AJ Laser 230z 73" Build Thread

[mikeh]

I've been scared to fly my 73" AJ Laser ever since my two or three 2-3 sec "brown outs"... even though the engine kept running smoothly with no response (kind of nightmare really) - I put that receiver in a cub and it worked fine for multiple flights - so I have a new Rx in the bird but not confident that was the issue. So I am going to update the battery setup with something else and replace the Tech Aero. Sounds silly I know to go to the battery system since the engine was running fine when I had no control (maybe there is enough stored capacitance in the TechAero to let it run for few seconds??), only doing engine break in flights, happened in close proximity and at least 2min after airborne, curious if there is some ignition RMI or a faulty servo overloading the system somehow... dunno, but as intermittent as it is I don't want to risk loosing the plane or worse. So frustrating looking at that beauty hanging up in the garage... thinking WHY!!!?? Got to figure this out.

I hope you figure it out, it sure is a nice flying airplane!

 

[AKNick]

Well I have a positive flight report. I flew the laser for four 10-13min flights with no issues!!!



New receiver (don't think that was it - it's flying in another plane) and antenna orientation, new battery connection (from Deans to XT60 doubt that was it either), Thought the plug cap seemed loose, goes on and off with not much effort. So I tightened the hog ring over the plug cap, re-installed it and put in a new NGK CM-6 plug... I think this may have been it. I check the plug cap on my pre-flight now to make sure it doesn't get loose. It feels much more firm now than it has ever been. My educated guess was this was creating some small arc or fretting that temporarily locked out my tx for 2-3 sec. I'm going to stick with that unless it happens again .

Just getting to know the plane a bit. A little nose heavy on a full tank of gas (16oz) - upline 45 inverted it falls to the nose slowly. This plane tracks beautifully. Lands smooth as can be. Still am pretty amazed with how well this plane can precision fly. Engine ran pretty good, still breaking in, overall could use a little more tuning, but is good enough to huck around. Feels like it could use more rudder in high alpha rolling circles... but I'm just getting to know the plane. WAY to early to jump to conclusions. Excited to take to the field again!!

 

[AKNick]

Put in another 10 min flight last night. I'm confirming that the CG needs to be back a bit. Think I am going to work on extending my battery tray aft. Guessing this is why It doesn't feel like I have a lot of tail authority in high alpha. Still pretty baffled how well this plane tracks in the air. Point the nose where you want it to go and it stays on that course.

 

[AKNick]

Looked over the laser and found a loose muffler. Cleaned it up and put it back on with new copper RTV and nordlocks.
Replaced the poly fuel tube with tygon, the fuel dot was almost impossible to remove from the barb. Guessing it's these colder Alaska temps. Also put a carbon spinner on.

Note at a 10min flight on my setup drew 300mAh from a single A123 2500mAh
(With a tachaero ibec)


Sent from my iPhone using Tapatalk

 

[AKNick]

Made another new battery shelf out of some G10 board. This moves the battery aft 4"
Next nice day.... let the thumb twiddling begin for that day... lots of rain forecasted and confirmed.


Sent from my iPhone using Tapatalk

 

[AKNick]

Moving the battery aft did the trick. Plane does rolling circles in high alpha with much more ease.
Plane feels more of a 3D bird now!
On a left wing down knife edge the engine Boggs down a bit... probably some weird airflow in the cowl. Hmm one more thing to investigate.


Sent from my iPhone using Tapatalk

 

[AKNick]

So carb plate? mine is the old stamped style, the hole appears to be on the left side facing forward. Any recommendations to orientation? I was thinking aft.. but dunno. I'm guessing in a left wing down knife edge it's getting some direct airflow as of now.

 

[AKNick]

So carb plate? mine is the old stamped style, the hole appears to be on the left side facing forward. Any recommendations to orientation? I was thinking aft.. but dunno. I'm guessing in a left wing down knife edge it's getting some direct airflow as of now.

well It was facing forward, so I flipped it 180 degrees (vent hole facing aft). I can now fly knife edge without the engine bogging down... too much, still a little loss in rpm at a slower knife edge. Thinking about calling DA and seeing if they would sent me a fancy new red carb plate. or maybe even try a carb plate from VVRC;
https://www.valleyviewrc.com/carburetor-plate
As of know I can fly a high speed knife edge or even a four point roll and not notice the engine bogging down. I don't want to run a line from the carb plate to the fuse if I can get away with it.

Today I completed one gallon of fuel with the DA35, ten flights ago it seemed pretty "weak" on an upline, now it's a strong unlimited vertical, consuming less fuel, and less black residue out the exhaust, mostly just a little oil. I'm taking it off the 32:1 and onto the 40:1, retune the needles (can tell the engine is starting to run a bit on the rich side) and have more fun!

I'll have to charge it tonight and see how many mAh I put through my 2500 A123 after 5 flights @ 13min a flight (65min flight time not including ground time warm up).

EDIT: 1590mAh was put in! So roughly 318mAh per flight of mixed IMAC and 3D flying. Not bad at all, roughly 64% used of the total capacity. If I was smart I would have checked the voltage too.

 

[Alky6]

This airframe would be a nice fit for my VVRC 40 to replace my EF78" extra. Sounds like you are really enjoying it.

 

[AKNick]

Flew the Laser a couple times yesterday after finally figuring out how to re tune the needles properly. Two 13min flights drew 656mAh with a 5 min warm up. Engine still sounds a little funny in a left wing down knife edge, seriously considering buying a fancy carb plate, or even opening up the lower cowling some more. Been doing some more 3D with it and with a full tank of gas it still doesn't have the tail authority like the slick did, so might consider putting some sticky weights in the tail to see if that makes a difference.