I am passionate about building and flying scratch built foam park jets and passing on my experiences and lessons learned from more than five years of experience. Blog is purely based on my own opinions and experiences. If you have questions, please e-mail me at scott.parkjet@gmail.com. Park Jet noise...the "other" sound of freedom :) Happy flying! Cheers, Scott
Showing posts with label RC Powers T-50 V5. Show all posts
Showing posts with label RC Powers T-50 V5. Show all posts
Had these two beauties at the field today having a bit of a "stealth" park jet fly off😎
Here is today's flight video.
The RC Powers F-22 V5 and the T-50 V5 (on the left) were released at the same time and I have been enjoying the F-22 for a long time as it is my favorite of all the RC Powers V5 park jets. I am a newcomer to the T-50 V5, but have been enjoying it immensely. Both planes are modified quite a bit, you can read more about my F-22 V5 build at this blog post, and the T-50 build by watching this table talk video. Also, through this blog starting in December 2017, you will find a multi part build log documenting everything I did with my T-50 build.
For today's flight, the power setups were exactly the same.
I guess one of the biggest parts of today's flyoff was to see which one is faster😊 In the promo for the T-50 V5, Dave Powers says "This one is even faster". I suppose I assumed that was meaning it was faster than the F-22 since they were released at the same time. Now perhaps it means it is faster than maybe the last version of the T-50, the V2 which was huge with a 39.5" wingspan?
Both these planes have the same wingspan, the T50 is actually almost 1 oz/28 gr lighter than the F22, but I don't know, after watching the video a couple times, it is a very close call which is faster😑 In my previous videos with the T50, I had said it was the fastest plane in my hangar at the time and it is certainly one of the quickest planes I have ever flow, but that was before I gave the F22 a 160 gr/5.6 oz thrust increase, so who knows?! Guess I'll be happy having two really fast stealth park jets in my hangar😀
They are both a lot of fun to fly and certainly fast. The F22 with more weight below the wing plate than the T50 is certainly more stable and a bit smoother to fly. Also, looking at the picture above, the F22 seems to have more wing area and coupled with the lift of the flat bottom shown below makes it feel like it has a much lower wing loading.
The T50 is noticeably more agile and responsive than the F22 even with smaller elevons and less control surface travel in the pitch and the roll. In fact it is almost borderline "twitchy" which isn't always a bad thing as it certainly allows me to fly it aggressively, however it is not as forgiving as the F22, so it really forces me to fly smoothly and stay ahead of the plane😳 While it will respond more quickly that the F22, the T50 is like flying very close to the razor's edge, push just a bit too far and it can become a bit of a handful. Whereas with the F22, I can push hard but because it is a bit more stable and forgiving, I have a second or two more to recover if I do something a bit beyond my skill level😵
These are both excellent planes, RC Powers did a great job on the designs. If I was to recommend a stealth park jet to try first, it would be the F-22 V5 hands down. RC Powers has been the leader in getting an F-22 park jet that flies will without being a complete handful to fly. The T50 would be good for a second stealth park jet once you feel you are ready to handle it's incredible responsiveness and want to really push the envelope😀
As mentioned in this video below where I discuss my process for finding the ideal balance point on my planes, trimming and adjusting the throws, sometimes it takes more than one session to get my planes really "dialed in" the way I want them and this was no exception.
In my experience, the more high performance the plane is, the more time and fine tuning it takes to get things just right so that I can push the plane and my skills hard without feeling like I am constantly "behind" the plane.😟 This is definitely a high performance plane in speed, acceleration and agility 😀
I ended up adjusting my CG back about 1/8" from what I found was working in the first flight session. This then tightened things up even more around the CG as I moved my battery back about 3/8" to get it optimally balanced. This made response in the pitch and roll even quicker, so as I mention in the video, I dialed back the throws in pitch and roll by 10% (both elevons and ailerons) so that I could keep the plane under control within the limits of my skill level.
