SU27 Control Surface Setup for ARF
03-04-2009, 07:51 AM
#1
Thread Starter
SU27 Control Surface Setup for ARF
I just received a [link=http://www.nitroplanes.com/4-ch-russian-knight-su-27-.html]Nitro Planes SU-27 Flanker ARF [/link] yesterday and laid parts out to see what is entailed in assembly. Looks pretty straight forth, however, the manual seems more specific to an RTF which is already set up to fly meaning Rx is included with the plane and already wired and installed in the fuselage. There is also a radio Tx included with the RTF version that is not included with the ARF version. I opted for the ARF verison in order to use my own radio which I am comfortable with which includes many key features such as dual rates and exponential controls not customarily seen on the RTF radios. In laying out the wiring, it is not difficult to figure out which wires connect to which channels on my Rx unit but labelling the wires would not be a bad idea especially for the novice.
As for control throw limits and main reason for my post, there is nothing in the manual anywhere to specify what the throws are normally set to for starting out and for aerodynamics. For anyone that flies, we all know that there can be a huge difference in controlability based on where the control surface deflection is set to start. I can only assume that 3/16 deflection up and down on low rate should suffice with higher deflection for high rate but a diagram or notes would be a big help and takes nothign for the company making this model to include.
It appears that there is no rudder control for this plane aside from the steerign front wheel and I also assume that there is no mixing of channels as in flapperon or elevon. If there is any requirement or recommednation that I might have overlooked, please let me know.
As for control throw limits and main reason for my post, there is nothing in the manual anywhere to specify what the throws are normally set to for starting out and for aerodynamics. For anyone that flies, we all know that there can be a huge difference in controlability based on where the control surface deflection is set to start. I can only assume that 3/16 deflection up and down on low rate should suffice with higher deflection for high rate but a diagram or notes would be a big help and takes nothign for the company making this model to include.
It appears that there is no rudder control for this plane aside from the steerign front wheel and I also assume that there is no mixing of channels as in flapperon or elevon. If there is any requirement or recommednation that I might have overlooked, please let me know.
03-04-2009, 12:54 PM
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RE: SU27 Control Surface Setup for ARF
Re: Setup
You want about 8mm of deflection up and 6mm of deflection down.
If your radio has Expo ( recommended! ) you could use a bit more deflection, about 10-12mm up and 8mm down.
If you have Expo set your low rates to give you about 7-8 mm and 10-12mm at high rates, with about 35% and 50% expo respectively.
Take off with low rates and trim the plane out before you play with high rates.
Re: Mixing
Your TX must be set for Elevon mixing.
The RTF version of the plane has the right wing plugged into channel 1 and the left wing into channel 2.
The included TX then has a switch for Elevon mixing.
Most second party TX's put the left wing on a different channel, typically channel 6, so bear this in mind... however how you go about this depends upon your TX.
BTW: What your doing is IMHO the best way to deal with these EDF's.
Your radio will provide much better control and reliability than the one that is packed in the RTF units.
Re: Rudder
Nope, this is what I term a "strange Delta" flyer, which uses only two control surface servos.
In spite of this it flies pretty well.
Be sure the throughly check out and run up the two EDF's in your plane before you fly it.
Re: Starting out
Make sure that the elevator control surface trailing edge ( T.E. ) lies level or oh so slightly above the elevator plane on both sides with your stick centered. They should be even with each other... in effect you want just about or LESS than the thickness of the foam in up elevator deflection as seen at the trailing edge.
The ailerons should be level with the fuselage/wing root contours as with any other plane.
You want about 8mm of deflection up and 6mm of deflection down.
If your radio has Expo ( recommended! ) you could use a bit more deflection, about 10-12mm up and 8mm down.
If you have Expo set your low rates to give you about 7-8 mm and 10-12mm at high rates, with about 35% and 50% expo respectively.
Take off with low rates and trim the plane out before you play with high rates.
Re: Mixing
Your TX must be set for Elevon mixing.
The RTF version of the plane has the right wing plugged into channel 1 and the left wing into channel 2.
The included TX then has a switch for Elevon mixing.
Most second party TX's put the left wing on a different channel, typically channel 6, so bear this in mind... however how you go about this depends upon your TX.
BTW: What your doing is IMHO the best way to deal with these EDF's.
Your radio will provide much better control and reliability than the one that is packed in the RTF units.
Re: Rudder
Nope, this is what I term a "strange Delta" flyer, which uses only two control surface servos.
In spite of this it flies pretty well.
Be sure the throughly check out and run up the two EDF's in your plane before you fly it.
Re: Starting out
Make sure that the elevator control surface trailing edge ( T.E. ) lies level or oh so slightly above the elevator plane on both sides with your stick centered. They should be even with each other... in effect you want just about or LESS than the thickness of the foam in up elevator deflection as seen at the trailing edge.
