jloane

Oh yeah..it can be a balloon on landing ...but  no problems really. I went up to a larger set of tires(more weight) and that will probably help to set the CG a little more forward..tail heavy I don't want

AA5BY

What expo does is change the linearity of the servo travel. It reduces mid stick servo travel but preserves the total travel that is set by increasing servo rate the farther one moves the stick from center. Another way of saying it is that it reduces mid stick sensitivity.

I agree that the Spacewalker needs sport throws, but mine is sensitive to very slight stick movement. And... the more that I think about it, the problem might be my setup. I'm using 65% throw on the ailerons and only 40% throw on the elevator. All are setup on the outside hole of the servo arms. It would likely be much better if moving in on the servo arms and programming the throw to keep the sport travel while trying to stay closer to 100% servo travel. I'll make the changes.

rowdyjoe

My Feedback: (9)

Irun different travel adjustments on my controls but, all expo is set at 50%. I adjusted the aileron travel to 75% yesterday and the roll rate is pretty close to what Iwant now. Rudder is set at 80% travel and elevator is at 25%. Even at 25% travel, I'm getting some pretty tight loops ....that is, when it will actualy do a nice loop. Until Imake the engine angle adjustment Ineed pretty good speed to keep her from flopping in loop maneuvers.

jloane,
Expo softens up the center of your stick ...diminishes the sensitivity and helps prevent over-controlling. The expo I'm using on my SW gives me slower response on the controls without affecting the travel. Istill have full travel but, expo slows down the control surface/servo reaction until you reach the limit of the expo you have set. As Ihave mine set, normal servo travel speed will kick in at the 51% point. Up to that point the rate of movement is about 1/2 what it would normally be. The advantage is better, more precise, control over each surface.It allows you to make minor adjustments much easier.
Try experimenting a bit and see if you like it. Start with about 20% on the ailerons and see how it feels to you. Most folks Iknow who are flying giant scale planes are using lots of expo due to the large control surfaces and the fact that most are flying IMAC and want very smooth and precise maneuvers.
If you fly 3D, you might not want much expo but, a little helps take the jitters out of the controls.


Arlyn,
You beat me to the punch on this one. Hope Ihaven't contradicted anything you've said.

RJ

AA5BY

Just got in from an afternoon flight. I'd moved the control rods in on the servo arms three holes, which of course allowed programming more travel and the feel was much better.

And... a good report on the power on/off trim... both are now aligned together with a very close to neutral elevator. As suspected, the filing of the holes on the opposite side of the shims did the trick to clear the last of the up trim.

The other noteworthy comment, this plane is not a good gusty conditions flyer. The combination of generous dihedral and a large wing make it vulnerable. There was again gusty winds out of the bad quarter for our field this evening and I admit being concerned about getting the plane down without a mishap. Took three passes and my thought was I'll not put it up again in such conditions.

Yeah... the plane does suffer left yaw on up lines but it corrects well with rudder. And... given that it has a spinner centered on the cowl, to shim right thrust would require new cowl mounting screw holes and with blind nuts set for the cowl screws... too much trouble so will do the corrections with rudder. From my experience, even three degrees right thrust and it would probably still require some rudder so why not just resign to using the rudder.

Did do some spins today... goes into and comes out of them very easily. Knife edge.... not so good... perhaps closer to worse than a stick.

rowdyjoe

My Feedback: (9)

Glad you got the incidence issue solved. The wind conditions you describe remind of a few hair raising moments I've had. "White knuckles" describes it pretty well for me. There have also been times that I had to leave early for a change in under-garments. Not all of those moments were caused by the wind though.

Fortunately for me my engine positioning issue is in pitch so, there's room to move it up a bit without modifying anything. I installed a washer between the bottom two mounting studs and the motor mount tabs. It moved it up slightly but, the results will be seen when Ifly it again.

I'm trying to solve the hard staring issue when the engine is cold. I've determined that the carb isn't pumping fuel from the tank. The choke is on full and the throttle wide open but, no gas to the combustion chamber. I turn the prop through about 50 times and you'd think that would flood the heck out of it but, when Ipull the plug it's dry. I think it may be a stiff diaphram. If I can determine which diaphram it uses I'll order a new one and install it. It's really crazy. I can use an electric starter and get it to fire up with the choke on and continue running after the choke is off. Once it's warmed up, it will start with a max. of 3 flips. I reset the timing this evening to make sure it was in spec. It's dead-on 28 deg. BTDC now. I think it was a bit off before. I haven't tried to start it again as one of my muffler bolts is too short and has stripped out the first few threads in the hole. I'll go to the hardware store tomorrow and buy a longer one.

