever designed to do it for real.  It is definitely a skill that in my experience requires practice and patience, not only to get the plane set up correctly, but to get myself into the right mindset to really focus on doing it well.  I do enjoy it as a way to challenge myself primarily in keeping my control and power inputs smooth and forcing myself to use more finesse rather than just slamming the sticks around.  I find as I practice high alpha flying occasionally that these principles spill over into my normal flying and make me a better pilot from a standpoint of staying smooth with my control inputs.  Although sometimes you just gotta slam the sticks around anyway, all part of the fun... :)

I did experiment with the deflection of the spoilerons a bit to see if that made a difference since the ailerons are different from stock and the V1, but lo and behold, 5/8" of deflection seemed to be where it worked best which is the common thread between the V1 and stock Mig V4 as well.

Not by a whole lot compared to the V1, but the V2 is the best high alpha performer of the three Mig V4s in my hangar.  Maybe because I have more weight shifted forward and in closer proximity to the CofG and the different shape of aileron, I'm not sure.  The larger rudders are of course a big winner also.

I flew about six flights of pretty much nothing but high alpha from launch to landing and was very impressed with how this plane handled.  When first getting setup to start high alpha, it wing rocked somewhat when the spoilerons were deployed, but once it settled in and I got the power setting and elevon deflection just right, it really was very solid.  Wing rock when it came on was very gradual and normally just by easing off a bit on the elevator, it stabilized right away.  I'm "guesstimating" here, but I would say that I was holding a good solid 40-45 degrees AOA (angle of attack) throughout my high alpha sessions.

This plane is more susceptible to the helix effect of prop wash and prop torque that I quoted and described in this post http://migsrus.blogspot.ca/2014/08/mig29-v4m3e3-hi-alpha-testing.html  than the stock Mig and the V1.  As I mentioned in my first impressions of this plane's high alpha abilities, if I took my thumb off the rudder, it would slowly drift left, so a bit of right rudder was always needed to get it to hold a solid heading (more on that later).  Although because of the phenomena described in the link above all planes including this one are more of a challenge to turn right in high alpha, this one responds much better than stock and the V1 taking less rudder input to turn right and less delay before the nose responds to the input.

So what does it take for me to keep this plane in good solid high alpha?  I will discuss my findings as a function more of how much surface deflection is required versus stick input as everyone's throws and expos can be different.  Remembering also that the moving surface area of the elevons on this plane are about 10-15% smaller than stock (however, more interesting observations on that in a moment... :) )  Your deflections may also be different depending on your plane's weight, your power system and how your weight is distributed, I post these numbers as a point of reference.

• throttle - I found that around 45-55% throttle was the power envelope needed to maintain good altitude and attitude hold.  Obviously more if I was getting into trouble or got the nose up too high and needed to power out of a stall, and a bit less if I was climbing, but 45-55% was a very consistent power setting;
• I mentioned my spoileron deflection already, 5/8";
• I was holding about 1.5" of elevator deflection to keep the correct attitude, obviously with minor adjustments as needed to prevent wing rock; and
• as mentioned, to keep it from drifting left, I had about 1/4" right rudder deflection.

So how does it compare in high alpha to my other two Mig V4s?  The V1 and this V2 are very similar in fact, the slight nod in stability and rudder authority going to the V2, but overall, capable of about the same AOA with the same spoileron and elevon deflection and power input.

I also did some more high alpha with the stock Mig today.  It is also a very good high alpha platform, but not capable of the same AOA, maybe 5-10% less, not a lot, but noticeable.  Wing rock comes on more quickly and aggressively and requires a more aggressive dropping of the nose to recover from it.  The rudder authority is good, but can very easily cause the plane to want to roll and as a result if I get too aggressive on the rudders, this tendency to roll can then cause wing rock and potential tip stall, most of which can happen in a very short time span... :/.

Additionally, maybe cause she is much more "battle worn" and has had a few good "gonks", a lot more rudder input is required to hold the stock Mig straight as the nose tends to wander all over the place at times.  It also seems to require more throttle movement to maintain altitude and attitude, so a bit more challenging in those aspects than the V1 and V2.  What is interesting is that even though the elevons are bigger on stock than the V1 and V2, the amount of deflection required to hold the nose up was about the same, 1.5".

Now don't get me wrong, I'm not saying the stock V4 is a "train wreck" in high alpha, from my experience it is better than the Mig V3 and equally as good as the F18 V3 although I have exponentially more high alpha time on my F18 V3 than the Mig V4, so it may not completely be a fair comparison.

