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811 digital servo gear slop

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Old 11-26-2002, 12:35 AM
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stickman/vic
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Default 811 digital servo gear slop

I wanted to try the 811 Digital for precision of aileron operation on my 2 meter Viper. They are about as fast a servo as you could ask for and I feel are a step up from the benchmark of the industry 4131. I seem to have much more gear train slop than is acceptable for the application and what I'd expect from a JR product on the ones I received. Is there a metal gear that I can retrofit or did I get two bad ones?
Also could JR start to send longer servo arm screws please. If you need to use an aftermarket highr strength arm you may not get enough bite on the sccrew keeping the arm on.
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Old 11-26-2002, 03:22 PM
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Default Noticed it to

It looks to me like the shaft the servo arm is attached to has some play in it.
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Old 11-26-2002, 03:56 PM
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Default 811 digital servo gear slop

The 811 has a wide bearing spacing, so I'm not sure why there would be a noticable play there in the output gear. I'm not sure where you are finding slop, it may be just a bad set of gears. A metal gear set will likely have more slop than a nylon gear train, but I don't know of a metal gear set for the 811. JR does have some long servo horn screws available, part number JRPA232L.
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Old 11-26-2002, 05:40 PM
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Default 811 digital servo gear slop

The gear slop is in the direction of arm travel and not a wobble of the shaft (the wide spacing of the bearings solved that). It allows the aileron to exibit the first sign of flutter. I am afraid the 4131 and 8411 have raised my level of expectation of JR servos and I hasten to add that my Hitec digitals don't have any gear slop at all. Vic Koenig
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Old 11-26-2002, 10:16 PM
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Default 811 digital servo gear slop

The slop of the 811 should be less than the 8411 since the 811 has nylon gears and the output shaft slop should be less than the 4131 so overall the 811 should be better than both of those servos as far as amount of slop anyway. My first thought would be to make sure that the arm is not loose on the output shaft or slop in the linkages. The gear set itself should be very slop free. If not, it may just be those gears in those servos.
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Old 11-26-2002, 11:00 PM
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Default 811 gears

I went into the servo today and determined it is the gear train. I tightened the arm first but still saw the arm rotate in its normal direction, much more than it should have. I drug out an old 4131 and its gears were still slop free, and this is an older servo, a vetran of two years in another pattern plane. I suppose I need to send them back for repair. I bought two at the same time and one is worse than the other, but both exibit some looseness. Vic Koenig
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Old 12-15-2002, 04:23 AM
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Default 811 digital servo gear slop

The 4131 is a better servo than the 811. That is why they usually cost more. The 4131 is one of the most reliable servos ever made by any manufacturer.

Just my opinion.
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