RCU Forums

RCU Forums (http://www.rcuniverse.com/forum/)
-   Giant Scale Aircraft - 3D & Aerobatic (http://www.rcuniverse.com/forum/giant-scale-aircraft-3d-aerobatic-110/)
-   -   Maiden Day (http://www.rcuniverse.com/forum/giant-scale-aircraft-3d-aerobatic-110/11220604-maiden-day.html)

speedracerntrixie 09-07-2012 06:10 AM

Maiden Day
1 Attachment(s)
At times I thought this day would never come. What was I thinking? Scratch building a 33% airplane. Simple right? Buy some wood, foam, fiberglass cloth, resin. In a few months I would have something fairly unique that nobody else had. Well here we are 2 years later ready to fly. Not that I have spent all 2 years on her. I have built a few race planes during that time. So here we are finished, the engine has been run up and needles set, the prop has been checked for balance. I've done my first range check, all control throws have been set and checked for direction. Not much more to do, range check again at the field with and without engine running. Check for leaks and loose hardware and then send her into the air. I will be back later today to post results and more pictures.

maukaonyx 09-07-2012 06:26 AM

RE: Maiden Day
NICE plane and color scheme! What are you naming it? Give us some specs on it. Jon

JUGFLIER 09-07-2012 08:05 AM

RE: Maiden Day
Nice finished product. I like the trim scheme as well. Hope the flight went well.

zacharyR 09-07-2012 10:11 AM

RE: Maiden Day
looks like someones a lazer fan [X(]

dave pattern 09-07-2012 02:00 PM

RE: Maiden Day
hey shawn
well how did it go?
you going flying tommorow?

speedracerntrixie 09-07-2012 08:18 PM

RE: Maiden Day
1 Attachment(s)
Been a quite busy day but i finally found time to sit down and report on the maiden flights. I got to the field this morning at 9:00. Not another soul in sight. No problem I will just attach the wings, look her over really well and by the time I am ready someone else will be here. After waiting untill almost 11:00 somone did show up. I did my engine off range check. I got 110 yards and still solid. Filled her up and had my new friend Dale hold her while I did an engine on range check. Got to the same spot and still solid. No more excuses. I taxied out onto the runway while doing the 100th control direction check. Pointed her into the breeze and advanced the throttle. In about 50 feet she was airborne and climbing at 1/2 throttle. Did a few circles around the field, a couple clicks of aileron one or two clicks of elevator and she was tracking good. OK how about a roll, a humpty bump? Soon I was doing a rolling circle, snap rolls, hammerheads, point rolls both 4 and 8.

Obviously I am quite pleased. the CG is really close but a tad aft. Still have to dial in the rates and there will be a little mixing needed. Not much though. The DLE 55 is running strong. The prop is a Falcon 23X9 and the DLE is spinning it at 6,700 on the ground. Needles still need some tweaking as it was a bit rich on the bottom end. The additional shake because of the rich mixture at idle broke the original canister mount. All fixed now and ready for the next trip out to the field.

Dave, Yes I am going to try to get back out tomorrow morning.

speedracerntrixie 09-08-2012 04:08 PM

RE: Maiden Day
Iwas able to fly the Laser a couple more flights today. Still a little more tuning required on the engine but nothing vibrated loose this time out. Now that I have a few flights on her and feel more comfortable, I can more concentrate on getting the trimming process started. Not that there is alot to do but she will benifit from some " Tweaks ". So here is a quick rundown of where she is and what I anticipate trying and then I will come back with the results. Maybe we could consider this as trimming 101 and if anyone else has suggestions by all means throw them out.

Engine: DLE 55, K&S stainless flex header, MTW caninster. All in all I ame very happy with this setup. The engine sat around for a few months so the tune I did at home did not work at all once at the field. I assume that the flapper valves in the carb got a little stiff and now that they have seen gas for a few days are working better and now my settings are too rich. The engine has performed well though. Easy to start, good power reliable idle. The throttle response is a little soft at the bottom end. Pretty sure this will clear up as soon as the idle mixture is leaned to optimum. If not I will adjust the throttle curve some.

CG: Right now it is very nuetral. level inverted flight requires very little forward stick and inverted 45 degree uplines requires no forward stick. I plan to take a little weight off the tail. I am running an IBEC and if I end up having to move CG forward I will just add a seperate ignition battery and switch.