Anyway, enough about high alpha...this was the first time since I maidened this plane that I was able to really blast around without worrying about what the wind was going to do to it.  I had also dropped the "hot" motor into it that I spoke about in this thread http://migsrus.blogspot.ca/2014/09/not-all-components-are-created-equally.html , so big smiles all around... :)  

This plane in this configuration with this weight is just amazing.  I know it might seem scatter brained of me to keep saying with every new Mig I modify that it is the best plane I have ever flown, but on the other hand, this is a progression, learning from the previous plane/planes and working to improve on the next, so why not?  

As I got into really thrashing this plane around, it was like it was a thoroughbred being let free in the pasture on a cool fall morning, it just wanted to run and turn and just kick up it's heels.  I know it might seem goofy to speak about an inanimate plane like that, but it is just pure fun to fly, even more fun when wind is not a factor... :)  It almost seemed that the plane was having as much fun as I was... :).

I also did some slow flying comparisons between the stock Mig and the V2, but will probably write that up in another post comparing downsized elevons and ailerons to stock, so more to follow on that in the very near future, some interesting observations... :)

Cheers,

Scott

Not all components are created equally... :)

Hi everyone -

For those of us that build and fly scratch built park jets, we have probably all experienced some significant differences in quality control and performance, even with the same component.  I guess that is part of the risk/reward of using mass produced inexpensive components from various online manufacturers and distributors.

Early on in my park jet career, I went through a run of bad luck with frustrating/inferior ESCs.  I found Grayson Hobby to be the absolute worst.  I bought 3 of their 50A ESCs to go with my SMJV2 motors, one never worked properly, one lasted about 10 flights and magically I got about 100 flights out of the third one before that packed it in.  Less than stellar quality and performance!  I also went through a myriad of the Red Brick and HobbyKing SS ESCs, many of which were very heavy, a pain to set up and often required the use of a UBEC which made the setup even heavier and bulkier.  Fortunately about a year ago I switched to Turnigy Plush ESCs and have not looked back since, maybe I just got lucky, but they have all worked extremely well, some for hundreds of flights.

Servos are another component that can be hit and miss.  While I find the RC Timer servos to be superior to the HK servos I have used, even then I occasionally get one that just chatters like crazy or doesn't work as expected.  Into the spare parts bin with those!

Batteries have also been an adventure for me, awhile back I bought a bunch of the Turnigy Nanotech high discharge batteries that I figured even with my NTM setups would be indestructible. http://hobbyking.com/hobbyking/store/__11951__Turnigy_nano_tech_2200mah_3S_45_90C_Lipo_Pack.html  When I first bought them, they were about $17, they are now $20!  Some of these batteries used to get warm with my Focal Price motors which draw just over half the amps of the NTM motors!  I will be hard pressed to buy another Nano Tech battery for a very long time, I have been very disappointed in their durability and performance for the price.  I have been having great luck with these batteries for the last few months, they even work really well with my NTM setups http://hobbyking.com/hobbyking/store/__9942__ZIPPY_Flightmax_2200mAh_3S1P_40C.html  I do find that they take a little bit longer to fully balance charge, but they run very cool and give nice, even discharge and are only $13.60.

So this leads me to motors, sometimes you get cold ones, sometimes you get average ones, and sometimes you get lucky and get a "hot" one.  And I don't mean hot in that it gets hot when it runs, but gives just a bit more power than it's peers.  I found quite a few differences between motors and ESCs when I did a bunch of field and bench testing of several motors last fall/winter.  I started a thread here http://www.rcpowers.com/community/threads/parkjet-motor-bench-testing.15685/  If you go to post #127 of that thread, you can download the most current version of the spreadsheet I maintained through the bench testing.

So I had dropped a completely new Focal Price motor into my RCP Mig29 V4 NAMC2, ready to see how fast it will go compared to the V1 since the first motor I put in it was running rough.  So I was excited when I got to the field today to do a "fly off" to see if it was faster since I built it about 0.7 oz/20 grams lighter and expected great things... :/  You can read more about my "fly off" comparison here http://migsrus.blogspot.ca/2014/09/rcp-mig29-v4-namc-v1-and-v2-fly-off.html

So as I got into the flying, I noticed immediately that the V2 even with the new motor was slower on the "hole shot" and at top end.  I didn't even need to clock them to be able to tell it was slower.  So swallowing my disappointment, I started to wonder what was going on....?!  Of course being overly self critical and self deprecating (probably more than you want to know about me... :) ), I immediately thought it had something to do with how I redesigned the tails that was causing drag or other speed problems.