This plane is just fast!😀 Even at half to 60% throttle, it is moving faster than all of my other planes of this size (27" wingspan).
After I shot the table talk video above, I went over my control surfaces with a fine tooth comb to ensure I had no deflection with zero trim and it paid off as I was able to take out about half the left roll trim I had from the first flight session. This helps make the plane feel better balanced and I think reduces the drag even more.
As I started to push it harder and faster in tight high speed turns, figure eights, hard pull ups into the vertical, it just seemed to want more, the faster it went, the more stable it feels and it transitions from one maneuver to another at high speed with no problem whatsoever. 👍
It doesn't quite have as broad a speed envelope of it's counterpart the F-22 V5 nor is it quite as stable at lower to mid range throttle, but for top speed and agility, it is quite impressive and easily faster than the F-22 V5. Once I got things dialed in and balanced the way I like them, it wasn't a difficult or scary plane to fly, but because it is moving just that much faster compared to other planes in my hangar, I couldn't relax too much or look away for very long because by the time I looked back at it again it was much further away than I anticipate my other planes to be😲
That is a good thing actually, it is good for me to build and fly a plane once in awhile that pushes me a bit out of my comfort zone and forces me really keep my control inputs even smoother and under control.
Thus far I am very pleased with how well this plane flies and how my build process and modifications have worked out, a real little "rocket" and a blast to fly. Did somebody say 4S?! 😵😏😉
One modified RC Powers T-50 V5 ready to "slip the surly bonds of earth"😊
I may have mentioned in a previous post that I was thinking of doing the black, white and grey Arctic camo scheme like I have on my test bed Mig-35B, but I decided to go with a "blue" theme this time for something different. I think it turned out OK, either I thinned the paint too much or the Minwax treatment on the DTF where the paper is didn't allow for terribly good paint coverage. No matter, I could put another coat of paint on, but that would add weight. I'm more worried about how it looks at 200 ft away (to help my poor old 56 yr old eyeglass assisted MK 1 eyeballs keep track of it😒) than how it looks at 2 ft away😉
My AUW with 2200 3S battery is pretty good, 552 gr/19.5 oz, so I think it should be pretty light and quick. I decided to put the EMAX RS2306 2750 Kv motor in this plane as it is billed as being pretty fast according to RC Powers, so I might as well give it the motor it deserves😉. I will run a 6x4 APC prop and 40A ESC.
I mounted my rudder servos in the back first so that I could then run the rudder servo wire outside the prop slot and then back in through the hole where the elevon servo is mounted. This will ensure no possible interference with the prop by the rudder servo wires.
As I discussed in my servo video, the wires on the 5 gr servos aren't very long, so since I use a "Y" harness to connect my servos to the receiver, I ran the two Y leads out from the electronics bay so that I could connect the rudder servos, then tacked everything down with a bit of hot glue, including making sure the rudder servo leads were secure in the Y harness plugs.
I decided to trim a bit off the rudders themselves as when it was sitting on the table, these were completely flat on the surface, so by putting a slight angle on them, hopefully this won't cause such an abrupt landing as I flare it in. I probably trimmed about 1/4" off the back and then angled it down to the rudder hinge line.
For durability, I always spread a very thin layer of glue (this glue which is identical to BSI Foam Cure) on the nacelles and along the bottom of the nose. It dries light, clear and hard like epoxy, but doesn't turn yellow over time like epoxy does. Fortunately, I can get this at a local dollar store and it is much cheaper than Foam Cure.
A bit hard to see the glue in this picture, but where it is shiny shows the glue. I darkened this with black magic marker first to help with orientation.
I put a thin layer on the bottom of the nose forward of the small air vent. Since the T-50 doesn't have a lot of nose clearance off the ground (especially since I lowered the nacelles by 7 mm), I suspect occassionally on landing it may tilt forward as it comes to a stop. This glue will help the foam from getting gouged and torn.