The ailerons should be level with the fuselage/wing root contours as with any other plane.
03-04-2009, 01:07 PM
#3
Thread Starter
RE: SU27 Control Surface Setup for ARF
Wow I am going to print this out and post it above me as I work. I have been flying for many years and knew there had to be some mixing just from looking at this. The instructions really ought to include this as I would not know.
Anyway, I am using a Futaba 6EXA which has dual rates and exponential. For Futaba, exponential is negative where other Tx units may be positive. So you are saying 35% Expo on low rate and upward of 50% on high rate or are you talking about the percentage of throw to set up on full and low rate. I really want to make sure and clarify this. 7-8mm and 10 - 12mm on high and low rate is easy enough by setting the dual rate high or low to get the right throw. I have not used 50% Expo though.
As long as we are getting into the nitty gritty, I have a Hitec Supreme 8 channel Rx and Futaba 6EXA Tx as mentioned. I can use channel 6 for left wing (flaps) and run the right wing to channel 1 (standard Airleron). Note the two wings are routed to a single plug so i will have to remove the Y connector and then connect these separately as noted?
Elevators are also run in parallel through a Y conenctor and I assume goto channel 2 (elevator)
I will of course refer to the Futaba instructions but again want to be sure with an expert on this before doign anything. I did by the way run the battery and motors to cycle them. I assume 2 -3 times should adequatley condition this battery.
I did note that there is a 2200 Mah hour battery and wondered about upgrades to this mainly along the lines of the 2200 20C batteries that are on sale on NitroPlanes. I know I will want a spare battery but the higher C rate I assume out to give this thing more push and perhaps better flight time. Any advice for upgrading that won't have me bruning out parts.
Thanks in advance
Andy F.
Anyway, I am using a Futaba 6EXA which has dual rates and exponential. For Futaba, exponential is negative where other Tx units may be positive. So you are saying 35% Expo on low rate and upward of 50% on high rate or are you talking about the percentage of throw to set up on full and low rate. I really want to make sure and clarify this. 7-8mm and 10 - 12mm on high and low rate is easy enough by setting the dual rate high or low to get the right throw. I have not used 50% Expo though.
As long as we are getting into the nitty gritty, I have a Hitec Supreme 8 channel Rx and Futaba 6EXA Tx as mentioned. I can use channel 6 for left wing (flaps) and run the right wing to channel 1 (standard Airleron). Note the two wings are routed to a single plug so i will have to remove the Y connector and then connect these separately as noted?
Elevators are also run in parallel through a Y conenctor and I assume goto channel 2 (elevator)
I will of course refer to the Futaba instructions but again want to be sure with an expert on this before doign anything. I did by the way run the battery and motors to cycle them. I assume 2 -3 times should adequatley condition this battery.
I did note that there is a 2200 Mah hour battery and wondered about upgrades to this mainly along the lines of the 2200 20C batteries that are on sale on NitroPlanes. I know I will want a spare battery but the higher C rate I assume out to give this thing more push and perhaps better flight time. Any advice for upgrading that won't have me bruning out parts.
Thanks in advance
Andy F.
03-04-2009, 01:26 PM
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RE: SU27 Control Surface Setup for ARF
WARNING BELOW: I made a mistake!
Unfortunately mixing is dependant upon your radio so the instructions on most ARF's leave this to you.
Since you are using a Futaba I'm talking about -35% expo on low rates and -50% expo on high rates.
This is different than "throw" or surface deflection, which I gave you separately above... e.g. the 8mm, etc.
You want the control surface to deflect UP AND DOWN by 7-8 mm when your TX is set to low rates and 10-12mm when the TX is set to high rates.
Likewise you want 35% expo on low rates and 50% expo on high rates respectively.
Remember Expo is a mechanism to compensate for the fact that you have a server that provides circular motion, while driving a linear rod.
That means ( remember your Geometry? ) that the rod moves SLOWER or to put it another way, your control surfaces move SLOWER as your TX stick approaches the extremes of movement, while the rod moves faster when the stick is close to center.
In effect slight stick movements around center cause much bigger deflection changes of the control surface.
Expo compensates for this. 50% produces a LINEAR correspondence of your control surface to your stick giving you nice smooth control.
However "Throws" ( or control surface deflection, AKA "end point adjustment" ) is not the same as Expo.
Normally the more deflection you have, the more you want the movement around center equalized.
I'm sorry I have several of the NP planes and I was getting yours confused for a moment with the Mig-29.
No on yours you can leave the ailerons on the single channel. I forgot that your has separate elevator servos and that one is already reversed.
You can leave the wings on channel 1 and the elevator on channel 2 as is standard.
WARNING: - I had the Delta winged Mig-29 configuration in mind when I first spoke about elevon mixing, you - DO NOT - need Elevon mixing with this plane, nor would it work. WARNING! Danger Will Robinson! Danger!
