This too would be a very nice ARF !!! MM

I was succesful in getting all the servos on the front rail, it balances this way like it should. I am having a problem getting the Evolution 46 to run with a Bisson pitts muffler. I burned up one before I realized it. I could not get the motor rich enough. Right at 1/2 throttle the motor would be too lean. I kept making the HS needle rich until I noticed fuel coming from around it, I had unscrewed it fully. That won't work.. I replumbed the original fuel tank with brass because I felt that the plastic lines that came with the tank were too small on the inner diameter, drilled out the clunk, and finally plugged one of the exhaust tubes. This all seemed to help, but didn't fix the problem entirely. I took the second motor from another plane, it is only about 1 year old, the other was at least 3. I hooked it up, much better compression, but while it ran reliably, it too got too lean as I gave it throttle. I didn't run it long like this, needless to say. Next step is to put the original muffler on it, and try that. If that works, then there is the issue of the cowl which is already cut out for the Bisson muffler. There is no baffle in the Bisson, I am wondering if that may not contribute to the problem. I wanted to maiden this thing this weekend, now I wonder if it will fly this month.....

I have the evo 46 on my alpha this may be a newb answere but what about richening up the low end needle because doesnt it control up to about half way on the throttle some mabe that would give you enough with that bisson pitts to keep from burning up your motor.

Chris

Yah, Nubie, I tried that. Good logic. I may have found something though. Take a look at the carb on your Alpha, then look at the fuel tank. Notice that the fuel tank is almost 1/2" lower than the carb. I think I am fighting a fuel feed problem of some sort the Evo may want the fuel supply down lower to run properly. Maybe I need a check valve on the fuel line, or on the pressure line from the exhaust. Maybe someone here has a good idea of what to do....

Bingo, strange, an Enya .50 will work with a bisson Pitts style muff but an Evolution .46 wont.... Don't know what to tell you. MM

I know it should work, probably something minor. With the cowl off, I primed the motor, and watched as the fuel gets sucked back into the tank. That was with both tanks. I think it may have to do with the exhaust port being below the level of the tank, which wasn't the case when I mounted the motor upright. I can also get the old motor to start in 3 or 4 flips, once I reset the needle valve, and leaned the idle mix back to normal. In the old plane, the carb is a full 1/2" higher than the tank itself, along with the exhaust pressure port. On the Rocket, the carb is in line with the center of the tank, the exhaust pressure port is below the tank. This was why came up with the idea of a check valve on both lines.

After I aquired a check valve and tried it on the pressure line, that didn't fix it. I then tried it on the fuel line, and that stopped fuel from being sucked back into the tank. But it didn't fix the running problem. I removed the fuel tank, and hooked it up outside the airframe, so I could move it up and down, trying various heights. Guess what, still not fixed. I called Horizon, and they suggested a hotter plug after I explained all of the different steps I have tried. I never thought of that one. So, it looks like another few days before I get to try that theory out. The motor runs fine upright, along with the first one I tried. It seems to be an issue of running the motor with the cylinder horizontal. Any constructive comments are welcome, I am almost out of ideas.....

I recently picked up the Rocket. This is my first ARTF kit and my past experience with building is with the 3 "Deamon" SPADS I have put together. I've gotten the wing together and now Im working on the fuel cell.
1. My first question would be what are my options in securing the fuel cell into place? Pros and cons of those options.
2. Options for mounting the receiver switch. I really do not like the idea of mounting the switch as the instructions specify.

I'll be using the Thunder Tiger .46 with a Pitts muffler, so I can also use your ides for mounting of the engine cowling. Again this is my first experience wit this kind of kit.

Just a few tips. Whether you run a cold plug or hot plug, you still can not run the engine at a lean setting without eventually burning it up. A hot plug may help the engine run better lean, but lean running is not good, and this sounds more like a fuel draw issue to me. When using the pitts style muffler with two exaust outlets, you may find that you need to plug one outlet off to create enough backpressure in the exaust to properly pressurize the fuel tank for a good fuel draw. For some reason some engines just draw better than others. Some engines will even run without a pressure line, and some have to have it. Then there are some that will not run properly outside of using the stock exaust pipe. Make sure to blow thru the nipple on the pitts to make sure it is not plugged, and try blocking off one exaust outlet with a cap of some sorts. I use a rubber exaust extention piece with a dowel plug.

