CMP Beaver conversion
#26
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Hello Phalco,
I had used one of these stabilizer many years ago on a nitro airplane when I was learning to fly.
Although the airplane flew well, I felt there was an intermediate pilot between myself and the airplane. I did not like the feeling and on the next flight I remove it.
I had used one of these stabilizer many years ago on a nitro airplane when I was learning to fly.
Although the airplane flew well, I felt there was an intermediate pilot between myself and the airplane. I did not like the feeling and on the next flight I remove it.
#27
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Tomd, I think I'll install one on of my old planes and see if it's actually capable of correcting for wind gusts and drifts.
I balanced the BH-2 today. CG is right at 70mm, with no additional lead for balance. The only real concession to balance I made was the use of a Dubro chromed brass spinner nut. I don't know what that spinner nut actually weighs, but it did the trick. So, with the Magnum 52, and a 6 volt (5 cell) battery mounted underneath the fuel tank, a Master Airscrew 11x6 three bladed prop and the Dubro chromed brass spinner...the airplane balances where it should.
Tomorrow, I'll tweak the motor. It's already broken in but needs some low end tweaking. Then just wait for a reasonably light wind day for the maiden flight.
I balanced the BH-2 today. CG is right at 70mm, with no additional lead for balance. The only real concession to balance I made was the use of a Dubro chromed brass spinner nut. I don't know what that spinner nut actually weighs, but it did the trick. So, with the Magnum 52, and a 6 volt (5 cell) battery mounted underneath the fuel tank, a Master Airscrew 11x6 three bladed prop and the Dubro chromed brass spinner...the airplane balances where it should.
Tomorrow, I'll tweak the motor. It's already broken in but needs some low end tweaking. Then just wait for a reasonably light wind day for the maiden flight.
#29
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Well, I finally got to maiden the beaver. Sorry, but I didn't get any pictures. I'll try to get some pictures within the next couple of days...hopefully, this coming Saturday.
Luckily, the four stroke Magnum 52 was already broken in so none of those unpleasant new engine surprises. Fired her up and lined her up on the runway. We had about a 7mph crosswind from the left., so the plane immediately tried to turn into the wind as soon as the tail came up. Some right rudder and she was off the ground in about 50 feet. A steady climb at full power to about a hundred feet. Had to keep back pressure on the stick during the climb. Leveled out and reduced power to about 60%. Even though CG is at 70mm, she was a good bit nose heavy. I was able to get it to fly hands off and level with a fair amount of up trim...approximately half the trim range. Ailerons required only a couple of clicks of right trim and the rudder was spot on.
With the recommended control throws she flies very much like a trainer...barely able to do a roll or loop. On the second flight I increased the aileron and elevator throws a bit and it flew with a bit more authority. Could still use just a tad more. Once, I've got the throws where I like the response, I'll post some measurements.
The Magnum 52 provides adequate power for pretty quick take-offs but probably not enough to fly it with floats. During the two maiden flights I flew around at 60-70 percent throttle most of the time, which is great for nice relaxed flying.
During each flight I tested the flaps down. On the first flight I had 5% down elevator mixed in and on the second flight, 7%. Both times the plane wanted to climb. I'll probably mix in 15% and test it.
All in all, some good maiden flights and quite a few positive comments from the guys at the field.
Luckily, the four stroke Magnum 52 was already broken in so none of those unpleasant new engine surprises. Fired her up and lined her up on the runway. We had about a 7mph crosswind from the left., so the plane immediately tried to turn into the wind as soon as the tail came up. Some right rudder and she was off the ground in about 50 feet. A steady climb at full power to about a hundred feet. Had to keep back pressure on the stick during the climb. Leveled out and reduced power to about 60%. Even though CG is at 70mm, she was a good bit nose heavy. I was able to get it to fly hands off and level with a fair amount of up trim...approximately half the trim range. Ailerons required only a couple of clicks of right trim and the rudder was spot on.
With the recommended control throws she flies very much like a trainer...barely able to do a roll or loop. On the second flight I increased the aileron and elevator throws a bit and it flew with a bit more authority. Could still use just a tad more. Once, I've got the throws where I like the response, I'll post some measurements.
The Magnum 52 provides adequate power for pretty quick take-offs but probably not enough to fly it with floats. During the two maiden flights I flew around at 60-70 percent throttle most of the time, which is great for nice relaxed flying.
During each flight I tested the flaps down. On the first flight I had 5% down elevator mixed in and on the second flight, 7%. Both times the plane wanted to climb. I'll probably mix in 15% and test it.
All in all, some good maiden flights and quite a few positive comments from the guys at the field.
#30
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Hello Phalco,
Congratulations for the success of the maiden flight.,
Thank you for this complete report.
You say the airplane is nose heavy. Can you move the battery rearward to move the CG ?
Here it is still raining and cold. The flying season is not here yet. I am really anxious to begin flying.
Congratulations for the success of the maiden flight.,
Thank you for this complete report.
You say the airplane is nose heavy. Can you move the battery rearward to move the CG ?
Here it is still raining and cold. The flying season is not here yet. I am really anxious to begin flying.
#31
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Since the battery is strapped down under the fuel tank, it could easily be moved towards the rear. I could also remove the heavy brass prop nut and go back to the aluminum one. (They look exactly the same.) Haven't decided which route to take. However, you might want to fly the plane with the CG at 70mm as the starting point. Hopefully, your flying weather will be there soon.
P.S. One of our club members actually flew many hours in 156233. Cool, huh?
P.S. One of our club members actually flew many hours in 156233. Cool, huh?
Last edited by Phalco; 05-02-2014 at 03:47 AM.
#32
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I took the brass spinner nut and the three bladed Master Airscrew off and replaced them with an aluminum spinner nut and a two bladed 12x6 APC prop. This removed approximately 1.75 ounces off the nose moving the CG back to approximately 76mm. Before flying it again, I returned the elevator trim back to zero. This time the plane flew much better and it only required a couple of clicks of up elevator trim. Which tells me the CG of 68-72mm stated in the instructions is definitely too far forward.
Next time I go out and fly it, I'll mix in about 10% rudder into the ailerons. See how that goes.
Next time I go out and fly it, I'll mix in about 10% rudder into the ailerons. See how that goes.
#33


I used a firewall from a crashed Horizonhobby Beast 60E into this bird and powered it by an evolution 10CC gas engine. It flew well but the landing gear was too soft... Cowl was smashed in its 3rd landing and I had to suspend its flight over years.
#35
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In hopes of finding an answer to this late post, what kind of glue works for the wheel fairings and what kind of upgrades are needed for the limp landing gear?
Last edited by shsober; 04-05-2023 at 02:41 PM.