Dummy Servo
#1
Leaving the build threads to the pros, I was thinking about how annoying is to be installing servos and measuring on new installations, and because I need to install 6 3421 on my Xurama I thought about making a dummy.
I took five minutes to make, two little pieces of 3/16 and one 1/16,CA toguether, outlined the servo on the wood with grommets and everything for correct height and cut it with the old faithfull Dremel saw, so no worries about the damm wire being squeezed in and out six time.
Maybe it does exist already or there's a better idea, but this one worked good for me and it was free
, if it is of use to anybody then great!Regards
#2
Silly question, but why aren't the boxes done from the factory BEFORE the plane is covered? Be careful with the torque on that one... sometimes a light weight servo just isn't strong enough
#3
Hi Jason, It's done that way because some people like it inside the stab and other on the outside, so it does not matter what servo brand you use.
I got my Osmoses with the internal servo pocket already done and ready for install, but I ordered it that way.
I've been using 3421 on my Osmoses but the metal gear version on the stabs with no problems, I'm a little concerned about the SA, but Marcelos Xuramas has the 3421 on ail and elev.
It's electric, do you think I should be concerned?
I got my Osmoses with the internal servo pocket already done and ready for install, but I ordered it that way.
I've been using 3421 on my Osmoses but the metal gear version on the stabs with no problems, I'm a little concerned about the SA, but Marcelos Xuramas has the 3421 on ail and elev.
It's electric, do you think I should be concerned?
#4
I don't recognize those numbers as Futaba servo's...lol. I honestly don't know, but Dave's Proline has SA's on the stab and no problem with the 160, so I don't see an issue with electric.
#5
Yes, I'm not concerned on the the torque, but the gears are extremely fragile and that is my real concern, I put a pair in a Funtana when they (the servos) came out, pulled on the stab (with absolutely no binding) and stripped the gears, I really don't know what I did wrong but I have been worried since then and always used the metal gear.
But if Dave's plane is doing good, then that's a relief for me, BTW, send me regards to him for me.
Regards
But if Dave's plane is doing good, then that's a relief for me, BTW, send me regards to him for me.
Regards
#8
Hi,
I have used both the JR 3421SA and Futaba 9650 (the equivalent) on 2m F3A glow models. All I can say is that 9650 has slope from the first flights which becomes bigger due to vibration. 3421SA has a lot less slope and is a very precise servo. Now it has been discontinued I think.
By the way I think SAVOX makes a similar size servo which for sure worths a try as it is slope free.
FYI I fly Futaba so I am not JR biased...
rgrds,
Nikos
I have used both the JR 3421SA and Futaba 9650 (the equivalent) on 2m F3A glow models. All I can say is that 9650 has slope from the first flights which becomes bigger due to vibration. 3421SA has a lot less slope and is a very precise servo. Now it has been discontinued I think.
By the way I think SAVOX makes a similar size servo which for sure worths a try as it is slope free.
FYI I fly Futaba so I am not JR biased...

rgrds,
Nikos
#10
I have been using the 3421 but metal gear as I striped the nylon gears on my first two, my fault completely, and I was concerned on the gears being too fragile, after all of your comments which I appreciate, I will install the SA confident everything will be ok.
Thank you all for the support
Thank you all for the support
#11
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Alejandro,
FWIW, the Ventura uses just two 3421SA's for the ailerons, that are connected by a carbon rod. I've always used them for elevators, however for ailerons, you will be just fine.
FWIW, the Ventura uses just two 3421SA's for the ailerons, that are connected by a carbon rod. I've always used them for elevators, however for ailerons, you will be just fine.
#12
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From: Adelaide, AUSTRALIA
Not doubting you Ryan . . but they seem really light for that. One per aileron I'd maybe consider (4 of them) . .
I guess they work OK, but maybe the life is shortened ???
Just surprised, really . .
Cheers, JB
I guess they work OK, but maybe the life is shortened ???
Just surprised, really . .
Cheers, JB
#13
I think if your geometrical symmetries are ok and you have the appropriate mechanical advantage it is very difficult to break plastic gears on a F3A model.
Here is the 3421SAs on my OTOP, never had a problem and this is the glow version.
On a 2m 3D/freestyle model I fly now I consider seriously transforming its metal gear aileron servos JR 8411 onto 8401 plastic, some times I fly pattern with it. Metal gears are very sloppy and servos never center properly, specially for JR they lose their high performance POTs potential due to slop.
rgrds,
Nikos
Here is the 3421SAs on my OTOP, never had a problem and this is the glow version.
On a 2m 3D/freestyle model I fly now I consider seriously transforming its metal gear aileron servos JR 8411 onto 8401 plastic, some times I fly pattern with it. Metal gears are very sloppy and servos never center properly, specially for JR they lose their high performance POTs potential due to slop.
rgrds,
Nikos
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I had my doubts as well. You can't fit a 9411 or equivalent Futaba in the Ventura wings. After watching Quique flying it, I don't have doubts anymore. He even flew the glow version like that.
#15
Yes I was really amazed when QQ told me that he uses only one 3421SA per two ailerons on the Ventura.[X(]
Anyway he knows better than anyone I suppose, QQ is amazing a great person and great pilot (IMO the greatest pilot ever).
Ryan is there a glow version of the Ventura?
rgrds,
Nikos
Anyway he knows better than anyone I suppose, QQ is amazing a great person and great pilot (IMO the greatest pilot ever).
Ryan is there a glow version of the Ventura?
rgrds,
Nikos