If you are using the Evolution TPS engine, make sure you have the needle valve limiters removed(Little Blue Anodized Collar on the High End Needle). They will not allow you enough room to properly dial in the engine if you have changed out the exaust for an aftermarket type. Always remember that the engine should never get so hot that you cannot touch it for a couple seconds even after running it at full for a few minutes.Good Luck

Bingo, Ole' Ray here certainly has very good remarks to follow, all you can do is try it and see what happens. I run quite a number of different size diameter exhaust tube "Pitts" style mufflers on side mounted engines and have not had any pressure blow-back problems, but it does'nt mean that your Evolution engine wont. Some engines just wont work side mounted or inverted no matter what you do. Wish I could be there to work with you to resolve this, your losing valuable flying time. Keep talking to us here. MM

I got you there, Ray. I don't want to run lean. I did notice that I can keep it running if I leave the ignitor attached, that tells me that the thing is rich. What the guy from Horizon was saying is that it may need a hotter plug to burn off all the fuel when the engine is mounted horizontally, not an issue when the engine is mounted vertically. I agree that it is some issue with fuel draw, but the problem goes away if I mount the engine vertically. I took the motor out and put it in another plane, and within minutes the thing was adjusted and flying. This was why I took a second tank and tried it, and eventually took the tank out, and varied the height of the tank + - 2 inches. It didn't have an effect on how the motor ran horizontally. Mounted in the old aircraft, the carb is about 1/2" higher than the top of the tank, but the carb is also horizontal, not vertical. This is the only thing that varies. Same fuel, Omega 10%, sometimes Coolpower. I forgot to mention, I put a complete o-ring and gasket set in the first motor, thinking that I may have a hard to detect leak somewhere.


Fly64s, I will post a picture of how I got the switch mounted, it's really simple, I drilled a tiny hole in the switch stem to accept a small length of pushrod. I picked up a drill from a welding supply store that has very tiny bits for clearing the orifices in welding equip. It has bits that go up to around 1.5mm or so. It was about $8. I didn't want a knob to look like a switch knob, so I took a short length of brass tube and glued it to the stem after I bent it at a 90. Makes it look somewhat like a pitot tube...

This is the position of the engine in relation to the tank, I don't believe there is anything unusual there. I have dropped back to the original muffler to remove that variable from the equation. And in case no one else questioned it, I have an 11x5 prop on it, so that shouldn't be an issue.

One thing I notice in your photo is that the needle valve limiter is still in place on your engine. This has to be removed to get a full range of adjustment on the Evolution engine. I have to many engines to mention, but the Evolution I have runs as good as any, but since I have many Airplanes that this engine could work in, and several requiring different engine positions, I removed the limiter first thing so I would have a full range of adjustment on the high needle. I have run mine in several different positions with never any trouble. The only thing I ever had to do was reset the needles with the limiter off. Just something to think about. Good Luck.

The limiter with the pins in it is on the idle jet. The blue collar on the main needle is the locking collar for the needle valve ratchet spring, $1.50 each when you break one, as I did last week. The 1.5 mm setscrew allows you to turn the ratchet spring in a convienient direction to stop the needle valve pin if your adjustment locates the pin at the ratchet spring proper. Loosen the setscrew, and rotate the ratchet until it doesn't interfere, tighten and you should be good. I installed an A3 glo plug, it now runs up and down throttle like it should. I still have it a little rich until I see what tendencies it develops in the air. Nice smooth idle, good transition. Now I just hope the hotter plug doesn't burn up the motor or cause some other unforseen problem..... Getting ready to take it up in about 20 minutes, so we'll see...

It flies with the A3 plug. I got in 3 flights until I got the wheel pants tied up in some weeds on the approach. No damage, just bent the gear sideways, grass stained one wingtip.

A Hangar 9 Dural .60 gear is nice and sturdy, I cut it in half, and cut down the ends to insert. I took off about 4mm on both sides, and yes, the cutout is longer on the front of the gear, to accomodate the thickness of the cowl. I didn't want it to rub. I will use the old gear for the screw pattern.

I want to push the CG to the rear a little, at the front, it gets nose heavy, but still flies ok. You just have to watch your speed as you slow it down, it will drop a wingtip. The CG is 3 1/4" from the l.e. at this point.

Bingo, glad it's working. I JUST WISH TO HECK I CAN POST PHOTOS FROM MY JOB SITE COMPUTOR !![:@] MM

The only reason I posted so many notes about what I did up to this point was to point out some logical troubleshooting proceedures, and some ways to try and think around problems, ask questions, and get responses. If even one person looked at the landing gear issue and said, hey, that's a cheap way to fix my problem, I did what I set out to accomplish. There are times when I wish there were other people in the area to bounce things off of, but sometimes I guess that would take the fun out of doing things the long way and really learning from the experience.

MM - how far back is your C.G.? You mentioned that yours is a floater, I wouldn't mind getting more float. It's now nose heavy, maybe later today I will see what I can move around to the rear more. With that short wingspan, it does pick up some speed on the straights, the people flying with .60's in this must really be moving.

Hi guys, just flew my new Harmon a few days ago...she's a sweet little bird. I posted a photo with text overlay in my gallery: Hope this will help
someone with their build. The thing just looks and flys so cool.

http://www.rcuniverse.com/gallery/ga...emberID=120772

Regards

Hi Bingo, will you let me know how the new gear rig works....I can see I am having the same trouble with
my landing gear. Would much appreciate it. Nice idea.