So after a brief "pity party", my inner "Bill Nye the Science Guy" kicked in and started to look at things more logically.  So since all the control surfaces were dead centre, no trim, there can't be that big a difference in drag, I started to look at other components.  Both ESCs were set up exactly the same, props both the same, both balanced.

So luckily I had my "park jet dyno" with me at the field (my handy wattmeter... :) ) and decided to check what was going on with the two motors.  As a side note, I find a wattmeter a valuable little tool for evaluating what is really happening with a power setup.  I use this one from HK.  http://hobbyking.com/hobbyking/store/__10080__Turnigy_130A_Watt_Meter_and_Power_Analyzer.html  It is probably big overkill for what I might ever need and I am not smart enough to really use all that it tells me, but it gives good precise feedback on how many amps a power system is drawing and how many watts are being produced.

So, interesting results, both motors have the 6x3 EMP prop and I used a freshly charged 40C discharge 3S battery when I tested each motor.

The new motor in the V2 draws 32A and produces 356W.  This is pretty normal for most of the Focal Price motors I have tested.

The older motor in the V1 draws 36.5A and produces 413W... :), this is what I call a "hot" motor... :)

Good thing I switched to a 40A ESC a long time ago for use with this motor...a 30A ESC would get beat up pretty badly over time with those amp draws... :/

Interestingly enough, when conducting the highly scientific and reliable "finger touch test", both motors run about the same temperature, but one produces quite a bit more power.

So I think from now on that I will do this watt meter test on every setup I have to see what is going on so that my expectations don't exceed reality!  I have also noticed big discrepancies in a couple of my NTM motors, one draws about 48A and produces 488W (lower than it's rating) and another draws 61A and produces 600W (higher than it's rating).  So like I said, I think I will check each power setup now and try to keep the really "hot" motors for planes that I really want to scream... :)

Anyway, just another interesting lesson that I have learned in this exciting park jet journey... :)

Cheers,

Scott

RCP Mig29 V4 NAMC V1 and V2 fly off comparisons

Hi everyone -

Bit of a "Blue Mig Group" performance at the field today (groan... :/ )... :)  I had a chance to do a decent "fly off" between my NAMCV1 (the mostly blue plane on the right) and my NAMCV2 (the blue camo on the left).

It was an exciting day at the field today, almost too exciting... :/  I think due to the vibration I might have been getting from the older motor I was using in my V2 that the motor mount started to loosen!  I managed to get six good flights, then on the seventh flight it started to make a lot more noise than usual, so I landed as quickly as I could.  Fortunately, the motor mount didn't completely break off, but part of the glue joint was broken.  So all is good and nothing a little Gorilla Glue won't fix... :)

It was another windy fall day, so I really didn't evaluate any slow flight or high alpha handling, but I find that a little wind brings out the true character of a plane and amplifies good or bad behaviors.  I now have 36 flights on my V2, so I feel a bit more comfortable doing a valid comparison between the two planes.  I now have 136 flights on the V1, so I know it very, very well.

Just as a recap, here are the differences between the two planes -

• V2 is a bit lighter 0.7 oz/20 grams lighter;
• aileron and elevon servos and Rx are all moved about 1 and 3/4" further forward on the V2 than the V1, concentrating more weight in closer vicinity to the CofG;
• V2 has almost 60% more moving rudder surface and vertical stabs are 3/4" wider/deeper at the top; and
• ailerons are 1" wider in span and 3/8" narrower in chord.

All other aspects of the planes are the same including all throws and expos and luckily I have been able to balance both so that I can fly with zero trim in all axes.

So since today was a bit windy, 10-15 mph winds, I decided to evaluate fairly simple handling and aerobatics, lots of turns at medium to high speed, loops, rolls and stall turns.

There is definitely a difference in how these two planes handle and perform.  Not the "oh wow" difference say between the stock Mig and the V1, but rather differences that can only really be seen when flying repeated maneuvers and focusing on how the plane feels and performs.  So that is to say that the V1 is an awesome plane, but depending on what you are looking for, the V2 is just that tiny bit better in a few categories.

Turns

In medium speed turns, say 50-60% throttle, the V2 is just a bit more stable and tracks just that tiny bit truer.  It still is affected by the wind, but I would say it is noticeably "quieter" in these medium speed turns.  I'm suspecting this is due to the slightly larger top surface of the vertical stabs and maybe a little bit to do with the slightly extended ailerons which are now about 50% of the total trailing edge of the wing.  The V1 ailerons are about 40-45% of the trailing edge of the wing and deeper in chord, the amount of moving surface is about the same. 