Although I won't know how the build and my modifications turned out until I get a chance to fly it, I'm quite pleased with how it looks and with my final flying weight, I think with the fairly low profile it will be a pretty speedy little beast. More to come as I get it in the air and start putting it through it's paces.😊
My build is starting to look much more "T-50ish" now😊 The vertical stabilizers are dry fit for now and won't be glued on til later on in the build to make installing servos on the bottom easier. In this current state with no gear, sanded, it weighs 177 gr/6.2 gr which is about what most of my planes weigh at this point.
I'm very happy with how the vertical stabs turned out, still a bit bigger than scale but I think much closer to the right shape than the stock vertical stabs.
I decided to make the nacelles a bit more scale and lowered them somewhat. I measured what they would be on the T-50 V1 (which has a 24" wingspan), then converted that number to what it would be on a plane with a 27" wingspan and ended up trimming 7 mm off where it meets the wing plate and also made the rudder less wide as well. I know you wouldn't know the difference in this picture, but it does lower the profile of the plane considerably.
I remember when we were testing the NAMC Mig-FA which is a concept design my former NAMC partner Stephan designed, the nacelles were similar in depth to what was on the Mig-35, our first plane. As we dialed down on more "scalish" looks since it was loosely based on the T-50, when we lowered the nacelles, the plane was faster, more efficient and much quicker in the pitch and roll as the vertical profile had been reduced considerably.
Perhaps because I lowered the nacelles down, when I dry fit the motor with prop attached, it was hitting the bottom of the nacelle. I had to trim quite a bit off to give the prop clearance. Starting where the pen is pointing in this picture, I trimmed forward about 1 and 1/4" along the outside, just angling in towards the inner part at an angle so as not reduce any strength and structure around the motor mount area.
To taper the leading edge of my wing and LERX, I draw a line about 3/8" back from the squared leading edge and then use this as a guide to trim the foam off before sanding. Bottom.
Top
I have always done a bit of a "sharp edge" on the leading edge of the wing with the KFs. I have read and heard arguments that this leading edge should be rounded, and maybe I'll try that sometime and see if it makes a difference, but I have done it this way with dozens of plans, so perhaps a case of stubbornness on my part or "if it ain't broke, don't fix it"😏
Finished product, I know it is hard to see with everything being white, but it is smooth and sleek now😉
Holes are cut out for the servos and I have also cut a relief out of the bottom KF so that the elevon and aileron servos can be installed easily. In the first picture, from left to right will be the aileron, elevon and rudder servos (same on the other side of the plane)
This relief is cut about 3/4" inch away from the nacelle to allow the servos to be installed easily and also allows for the "flanges" on the aileron servo in the front.
Still a bit more fussy work to do, I will apply the oil-based Minwax to the paper on the bottom of the plane and let it dry overnight, then paint the sides of the nacelles, install all the servos and pushrods so that all the work on the bottom of the plane will be done. Once that is done, flip it over, glue on the vertical stabilizers and then treat the paper on the top of the plane and ensure that is completely dry before painting the rest of the plane, installing the motor and it should be ready to "slip the surly bonds of earth"😀
In among all the holiday cheer, I managed to putter away a bit on my T-50 V5, mostly getting things ready before mating the fuselage to the wing plate. One thing I like to do is mark where my elevon control horns will go. Knowing that where I will be connecting the pushrod to the servo is approx 3/4" out from where the servo will be mounted in the side of the "nacelles", I use the slot that marks where the nacelle will fit into the wing plate as shown in the second picture.
Then using one straight edge as guide, I make a mark on the elevon on both sides so that I remember where the control horn will be mounted. I rarely use the control horn marks that are indicated on the plans as they rarely line up with where I want to put my control horns.
I used 150 grit sandpaper to taper the trailing edge of the wing, the leading and trailing edge of the prop slot, the leading edge of the horizontal stabilizer and all around the outside edge of the elevons to help keep things sleek. I like to do all this sanding before mounting the control horns, but I forgot to take a picture of that😏 While I can lay the wing plate flat is also when I sand the hinge tape on the ailerons and elevons so that it is no longer shiny and paint will adhere to it much more easily.
