Digital servo squeals
07-12-2002, 09:17 AM
#1
Thread Starter
My Feedback: (2)
Join Date: Dec 2001
Location: Yoder,
CO
Posts: 555
Likes: 0
Received 0 Likes
on
0 Posts
Digital servo squeals
Hi guys,
I just bought a Hitec 5945 Digital servo and it squeals when at neutral and when moving. After a minute if I don't touch it it will stop squealing at center, but then it starts back up again. I don't care about the noise, but I'm concerned the servo is defective. This is a 180 in/oz servo @ 6V but it also squeals at 4.8v. Is this normal? I have two 5625's that are also digital but they're quiet.
-Tom
I just bought a Hitec 5945 Digital servo and it squeals when at neutral and when moving. After a minute if I don't touch it it will stop squealing at center, but then it starts back up again. I don't care about the noise, but I'm concerned the servo is defective. This is a 180 in/oz servo @ 6V but it also squeals at 4.8v. Is this normal? I have two 5625's that are also digital but they're quiet.
-Tom
07-12-2002, 12:36 PM
#3
Senior Member
My Feedback: (3)
Join Date: Mar 2002
Location: League City, TX
Posts: 252
Likes: 0
Received 0 Likes
on
0 Posts
Digital servo squeals
You should post this over in the Manufactures area under Hitec. Mike will be happy to address your concerns. He has been a good resource. I'm curious about this as well, as I have a new Digital wing servo HS-5125MG that does the same darn thing. I two thought maybe it's defective. No comparison though as its the first one I have ever owned. Anyway jump over there and give Mike a shout.
Shawnusa
Shawnusa
07-16-2002, 12:47 AM
#9
Thread Starter
My Feedback: (2)
Join Date: Dec 2001
Location: Yoder,
CO
Posts: 555
Likes: 0
Received 0 Likes
on
0 Posts
Thanks guys.
Thanks to all who responded to my question. I'm glad it's not a problem with the servo. I do wish Hitec would include a longer metal servo arm with their digital servos. An arm about 1/2" longer would be nice, then I could run my pushrods further up the control horns and minimize the effect of any slop in the clevises.
-Tom
-Tom
07-16-2002, 02:33 AM
#10
Senior Member
Digital servo squeals
I am using Futaba 9151's and they squeal too! I was told that it was normal for it to do that, but it is still unnerving. Especially when I have an on-board battery checker and can see the extra drain on the battery when it does that.
Found out that the weight of the aileron/elevator actually caused it. We are talking about a Dave Patrick Extra 330L aileron which is not exactly beefy.
Found out that the weight of the aileron/elevator actually caused it. We are talking about a Dave Patrick Extra 330L aileron which is not exactly beefy.
07-16-2002, 03:47 PM
#11
My Feedback: (6)
Join Date: Jan 2002
Location: Plano,
TX
Posts: 821
Likes: 0
Received 0 Likes
on
0 Posts
DIGITAL BUZZ
Get used to it... they are so precise that they will be constantly trying to hold center. SO if you have large control surfaces and especially if you gang servo's they will be a singing the buzz song.
Because of thier superior holding power and centering they will absorb more power, so up your mil's by about 25% to 50% for comparable flight times as if you where using coreless or std servo's.
Because of thier superior holding power and centering they will absorb more power, so up your mil's by about 25% to 50% for comparable flight times as if you where using coreless or std servo's.
07-19-2002, 06:30 PM
#12
Senior Member
My Feedback: (1)
Join Date: Jan 2002
Location: Poway, CA
Posts: 3,531
Likes: 0
Received 0 Likes
on
0 Posts
Yes, it is normal
Hi All,
Yes, the high pitched noise from the digital servos is normal. It is due to the high refresh rate from the amp to the motor. An analog servo is refreshed 30 times per second where the digitals are refreshed 300 tps! This is what contributes to the high holding power.
The deadband is also much tighter (1us) compared to the analog of 8us. By increasing the width of the deadband you can quiet them at neutral but you sacrifice the ultra precise centering.
Mike.
Yes, the high pitched noise from the digital servos is normal. It is due to the high refresh rate from the amp to the motor. An analog servo is refreshed 30 times per second where the digitals are refreshed 300 tps! This is what contributes to the high holding power.
The deadband is also much tighter (1us) compared to the analog of 8us. By increasing the width of the deadband you can quiet them at neutral but you sacrifice the ultra precise centering.
Mike.