At higher speeds, say 75-100% throttle, there is really no difference, both are very stable and locked in through tight, high speed turns.

Loops

In large, sustained loops, both planes were pretty much equally stable and tracked very true.  Because of the forward distribution of weight on the V2 compared to the V1 that "first step" when I pull back on the stick is a little quicker, but after that everything is about the same.

In tighter loops, the V1 tends to get bounced around a bit more and does not track quite as true unless I keep on a bit more speed than with the V2 and feed in rudder input.  I rarely had to use any increase in speed or rudder to get the V2 to track straight and true regardless of the size of the loop.  Again, perhaps due to the redistribution of weight and the vert stabs, but not sure, just a noticeable difference.

Rolls

In both slow and tight rolls, the V2 is more responsive and tends to track truer, perhaps because of it's lower wing loading and the aileron shape.  Not a huge difference again, but noticeable after repeating enough rolls with both planes.  The faster the speed, the smoother the V2 handled the rolls.

Stall turns

Both planes perform very smooth, direct stall turns with little to no opposite aileron input required (except to compensate for pilot error/skill :/).  With all the extra moving surface, the V2 just requires about 25% less stick movement to execute the same maneuver as the V1 with it's smaller rudders.  As Stephan mentioned in a recent post, it is a trade off, if you like to do knife edge type maneuvers, then the full hinged rudder although having more authority in other flight regimes will make knife edge flying far more difficult.

So both planes are excellent performers, there is no doubt.  They both are a blast to fly even with slightly different characteristics.  Although right now I might be leaning slightly towards the V2 as being my slight favorite of the two, I want to log several more flights before really giving my final verdict.

One thing I have been noticing with my V1 over the last 10 flights or so though is that my CofG seems to be slowly "migrating" even further forward... :/  I started to notice a bit of zooming in high speed runs, so I double checked that my elevons and all other control surfaces were still centred and true which they were and the zooming continued.  So I slowly started to move the battery forward a bit at a time until now it is 1/2" further ahead...What the...?!  I pray that this tendency does not continue too drastically as I now have my 2200 battery all the way up against the bulkhead to get it to fly with zero trim in the pitch.

Since I will be swapping out the Focal Price motor for the NTM 2700 motor very soon, I might have to consider a whole new weight distribution setup to get it to balance since the NTM motor is an oz heavier than the FP motor and I also want to put heavier MG servos in for my elevons.  I might have to shift the servos forward somewhat as well as my Rx and the heavier 60A ESC I will need with the NTM motor.

I find it very interesting the difference in CofG placement between the V3 and V4 Migs.  The motor on the V4 is almost 1" further forward than on the V3 and I have been flying with my CofG 3/4" of an inch ahead of stock on the V4 where with my V3, I was regularly flying with my CofG about 1" behind RCP stock.  In fact my CofG on the V4 is right about where the wing break occurs at the intersection of the LERX and the wing.  On my V3, it was over 2.5" behind the wing break...interesting stuff.  Perhaps the enlarged wing, larger rear deck plate and other things have significantly shifted the center of lift and center of gravity on this plane from the V3 to the V4.  

Since I don't frequent the RC Powers forum any longer, I don't know if others have been experiencing this phenomenon, but to have it happen to me in both stock and modified planes, it makes me wonder if the stock CofG per the plans isn't off somewhat.  To have the same thing happen to me on three planes is a bit more than coincidental I would think...but oh well, I have managed to balance them OK, I just lose some flexibility now with my stock Mig and the V1 to be able to use lighter batteries as they won't have enough weight forward to keep the nose down without inputting significant down trim.

I also learned another lesson today about components and how they are not all created equally, but will discuss that in another post... :)

Cheers,

Scott

FRC Su35 MK2 NAMCV2 Build log - Part 1

Hi everyone -

I just wanted to post a few pictures showing some updates mostly about mods I am making now that I am almost done cutting foam.

I am  going to be using modified elevons just like I did on the Su35 MK2 NAMCV1, but this time I will be using a fixed horizontal stabilizer and moving elevon surface similar to what is being used on the RCP Mig29 V4 and I think the Su34 V4.

After I finished drawing out what I wanted my elevon to look like, I made a template out of scrap foam so that I could trace it's outline on the plans, you can see the template in this picture.