RJ

AA5BY

Gary... did you solder the hole in the choke plate closed? If not, do so and your priming problems should go away. I've never had to take the choke plate out to solder them. Use a wire wheel in the dremel to clean both sides and simply solder them with a solder gun using electrical rosin core solder. Solder both sides. After the first time, I now do it as a matter of course for every cowled engine where the ventura can't be reached.

As you say, the other possible issue could be the pump diaphragm. It is the one under the single large screw plate. There are three different materials that the diaphragms are made of. The traditional is black rubber. It pumps well but don't seem to hold up to modern fuel blends. The second is bluish tinted and looks like acetate. It is the weakest pumping of the three materials. The third and I think the best is the beige colored teflon. It is the most recent Walbro design to deal with modern fuel mixtures.

As to your comments about adjusting up thrust. Your previous statement, "Hands-off in the vertical, she falls toward the wheels so I'll add a washer to the lower engine mounts to see how much it improves the vertical line. I have a couple of clicks of up elevator"

This section edited to make thought corrections and corrections to which way you said the plane was tucking:

I've noted that the plane tucks strongly to the wheels during attempts to knife edge. I don't know exactly what is going on with that but it is probably the same thing you noted above.

It could be the drag of a low wing plane with a thick air foil and lots of inches simply levering the plane. And... that might be why the up trim is needed during power when the drag increases and is not needed for power off flight. So... I'm changing my mind and your up thrust may be of value to counter that drag lever. I'd be interesting in your observations of the results.

As you likely know, most aerobatic designs have gone mid wing to eliminate the drag of the wing from levering the pitch either up or down so again, this is likely what is going on, especially considering the size and thickness of the wing.

Also as you know I've adjusted the wing incidence up slightly to counter the drag lever during powered flight. I don't recall attempting a knife edge after making that adjustment... I'll do so next time as well as take my hands off during the up line to see what it does.


Arlyn

AA5BY

A final thought about the incidence adjustment. I think the original setup by Seagull is 0-0-0 meaning no wing or stab incidence and no engine thrust. The problem is a wing with a lot of drag at a position on the plane with pitch leverage. That force needs countering and gets up trim in the elevator during power on flight. When power is off, that up trim is too much and the plane doesn't establish a proper power off attitude for landing.

I countered that couple by an incidence trim change but there is nothing wrong with doing so with a throttle to elevator mix. Simply add a mix that returns the elevator neutral when coming off the power.

The same scenario plays into high wing planes but opposite and we often see down thrust used to counter the drag induced pitch so it might be that up thrust is a valid way to deal with it. I'll be interested in Gary's results.

rowdyjoe

My Feedback: (9)

OK Arlyn, I'll keep you posted. It may take a few days as Ineed to get the engine start issue fixed and then look for a good WX day.

Garry

rowdyjoe

My Feedback: (9)

The engine start issue has suffered a set-back. I discovered that my CDIis faulty and have ordered another one. It was shorting between the shield and cap spring so, some component has failed inside the unit. It will be interesting to see what's inside when Itake it apart and try to fix it. If Ican determine which component is faulty, I can replace it and it should work (?).
Ibegan hearing a spark when I turned the ignition on and a double spark when Iwould turn the crankshaft through 360. I traced it to the plug cap and shield wire coming from the unit. The spark was a nice hot blue color ...and it was jumping approx. 1.5 inches from the braided shield to the spring.

Of course, I discovered that after I had replaced the diaphram and pump in the carb. It definitely needed the diaphram but, not sure about the pump. I'll have to wait a couple of weeks (ordered from China) to find out if my carb repair had any affect.

IDEA ! I think I'll pull the ignition out of the Yak and use it on the SW. I won't be flying the Yak until the new fuselage gets here so Imight as well use it until the parts come in.

RJ

AA5BY

The gremlins have moved into your plane hanger... chase them suckers off.

rowdyjoe

My Feedback: (9)

That's for sure. I'm gonna get the scattergun after 'em.