Servos ( Savox 1258 TG ) Looks to be a good servo. it's fast and has good power. I have noticed that elevator and rudder have great power. Maybe a little too much as rolling circles are all over the place as far as altitude goes. This means that in that manuver I am overcontrolling the tail. The airplane has some pitch drift too. Could be that CG needs to be moved forward or the servos arent centering 100%. More flight testing and a CG shift along with reduced rates will answer this. One of these will be changed at a time. I never make more then one change and then fly with that change a few flights before calling it fixed or not.

Incidences and thrust line. Everything here looks good right now but a CG shift can affect that. One thing I have noticed and have never seen before is that downlines require no forward stick. She stays strait as can be on downlines. Uplines will go a good 300 feet before needing to lean on right rudder.

Mixes: All airplanes exibit some degree of control cross coupling. My previous Laser was a fairly stock Lanier kit with mods done only to lighten it. I kept that models program on my TX and used it for this airplane. This one requires less mix. I have some up elivator mix with the application of rudder. This airplane is pulling towards the canopy in knife egde. So the need for that mix on this airplane has been reduced. Again with a more forward CG the need for that mix may just go away completely. I did today take out the rudder/aileron mix today as the airplane had no tendancy to roll couple when rudder was applied.

So where does that all bring us? I will move the CF forward about 3/8 to 1/2" and see what happens with the pitch stability issue. As a side benifit, all requirements for mixes may dissapear. That would be a first for me. Leaning the engine at the low end should reduce vibration at idle and tighten up the throttle response too. These are the only adjustments that I will be making before putting in another 4 flights and then re-evaluating further changes.

JRgraham 09-11-2012 09:45 AM

RE: Maiden Day
Wow, thats a really nice looking plane! Id have to say 2 years well spent, for sure, and very well built, based on the flight reports so far :) What did you end up for weight?

Nice job speedracerntrixie!

speedracerntrixie 09-11-2012 04:03 PM

RE: Maiden Day
Thanks Shimano. she came in at 16.25 lbs

thepamster 09-21-2012 10:43 PM

RE: Maiden Day
Hey Speed. Congrats on the finished Laser. How are the Savox's looking so far? Any gear slop? Are you happy with them?

speedracerntrixie 09-24-2012 04:08 PM

RE: Maiden Day
I've got about 20 flights at this point. I'm still not 100% sure about the Savox's. I am having a small pitch hunt with the airplane. I'm fairly sure moving the CG forward will solve this but I want to try first before commenting on the servos. They are very fast and the gear play was not more then I have seen from Hitecs or JR servos. They do buzz a bit more then I am used to but I'm sure that is because of the tight deadband. Right now I am more concerned about the engine. Seems to shake more then I am comfortable with. At this point I am concerned about the longevity of the airframe. It seems to be running rich at idle and midrange and has the usual rich 2 stroke shake but when I lean the low speed needle at all then I get no transition. During flight a smoke trail is barely visable at anything but full throttle. It is turning a Falcon CF 23X9 at 6,900 RPM. I have checked the prop for balance ( before even mounting ) as well as the spinner.. I dial indicated the crank and it was true. I have adjusted the timing a couple degrees both ways and so far nothing has worked at reducing the vibration. It dosent seem to be running hot. The things that I will try next is fresh oil ( the oil I had was 2 years old ) and some 91 octane gas. Over the weekend I was at a pylon race with Dave Sullivan and he offered up one of his Plane Bender canisters to try out so I will be installing that as soon as it shows up. If anyone else has any suggestions, I'm all ears. I have run lots of gassers over the years and have never had a shaker like this. Difference here is this is my first DLE and first canister equipped airplane.

speedracerntrixie 09-26-2012 04:37 PM

RE: Maiden Day
Took a look at the Laser today to make some adjustments and found that the elevator servo is bad. I'm positive that it was bad from the start and it was the pitch hunt problem. The gears are fine but the motor appears to be bad. I have sent an email to the retailer that I bought the servos from to alert him of the issue and to see how we can handle the return/replacement. I still feel confident in the servos as the rudder has been used much harder then elevator and that servo is holding up fine and has no centering issues. I'll keep you informed.

thepamster 09-26-2012 04:57 PM

RE: Maiden Day
That's a bummer Speed. At least it did not cost you an airplane, especially a scratch built one that you can't put a price on.
Bad motor? Bad pot? Do they still use potentiometers in servos?
I am bummed about this news and am anxious to hear how they handle the situation. I don't trust Hi-techs at all and the name brand servos are absolutely rediculous in price for what you are buying.
Please keep us informed Speed.