I then cut this out as part of the wing plate (well half a wing plate actually in the case of this plane) and then scored what will be the hinge line.  The pen in the picture is pointing to the part that will remain attached to the wing plate and act as a horizontal stabilizer.

Another mod I wanted to mention that I have been thinking about is to the bottom part of the nacelles/intakes.  As you can see in the first picture, I had a bit of a "gonk" when I pancaked a landing pretty hard and the tip of the prop cut out a chunk of foam.  Fortunately it didn't happen in the air... :/  So I had a closer look and realized that where the prop disk is with the Focal Price 2700 motor (which I will be using in the V2 plane as well), there is only about an 1/8" inch clearance between that part of the foam and the prop tip.  So I decided to cut some foam away to give a bit more clearance to that area and hopefully prevent any clipping of the prop.

First picture shows the damage by my "pancake gonk landing".

This picture shows where I will cut away some foam. 

I have most of the parts cut out now (except for the KF airfoils) and will continue to shoot the build video in steps to discuss my tips and techniques learned from building a few FRC Foamies park jets.

Cheers,

Scott

FRC Su35 MK2 NAMCV2 Build rebooted... :)

Hi everyone -

Well I guess I must still have the "build bug" as I am motivated to get the next version of my FRC Su35 MK2 build going now... :)  As I have mentioned, I will be shooting a build video pointing out my build techniques and some lessons I have learned building a total of 8 different FRC Foamies park jets (F15 MK1 x 2, Su37 MK1 x1, Su37 MK2 x1, Su35 MK2 x3 and F15 MK2 x 1).

To the best of my knowledge, there is not really a build video for the Su37/35 MK2, there are pictures on the FRC Foamies website, but I have not seen or heard of a build video.  I still get regular questions through my You Tube channel on my Su37 MK1 walkaround video that I shot 18 months ago, but this shows a completed plane, not the steps on how to get there, so I thought this would be a good opportunity to get one done.

I already shot the first part on how I prepare my plans before cutting out the foam as there are a few adjustments/modifications that I make even if I am building stock.  In addition to lessons learned from building this plane stock 3 times and once modified, I will be discussing the modifications I am making to this NAMCV2.

I have taken a couple pictures that will serve to demonstrate the main modifications I am making, smaller ailerons and "kicked out" vertical stabilizers (similar to the RCP Mig29 V3 and V4).  My elevons are also quite different from stock, but I will discuss that when I get to that stage.

Here is a picture of the dimensions of my ailerons.  I decided to go with what I have had great success with on the NAMC V1.  Even though I am reducing the moving surface on my elevons, I decided to keep the ailerons the same size and if need be I can crank up the throws to adjust the roll response to my liking.

This next picture shows how I widen the back portion of the wing plate so that I can angle the vertical stabs inwards by 3 degrees.  If I don't move the back slot outwards, the vertical stab would interfere with the prop slot and prop, so by widening it, it alleviates this problem.  The orange line also shows where I will cut the rear of the prop slot to open that up, I just always do that no matter what plane I build.  I noticed in the picture that I cut off the amount to draw the line back, it is 3/8" back from where the centre part of the stock prop slot ends on the plans.

I will do my best not to bore you to death with all the different stages of my build like I did with the Mig29 V4 NAMCV2...I'll let the video do that... :/  But I will take pictures mostly of things that might be critical to adopting the mods I am making to this plane as they might not show up well enough in the video.

Cheers,

Scott

RCP Mig29 V4 NAMCV2 initial high alpha results

Hi everyone -

Another fun day at the field yesterday, blasted another 12 batteries through my new Mig29 V4 NAMCV2 and 5 through my Su35.

It was still a tricky day wind wise, but I did manage to get a couple bursts of high alpha with my NAMCV2... :)

I'm happy to report that the larger rudders now make it much easier to turn right compared to the challenges I seemed to be having with the NAMCV1.  Interestingly, now when I take "hands off" the rudder, it will start to drift left where "hands off" the NAMCV1 would stay straight.  That is the thing I love about scratch building, each plane has it's own little soul and idiosyncrasies.. :)  In fact to keep it straight in high alpha I needed to keep just the tiniest bit of right rudder input.  This is very similar to what happens with my old RCP F18 V3, so not surprising.  The drift to the left is more than likely caused by a couple factors that were already discussed at length in this previous post http://migsrus.blogspot.ca/2014/08/mig29-v4m3e3-hi-alpha-testing.html

With each flight I log, I am more and more pleased with how this NAMCV2 flies, I think by concentrating on losing a little bit of weight and really paying attention to the sanding and finish, the combination really makes this plane perform well.  I'm really liking the smooth yet direct input I get from these rudders for how I like to fly anyway.  The different shape of ailerons as I mentioned in my first post flight report also seem to make turns and rolls just a little crisper and direct.  I still need to swap out the motor, I think the current motor is working too hard, maybe bad bearings or something in the motor, not sure.  So I will do that later today before more testing coming up this week.