It sure seems as though something is after my birds. My MX2 engine is not running right either. It tried to die on me at mid throttle a couple of times the last time I flew it. Must have some junk in the carb. At the moment, I have nothing flyable.

Oooops, forgot to answer your question ...Yes the hole in the choke flap is filled with solder. I did it before Iflew it the last time and it didn't seem to help. I've checked the linkage and it appears to be closing completely but, can't see it well enough to be sure.

RJ

jloane

Thanks rowdyjoe..I'll give expo a try and see if I like it..

rowdyjoe

My Feedback: (9)

My spark plug adapter arrived today and Iinstalled it in the head along with a new CM6 plug. The blasted thing still won't start. Looks like I'm still having trouble getting fuel to the carb for some reason. All lines are clear and it's getting spark but, won't fire. The carb takes a loooooooong time to get wet with the choke on and my finger over the flap to help it seal. It still won't pop when Iturn it through. When Ipull the plug, it's dry. Can't figure out why it won't draw fuel.

Wish I hadn't broken my starter motor. Idropped it on the garage floor and broke the back end out of it. I'm trying to epoxy it back together but, I don't think it's gonna hold. Looks like I'll have to spend $40 on a new one.
I haven't given up but, I'm discouraged right now. Hope the repair on the starter will work long enough to get her spinning quick enough to at least pop.

RJ

ShuttleAU

Hi

I had a similar problem with a new DLE 20. It seems that the fuel pump needs to be wet to work and draw fuel.

The solution ( from some long term gasser pilots was to take the plug out and put a few drops of fuel in the cylinder. Then rock the prop back and forward a few times.

The put the plug back in , choke on , flip until it coughs , choke off and it started.

BC

rowdyjoe

My Feedback: (9)

Hey, it started.

BC,
Thanks for the tip. I've wrestled with every fuel issue Ican think of but, can't say that it's had much effect.

However, after determining that it was getting plenty of fuel (when it wasn't before), I started chasing spark issues. I was getting fuel and air but, it didn't seem to want to fire of a regular basis. Very frustrating. Ichecked and rechecked the timing and made sure all connections were good but, the plug wouldn't fire every time. Sometimes it wouldn't fire at all. So, I decided to inspect the plug cap and see if it could be the culprit. Ipoked around inside the cap with a small screw driver to make sure the spring was in the right position and tried to get it to fire again ...no soap.
So, I decided to disassemble the plug cap and when Igot the retainer off and looked inside, it was dirty, dirty, dirty. I sprayed the devil out of it with contact cleaner and put back together with a couple of small zip ties to make sure it was tight. I then put the plug in the cap and rotated the prop and it fired every time.
I reinstalled the plug in the engine, put the cap on, and primed the engine with a few rotations with the choke on. I turned on the ignition and flipped the prop through about 5 times and it fired right up and kept running. Boy, was Ia happy pilot ....Iwon't have to shoot it after all.

However, since it was 1 AM, I decided to kill the engine after about a minute so as not to bring the wrath of neighbors down on me. Good thing I had the garage door closed. Fortunately, my wife was still awake reading a good book so, I didn't get chewed out for waking her up.

Sure hope it will do a repeat performance for me tomorrow. I'd like to fly it again soon.

RJ

AA5BY

RJ... Have you flown the Spacewalker? Hope all went well.

codedlanguage

My Spacewalker will enter a new phase of it's life. After a year of flying allmost every weekend I will replace the DLE 30 with a Thunder Tiger 1.20 2 strokes, side exhaust. The DLE is needed to power a EG aircraft 27% Raven. I'll let you know how it goes.

rowdyjoe

My Feedback: (9)

Yes. Iflew it yesterday and it flew well. I didn't get a chance to completely check out the engine thrust angle correction but, it appears the "up"Iadded to it has helped. The engine is still a bear to start when it's cold so, Ihave to use my electric starter. That will do it every time but, there are a few false starts until the fuel starts flowing smoothly. After it's warm it only takes a flip or two to get here going again. She's reliable once airborne.
Iwould like more thrust in the up lines. Ihave a 16x8 it now but, I'm considering a 17x6. I'll have to check ground clearance first though.
While inverted, I've noticed that she wants to climb depending on throttle position. Imay have an incidence issue too. I'll check it out further next time Itake her out to the field.

