New hitec 7950TH

[Chris Todd]

	Quote: Originally Posted by rcpilot82
	Mike, I have no personal agenda towards you, nor am I as upset as you apparently. My goal is to have a safe servo that does what it was advertized to do. Mrs.R has provided PROOF of the failed G2 circuit and the effects that it has on the other componets in the servo (pot, gear train). This is not BS!! We are not "hiding" behind keyboards, Rather using them to make sure is no more Smoke and mirrors from Hitec. Hitecs first firmware fix was an immediate failure, now there is a second one that is supposed to"minimize" the jittering. Where is the testing that proves this?

I tend to agree with this statement.

My question reasoning is a little bit different, though. Mike, Thanks for the work that Hitec is actively doing on this issue. My 7XXX servos have been flawless. (I have a good number of 7955's and 7950's, and a couple 7980's...) Here's where my opinion about this "issue" comes from...


#1 The 7950's in my Yak, I purchased from a prominent member of the RC internet community. His setup led to a lot of jittering issues. For some reason, they work flawlessly for me. Zero issues using a JR 9303, and twin A123 packs. (they also worked great on another setup using my Aurora9 and unregulated LiPo's. )

#2 I received parts to a crashed airframe that the owner claimed to have his Hitec 7950's "lock up". He sent them into to Hitec, and you called him and told them that there was nothing wrong with the servos. I was surprised when I saw the linkage geometry that was setup when I received the part. I'm not going to go into detail on my observation, but I have not seen the working setup, just the horns and linkages. My guess is that the servo over rotated and locked at more than full deflection. Not a Hitec fault.

#3 I have seen several aircraft, using similar setups, and excellent servo geometry have the bad issues that Buttface, and several others are talking about, and posting videos of. (I'm only referencing the issues that folks have posted videos of here to clarify what I have seen in person.)



There has been a lot of heated keyboard huckin in this thread. But please try to understand it from my point of view, and that of most of us here.

#1 We love Hitec servos. They are awesome in many ways. I don't want to switch brands.
#2 Issues are happening that may compromise the safety of our aircraft, and God forbid, the safety of spectators, or us.
#3 Several individuals have spent a large amount of time and money to fix these issues, but Hitec appears to not care.



So, my questions are:

#1 Where are these issues coming from?
#2 What is the difference between my setup, and someone similar setup, where one has the issues, and the other doesn't?(Including the case where both setups used the same servos)
#3 If these issues happen with my aircraft, what are you, and Hitec RCD going to do to remedy the problem for me?


And the big one:

#4 These issues have been identified for two years. What is taking Hitec so long to fix this. Most of us are getting tired of the failed band-aids, and just want to see Hitec identify what the defects are, fix the servos, and we all fly in happier skys.

So far, Rachel and Tavis are the only ones who have identified any possible causes, yet Hitec seems to throw them under the bus. This inspires little confidence in Hitec, for me. I am now ashamed to say that I have influenced a number of people to buy the 7XXX servos. I am considering dumping my whole fleet of servos and switching to a brand that I can trust.

So I ask again, what is taking 2 years for Hitec to fix this, and does Hitec even care about their customers? What is Hitec doing to keep me buying their products?


Mike, my intention is not to flame you, or Hitec. I'm merely trying to explain why this thread has degenerated into negativity. Additionally, I'm trying to help you see this from the point of view that many of us have taken.

So, here's my challenge, Mike: Hitec servo issues are big talk at the flying field. A lot of folks are switching brands. Currently, Hitec's name is mud. Does Hitec even care? As it is, many people outside of this thread don't even bother contacting Hitec, they are just dumping their servos, and buying some other brand. (Savox and Futaba are popular at my field) They've read this thread, and seen that Tavis has sent his servos back to Hitec multiple times over two years. They see that he still has issues, and that Mrs. R's modification might be the ticket, but they refuse to modify their servos without Hitec's approval.

V/R,
C. Todd
(again, not trying to flame, just trying to explain)

[BeverleyFlyer]

Mike my gripe is n ot with you and never has been you are just the spokesperson and can only say what you are told to say by your millionare bosses that are taking all our hard earned money for these defective servos over here in australia we pay $130 each for the 7955's and $160 each for the 7950's , So for a 50cc plane that's around $650 to $700 just for servos and to have all 5 ( 4x7955 and 1x 7950) all jitter out the box and then to lose a plane due to the rudder servo glitching on a landing approch after 20 flights you can see why i'm upset about the problem. The other thing i wasn't happy about is that this problem had been going on for 2 years before hitec even said anything about looking at a fix,
So my complaint is with hitec themselves not you. Also why havn't hitec taken MrsR's or Travis's fixes on board?
Or why not just go back to the old 5955's that are a good servo.