I am also hoping to get cutting foam on my Su35 MK2 NAMCV2 this week.  I have decided that the only real significant mod I will make is to use Mig29 V4 horizontal stabs and elevons.  I had discussed modifying the vert stabs, rudders and ailerons, but decided against that, it flies just fine the way it is with those surfaces.  Other changes will be to build techniques like symmetrical leading edges on the wings and elevons/horizontal stabs and a few other tweaks.  As mentioned before, I will try to shoot a build video which will be shot in stages and edited together to discuss some of the "FRCcentric" build steps and techniques that have worked for me in the past.

Cheers,

Scott

More food for thought

Here is a picture of my friend's SebArt Mig-29.  It has thrust vectoring nozzles with EDFs.  If you've watched the video of YouTube, this plane rocks.   Take note of the ailerons, look a lot like Scott's NAMCv2.  The SebArt has a fixed horizontal stabilizers with elevator sized angled elevons.  The V4's improved flight characteristics are due to this modification as well (my humble opinion).

Here is a another overly of the scale Mig, V4 and SebArt.  I'm rethinking my LERXs on my next build.  I'm going to downsized the LERXs and the leading edges.

If you ain't crashing, you ain't pushing the envelope. Additionally, why no more balsa.

Yep, Ouch squared.  Well, trying to make myself feel better with that title.  After two years of collecting dust, I got out my 3D Hobby Pattern plane and thought I'd go through some batteries.  I got through one.  Not making excuses, but I learned a few lessons.  When I go fly at my neighborhood field, I move around so I have the sun at my back.  Well today, I went to the RC flying field for the runway and plenty of room.  To avoid the heat of the day, I went out this morning and the runway is lined up North South and faces East.  So the lighting was difficult and the contrast was not good on the plane.

Since I hadn't used the batteries in a while, I used an alarm to warn me at 3.7 volts/cell.  Of course, the alarm goes off at the furtherest point, the contrast is not good, and I haven't flown this plane a while.  I forgot how it tip stalls very easily.  So I make a turn to base too slow and she fell out of the sky.  Broke in half.  So look on eBay for some used batteries, motor, servos.  30 years ago I hung up the hobby after crashing my Carl Goldberg Super Chipmunk.  This time around, I'm just saying no to balsa and store bought planes.

I had also taken my balsa Edge to the field.  She is going to collect some dust as well. Then I had crash number 2 of the day.  Yep.  Been there done that, repeated.  Saddest part, I've crashed before the same way.  I swapped out the FP for the NTM 2700 on my Mig-V4 NAMC v1.  During the build I added carbon square tube to the back of the motor mount and on top on the wing carbon spar to reinforce the motor mount.  Previously on a prior Mig, I had ESC set with the engine brake on.  During a rapid deceleration it ripped the motor right off but I was able to save the plane and land.

Today, I was having a blast ripping up the sky.  The plane made a really cool sound that must have come from the hollow carbon square tube acting like a resonator.    Not so lucky today with the motor mount.  The ESC engine brake was off, but during a Cobra maneuver it ripped the motor off which then took out my aileron and elevon on the same side.  High speed lawn dart into the ground.  Either I be more gentle with the deceleration maneuvers or I further reinforce my mount.  With the extra power and speed I was able to do my first ever straight line knife edge.  Not all was lost!

This brings me to my next build.  I've been closely following Scott and our NAMC evolution.  As we have said before, we are fine tuning these planes to our flying styles.  My brain has been churning so back to the real deal for me.  Here is a drawing of the scale Mig vs the v4 wing plate and NAMC tail plate and elevons.  I am waiting on a picture of the SebArt Mig from a friend for another comparison.  I'm leaning towards cutting back the wing leading edge to scale which would also increase the LERX.  I will probably leave the v4 LERX because the HOA flight characteristics are excellent.   Scott and If have found it is better to make one major change at a time.  Though I'm all for braking rules!  I'll try Scott's new ailerons, but I'l stick to the NAMCv2a rudders (will increase size and use same leading edge as Scott) because of knife edge flight.  The full length rudders add some roll that makes knife edge very difficult though.

Hopefully next time I'll keep in the blue skies above!

Stephan