Hobby King has a foam electric plane that is a replica of my MX2. I bought one thinking I could use it to practice new maneuvers without risking my expensive 50cc bird. I arrived yesterday evening and I've been working on it since it got here. Ithink it's read to fly but, still must come up with springs for the tail wheel steering. The weren't included in the kit. It has a 55" wing span and weighs nearly 5 lbs so, it should do fairly well in our TX winds.

I also completed asssembly of the old pattern nitro bird i've been working on. She's not pretty but, flies really well. It's an older version of the Intruder by World Models and was given to me about a year ago. I ordered a new fuel tank and canopy and did a few minor repairs. We had trouble getting her started yesterday and it turned out to be a split fuel line inside the tank. Once that was fixed we had very little time to get it read for flight before dark. We took a chance at dusk and could see her well enough to put her up for about 5 min. Wow, is it fast. It will take lots of practice for me to get comfortable with this one.

I've got two more birds on the way ...both stick built ARFs but,that's another story.

RJ

AA5BY

Gary.... sounds like you have been busy building. We haven't had many good flying days but as you indicated, Sunday was a good one.

Glad to hear the Spacewalker flew well. I've been flying mine but it is not endearing itself to me as a real good flyer but some of that might be that it's not dialed in yet. I've got it right on published CG and it might be a little tail heavy based on elevator being more sensitive than I like and that with not a great deal of throw and generous expo. Ailerons needed cranked up some as the roll was sluggish and that now seems ok.

I'd balanced by adding one oz (four 1/4oz weights aft and will start removing them one at a time and see what happens. My landings have been mostly long, not used to its wing area yet I guess.

The pants need removed to get some additional glass inside. They shake and are cracking.

As you observed long ago, it needs a lot of right rudder on takeoff and vertical.

It is a little awkward to get my large clumsy fingers so low in the plane to install the wing bolts... but that is minor.

My scratch built project is progressing with no major problems as of yet, other than a concern about how heavy it's looking. Like many, I'm an over builder. Have yet to epoxy in the firewall and gear mounts, after which it can come off the board freeing it for the tail feathers. There will of course be plenty of work left on it once it comes off the board as it will get a round cowl ring for the cowl, various stringers and forward and aft turtle decks and a top hatch.

I'm having a lot of fun with the effort and it has served as a reminder of how much I enjoy building. It sunk in that I've missed that doing arfs. I wish I could build as light as arfs, but it is not in my DNA. I'll attach a pic of current progress.

How far is your flying site off I-20? A friend or two and I are planning to do the Weatherford swap. We usually do it on the Friday (would that be the 15th?) evening and leave Longview about 1pm. I asked if they would be willing to leave earlier and visit your field to see it and they were game as long as it wasn't a major distance off the track. If we left about 10am, we could catch lunch entering DFW area and then spend a couple of hours diverted off the track to see your new facility and then make Weatherford by 4:30 - 5pm. This is only if all is convenient for all concerned.

AA5BY

I had a mishap with my Spacewalker today. It spins well so I got high, put it into a spin, crossed ailerons and gave it a little throttle to flatten the spin. Mistake... when releasing everything to neutral to come out of the spin, it kept spinning. I gave opposite rudder and down elevator... still nothing. I punched the throttle with neutral controls... nothing. Actually I had a good bit of time to try what I knew to try... nothing worked... she kept flat spinning and went into the woods.

Some how, the only damage to the fuselage was one lower flying wire was snapped, the muffler stack was bent very slightly with a slight cowl crack beside it, and the Vess prop had taken just enough of a hit to nick it. The wings weren't so fortunate... one was damaged slightly whereas the other lost a wing tip along with the next to last rib bay and aileron. When the aileron ripped off it took the servo bay with it.

The wing set is available and not expensive, but I didn't really enjoy the flying manners that much so will move the engine and radio gear onto something that might be more fun for me.

So... do a flat spin with a Spacewalker at the risk of not getting it to come out.

rowdyjoe

My Feedback: (9)

Very sorry to hear about your Spacewalker wreck. Don't blame you for moving on. It's a fun plane to fly but, that big fat wing limits it's acrobatic ability. You have to work hard to make them look good with that bird.
I like the way mine flies but, the blasted engine is driving me nuts. I flew mine today too but, the engine quit about 5 min. into the flight and Ihad to dead stick. No damage but, the danged thing woulldn't start after that. I think it's the same old problem ...carburetor. It would try to start with the choke on and without the choke it would run at about half throttle and then die after about 30 seconds (sound familiar?). So, I tweaked the carb settings and it began to run better but, the idle would not come down. I'm beginning to think this engine is haunted. I suspect the linkage got out of adjustment somehow. I'll have to pull the cowl and get under the hood.

