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Old Jan 20, 2013, 12:00 PM
Got the Slickness
gabrielisrael's Avatar
Seattle, WA
Joined Jul 2010
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Quote:
Originally Posted by Doc Austin View Post
How far out were your deadbands?

My understandijg is that Hi Tec hyas corrected the problem, but there are still a lot of servos out there with dead bands set at random.
Doc, all of them were set at factory 2:1, but one was out at 2:4. I dialed them all in last night to 1:1.
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Old Jan 20, 2013, 12:33 PM
TEAM EXTREME FLIGHT
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USA, FL, Largo
Joined Dec 2005
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Quote:
Originally Posted by gabrielisrael View Post
Doc, all of them were set at factory 2:1, but one was out at 2:4. I dialed them all in last night to 1:1.
That's where I set mine. On my new 60" MXS I had two servos that were set at 16! They centered so poorly that I could not even get close to setting the plane up. I though something was wrong with my radio until I checked the dead bands. The elevator counterbalance would center 1/4 differently from one movement to the next!

Funny thing is, we see a lot of 5242 non-love we see around here, but once I set my dead bands, those servos have been golden for me. They center precisely, and I get no stalling or blowback. Unless you are going to fly harder than I do, I just can't see a need for $100 servos in these planes.

However, just for the hell of it, on my 60" Laser I just might try some of those gold plated servos
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Old Jan 20, 2013, 12:39 PM
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United Kingdom, London
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i think one of the reasons why those gold plated servos are more desirable is that they would be much more tolerant to less than perfect setup? i would really, really, really love to put savox 1250 in my edge (and save 7245 for laser or mxs) but seing as they seemed just enough for a 57", im kinda scared...
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Old Jan 20, 2013, 01:01 PM
Wherever you go there you are
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United States, MN, Minneapolis
Joined Nov 2011
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I've thought about creating a pdf/video tutorial of using the hitec programmer for the ultimate setup. However, there is always a point of diminnishing returns, and as time consuming as the process is, and the number of different possible forks in the road as there are, creating a general RC audience pdf/video tutorial is a *LOT* of work. Maybe sometime this summer.

Meanwhile, we should all be greatful for people like DocAustin, and many other rcgroup users, who do take the time to share their knowledge.
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Old Jan 20, 2013, 01:25 PM
Got the Slickness
gabrielisrael's Avatar
Seattle, WA
Joined Jul 2010
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Quote:
Originally Posted by LoneWolfRC View Post
I've thought about creating a pdf/video tutorial of using the hitec programmer for the ultimate setup. However, there is always a point of diminnishing returns, and as time consuming as the process is, and the number of different possible forks in the road as there are, creating a general RC audience pdf/video tutorial is a *LOT* of work. Maybe sometime this summer.

Meanwhile, we should all be greatful for people like DocAustin, and many other rcgroup users, who do take the time to share their knowledge.
Is there anything else we should be modifying with the Hitec Programmer besides the deadband width that would not be a factory default setup?
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Old Jan 20, 2013, 01:27 PM
On loan to Texas
Ohio AV8TOR's Avatar
United States, TX, Benbrook
Joined Oct 2005
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Originally Posted by LoneWolfRC View Post
I've thought about creating a pdf/video tutorial of using the hitec programmer for the ultimate setup.
Please do as I have been searching and not much out there.
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Old Jan 20, 2013, 01:51 PM
bryansifsof44's Avatar
United States, AK, Anchorage
Joined Oct 2011
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Quote:
Originally Posted by Doc Austin View Post
That's where I set mine.

Funny thing is, we see a lot of 5242 non-love we see around here, but once I set my dead bands, those servos have been golden for me. They center precisely, and I get no stalling or blowback. Unkess you are going to fly harder than I do, I just can't see a need for $100 servos in these planes.

However, just for the hell of it, on my 60" Laser I just might try some of those gold plated servos
Have you ever seen the servos operate next to each other? The 7245s make the 5245s look very doggy. The 7245s are faster, stronger and more precise. My 60" edge's roll rates are way faster then my flying partners at WOT... And I don't think it's because mine is RWB and he has the BY. I assume he is getting some blowback at WOT.... But they work fine for him. For me I wouldn't settle for anything other then HV in a 60" EXP.