[Snooper]

	Quote: Originally Posted by Sukhoikid
	I have seen several people at the flying field with zero issues with the 7950 or 7955 servos. I have been using them for about almost two years now with zero issues. Heck I even have 5955 servos in my freestyle plane that I purchased 6 years ago and they still work great....

We are attempting to influence Hitec to set the bar higher to make better servos. Posts like yours are showing resistance to this. You are one that is content with mediocre . However most of us want improvement.

And no one ever said they had problems with 5955...most of them are still going strong even still today with zero issues. We all know this. I'm still running 40 of them in all my 40%ers with over 500 flights and no issues.

[Snooper]

	Quote: Originally Posted by Chris Todd
	I tend to agree with this statement. My question reasoning is a little bit different, though. Mike, Thanks for the work that Hitec is actively doing on this issue. My 7XXX servos have been flawless. (I have a good number of 7955's and 7950's, and a couple 7980's...) Here's where my opinion about this "issue comes from... #1 The 7950's in my Yak, I purchased from a prominent member of the RC internet community. His setup led to a lot of jittering issues. For some reason, they work flawlessly for me. Zero issues using a JR 9303, and twin A123 packs. (they also worked great on another setup using my Aurora9 and unregulated LiPo's. ) #2 I received parts to a crashed airframe that the owner claimed to have his Hitec 7950's "lock up". He sent them into to Hitec, and you called him and told them that there was nothing wrong with the servos. I was surprised when I saw the linkage geometry that was setup when I received the part. I'm not going to go into detail on my observation, but I have not seen the working setup, just the horns and linkages. My guess is that the servo over rotated and locked at more than full deflection. Not a Hitec fault. #3 I have seen several aircraft, using similar setups, and excellent servo geometry have the bad issues that Buttface, and several others are talking about, and posting videos of. (I'm only referencing the issues that folks have posted videos of here to clarify what I have seen in person.) There has been a lot of heated keyboard huckin in this thread. But please try to understand it from my point of view, and that of most of us here. #1 We love Hitec servos. They are awesome in many ways. I don't want to switch brands. #2 Issues are happening that may compromise the safety of our aircraft, and God forbid, the safety of spectators, or us. #3 Several individuals have spent a large amount of time and money to fix these issues, but Hitec appears to not care. So, my questions are: #1 Where are these issues coming from? #2 What is the difference between my setup, and someone similar setup, where one has the issues, and the other doesn't?(Including the case where both setups used the same servos) #3 If these issues happen with my aircraft, what are you, and Hitec RCD going to do to remedy the problem for me?

Good post my man

[Phil Griffin]

	Quote: Originally Posted by lxcoupe
	I bought savox.... We'll see how that works out. I only learned about the KO servos in the last week. I'll keep my eye out and on them. To me they aren't so far out of line price wise as long as they do what they are supposed to do. Which is just frikken work.

Same here. I bought the 1256's for my 50cc WW profile. We'll see how they work out.

[Sukhoikid]

	Quote: Originally Posted by Snooper
	We are attempting to influence Hitec to set the bar higher to make better servos. Posts like yours are showing resistance to this. You are one that is content with mediocre . However most of us want improvement. And no one ever said they had problems with 5955...most of them are still going strong even still today with zero issues. We all know this. I'm still running 40 of them in all my 40%ers with over 500 flights and no issues.

I am just sharing my opinion and my experience with hitec servos and other peoples experience considering I attend 5-10 IMAC contest per year and several 3d events through out the year....If anything I have seen more JR servos with jitters than hitec

[Jaybird]

	Quote: Originally Posted by boggintuff
	Yeah Toledo will be a hoot if MM is there. Can't wait to see him ignore me when I'm in his face with my loud ass voice asking the question so others can hear his answer.... Ignore us then. My bet is he won't show to Toledo....what a shocker that will be. I'm tempted to get a t-shirt made up with the pissing on hitec avatar on the back of it.

So you have some jittering Hitecs also?

[rcpilot82]

	Quote: Originally Posted by boggintuff
	Yeah Toledo will be a hoot if MM is there. Can't wait to see him ignore me when I'm in his face with my loud ass voice asking the question so others can hear his answer.... Ignore us then. My bet is he won't show to Toledo....what a shocker that will be. I'm tempted to get a t-shirt made up with the pissing on hitec avatar on the back of it.

