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4G3 Walkera 4G3 Helicopter Support |
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04-07-2009, 08:42 AM | #1 (permalink) |
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Join Date: Jan 2009
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4G3 2.9g BL tail/FLEA ESC problem with full battery
Set up the 4G3 with 2.9g tail/FLEA combination yesterday. I'm using the standard 4G3 tail rotor blades. With a partially discharged battery it flies like a dream. Good tail holding power even with max pitch. However when battery is fully charged the tail becomes erratic. It darts left and right in a very unpredictable manner. Turning gyro sensitivity as low as it can be set helps (using DIP 12 and V1 knob full CCW). I found a lower main shaft bearing had some slop so it was replaced. I've reduced head vibration as much as possible by insuring all new straight and balanced parts which helped some more (but I still need to have gyro set to full minimum). Again, as battery is drained things get back to normal and more GYRO sensitivity can be selected.
Apparently the FLEA ESC can be made less sensitive by de-soldering a section of the board. Before I try this, has anyone else? Any ideas? Thanks Eric P.S. I never had this problem with the original brushed tail motor. |
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04-07-2009, 03:52 PM | #2 (permalink) |
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Found my problem.
The upper main shaft bearing had some play causing enough vibration to confuse the gyro at high speed. |
05-01-2009, 07:02 PM | #3 (permalink) |
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Join Date: May 2009
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Uncontrollable 4g3 with a fresh battery
I am running the same set up as you and am having the same trouble you were. With a fresh battery, my 4g3 is completely eratic and about half way through it flies perfectly. What exactly did you find to correct this? I don't really seem to have much vibration and can't figure this out. Have you had anymore trouble since?
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05-03-2009, 05:17 PM | #4 (permalink) |
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problem solved, finally
The 2.9g BL tail motor with FLEA ESC caused me grief with the gyro becoming way too sensitive. I would turn the sensitivity down fully but with a full battery the tail would still dart randomly back and forth. I tried making the rotor as perfect as possible with some improvement but the problem never was completely eliminated (until now).
I wedged some thin plastic between the tail boom and the servos to make the boom more rigid. The boom must have been flexing enough to confuse the gyro at high rotor RPM. With the boom now more solid, the gyro sensitivity can be set to normal high levels. |
05-06-2009, 08:54 PM | #5 (permalink) |
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Join Date: May 2009
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4G3 Now controllable
4STRIPES, Just wanted to say thanks for your help. I was able to get my heli under control.
For all others that may have this problem, I just wanted to post that you want to make sure you have a scale to weigh your blades. The problem with mine was the one blade weighed about .1 gram more than the other (carbon fiber blades). After evening out the weight, the vibration was gone and I was able to fly the 4G3 with normal gyro settings. Last edited by Jaydawgx7; 05-06-2009 at 11:52 PM.. |
05-07-2009, 06:06 AM | #6 (permalink) |
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Join Date: Jan 2009
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Yes, It is important to have balanced blades. I've managed to balance them just using a blade bolt and nut holding the two blades together. Spread them completely apart and balance on the head of the bolt. The heavy blade will be pretty obvious. Just keep sanding, or use tape to balance as close as possible.
Cheers Eric PS another source of vibration is a slightly bent flybar which can be straightened by hand on the head. |
05-14-2009, 09:58 PM | #7 (permalink) |
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Further troubleshooting shows that the original 12 tooth pinion on the
Walkera BL motor is far less susceptible to GYRO induced tail wag. My 14 tooth increases the head speed enough to cause problems if there is any imperfection in the rotor head (bent feathering shaft or blade imbalance/tracking errors). The 12 tooth pinion is tame compared to the 14 for performance but it does fly more docile (good for indoors or learning). I noticed flight times of 7 minutes for the 14 tooth and 9 for the 12! Something to consider when choosing pinions. Cheers Eric |
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