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8411 and 2721 gears/deadband

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Old 12-05-2002, 02:48 PM
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woodscra
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Default 8411 and 2721 gears/deadband

1. Are the gears in the 2721 the same as those in the 8411?
Or are the 8411 gears stronger?

2. What is the deadband on the 8411 servos in milliseconds?

3. 2721 deadband?

4. I may be using 2-8411s on aileron, do you have any suggestions with using the matchbox that somehow would allow me to be sure the servos are centered exactly the same?

5. Is it possible to send my 8411 servos to Horizon and have them rotate gears on my 8411 servos so that when the servo is centered with the TX that the output gears on all of them will allow for each servo will allow a servo horn to almost exactly in the same spot? This would make only very minor adjustments with the matchbox necessary.

Thanks
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Old 12-09-2002, 02:39 PM
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Default 8411 and 2721 gears/deadband

Danny:
Do you not have specs on the 8411 deadband? I thought surely this info would have been recorded somewhere.

Also, what about question 5, what would you guys do that and if so how much?
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Old 12-09-2002, 03:38 PM
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Default 8411 and 2721 gears/deadband

I've been trying to dig up the numbers on the dead band of the servos. Here is the info I have right now.

1. The gears are not the same, but they are similar materials. The 8411 has a wider bearing spacing on the output gear which makes it have less wobble.

2. The 8411 has less than 1 ms dead band.

3. I haven't found a number on this yet, but it is higher than the 8411.

4. Using the matchbox for adjusting the center and end points of each servo will allow you to make up the differences between the servos.

5. The center is determined by the pot, not by the gear train. Unless the pot is off, you can determine this by setting dual rates up at 100% on high, and 50% on low, and switching between them and seeing if the servo moves when flipping the dual rate switch, your servos do not need adjusted. If it does not, the pot in the servo is set correctly. If there are differences between the centering of the servos, you will need to use a matchbox to correct any difference, or have each servo plugged into different channels to allow you to use sub trims and travel adjust on each servo.
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Old 12-09-2002, 06:29 PM
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Default 8411 and 2721 gears/deadband

Thanks Danny. Is it possible to send my 8411s to you and have the deadband changed?

I will try your experiment sometime and see what i get.

Will Horizon ever offer a tool so the consumer can alter deadband on their own servos?
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Old 12-09-2002, 06:48 PM
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Default 8411 and 2721 gears/deadband

It is something we can change somewhat, but does require soldering in different components, so it is not something a customer can do.
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Old 12-09-2002, 09:56 PM
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Default Can you guys enlighten me

I thought 1ms deadband was pretty good! How are they changed, and what would they be changed to? Thanks_bob
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Old 12-09-2002, 10:19 PM
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Default 8411 and 2721 gears/deadband

It is actually less than 1ms. This is changed with internal components, and is not something you would want to do, unless you are having problems with them.
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Old 12-10-2002, 11:27 AM
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Default Sorry, I guess what I meant to ask was

Why would anyone want to change that spec?
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Old 12-10-2002, 02:18 PM
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Default 8411 and 2721 gears/deadband

The only reason is if the servos have a jittering problem and it is not caused by other issues.
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Old 12-11-2002, 10:22 AM
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Default 8411 and 2721 gears/deadband

This is caused by off-center gimbal pot in the TX, not the servo.


Originally posted by dsnyder
5. The center is determined by the pot, not by the gear train. Unless the pot is off, you can determine this by setting dual rates up at 100% on high, and 50% on low, and switching between them and seeing if the servo moves when flipping the dual rate switch, your servos do not need adjusted. If it does not, the pot in the servo is set correctly. If there are differences between the centering of the servos, you will need to use a matchbox to correct any difference, or have each servo plugged into different channels to allow you to use sub trims and travel adjust on each servo.
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