Already in the works

[XJet]

Looking at the videos, it's pretty clear that the problem is primarily when the servos are driving high-mass surfaces such as rudder or ailerons -- or when ganged.

This would indicate that the PID code (firmware) is not capable of coping adequately with the variance in mass-loadings that the servo is seeing in different applications.

I now have a jittery 7955 on the bench and next week I'll be doing a tear-down and some experimentation to see if there's also a hardware issue (as has also been suggested).

I'll probably make a video of the whole process so everyone can see what I find and how I went about investigating.

To be honest, looking at the yellow Dalton, I've seen birds here with JR servos that are far worse than that and for years, I could never figure out how JR users were happy to tolerate all that servo-jitter. The usual response was "it doesn't do it in the air".

The reality is that designing a servo to cope with the conflicting goals of high resolution, hi torque, fast transit, good centering and perfect damping is a damned hard task -- which is why there are so many "bad" servos out there.

Stay tuned...

[planecajun]

	Quote: Originally Posted by XJet
	Looking at the videos, it's pretty clear that the problem is primarily when the servos are driving high-mass surfaces such as rudder or ailerons -- or when ganged.

The only issue i have with this statement is this: when a plane is sitting on the ground, there is no weight on the rudder at all. Its not like a heavy aileron sitting on the linkage and loading a servo. Seems like the rudder would not have the same issue due to loading at neutral. Not saying you are wrong, just sharing my thoughts with you XJet. Please post videos of your testing if at all possible. Thanks

[Smacka]

	Quote: Originally Posted by XJet
	Looking at the videos, it's pretty clear that the problem is primarily when the servos are driving high-mass surfaces such as rudder or ailerons -- or when ganged. This would indicate that the PID code (firmware) is not capable of coping adequately with the variance in mass-loadings that the servo is seeing in different applications. I now have a jittery 7955 on the bench and next week I'll be doing a tear-down and some experimentation to see if there's also a hardware issue (as has also been suggested). I'll probably make a video of the whole process so everyone can see what I find and how I went about investigating. To be honest, looking at the yellow Dalton, I've seen birds here with JR servos that are far worse than that and for years, I could never figure out how JR users were happy to tolerate all that servo-jitter. The usual response was "it doesn't do it in the air". The reality is that designing a servo to cope with the conflicting goals of high resolution, hi torque, fast transit, good centering and perfect damping is a damned hard task -- which is why there are so many "bad" servos out there. Stay tuned...

Yep, look forward to the vids as well

[ghoffman]

Interesting note on the new JR brushless servos;
http://www.jrpropo.co.jp/english/propo/Servo/

"If used on a large control surface - typically aileron, rudder, elevator or flap on an airplane, Digital servos (DS・MP・MPH series) may move slightly around center while on the ground. This is an expected phenomenon, and will not occur in the air."

[BeverleyFlyer]

	Quote: Originally Posted by XJet
	Looking at the videos, it's pretty clear that the problem is primarily when the servos are driving high-mass surfaces such as rudder or ailerons -- or when ganged. This would indicate that the PID code (firmware) is not capable of coping adequately with the variance in mass-loadings that the servo is seeing in different applications. I now have a jittery 7955 on the bench and next week I'll be doing a tear-down and some experimentation to see if there's also a hardware issue (as has also been suggested). I'll probably make a video of the whole process so everyone can see what I find and how I went about investigating. To be honest, looking at the yellow Dalton, I've seen birds here with JR servos that are far worse than that and for years, I could never figure out how JR users were happy to tolerate all that servo-jitter. The usual response was "it doesn't do it in the air". The reality is that designing a servo to cope with the conflicting goals of high resolution, hi torque, fast transit, good centering and perfect damping is a damned hard task -- which is why there are so many "bad" servos out there. Stay tuned...

If your hteory is correct how come they jitter out of the plane with no load except a servo arm?

[BeverleyFlyer]

	Quote: Originally Posted by Sukhoikid
	I am just sharing my opinion and my experience with hitec servos and other peoples experience considering I attend 5-10 IMAC contest per year and several 3d events through out the year....If anything I have seen more JR servos with jitters than hitec

So then why is it that most of the IMAC guys i fly with have removed there hitecs for either jr or futaba?
There used to be around 20 IMAC guys here using them now thee is about 3 or 4