However, I have a sadder tail than yours ...I totaled the fuselage and right wing on my 30% MX2 today. I forgot to remove my "starting glove" and was flying with it on and kept hitting switches on my transmitter inadvertently. After the last maneuver, the timer was going off so, Ibegan to set up for landing and when I tried to turn left for base leg, it did a complete roll and lost altitude. Ipanicked and pushed opposite aileron and it did a complete roll to the right and lost more altitude. By then I was so close to the ground I didn't have time to think about what could be wrong and it dived right into the lake. When I checked my transmitter after the crash Inoticed that I had hit the aileron "high rate" switch. You know what they say ..."you can't fix stupid".
I waded in up to my belly button to salvage what I could and got everything but, the right wing as the wind carried it further out in the lake. One expensive servo gone. Everything else was there but, who knows if any of it will work again. I'll send the engine off to a good shop and have it checked out. It was running when it hit the water and the prop is mencemeat. Could have some internal engine damage.

Ihave had my eye on a very nice 50cc size Extra 330 sold by Texas RC Planes. Ihad planned to replace the MX2 airframe this year but, Iwasn't planning on it being this soon.

Again, sorry to hear about your Spacewalker. Today was a double bummer.

On a lighter note ...Igot the parts to rebuild my Seagull Yak 54 and ordered a 26cc engine for it. I've started the rebuild and had planned to take my time but, guess I'll be stepping up the pace now that it will be my primary IMACbird.

RJ

AA5BY

Gary... sorry to hear of the loss of the MX. I didn't suffer any emotional loss over the Spacewalker as it wasn't an endeared plane but know you thought highly of your MX.

It was a beautiful flying day here, warm and with a nice breeze down the runway to slow a plane for landing nicely and it was so nice to get outside after several days of rain. Not complaining about the rain however...

I plan on ordering a set of wings as they are moderately priced and my fuselage is basically undamaged but only to see it in the hands of someone else.

Your engine problems strike me as possibly a vent line problem. I've had a couple of times a vent line that would open ok for filling but then close off and give a dead stick after about five minutes of run. One way to detect this on a gasser if a tee is used from the fuel dot on a two line setup is to empty a full tank of fuel. If the vent line is not staying open, after about half the tank is emptied it will start showing bubbles as it draws air from the carb instead of fuel from the tank. Suspect a kinked vent line.

I think we are still planning the Weatherford swap meet Friday evening... do you have plans to go?

btw... my scratch build 35cc sport is nearing completion of the framing. Plans are to mock it up for pics prior to covering and I'll send a pic.

regards,
arlyn

rowdyjoe

My Feedback: (9)

Arlyn,
Thanks for tip on the engine. lIsuspected a leak somewhere but, have been chasing my tail on this engine for a long time. I'm considering replacing it but, the fix should be fairly simple if Ican just find the problem. I believe you're right about the air leak as I had to fatten it up quite a bit to get it to run better. I'll do a thorough search of secure all connections and fuel llines.
The weather was the same here. Winds were quartering from the southwest and gusting from the west at times but, nothing of concern to the bigger birds.
You're right ...Ireally liked the MX2. I'm going to miss it. I started the search for another bird last night but, the Extra 330 from TX RC Planes was out of stock so ....the search goes on.

Good luck with your next project. Hope you continue to check in on this thread from time to time.

God Bless,
Garry

AA5BY

Gary... actually I'm not thinking leak... I'm thinking the vent line to the tank is getting pinched off allowing air to exit the tank under pressure but not enter the tank under much less pressure.

Good luck with your search for a plane. Have you investigate 3D Hobbies... I've received a couple of advertisements from them and they had several offerings in the 30cc range.

I'll post the pics of my current project in the thread under scratch build that I've been posting in rather than to stray from this thread.
I'll have them posted there in a moment.

http://www.rcuniverse.com/forum/m_10...m.htm#10995371

rowdyjoe

My Feedback: (9)

Thanks again Arlyn. I'll check that too. I recently bought a small tube bender so I can reduce the opportunity for pinched lines, etc. but, haven't put to use yet. This will be my first opportunity to use it.

Garry