Mig 3 finished/does maneuvers

Jim Walker · Nov 26, 2001, 02:32 PM

I finished my JK Aerotech Mig 3 Friday right on schedule so I could fly it at the Saturday morning electric get together. Sorry, no pictures to post yet. I took some with my digital and forgot to download them on a disk so I could share them today from work. I'll do that tomorrow.

The first maneuver was the propspring into a multiple cartwheel. I got someone to give it a toss with me at the transmitter. I counseled them to not try and lean back and throw it hard, just give it a good straight shove forward. It seemed as if they did as I asked and the plane moved a few yards forward then nosed up, flipped over and hit nose first. The torque of the spinning prop bounced the plane several feet in the air and then the forward speed made it cartwheel 3 times before it came to rest.

Damage - broken prop

No extra props on hand, so that was it for Saturday. Bought some props and tried again Sunday morning. Second maneuver was the inverted canopy skid. I tried launching it myself this time and finger caught on the trailing edge of the wing. There's just not much place to grab this thing. Anyway it flipped over hit the ground and skidded to a stop.

Damage - broken prop

I had extra props this time so I tried a larger diameter prop. Motocalc predicted much lower top end but several ounces more static thrust. This time I took a running start and gave it a reasonably straight and true shove. Third maneuver was the sliding wing toss. The plane tracked straight for several yards and seemed to pick up some speed and I thought maybe I was going to get to fly it. Just as the nose came up slightly to climb, the plane immediately flipped over and hit hard enough to break the rubber bands and send the wing tumbling past the fuselage along the ground. Everything eventually skidded to a halt.

Damage - A few paint scuffs, aileron servo pulled from wing pocket.

Repair time - 2 minutes after I got home and used some oderless C/A.

I have to say that this plane is outstandingly strong and has survived 3 crashes that would have sent most planes to the garbage bin. However, Eprops aren't exactly cheap and eventually one of these crashes will probably do some serious harm. So now I'm not sure what to do.

Possible problems:

CG too far back - It balances 2 5/8 back from the leading edge at the fuselage just as the kit specifies. I don't know how I could get it any farther forward without adding lead to the nose since the pack is already against the firewall.

Ailerons out of whack - the instructions said that the ailerons should split the top and bottom surfaces of the semi-symetrical wing or there would be problems. Could the ailerons be messing things up?

Too heavy for hand launch - Maybe the wing loading is just too high to hand launch and I need a bungie. It came out a little heavier than I wanted at 43.6 ounces, but that is lighter than Deans Zero at 45 ounces and he said his pretty much flew out of his hand. Motocalc says I have close to a 1:1 static thrust to weight ration which means it should be easy to hand launch, right??

Need to add exponential - maybe the plane is just so much more responsive than what I'm used to, I need some exponential to keep it steadier in take offs and landings. I thought I was giving it minimal or none inputs during the three flights, but maybe I was overcontrolling this new, fast plane?

All suggestions are appreciated. We're having a sponsored get together next Sunday and I'd like to fly my new plane there. However, if I haven't got at least a couple of successful flights next Saturday, I will leave it home so I don't kill somebody.

Thanks..........

DeaninMilwaukee · Nov 26, 2001, 06:52 PM

The plane should fly.

I'm assuming your combo has a ps speed around 60 mph or better per motocalc?

I fly my zero with the 12x10 normally, with about a 60 mph ps speed, but tried out a 12x8 with 50 mph ps and the plane had a tough time getting on step, and launches had to allow the plane to go flat and level for a little bit just to build up speed and get " on step ".

It was much harder to launch with the low ps.

The cg you used is towards the front of the recommended range?

Control throws are around the recommended?

Ailerons not reversed. ( happened to me

)

My zeros elevator is very powerful even at the stock small throws. I am using about 75% expo on my flash 5. The expo does help.

I belive your wing loading is even higher than my zero ( I have about 320 in/sq) so your stall should be higher too.

Combine high stall with a plane just past stall speed and a bit too much up elevator and you have instant tip stall and roll over.

A strong elevator can produce and instant stall even if you are above stall speed.

These planes are designed to fly fast. I had the same prob as you except on landings untill I learned to land without the flare by swooping down low and fast power off and just let the plane settle. If I tried to hold it up till it really slowed down, it would drop a wing tip

and do a little ground loop.

One last thing. After much probs and close calls with my hand launches, I tried actually running with a gentle toss and full throttle instead of a stationary manly hail mary pass.
This is much easier and less stressful.

Good luck and looking forward to the pics!

Jim Walker · Nov 28, 2001, 09:45 AM

Here's some pictures...........