I also tapered the outside edge of the vertical stabilizers and added some bamboo skewers for extra reinforcement.
Before being able to join the fuselage to the wing plate, I needed to glue the front part of the wing plate on. You may remember that this part was cut out separately so that I could get the wing on a 20x30" sheet of Dollar Tree foam (DTF).
I start by taping the two pieces together as shown below.
I then hinge these two pieces open, exposing the edges of the foam as shown in this picture.
Then using 5 minute epoxy, I spread a fine layer on each side of the foam, then lay it flat with the tape down (I always put wax paper under it so that I don't have any ooze out and glue my wing plate to my work table). If any excess epoxy oozes out on the top as shown here, I take some scrap foam and spread it smooth ensuring any gaps between the two pieces of foam are filled.
Then another piece of wax paper goes on top of that seam and I weight it down with something so that the joint dries nice and flat.
In the next picture below the video, you can see that I have put the "insurance" tape on the bottom of the elevon hinge as I describe in this video at about the 7:50 mark.
Control horns mounted using epoxy.
So lots of "fussy" work done now, it is just a matter of mating the larger parts of the plane together, finish constructing the fuselage, attach the "nacelles" and "under rudders".
Last evening and today were busy getting the plans taped together, doing some measuring, drawing and even quite a bit of math...brain is tired now!😖 I think I have the vast majority of the work done to satisfy my planned modifications, so it will be much easier to start cutting foam and get building😊
I'll try to keep this organized and explain in detail what I did as well as why and how I did it, so this will be a bit of a lengthy post, but should be lots of pictures for distraction😉 Either way, you might want to grab a snack and a beverage, or read it in small chunks! This is normally the longest part of the build process for me when I am doing several mods on a plane, lots of measuring, figuring, drawing, redrawing, etc, but once I am happy with it, the rest goes along a lot quicker and smoother😊
I'll start with the wing plate since that is the most detailed and required the most measuring and drawing to accommodate my planned modifications.
One of the things common to all the V5s I have built is the wing plate is in two separate identical pieces. I prefer to tape these together first before putting them on the foam and cutting, especially if I am going to make modifications as you can see above in this picture. I have roughly laid out my carbon reinforcement ahead and behind the prop slot and along the elevon hinge line. One main difference between this and the F-22 is that she has a little extra "junk in the trunk" behind the wing as it is much wider than the F-22 V5.
In this current size, while I could lay it down on a 20x30" sheet of Dollar Tree foam (DTF) to get the 27" wingspan in one piece, it is far too long and needs to be cut in a couple of spots. I chose to draw lines here in front where the LERX (leading edge root extension starts to angle back more dramatically. This piece will get glued back to the main wing plate at a later point in the build once other things have been completed with the main wing plate.
In the rear, it made sense to cut off the elevons as I will be making those out of Depron anyway.
This will leave me with a main wing plate piece that is about 19" long, so easy to fit across the 20" width of a full sheet of DTF and have that all one piece.
Motor mount/prop slot mod, etc
As I mentioned in part 1 of this series, one of the mods I will make is to move the motor further forward by 1", primarily to compensate for the weight of the paper on the DTF behind the trailing edge of the KF and also hopefully to help the plane be more balanced and rotate more easily in all three axes.
There is a lot going on in this picture above, so I'll try to make sense of it. Originally, when I drew the sides of the prop slot, I had forgotten to widen it out so that it will be even with the outside parts of the "engines/nacelles" underneath. The black dashed "-" lines indicate where that will be, drawn by lining up the slots fore and aft on the wing plate to see where those will be. The lines that are "squiggled" out in black were my original lines and it made for a very narrow prop slot, maybe 6 and 3/8" which caused me to remember I could widen it out.
Hopefully you can see where I moved the motor mount forward 1" and also trimmed 3/8" off the leading edge of the prop slot to accommodate shorter quad racing motors. I always like the back of my prop slots to be a straight line, so drew that in accordingly. Gives my prop lots of room to "breathe" and perhaps it is not aesthetically pleasing, but hopefully gives me best performance from my prop and motor.
