DS821 Servos
#28
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RE: DS821 Servos
The worse thing is, I was installing them in a .46 -size Corby Starlet. Not any bigger than a trainer, and the shafts sheared under zero stress, just sitting in the cradle. I took the linkage (loose) and moved it in and out, it was effortless. Not a reason in the world those servos should have sheared.
Trying to make up the difference where I can by using what I have hanging around. Way overkill, but the elevator now has an 8611A, which I think should be good forever! I'll likely switch it out when I get some ST126MGs in. One DS821 that wasn't part of the original batch has not sheared, and so I put it on the rudder. I already had a mini servo running the throttle to the Saito, that works fine. I still need both aileron servos. I have a 47 sitting here, but I think I'll wait on something better, since I only have one of them.
I think I have two of the Hextronics servos I was testing around here somewhere. They work really well. I'd use them, but with 220 oz-inches I'm guessing they're juice hogs. I already have the 8611A in there, which uses some amps itself, and this Corby, being a .46 size, is set up modestly battery-wise, with a 1650 NiMh pack. So, it's Ix-nay on the extronics-Hay.
The drawback right now is that it was already going to need noseweight, and the JR8611A weighs as much as both of the DS821s that were there originally. Ahh, well.
Jim
Trying to make up the difference where I can by using what I have hanging around. Way overkill, but the elevator now has an 8611A, which I think should be good forever! I'll likely switch it out when I get some ST126MGs in. One DS821 that wasn't part of the original batch has not sheared, and so I put it on the rudder. I already had a mini servo running the throttle to the Saito, that works fine. I still need both aileron servos. I have a 47 sitting here, but I think I'll wait on something better, since I only have one of them.
I think I have two of the Hextronics servos I was testing around here somewhere. They work really well. I'd use them, but with 220 oz-inches I'm guessing they're juice hogs. I already have the 8611A in there, which uses some amps itself, and this Corby, being a .46 size, is set up modestly battery-wise, with a 1650 NiMh pack. So, it's Ix-nay on the extronics-Hay.
The drawback right now is that it was already going to need noseweight, and the JR8611A weighs as much as both of the DS821s that were there originally. Ahh, well.
Jim
#30
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RE: DS821 Servos
No threadlock used on these ones. The only way these ones work is if you don't use the 821s.
I have them on a number of other planes, with no issues thus far. Though I have to say, it makes me nervous now that this has happened.
Not a real big confidence builder.
Jim
I have them on a number of other planes, with no issues thus far. Though I have to say, it makes me nervous now that this has happened.
Not a real big confidence builder.
Jim
#31
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RE: DS821 Servos
Hi all, I remember the longer screw thing, and have used a longer screw in most all of my servos. Haven't had any problem with breakage on any of the 821's since going to a longer screw, and yes I'm still using 821s in 90 size planes. Hope that helps.
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RE: DS821 Servos
That's just the point. The plane is a .46 size. The 821s should be enough, but the splines separate. A longer screw might do the trick, and I have a number of them in several other smaller planes that I'd like to switch out the screws on, BEFORE the problem arises there.
I have bigger, MG servos on my larger planes. No problems there.
I wonder if I should contact Horizon about these failures of brand-new servos.
Jim
I have bigger, MG servos on my larger planes. No problems there.
I wonder if I should contact Horizon about these failures of brand-new servos.
Jim
#36
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RE: DS821 Servos
Wouldn't put them on anything larger than a 90 size plane either, weight matters also as to servo selection. It wouldn't hurt to contact Horizon they may have more info on the 821 servos. Like I said earlier I have had no problems with the longer screws. I see where the other manufactures have gone to long screws also over the years.