I am not sure about the vibration thing. Maybe since it was scratch built you may have some kind of weird harmonics occurring within the airframe for which a brace of somesort needs to be added. Don't ask me where though.
Puzzling though about the smoke trail too. I guess one problem at a time.

speedracerntrixie 09-26-2012 05:09 PM

RE: Maiden Day
I had built one of these before using peices from an old Lanier Kit. The fuse is pretty much the same. The first one was powered with a DA 50 with stock muffler and it didn't shake near as much. While I am waiting for the servo issue to be resolved, I'm going to do a tear down and inspect the engine really well. One thing that comes to mind is that the ring may not be seated well as of yet. That may be the need for a slightly rich setting. Today I did notice a spot of blue Penzoil on the crankcase right on the seam. Looks like the airplane will be down for a couple weeks.

speedracerntrixie 10-09-2012 09:43 AM

RE: Maiden Day
More tuning has taken place. I found that the engines timing was way off. I advanced it as much as the sensor adjustment would go and now it's a happy engine. I did have to pull the case apart and re-seal. So thats done and working well. The servo situation is another thing. I have exchanged emails with both the retailer and Savox USA. I have sent Savox USA an E copy of the order confirmation and a copy/paste of my bank statement showing a payment to the retailer. The retailer has emailed Savox with a copy of the invoice. To this point in time Savox USA has not contacted me to send the servo in for inspection. I will be sending them a new email along with a link to this thread. It's a real shame as in today's economy one really has to choose who to send their fun money with to get the best value.

thepamster 10-09-2012 11:27 AM

RE: Maiden Day
Hey Speed,
  I am glad you got the engine going better. Did that reduce your vibration problem?
  I am a little suprised that Savox USA would not just handle this directly reguardless who the retailer was. I am pretty sure you can buy them direct as that is where I have been looking at them.
  Keep us posted. Thanks.

speedracerntrixie 10-09-2012 04:27 PM

RE: Maiden Day
Pamster. I mis spoke, it is Savox USA that I have been waiting on not the retailer. I took the airplane out again today with a more forward CG. I had taken the bad servo out and replaced it with the one I had on rudder. Used a Hitec on rudder. The airplane still had a hunt on pitch, the servos just arent centering. That coupled with the reliability issue and lack of communication from Savox has prompted me to give up on them. The airplane is covered on a shelf and will stay there until I get the servos replaced.

thepamster 10-09-2012 05:16 PM

RE: Maiden Day

That is sad news and not what I wanted to hear. How sure are you that it is a servo problem? Just to make sure I understand when you say "pitch hunt" you mean you continually have to trim the elevator and can't find a correctly trimmed spot?
Have you not seen a problem with those same servos with the ailerons? What are the chances the problem might be thrust angle?
I remember you said earlier about down lines and not requiring any elevator which is why I brought up thrust angle.
Are those servos plugged in directly into a "name" brand receiver and no power expanders?
Sorry about all the questions, just asking here Speed and hoping I might learn something as well.


speedracerntrixie 10-09-2012 07:10 PM

RE: Maiden Day
The airplane will not hold a pitch trim. It was originally happening enough that I thought it was just the aft CG allowing the airplane to get bounced around in the wind. Now that I have flown it with a more forward CG and it does the same thing I am positive it is a centering issue. There is no bind in the hinges anywhere and the elevator is on a pull pull arrangement just like the rudder. For the ailerons I am using Airtronics servos, no issues there. The servo arms are 1.25" metal units and the control horns are 1.75" from hinge to ball link so good mechanical advantage. The RX is a Hitec 9 channel that came with my Aroura 9. I have used both of them without issue in my pattern airplane and a pylon airplane. Servo power is direct from RX from a MPI 15 amp regulator. The battery is a 10c 3000 MAH lipo with 16 gauge wire leading to the switch, the reg outputs are dual 20 gauge. Switch is MPI HD with 18 gauge wire. plenty to feed 2 digitals and 3 analog servos.

All times are GMT -8. The time now is 06:19 PM.