Telepilot

The gear works very nicely. I do have a recommendation, however. If you look at the gear, it has a taper down to the axle. Make the taper sweep to the rear, the straight edge of the gear to the rear, the sweep to the front, or the gear gets borderline too far forward. I can keep it straight on takeoff, but it takes a little work. Occasionally, once I get slowed down on the ground, it's tough to keep it from spinning out. I just have to reverse the sides on the gear, and remount the wheels so they point in the proper direction. That will move the axles back about 3/4" or so.

Mine flies nose heavy, or so it seems. There is no flair at touchdown, and landing speed is pretty quick. I even increased the throw on the elevator to 110% to try and get it to go a little more nose up before touchdown. Flaperons make this plane a little squirrely, maybe I am just spooking myself. I figured for a small homebuilt RV type, this should slow down more and land a little easier. It seems to go fast quite well, handles good at speed. I currently have the CG set at 3.5", maybe I will send it back a little more and see what happens.

I wish someone else would post how this thing flies. This thing will just not slow down for landings. I also find the tendency to flip over sideways in a crosswind to be fairly disturbing. I have 2 Alpha's,one conventional, one modified with no dihedral in the wing, and it's a taildragger, an LT-40, and a Tiger 60 taildragger, and I can take these off in a 5 - 10 mph crosswind without too much pucker factor. Ok, the LT-40 does blow around some, but it's a kite anyway. The Harmon wants to just flip 90 away from the wind just as soon as there is enough speed to get the wheels to leave the ground. It has that same tendency in the air, and on approaches, it causes me concern. If you can fly it and land it at half throttle you should be ok. If it's calm out, and you get it slowed to where it looks like should be setting up for landing, it starts that wobble that lets you know you are on the bloody edge of losing it to a tip stall. Maybe I just got one that wasn't right, but everything looks ok, and it is a sharp looking plane. . . . .

Bingo, amazing differences ! I don't have a problem at all with mine. No cross-wind landing problems, smooth take-off rolls, it does like to float though. Have'nt had any nose-overs. It's not a real speedster with an 11-7 MA prop but it does perform. Don't know how else to help you. Hope you can resolve them before you get discouraged with it and "shelve it". respectfully, MM[]

MM - You specifically mentioned that yours floats. If you could assign that characteristic to a brick, then you could say mine floats. I wonder if it is a question of all up weight? Mine has to be moving well to have any control. With the large elevator, I can make the up travel 110%, and still can't get a flair for touchdown. It either flies, or drops. I have left the aileron throw to 75%, it is very sensitive to ailerons. I also noticed, one but not both of the wing tips curve up at the trailing edge. I thought it was some kind of method of washout or something, but yesterday I looked at the wingtips while I was wiping it down and found that difference in them. I have an 11x5 on it, but have an 11x7 and an 11x8 waiting, but since I can't get it to slow down without falling out of the sky,( it fell out of the sky at about 80 feet, it took that long to recover partially before it pancaked into the weeds with no damage) I don't need to use more than my 220ft runway to land on. I am thinking about decommissioning it. A fighter would have less hassles.

Bingo, I wish I could be where your at to check your plane and even test fly it along side mine. What is the all up front weight ? It just does'nt make sense why we have drastically different flying characteristics. Would you be interested in talking over the phone to me for comparisons. 1 -435-716-5470 at work. Lets get this resolved to your satisfaction. If I'm not in the shop, leave your return number. seeya then, Mike

I finished building my rocket last week, with the first flight this past saturday. Prefect day for a first flight, no wind sunny skies. I am running a super tiger G75 in mine, and cut the cowling to make it fit just right. I think you'd all be suprised as to how cool it looks. I just love the look of engines, they make the planes look much more mechanical. Anyway, on the first flight at half throttle the leading edge of both sides of the horizontal stabilizer cracked and fluttered really bad. I lost most elevator control but managed to pull it out of a dive by rolling knife edge and nosing it up with the rudder. Then brought it in goosing it from idle to half throttle to control the flutter and altitude. She's landed on the gear in one piece, and upon inspection of the stabilizers it appears that the grain in the leading edge doesnt run perfectly parallel with the leading edge, and it cracked right along the grain. Easy fix, and a check on the elevators themselves to make sure they werent damaged will mean she'll be in the air again by the end of the week. Ill either try and post pictures on here tonight, and if i cant get it to work maybe ill just post a link to my website. either way i also have a GP shoestring and like the performance of that plane, im hoping this flies anywhere near as well as the shoestring. The problem is i didnt even have a chance to get it fully dialed in while in the air. Theres shoestring pictures in my gallery. If anyone else has heard of this stabilizer issue id be interested to hear about it.

Thanks