You can see where I put my carbon ahead of the motor mount, I will be using a piece of 3mm carbon tube as shown below. It is recycled out of a previous plane, so I need to remove the foam and glue residue before it goes into this plane. If you look to the right of the motor mount area below the carbon tube, I have drawn a small 1/4" square, this will accept a 1/4" tab from the top of the fuselage. I made this change so that nothing would interfere with the carbon tube, it is primarily for alignment of the top of the fuselage, not for strength, so should be adequate. If you look at the far right, I also modified the slot that will accept one of the tabs on the "engines/nacelles" to accomplish the same thing. I will place the carbon tube so that it runs right through the dead center of the "CG spectrum" that RC Powers puts on their V5s. This way I know that where this tube is will be my starting CG point for the maiden flight.
Reinforcement of the wing plate
As you can see in this group of pictures, I will be using carbon to reinforce the wing plate in three areas, a 13" piece of 3mm carbon tube ahead of the prop slot as shown above. I'm hoping that since this will be "locked in" under the KF4 airfoils it will give sufficient strength without adding the extra weight of 4mm carbon rod. Plus I already had a piece that fit perfectly recycled from another plane😉
For the main wing spar, I am using a 25 and 1/2" piece of 4mm carbon rod for maximum strength across the widest part of the wing, again, this piece was recycled from another plane, glue and foam residue need to be removed.
On the back plate ahead of the elevon hinge line, I am using a 15 and 1/2" piece of 3mm carbon tube. Since the "nacelles/engines" don't extend all the way back due to the unique "under rudders" of the T-50 and it is pretty wide back there, I wanted extra strength to prevent torsional twist caused by the elevons.
Aileron mod
Like I did with the F-22 V5, I wanted to increase the size of the ailerons. Due to the width of the back end of the T-50, the trailing edge of the wing is not that long, only 17.5 cm. I "showed my work" as you can see, 60% of 17.5 is about 10.5 cm which is what I used for the span and I increased the depth/chord to hopefully have enough control surface area for the ailerons to be effective. Of note, I find it easier to use metric when I need to take percentages of things or work out ratios. Just much easier for me when things are all based on 10 or decimals of 10 than percentages of inches😃 Although I'm still a bit "old school" and use inches when it suits me😉
Elevon mod
As I mentioned in Part 1, I wanted to add the "boom" to the center of the elevons not only for scale looks, but to add a bit more surface area to the fairly tiny stock elevon surface.
I borrowed from the NAMC Mig-FA a concept stealth plane my NAMC partner Stephan designed and I helped with the test and validation phase. Plans are free at the link or you can e-mail me at scott.parkjet@gmail.com and I can send you the PDF files. It is a concept plane based on the T-50 with a 27" wingspan, so these worked out pretty well I think and will hopefully add more authority to the elevons and a bit more "cool factor" to my plane😎
Mods to the nacelles/engines
Since I moved the motor ahead by 1" and will be using a shorter quad racing motor, I needed to trim the back of the nacelles so that they wouldn't interfere with the prop.
Also, I modified the tab where it will go into the slot I already modified on the wing plate.
I will not be putting my servos in the indicated locations. I will have to put my rudder servos behind the prop slot due to the "under rudders", my aileron and elevon servos will go as far forward as I can get them to shift more weight forward of the CG.
Fuselage modifications
Again, due to the movement of the motor and mod of the prop slot, the fuselage also needed to be adjusted. Back of the hatch to the electronics bay shorted 1 and 3/8" inches to avoid interference with the prop slot.
On the fuselage, I moved the center where the motor mount supports go forward 1" and the top piece of the fuselage 1 and 3/8" so as not to interfere with the prop slot. You can also see where the pencil is pointing I modified the tabs to fit into the slots I modified on the wing plate.
KF airfoil modification
Normally if I am going to modify a KF airfoil, I will cut one from the plans out of scrap foam. I always like to start with the top as once I get that sorted, I can easily make another of proper size and then size the bottoms ones later on (I will show how I do this later in the build process).
I will then trace it out on the wing plate plans so that I have some reference to work with to start measuring and calculating, shown highlighted in yellow below. This actually shows the final size of my KF after all my math, but hopefully you get the idea😉
So this next part might be a little difficult to follow, I'm kind of "winging it" (pardon the horrible pun 😏), but I think it should work. The T-50 has a very unique wing shape so I had to make some compromises.
I started off measuring the rough chord of the wing where it would be meeting the fuselage. You will note in the picture above, I don't factor in the extra bit that goes forward over the LERX (leading edge root extension)/intakes.
I also didn't factor this little bit into the wing chord, the triangular area roughly marked in blue
Where you see the metal straight edge in this picture is essentially where I marked the trailing edge of the wing.
So measuring from the top point of the KF to where my "trailing edge" is (indicated by the blue arrow), this measures 40 cm. Since I like to have 40% of chord at the wing root on my KFs, 40 x .4 = 16cm, hence why in the picture of the KF above I have marked to add 1 cm when I cut out my own.
The RCP ones were very close and fortunately the trailing edge of the KF is right on my modified prop slot leading edge.
At the wing tip, I also had to do a bit of compromising. The very tip of the wing is actually quite narrow on the T-50, so if I took 35% of that, I feared my KF might be too narrow at the wing tip to function the way I want. So I measured the very wing tip at 4.5 cm, then drew the blue line where the tip of the wing area is a bit wider (10 cm), took the average of those at 7.5 x 0.35 = approx 2.5 cm which luckily enough is what the stock measurement is on the RCP plans, so I'll go with that.😊
As mentioned earlier, once I get the wing plate cut out of foam, I will demonstrate how I draw out the rest of the top KF and then size the bottom KF so that they will be proportional on the wing.
Vertical stab modification
Again, I hope my math and methodology make sense here on how I modified my vertical stab, I used a little bit of math and some "artistic licence", but I think/hope the final product will look good and be functional. Looking at the current vertical stabs, they looked too much like those on the F-22 and not like those on the T-50 for my liking. I wanted mine to have the more unique angle and proportional size that I see in this diagram.
Having the plans to the RC Powers T-50 V1 from a long way back (unfortunately no longer available), I printed off one from those plans as a starting point. I like the more scale size and shape of this stab.
So I started playing around with a few numbers knowing to match a 27" wingspan, the V1 stab would have to be about 13% bigger. Then looking at the current size of the stock V5 stabs, I took an average of that, mixed in a little "artistic licence" on what I thought looked good and came up with the dimensions below using the same angles as on the V1 stab. I estimate I have reduced the overall size by maybe 10-15% and made it look what I hope I will be a bit more scale, we will see. I will cut out an extra one when I build the plane to have as a template for later builds in the event this works😊
Motor shims
This last part really has nothing to do with the mods, more of a big lesson learned or word of caution. In the V5 series of planes, RC Powers came up with the idea of using foam motor shims to adjust the motor location to make it easier to balance the plane (I "think" that is what the logic is anyway😐), if you watch this video at about 0:50, you will hopefully see what I mean.
I tried this when I built my first V5, the Su-27 and I found these foam shims to be a significant point of failure. When I would epoxy my wooden motor mount to the flat face of the shim, over time, they would rip apart, the epoxy actually pulling a thin layer of foam off with it as this is not a strong bonding method for the epoxy.
I brought this to RC Powers' attention via e-mail, however it was not really addressed, fair enough, their designs. However, from my personal experience, I would steer clear of using these foam shims on any of your V5 planes lest you risk your motor coming off in the air or you could end up having to continually glue it back on over time creating hassle for you and more weight to your plane😒
Well, hopefully you are still with me, follow on installments of this build log should be much shorter and less detailed...fingers crossed!