Jim Walker · Nov 28, 2001, 09:46 AM

another

Jim Walker · Nov 28, 2001, 09:52 AM

and another...

Jim Walker · Nov 28, 2001, 10:38 AM

Dean,

With a 10-7 Motocalc says 58mph pitch speed.

The instructions didn't give a range, they just 2 5/8 from the leading edge measured next to the fuselage. I put the pack up against the firewall and it balanced perfectly at 2 5/8.

I set aileron throws at 3/16 up and down as per instructions. Elevator set to 3/16 as well. The instructions said a 1/4, but they also said less was OK if you wanted a more docile ship.

Ailerons..... move stick right, right wing up left wing down and vice versa....

I'm taking your advice and programming in 75% expo on my flash 5.

You're correct, the Mig 3 only has 241 sqin wing area. Motocalc says the stall speed is 27mph. I'm probably getting a stall and snap roll from a too low take off speed.

My last attempt, which was the most successful so far, at a hand launch was just as you describe. A run followed by a controlled forward shove. The plane flew several yards forward although losing altitude gradually at the same time. It started to get close to the ground and I gave it what I thought was just a tiny bit of up elevator and it dropped a tip and ground looped. Maybe since this plane is so responsive, I gave it a lot of up relatively speaking.

I ordered an 11-8 and a 12-8 folder from tower hobbies. I'm not going to try and fly it again until I get them. I'm also going to program in that exponential. Motocalc says that these two propellers have about the same pitch speed as the 10-7, but they get the static thrust above 1:1 which should help on the hand launch. Also I won't be breaking props on every launch and landing.

Thanks for your help Dean, and please let me know if you have any other suggestions.

Jim

DeaninMilwaukee · Nov 28, 2001, 12:29 PM

Hey Jim, nice looking plane! now I know I have to get one.

There is one more thing. At that stall, you need a ps of at least around 65 mph, and much better around 75.

My zero needed around 51 to 60 and it really flys poorly at the 51 but flys great at the 60. Only difference was prop pitch. 12x10 vs 12x8.

Calcualted thrust at 50 mph was double with the bigger pitch prop, and it was very noticable in flight. With the 12x8 I had to let it fly level for a distance before I could pull up. 12x10 was very different climbing immedietly and steeply.

Jim Walker · Dec 04, 2001, 10:58 AM

We had our first electric fly in this weekend in Las Cruces at the local slimer field. A guy named Gary came down from Albuquerque who works at the hobby shop there. Needless to say he has all the cool toys. He showed up with 21 planes!!! He had 4 warbirds that weighed about the same as my Mig 3 and used various power plants. They were FAST!!! He used a pedal launcher that is very cheap to build and works great! It uses surgical tubing from a high start doubled over with no fishing line. It's staked at one end toward the wind about 45 paces away from the launcher. The launcher is just a U shape made from wood with a board in the middle bolted at the middle. It creates a see-saw so to speak. The end toward the tubing has a 1/2 diameter pin sticking up and the middle board has a hole that the pin slides through when the board is see-sawed down. The tubing has a large ring that slips over the pin. A smaller metal ring is attached to the big ring with fishing line. The small ring is slipped over a hook mounted half way between the nose and the wing leading edge of the plane. When you step down on the see-saw board, the fixed pin in the front of the U shape box disappears through the hole of the moving board. The big ring is released and the plane gets a 5G pull nice and straight at a 5 degree angle. It's great!!

I got my MAS 12-8 folder installed and it definitely creates a lot more static thrust. I'm going to build one of those pedal launchers this week. Gary faxed me the plans. After watching Gary's warbirds fly at the same weight and similar power as mine, I have high hopes now for mine with a good bungie/pedal launch. I'll keep you posted and try to get some pic's this weekend.

Nov 26, 2001, 02:32 PM	#1
Jim Walker Use The Force Jim Join Date: Jul 2001 Location: Las Cruces, NM USA Posts: 2,319	Mig 3 finished/does maneuvers I finished my JK Aerotech Mig 3 Friday right on schedule so I could fly it at the Saturday morning electric get together. Sorry, no pictures to post yet. I took some with my digital and forgot to download them on a disk so I could share them today from work. I'll do that tomorrow. The first maneuver was the propspring into a multiple cartwheel. I got someone to give it a toss with me at the transmitter. I counseled them to not try and lean back and throw it hard, just give it a good straight shove forward. It seemed as if they did as I asked and the plane moved a few yards forward then nosed up, flipped over and hit nose first. The torque of the spinning prop bounced the plane several feet in the air and then the forward speed made it cartwheel 3 times before it came to rest. Damage - broken prop No extra props on hand, so that was it for Saturday. Bought some props and tried again Sunday morning. Second maneuver was the inverted canopy skid. I tried launching it myself this time and finger caught on the trailing edge of the wing. There's just not much place to grab this thing. Anyway it flipped over hit the ground and skidded to a stop. Damage - broken prop I had extra props this time so I tried a larger diameter prop. Motocalc predicted much lower top end but several ounces more static thrust. This time I took a running start and gave it a reasonably straight and true shove. Third maneuver was the sliding wing toss. The plane tracked straight for several yards and seemed to pick up some speed and I thought maybe I was going to get to fly it. Just as the nose came up slightly to climb, the plane immediately flipped over and hit hard enough to break the rubber bands and send the wing tumbling past the fuselage along the ground. Everything eventually skidded to a halt. Damage - A few paint scuffs, aileron servo pulled from wing pocket. Repair time - 2 minutes after I got home and used some oderless C/A. I have to say that this plane is outstandingly strong and has survived 3 crashes that would have sent most planes to the garbage bin. However, Eprops aren't exactly cheap and eventually one of these crashes will probably do some serious harm. So now I'm not sure what to do. Possible problems: CG too far back - It balances 2 5/8 back from the leading edge at the fuselage just as the kit specifies. I don't know how I could get it any farther forward without adding lead to the nose since the pack is already against the firewall. Ailerons out of whack - the instructions said that the ailerons should split the top and bottom surfaces of the semi-symetrical wing or there would be problems. Could the ailerons be messing things up? Too heavy for hand launch - Maybe the wing loading is just too high to hand launch and I need a bungie. It came out a little heavier than I wanted at 43.6 ounces, but that is lighter than Deans Zero at 45 ounces and he said his pretty much flew out of his hand. Motocalc says I have close to a 1:1 static thrust to weight ration which means it should be easy to hand launch, right?? Need to add exponential - maybe the plane is just so much more responsive than what I'm used to, I need some exponential to keep it steadier in take offs and landings. I thought I was giving it minimal or none inputs during the three flights, but maybe I was overcontrolling this new, fast plane? All suggestions are appreciated. We're having a sponsored get together next Sunday and I'd like to fly my new plane there. However, if I haven't got at least a couple of successful flights next Saturday, I will leave it home so I don't kill somebody. Thanks..........

Nov 28, 2001, 09:45 AM	#3
Jim Walker Use The Force Jim Join Date: Jul 2001 Location: Las Cruces, NM USA Posts: 2,319	Here's some pictures........... Attached Thumbnails 61.0 KB · Views: 274

Nov 28, 2001, 09:46 AM	#4
Jim Walker Use The Force Jim Join Date: Jul 2001 Location: Las Cruces, NM USA Posts: 2,319	another Attached Thumbnails 60.8 KB · Views: 255 Last edited by Jim Walker; Nov 28, 2001 at 09:50 AM.

Nov 28, 2001, 09:52 AM	#5
Jim Walker Use The Force Jim Join Date: Jul 2001 Location: Las Cruces, NM USA Posts: 2,319	and another... Attached Thumbnails 63.8 KB · Views: 269

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Discussion Finished the Mini MiG-3	mtflyr	Electric Warbirds	8	May 13, 2007 10:50 AM
JK Aerotech Mig 3 and .25 engine.	Paul Susbauer	Aircraft - Electric - Airplanes (FS/W)	2	Feb 09, 2002 08:03 PM
New Video clips, Mig 3 and SE5 ...	aeronutz	Indoor and Micro Models	8	Feb 03, 2002 06:38 AM
MIG 3 Flies!! Launcher a success!!	Jim Walker	Foamies (Kits)	11	Jan 12, 2002 09:03 AM
JKA MIG 3	Sal C	Foamies (Kits)	0	May 15, 2001 07:50 PM

Nov 26, 2001, 06:52 PM	#2
DeaninMilwaukee Motors beat engines! Join Date: Feb 2001 Location: Milwaukee Wisconsin, United States Posts: 4,355	The plane should fly. I'm assuming your combo has a ps speed around 60 mph or better per motocalc? I fly my zero with the 12x10 normally, with about a 60 mph ps speed, but tried out a 12x8 with 50 mph ps and the plane had a tough time getting on step, and launches had to allow the plane to go flat and level for a little bit just to build up speed and get " on step ". It was much harder to launch with the low ps. The cg you used is towards the front of the recommended range? Control throws are around the recommended? Ailerons not reversed. ( happened to me ) My zeros elevator is very powerful even at the stock small throws. I am using about 75% expo on my flash 5. The expo does help. I belive your wing loading is even higher than my zero ( I have about 320 in/sq) so your stall should be higher too. Combine high stall with a plane just past stall speed and a bit too much up elevator and you have instant tip stall and roll over. A strong elevator can produce and instant stall even if you are above stall speed. These planes are designed to fly fast. I had the same prob as you except on landings untill I learned to land without the flare by swooping down low and fast power off and just let the plane settle. If I tried to hold it up till it really slowed down, it would drop a wing tip and do a little ground loop. One last thing. After much probs and close calls with my hand launches, I tried actually running with a gentle toss and full throttle instead of a stationary manly hail mary pass. This is much easier and less stressful. Good luck and looking forward to the pics!