The throws and expo info is still all applicable.
Yup, good move!
Please PM me on the latter.
ORIGINAL: afioretti
The instructions really ought to include this as I would not know.
The instructions really ought to include this as I would not know.
ORIGINAL: afioretti
For Futaba, exponential is negative where other Tx units may be positive. So you are saying 35% Expo on low rate and upward of 50% on high rate or are you talking about the percentage of throw to set up on full and low rate.
For Futaba, exponential is negative where other Tx units may be positive. So you are saying 35% Expo on low rate and upward of 50% on high rate or are you talking about the percentage of throw to set up on full and low rate.
This is different than "throw" or surface deflection, which I gave you separately above... e.g. the 8mm, etc.
ORIGINAL: afioretti
7-8mm and 10 - 12mm on high and low rate is easy enough by setting the dual rate high or low to get the right throw. I have not used 50% Expo though.
7-8mm and 10 - 12mm on high and low rate is easy enough by setting the dual rate high or low to get the right throw. I have not used 50% Expo though.
Likewise you want 35% expo on low rates and 50% expo on high rates respectively.
Remember Expo is a mechanism to compensate for the fact that you have a server that provides circular motion, while driving a linear rod.
That means ( remember your Geometry? ) that the rod moves SLOWER or to put it another way, your control surfaces move SLOWER as your TX stick approaches the extremes of movement, while the rod moves faster when the stick is close to center.
In effect slight stick movements around center cause much bigger deflection changes of the control surface.
Expo compensates for this. 50% produces a LINEAR correspondence of your control surface to your stick giving you nice smooth control.
However "Throws" ( or control surface deflection, AKA "end point adjustment" ) is not the same as Expo.
Normally the more deflection you have, the more you want the movement around center equalized.
ORIGINAL: afioretti
As long as we are getting into the nitty gritty, I have a Hitec Supreme 8 channel Rx and Futaba 6exa Tx as mentioned. I can use channel 6 for left wing (flaps) and run the right wing to channel 1 (standard Airleron). Note the two wings are routed to a single plug so i will have to remove the Y connector and then connect these separately as noted?
Elevators are also run in parallel through a Y conenctor and I assume got to channel 2 (elevator)
As long as we are getting into the nitty gritty, I have a Hitec Supreme 8 channel Rx and Futaba 6exa Tx as mentioned. I can use channel 6 for left wing (flaps) and run the right wing to channel 1 (standard Airleron). Note the two wings are routed to a single plug so i will have to remove the Y connector and then connect these separately as noted?
Elevators are also run in parallel through a Y conenctor and I assume got to channel 2 (elevator)
No on yours you can leave the ailerons on the single channel. I forgot that your has separate elevator servos and that one is already reversed.
You can leave the wings on channel 1 and the elevator on channel 2 as is standard.
WARNING: - I had the Delta winged Mig-29 configuration in mind when I first spoke about elevon mixing, you - DO NOT - need Elevon mixing with this plane, nor would it work. WARNING! Danger Will Robinson! Danger!
The throws and expo info is still all applicable.
ORIGINAL: afioretti
I will of course refer to the Futaba instructions but again want to be sure with an expert on this before doign anythign. I did by the way run the battery and motors to cycle them. I assume 2 -3 times shoudl adequatley condition this battery.
I will of course refer to the Futaba instructions but again want to be sure with an expert on this before doign anythign. I did by the way run the battery and motors to cycle them. I assume 2 -3 times shoudl adequatley condition this battery.
ORIGINAL: afioretti
I did note that there is a 2200 Mah hour battery and wondered about upgrades to this mainly along the lines of the 2200 20C batteries that are on sale on NitroPlanes. I know I will want a spare battery but the higher C rate I assuem out to give this thing more push and perhaps better flight time. Any advice for upgrading that won't have me bruning out parts.
Thanks in advance
Andy F.
I did note that there is a 2200 Mah hour battery and wondered about upgrades to this mainly along the lines of the 2200 20C batteries that are on sale on NitroPlanes. I know I will want a spare battery but the higher C rate I assuem out to give this thing more push and perhaps better flight time. Any advice for upgrading that won't have me bruning out parts.
Thanks in advance
Andy F.
Please PM me on the latter.
03-04-2009, 01:35 PM
#5
Thread Starter
RE: SU27 Control Surface Setup for ARF
I read your response and will acknolwedge this here. I thought I was reading you right about the EXP settings. 35 - 50% says this sucker must be a real handful with the standard Tx that comes with the plane. The other thing is to have slight upward elevation when trimmed such that there is about 1/2 the stab thickness adjusted up. This is helful to know as I would naturally send off with all surfaces flush along the bottom of the wings.
Now that we are over that hurdle... NO ELEVON mixing. Will not do.