Edit: there not just cold plated
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Old Jan 20, 2013, 02:34 PM
Wherever you go there you are
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United States, MN, Minneapolis
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Quote:
Originally Posted by gabrielisrael View Post
Is there anything else we should be modifying with the Hitec Programmer besides the deadband width that would not be a factory default setup?
Many very good pilots only mess with the deadbands. I'm not a very good pilot, so I try for perfection in servo setup. (I think I first achieved in on my 48" MXS).

Others have reported, and it makes sense to me, that it's a good idea to setup those programmable servos that have the option to reduce power in the event of over current. Not all of the programmable servos have this feature, though. The 5245 do not if I remember correctly, but the 7245s do.

Another thing you can do is set up your ailerons and rudder for symmetrical defelections for symmetrical throws. This probably makes the most sense on the ailerons and rudders. Doing this is complicated, however, by both the hitec software, and what they consider 0, versus what your radio considers 0.

That issue aside, the easiest scenerio is when your control surface control horn hole for the control horn is perpindicular to the hinge line. In this case, set your 0 for the servo arm to be 90 degrees, and then you should be able to set your zero and end points even without a programmer.

For this reason, I personally try to not install control surface control arms in until after I have CA'd the hinges. That way, I can trim the control surface control arms if necessary to try to get the holes over the hinge line.

If for whatever reason that is not the case, what follows is speculative on my part, but I think DJMoose has said this is true somewhere if I remember correctly (I just haven't done the math to verify it). If the control surface control horn hole is not over the hinge line, that is, that the hinge to hole angle is not 90 degrees, adjust the zero of ther servo control arm to be the same angle. I suspect this is about right, but like I said, I haven't done the math to verify that it is always true. For example, there might be an angle offset based on the lengths of the control surface control horn hole to hinge line length, when that length differs from the servo arm hole in use to servo arm mounting screw length. I usually end up doing trial and error here in practice, and it is time consuming, frustrating, and one of the issues where the law of diminishing returns probably applies. There are a finite number of splines on the servo control arm, and this is where programming a new center at the servo can help. This is where some nice diagrams and a bit of time with some trig. will come in useful.

But since the PWM for zero used by the hitec programmer probably differs from your radio (it does for Spektrum), this is also a time consuming process. This summer I plan to measure the PW of the hitec programmer zero, and compare it to various spektrum receivers, and see if there is any consistency and and a consistent offset error. Such a measurment, if it is consistent, will reduce some of the frustration. Similar measurments would be necessary with hitec, futuba, etc., receivers.

Quote:
Originally Posted by Ohio AV8TOR View Post
Please do as I have been searching and not much out there.
It will be tough, as my rambling paragraph above alludes to. And, I think most people aren't so anal about the servo setup. I am, because I want to know that all of my bad flying is my fault
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Old Jan 20, 2013, 04:19 PM
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Burke, VA
Joined Sep 2009
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Quote:
Originally Posted by LoneWolfRC View Post
Many very good pilots only mess with the deadbands. I'm not a very good pilot, so I try for perfection in servo setup. (I think I first achieved in on my 48" MXS).

Others have reported, and it makes sense to me, that it's a good idea to setup those programmable servos that have the option to reduce power in the event of over current. Not all of the programmable servos have this feature, though. The 5245 do not if I remember correctly, but the 7245s do.

Another think you can do is set up your ailerons and rudder for symmetrical defelections for symmetrical throws. This probably makes the most sense on the ailerons and rudders. Doing this is complicated, however, by both the hitec software, and what they consider 0, versus what your radio considers 0.

That issue aside, the easiest scenerio is when your control surface control horn hole for the control horn is perpindicular to the hinge line. In this case, set your 0 for the servo arm to be 90 degrees, and then you should be able to set your zero and end points even without a programmer.

For this reason, I personally try to not install control surface control arms in until after I have CA'd the hinges. That way, I can trim the control surface control arms if necessary to try to get the holes over the hinge line.

If for whatever reason that is not the case, what follows is speculative on my part, but I think DJMoose has said this is true somewhere if I remember correctly (I just haven't done the math to verify it). If the control surface control horn hole is not over the hinge line, that is, that the hinge to hole angle is not 90 degrees, adjust the zero of ther servo control arm to be the same angle. I suspect this is about right, but like I said, I haven't done the math to verify that it is always true. For example, there might be an angle offset based on the lengths of the control surface control horn hole to hinge line length, when that length differs from the servo arm hole in use to servo arm mounting screw length. I usually end up doing trial and error here in practice, and it is time consuming, frustrating, and one of the issues where the law of diminishing returns might. There are a finite number of splines on the servo control arm, and this is where programming a new center at the servo can help. This is where some nice diagrams and a bit of time with some trig. will come in useful.

