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SJM SJM Helicopters including SJM180 |
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05-06-2009, 02:27 AM | #1 (permalink) |
Join Date: Mar 2009
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430 tail heavy?
Hello, I've bought a SJM 430 and finally try to fly it. The first thing i'v noticed while building up the "machine", it is tail heavy. I''ve tried a few things to improve, but still. I have changed the nice looking chrome tail supports to lightweight supports. I've placed the rudder servo as much as possible to the front. How should the 430 behave???
While standing on his feet, the main shaft is leaning to the front and the tail is a little upwards. But while flying??? should it be in the same position??? or with the tail horizontal en the main shaft vertical?? please advise. Regards, Heino van der Meer |
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05-06-2009, 03:13 AM | #2 (permalink) |
Registered Users
Join Date: Feb 2009
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Hi Heino,
what batteries are you flying with? For me, 400-450g battery weight is ideal. The heli is only tilted forward on the ground, not in the air - here the tail boom should be parallel to the ground. You can easily check the CG on your heli - remove the blades (you can leave them on, but it's much easier to do it without) and then pick up the heli by the blade holders and tilt it 90° sideways so the main shaft is horizontal (hope I'm making sense to you). Now see whether the nose or the tail go down - and turn the heli 180° as well, because in one direction the one-way bearing will block. Now you should know pretty exactly whether your heli is tail- or nose-heavy (mine was tail-heavy). With the default chickenwire that runs along the tail boom you can't move the tail servo far enough forward. I've made my own CF tail rods which work fine (about 4cm longer than the wire), and now the CG is perfect on my heli. Regards, Simon. |
05-08-2009, 09:54 AM | #3 (permalink) |
Thread Starter
Join Date: Mar 2009
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Hi Simon, haha thats the same i did, i made mine one tail rod aswell. but still.. . I'm using 2 2800mAh lipo's, each 210 grams. Another thing is maybe my gyro setup. Its a GY611 (64 grams) with a BLS251 servo (about 65 grams). this setup up could be to heavy for the 500 size
Regards Heino |
05-08-2009, 10:17 AM | #4 (permalink) |
Registered Users
Join Date: Feb 2009
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Hi,
yeah, that's a lot of difference to my setup - maybe you can mount the heavier GY611 computation unit somewhere closer to the CG, or even maybe forward of it? I'm using a 30g tail servo and a 20g AC3X FBL unit (3-axis gyro), so that's a lot less weight on the tail. You probably really need some added weight in the nose. Regards, Simon. |
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