elevator servos on a y-harness?
01-09-2007, 07:35 PM
#3
RE: elevator servos on a y-harness?
Plug the Y-harness into the RX and run a seperate extension out to each servo.
If you plug one servo extension into the RX and run it all the way down into the tail and THEN plug in your Y-harness-----it's possible you could be starving both servos for power and signal. This is because your asking only one extension to carry all the signal and power to run both servos---and your asking it to do it over a very long distance.
Better way is to use a heavy duty Y and plug it right into the RX. Then run a seperate extension down the fuse to power each servo. That way the Y only has to carry the signal and power a short distance before it gets split out into each individual servo extension. The Y will carry the voltage and signal that short distance.
It's just like a battery lead. They don't necessarily need to be huge 10ga wires, because it's only pushing the voltage a very short distance before it hits the receiver buss.
Plug your 50 gallon portable air compressor into a 200' extension cord and see if it will kick on when the pressure in the tank drops to 80PSI. It won't, because the voltage drop through 200' of extension cord is massive. Not even enough left to kick the electric motor on after 200' of cord and resistance.
Now plug the air compressor straight into the wall outlet and run a 200' air hose. What changed? It kicks on when you need it. AND--you don't suffer any pressure drop through 200' of air hose.
[sm=idea.gif]
If you plug one servo extension into the RX and run it all the way down into the tail and THEN plug in your Y-harness-----it's possible you could be starving both servos for power and signal. This is because your asking only one extension to carry all the signal and power to run both servos---and your asking it to do it over a very long distance.
Better way is to use a heavy duty Y and plug it right into the RX. Then run a seperate extension down the fuse to power each servo. That way the Y only has to carry the signal and power a short distance before it gets split out into each individual servo extension. The Y will carry the voltage and signal that short distance.
It's just like a battery lead. They don't necessarily need to be huge 10ga wires, because it's only pushing the voltage a very short distance before it hits the receiver buss.
Plug your 50 gallon portable air compressor into a 200' extension cord and see if it will kick on when the pressure in the tank drops to 80PSI. It won't, because the voltage drop through 200' of extension cord is massive. Not even enough left to kick the electric motor on after 200' of cord and resistance.
Now plug the air compressor straight into the wall outlet and run a 200' air hose. What changed? It kicks on when you need it. AND--you don't suffer any pressure drop through 200' of air hose.
[sm=idea.gif]
01-09-2007, 08:48 PM
#4
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RE: elevator servos on a y-harness?
ORIGINAL: Rcpilet
Plug the Y-harness into the RX and run a seperate extension out to each servo.
If you plug one servo extension into the RX and run it all the way down into the tail and THEN plug in your Y-harness-----it's possible you could be starving both servos for power and signal. This is because your asking only one extension to carry all the signal and power to run both servos---and your asking it to do it over a very long distance.
Better way is to use a heavy duty Y and plug it right into the RX. Then run a seperate extension down the fuse to power each servo. That way the Y only has to carry the signal and power a short distance before it gets split out into each individual servo extension. The Y will carry the voltage and signal that short distance.
It's just like a battery lead. They don't necessarily need to be huge 10ga wires, because it's only pushing the voltage a very short distance before it hits the receiver buss.
Plug your 50 gallon portable air compressor into a 200' extension cord and see if it will kick on when the pressure in the tank drops to 80PSI. It won't, because the voltage drop through 200' of extension cord is massive. Not even enough left to kick the electric motor on after 200' of cord and resistance.
Now plug the air compressor straight into the wall outlet and run a 200' air hose. What changed? It kicks on when you need it. AND--you don't suffer any pressure drop through 200' of air hose.
[sm=idea.gif]
Plug the Y-harness into the RX and run a seperate extension out to each servo.
If you plug one servo extension into the RX and run it all the way down into the tail and THEN plug in your Y-harness-----it's possible you could be starving both servos for power and signal. This is because your asking only one extension to carry all the signal and power to run both servos---and your asking it to do it over a very long distance.
Better way is to use a heavy duty Y and plug it right into the RX. Then run a seperate extension down the fuse to power each servo. That way the Y only has to carry the signal and power a short distance before it gets split out into each individual servo extension. The Y will carry the voltage and signal that short distance.
It's just like a battery lead. They don't necessarily need to be huge 10ga wires, because it's only pushing the voltage a very short distance before it hits the receiver buss.
Plug your 50 gallon portable air compressor into a 200' extension cord and see if it will kick on when the pressure in the tank drops to 80PSI. It won't, because the voltage drop through 200' of extension cord is massive. Not even enough left to kick the electric motor on after 200' of cord and resistance.
Now plug the air compressor straight into the wall outlet and run a 200' air hose. What changed? It kicks on when you need it. AND--you don't suffer any pressure drop through 200' of air hose.
[sm=idea.gif]
Not sure how much I agree with this, the bottleneck is still going to be the single connector feeding two high current servos.
personally I think that all "Y" connectors should be banned. