Haven't given up yet!

So I tried the new settings, it didn't end well... After studying the video footage and doing some Googling it is now evident to me that the T-28 is tail heavy. This is probable due to all the epoxy holding the tail together.
I made a center of gravity testing jig and sure enough it is very tail heavy.
I decided to combat this by making a new aluminum motor mount plate and setting the whole motor forward 35mm from the original position. I weighed the plane and it now weighed in at a hefty 580g. It was apparently 470g when I got it.

With this extra weight I had to wonder if the motor/ prop /battery combo could even generate enougth thrust for it to fly correctly. I built a few more jigs and decided to test it.

 Here is the youtube video of the testing:
https://www.youtube.com/watch?v=S9hFqzHK1L0


So the results weren't good, I thought well if it is to fly then it will need to be at full throttle. I took it up again but this time at full throttle, it was still flying like its tail heavy, by the time I got it trimmed out it was so far away that I couldnt work out which way it was facing... I crashed again.

This has lead me to a slightly new direction, firstly I managed to rip 40g from the plane (about 10 from the tail) I also decided to paint it a more viable color so I can work out which way is up and I have some 3S batteries on the way from hobbyking. I figured if I am to add more nose weight, it may as well be Lipo batteries. I also destroied my landing gear in the last crash, so decided to make it a belly lander.

Next flight was pretty much a repeat of the last except this time the plane was very random, there was no wind and I was in control until it again did some aerobatics and nose dived.
I was starting to think that this is a very hard plane to fly... Back to the repair shop!

The following weekend I was ready for another flight attempt, this time they had put the goal posts up in the field I use. I thought that I'm sure I will be able to miss them.... not true, shortly after take off the plane was like a heat seeking missile straight for the posts, I was doing everything I could to try to avoid them but the planes wing clipped and snapped it clean off, and yip it then nose dived and smashed the motor mount again. Back to the repair shop! Getting a bit over it at this stage.

Its now that I discovered wooden kebab sticks are a great thing. Using these sticks I stabbed two of them into the wing and using good old epoxy again, I got that wing reattached and it ended up actually quite straight.

I also decided to add some extra strength with an ice block stick which I cut into the leading edge of the wing and epoxied it in.

By this time I was a bit over cutting the nose off the plane every time it crashed, so I got some 12mm long M3 plastic standoffs (from an electronics shop), stacked 3 on end, drilled into the nose of the plane and epoxied them in place. The idea being that I can just unscrew the motor mount plate to fix it rather than taking to the plane with a hack saw each time. I also added some extra ice block sticks for extra reenforcing!

Now just reassemble and ready to fly again! with a little less enthusiasm...

The next flight attempt had a similar outcome, it was flying away from me, I was in control, then it barrel rolled and stalled shortly followed by another spectacular nose dive. At that moment I was feeling like this is imposable. As I was walking over to the wreckage I noticed that the ailerons were hard on, and once I got within 10 meters of the plane it suddenly returned to the neutral position. I was still in some kind of frustrated shock and didn't think any more of that. The next day I realized that that was rather odd, so I decided to range test the plane, I had a friend stay with the plane and I walked away while leaving the throttle on and moving the ailerons and elevator about. I had only got 30 meters away when the motor cut out and the ailerons stayed fixed, the ESC was beeping. I couldn't believe it I had spent over 10 hours fixing the plane and less than 2 minutes in the air!!

We bound my friends transmitter to my receiver and found that my receiver was faulty. I contacted the store I got the T-28 from and they sent me a replacement one. We then range tested the new receiver and found it was working over 400 meters! that is quite an improvement on the 30 meters I had with the old one. So warning guys and girls if you have an FMS radio system in your plane, I would recommend range testing it before you try to fly :)

So far I have broken 5 props (had to convert to a blade prop as they are cheaper) and have had to do some major alterations to keep this plane together. I fear now that it is so modified that once I do get it flying it will need all its thrust angles and center of gravity position set up again.

I decided to add some additional strength following that crash, I glued the wing on and added ice block sticks in the middle of the cockpit area and some between the wing. I also added plastic screws to keep the canopy on when it crashes, to help stiffen it up. I stabbed wooden kebab sticks into the front of the fuselage to strengthen the foam as it is getting very weak.

Ice block sticked epoxied in for extra strength.

Plastic standoffs glued in to the cockpit.

Plastic fastening points glued in to the body to clamp the cockpit in.

I removed the pilots to compensate for the crash proofing, they weighed 26 grams all up.

That mod really stiffened up the body, it now ready to fly.


11-04-2015 First actual flight with a working radio system!
After ordering some replacement plastic motor mounts from the states I reassembled the T-28 and headed down to the field. There was not a breath of wind around so I thought that I would have a good chance at getting a decent fly this time. I took off at about 60% throttle as I was on bumpy grass, it lifted off and started to climb like crazy! I backed off the throttle a bit to say 40% and it then it went into dive. I pulled up and applied around 50% throttle and it started to climb again, this time it all happened a bit fast and I ended up doing a loop. I was despritly trying to get some kind of level flight, its behavior was beyond trimming, I managed to keep in in the air for about a minute but I ended up crashing it again.

It crashed very hard nose first, the plastic motor mount smashed, the undercarriage wheel fell off and the motor shaft was a little bent. Because I have made this plastic motor mount very easy to change, the repairs only took 30 minutes.

After going over the planes behavior and doing some Google searches,  it seems I don't have enough down thrust and that is why it climbs like crazy with throttle. The center of gravity seemed correct before I took off so I will try angling the prop down about 3 degrees and  pointing it little to the right. My current/crash settings were pretty much horizontal and the pointing to the left a bit.

Now I await Wellington weather to calm down so I can try these new settings.

My junk shelf is getting full, if only I could spend more than a minute in the air!!

So I had a great idea! why dont I go and buy an FMS 800mm electric T-28 Trojan RC plane to learn to fly with? it's fitted with a 3 axis stability control receiver, so I figured it should pretty much fly itself right?

I had never flown before and had spent less than an hour on a pretty average simulator (which I actually found very helpful). Its an awesome looking plane and I figured what could possibly go wrong?
I like to think of my self as confident rather than stupid, I guess there may be other ways to describe this decision, but in the past there haven't been many things that I couldn't fix so I though ill give it a try.

First flight was yesterday morning, a fairly steady Wellington breeze about 13 kph, the T-28 was eager to get in the air, accelerating into the wind and me pulling about 50% on the elevators it quickly lifted off then rapidly darted to the left, which somehow I recovered from. I think I got a good 10 seconds fly time before I landed a bit earlier than I was planning and sure enough...  smashed the prop and gave the front wheel a good beating. I straightened the front wheel, fitted a new prop and went for another round.

This time I took off, much better than the last attempt, it seemed that I may actually have some control over it! I was about 60% throttle and I was thinking, man this thing is fast! then suddenly for some unknown reasons it did a crazy stall turn then a barrel roll and nose dived into the ground . This bit of attempted flying went for a good 25 seconds. I thought to myself, that was fun,  I think I might be able to get the hang of this.

I didn't stop to question the random behavior of the plane, I just put it down to me being a very amateur pilot.

I walked over to the wreckage and it didn't look too good, the motor had taken a beating and had been punched inside the fuselage it had broken the plastic motor mount plate, the motor cowling and again bent the front wheel. Well not to despair, to the repair shop I went!

The main problem was how to repair the plastic motor mount plate, as it is installed when the fuselage is in two pieces (long ways) and I wast too keen to cut it back in half to repair it. I decided to just cut the nose off the plane with a hack saw and this is how that went: SCARY

I cut about 10mm behind the motor mount plate, from the top, the cut was straight down and the bottom it was at about a 45 degrees angle. That way it had a larger surface area for when I was to glue it back on once the motor mount plate was all fixed.

The motor mount plate was smashed to pieces. I cleaned up each bit and made it so it all fitted back together nicely. I then cut a flat bit of plastic (approx 2mm thick), wiped a thin film of oil on it (to use as a thin separating compound) and screwed it to where the motor mounts too. I then mixed up some 5 minute epoxy and plastered it in to all the cracks, I also added some extra strengthening ribs to help keep it together.

After letting that set for about an hour I glued the nose back on using some more epoxy, I tried to set the thrust angle about where is was before the crash.

Once it was dry I reassembled it and needed to add 1.6mm plastic washers under the bottom of the aluminum motor mount. This put the thrust angle back where it was before the crash. Unfortunately things had moved while the glue was setting. I straightened the motor shaft using a DTI and a small vice and it was the ready to fly again!