How about batteries? 2200 that comes with it sounds like it is abotu a 5 C but I realy do not know. Is 2200 20 C a nice starting point? I woudl have to modifiy the openign some to accept the larger pack but this all seems reasonable. Do you think the stock circuitry , ie. ESC and motors would tolerate a 3000 MAh pack?
Now that we are over that hurdle... NO ELEVON mixing. Will not do.
How about batteries? 2200 that comes with it sounds like it is abotu a 5 C but I realy do not know. Is 2200 20 C a nice starting point? I woudl have to modifiy the openign some to accept the larger pack but this all seems reasonable. Do you think the stock circuitry , ie. ESC and motors would tolerate a 3000 MAh pack?
03-04-2009, 01:39 PM
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RE: SU27 Control Surface Setup for ARF
ORIGINAL: afioretti
I thought I was reading you right about the EXP settings. 35 - 50% says this sucker must be a real handful with the standard Tx that comes with the plane.
I thought I was reading you right about the EXP settings. 35 - 50% says this sucker must be a real handful with the standard Tx that comes with the plane.
ORIGINAL: afioretti
How about batteries? 2200 that comes with it sounds like it is abotu a 5 C but I realy do not know. Is 2200 20 C a nice starting point? I woudl have to modifiy the openign some to accept the larger pack but this all seems reasonable. Do you think the stock circuitry , ie. ESC and motors would tolerate a 3000 MAh pack?
How about batteries? 2200 that comes with it sounds like it is abotu a 5 C but I realy do not know. Is 2200 20 C a nice starting point? I woudl have to modifiy the openign some to accept the larger pack but this all seems reasonable. Do you think the stock circuitry , ie. ESC and motors would tolerate a 3000 MAh pack?
Click on my Name on the left and select the PM balloon.
03-08-2009, 08:31 AM
#9
Thread Starter
RE: SU27 Control Surface Setup for ARF
Well for anyone reading this, I set up the radio as told by the sysop here. If you have your own radio with Exponential and Dual Rates, you'll want it and it will make flying fun.
I have to say that there is no way I would ever try and hand launch this plane as some have reported doing or trying. I tried running this plane down a bare grass hill and still could not pick up enough speed to get off the ground. I finally opted for a school yard parking lot near me and used up a good 200 feet of pavement before this plane picked up off the ground. Once up, the thing was stable and responsive.
I have been flying gas airplanes for many years and asked many questions about this before flying. I would not recommend this plane to a first time flyer.
The manual is real bad for those who may want to use their own radio.
For my plane, I am using a Futaba 6exa radio and Hitec 8 channel Rx. Please note EXP on Futaba is negative (-)
Here is how I set this plane up to fly first time:
No mixing of control surfaces.
Ailerons set to 5 - 8mm lo rate and 10 - 12mm hi rate > channel 1 standard
Elevator same deflection but set elevator slightly up to start (thickness of stab) > Channel 2 standard
Channel 3 ESC control (throttle)
Channel 4 > steering nose wheel (no rudder on this plane)
EXP -30 Lo rate
EXP - 50 Hi rate
The only change I have made is to jack up the deflection of the ailerons (hi rate) to get a little more response but this up to the pilot
Landing is real stable. No need to land this thing at full go. Flight time for me was more than 8 minutes as I was able to take off twice on one charge.
Recommendation
: I have flown some hot airplanes and this is by far one exhilarating ride. Get some higher cap batteries to get more speed (20C)
I have to say that there is no way I would ever try and hand launch this plane as some have reported doing or trying. I tried running this plane down a bare grass hill and still could not pick up enough speed to get off the ground. I finally opted for a school yard parking lot near me and used up a good 200 feet of pavement before this plane picked up off the ground. Once up, the thing was stable and responsive.
I have been flying gas airplanes for many years and asked many questions about this before flying. I would not recommend this plane to a first time flyer.
The manual is real bad for those who may want to use their own radio.
For my plane, I am using a Futaba 6exa radio and Hitec 8 channel Rx. Please note EXP on Futaba is negative (-)
Here is how I set this plane up to fly first time:
No mixing of control surfaces.
Ailerons set to 5 - 8mm lo rate and 10 - 12mm hi rate > channel 1 standard
Elevator same deflection but set elevator slightly up to start (thickness of stab) > Channel 2 standard
Channel 3 ESC control (throttle)
Channel 4 > steering nose wheel (no rudder on this plane)
EXP -30 Lo rate
EXP - 50 Hi rate
The only change I have made is to jack up the deflection of the ailerons (hi rate) to get a little more response but this up to the pilot
Landing is real stable. No need to land this thing at full go. Flight time for me was more than 8 minutes as I was able to take off twice on one charge.
Recommendation
: I have flown some hot airplanes and this is by far one exhilarating ride. Get some higher cap batteries to get more speed (20C) 