Nov 28, 2001, 10:38 AM	#6
Jim Walker Use The Force Jim Join Date: Jul 2001 Location: Las Cruces, NM USA Posts: 2,319	Dean, With a 10-7 Motocalc says 58mph pitch speed. The instructions didn't give a range, they just 2 5/8 from the leading edge measured next to the fuselage. I put the pack up against the firewall and it balanced perfectly at 2 5/8. I set aileron throws at 3/16 up and down as per instructions. Elevator set to 3/16 as well. The instructions said a 1/4, but they also said less was OK if you wanted a more docile ship. Ailerons..... move stick right, right wing up left wing down and vice versa.... I'm taking your advice and programming in 75% expo on my flash 5. You're correct, the Mig 3 only has 241 sqin wing area. Motocalc says the stall speed is 27mph. I'm probably getting a stall and snap roll from a too low take off speed. My last attempt, which was the most successful so far, at a hand launch was just as you describe. A run followed by a controlled forward shove. The plane flew several yards forward although losing altitude gradually at the same time. It started to get close to the ground and I gave it what I thought was just a tiny bit of up elevator and it dropped a tip and ground looped. Maybe since this plane is so responsive, I gave it a lot of up relatively speaking. I ordered an 11-8 and a 12-8 folder from tower hobbies. I'm not going to try and fly it again until I get them. I'm also going to program in that exponential. Motocalc says that these two propellers have about the same pitch speed as the 10-7, but they get the static thrust above 1:1 which should help on the hand launch. Also I won't be breaking props on every launch and landing. Thanks for your help Dean, and please let me know if you have any other suggestions. Jim

Nov 28, 2001, 12:29 PM	#7
DeaninMilwaukee Motors beat engines! Join Date: Feb 2001 Location: Milwaukee Wisconsin, United States Posts: 4,355	Hey Jim, nice looking plane! now I know I have to get one. There is one more thing. At that stall, you need a ps of at least around 65 mph, and much better around 75. My zero needed around 51 to 60 and it really flys poorly at the 51 but flys great at the 60. Only difference was prop pitch. 12x10 vs 12x8. Calcualted thrust at 50 mph was double with the bigger pitch prop, and it was very noticable in flight. With the 12x8 I had to let it fly level for a distance before I could pull up. 12x10 was very different climbing immedietly and steeply.

Dec 04, 2001, 10:58 AM	#8
Jim Walker Use The Force Jim Join Date: Jul 2001 Location: Las Cruces, NM USA Posts: 2,319	We had our first electric fly in this weekend in Las Cruces at the local slimer field. A guy named Gary came down from Albuquerque who works at the hobby shop there. Needless to say he has all the cool toys. He showed up with 21 planes!!! He had 4 warbirds that weighed about the same as my Mig 3 and used various power plants. They were FAST!!! He used a pedal launcher that is very cheap to build and works great! It uses surgical tubing from a high start doubled over with no fishing line. It's staked at one end toward the wind about 45 paces away from the launcher. The launcher is just a U shape made from wood with a board in the middle bolted at the middle. It creates a see-saw so to speak. The end toward the tubing has a 1/2 diameter pin sticking up and the middle board has a hole that the pin slides through when the board is see-sawed down. The tubing has a large ring that slips over the pin. A smaller metal ring is attached to the big ring with fishing line. The small ring is slipped over a hook mounted half way between the nose and the wing leading edge of the plane. When you step down on the see-saw board, the fixed pin in the front of the U shape box disappears through the hole of the moving board. The big ring is released and the plane gets a 5G pull nice and straight at a 5 degree angle. It's great!! I got my MAS 12-8 folder installed and it definitely creates a lot more static thrust. I'm going to build one of those pedal launchers this week. Gary faxed me the plans. After watching Gary's warbirds fly at the same weight and similar power as mine, I have high hopes now for mine with a good bungie/pedal launch. I'll keep you posted and try to get some pic's this weekend.