But since the PWM for zero used by the hitec programmer probably differs from your radio (it does for Spektrum), this is also a time consuming process. This summer I plan to measure the PW of the hitec programmer zero, and compare it to various spektrum receivers, and see if there is any consistency and and a consistent offset error. Such a measurment, if it is consistent, will reduce some of the frustration. Similar measurments would be necessary with hitec, futuba, etc., receivers.



It will be tough, as my rambling paragraph above alludes to. And, I think most people aren't so anal about the servo setup. I am, because I want to know that all of my bad flying is my fault
You can sure tell it's January in Minnesota.
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Old Jan 20, 2013, 04:29 PM
Facts, Logic, 3D
Tom K.'s Avatar
Florida
Joined Nov 2010
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I like the way my Savox servos center

--Tom K.
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Old Jan 20, 2013, 05:19 PM
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United States, AK, Anchorage
Joined Oct 2011
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Tom what are you using in your 60" EXPs? Do they have anything close to the spec of the 7245's 89oz-in @ .11sec/60deg or the JR 3711HV's 86oz-in @ .13sec/60deg?
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Old Jan 20, 2013, 07:12 PM
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Ohio AV8TOR's Avatar
United States, TX, Benbrook
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I believe that Tom is running SH-1250MG's
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Old Jan 20, 2013, 07:26 PM
Facts, Logic, 3D
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Florida
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Quote:
Originally Posted by bryansifsof44 View Post
Tom what are you using in your 60" EXPs? Do they have anything close to the spec of the 7245's 89oz-in @ .11sec/60deg or the JR 3711HV's 86oz-in @ .13sec/60deg?
I'm running the SH-1250MG servos. There is a bit of blowback on them at high speeds, however if you're not hell bent on doing full throttle stuff constantly, they work fine in the Edge and I've been running them issue-free since December 2011 or January 2012... I forget exactly when I maidened it. To answer your question, no there isn't a Savox servo in this size that matches those specifications unless you want to go to standard size and carve the guts out of your wings to get them to fit. To be completely honest, I normally don't recommend any Savox servos for the 60" planes simply because the torque is on the low end of the spectrum for servos in this size, and if I recommend it and somebody has an issue with blow back and is dis-satisfied with spending $60 for a servo that has a relatively low torque rating, that's not good for anybody. However, that is what I run in my 60" Edge, it's what I've been running, and they're digital and center well even after a year of use.

Plus, all the videos of my 60" Edge is with that setup, so you can see it for yourself

Tom Kitt - Extreme Flight Edge 540T EXP__First Flight In A While (5 min 2 sec)


--Tom K.
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Old Jan 20, 2013, 07:30 PM
bryansifsof44's Avatar
United States, AK, Anchorage
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Originally Posted by Tom K. View Post
I'm running the SH-1250MG servos. There is a bit of blowback on them at high speeds, however if you're not hell bent on doing full throttle stuff constantly, they work fine in the Edge and I've been running them issue-free since December 2011 or January 2012... I forget exactly when I maidened it. To answer your question, no there isn't a Savox servo in this size that matches those specifications unless you want to go to standard size and carve the guts out of your wings to get them to fit. To be completely honest, I normally don't recommend any Savox servos for the 60" planes simply because the torque is on the low end of the spectrum for servos in this size, and if I recommend it and somebody has an issue with blow back and is dis-satisfied with spending $60 for a servo that has a relatively low torque rating, that's not good for anybody. However, that is what I run in my 60" Edge, it's what I've been running, and they're digital and center well even after a year of use.

Plus, all the videos of my 60" Edge is with that setup, so you can see it for yourself

http://www.youtube.com/watch?v=GOhSWJl6nRE

--Tom K.
Bet you would really enjoy a HV servo in the 60... world of difference. Nice flying BTW.
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Old Jan 20, 2013, 07:34 PM
Wherever you go there you are
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United States, MN, Minneapolis
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The 5245s have 76 oz-in at 6V, the 1250's have 63.9 oz-in at 6V. And the 5245s are a lot cheaper.

I'm not opposed to savox, have some in one of my planes...love the fact that the ones I have are available via amazon.

Just looking at the numbers.
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