Bob Toilet

Hi Ceeray
congrats with the maiden!!! It looked really Nice.
your ATJ is a 220 turbine, it is more than two VT 80!
You cant keep comparing the 220 with an 80.

we talk soon
Christian

Ceeray

Anyone has an idea why this one keeps stalling and snapping on its right side quite violently? I thought Mig would withstand high alpha pretty good , like my smaller f16 which I can throw around as much as I want.

I got this one snapping and almost into the spin when pulling up from a loop. I just installed a cortex pro which didnt help at all.

I measured thrust angles when I set up the plane but is there a possibility there is a difference which causes the plane to drop its nose on right and wing also?

Levi Wags

Hey Ceeray,

The cg is too far back on your Mig. You can move the cg back on an F16 and if it's too rearward, it will just go high alpha under elevator and wings will stay level.
With the Mig if the cg is too forward it will roll into the turns and is very pitchy, too far back and it will snap hard. Not just in turns or slow flight but even in a loop which you've discovered. I've flown my CARF Mig 29 in all cg settings and rearward is not fun. Mine snapped out of a loop also.

Ceeray

Thanks Levi! My cg is at around 22-23cm from LE. I was not able to get it to 24cm which is rearward limit in the manual.

I tested CG with inverted 45 degree climb with full throttle and I had to push a bit to keep it going straight, so maybe I am experiencing too forward CG and with that I get elevator stall etc at angles.

I changed thrust angle a bit and it helped some but still tight loops are no go, starts dropping on its wing. Also using TV for looping around makes plane go round the wing. I even tested servo forces on ground because I thought one elevator servo must be too weak to hold but no...

I want to fly noseup hi-alpha without fear of spinning this into the ground so I have to try experimenting with the CG.

TV on flatspins are nice, almost no altitude loss while spinning like a frisbee.. ��

Levi Wags

Cool mate. I loved my SM Mig but sold it a while back and I can't remember cg settings. It was good though. Maybe try to balance the plane laterally too and try another cg setting. I remember Michel from JetsRC said his SM Mig snapped as well when he moved the cg back.

Ceeray

Today 3 flights with cg moved 1cm back. Was better but every flight is still a test flight
Got my first flameout ever in the air ... luckily had enough altitude and I kept it clean until final and then dropped gear and wished all stuff would have come down before touchdown. Added flaps while approaching tarmac and got a really nice landing. And found out I had switched parking brake on that was a short landing roll.. luckily brakes setup pretty light so no damage to tires.

fuel usage is horrendous.. 40 liters in 11 flights and some ground testing. Thats around 3.5 l per flight , and I do not firewall it all the time. 6 min flighs...

Bob Toilet

The fuel usage is normal for a 220 turbine.
You are a big boy now��. You are not flying
around with a sodacan anymore������

Ceeray

Ceeray

Stock pipe has a small hole in the split area... I will try fix it by using heat resistant silicone (withstands flames and 1300°C) to keep it from spreading. That hole has been there from beginning I think.. 11 flights so far with this pipe.

HiCurrent

The spring in my nose strut has gone real soft and it can't support the weight of the nose anymore. I need to replace the spring inside. Does anyone know how to disassemble the nose strut to remove the spring ?
I removed the torque link but still couldn't take the metal rod out. Do I need to remove the C clip on the upper strut assembly off for the rod to go out ?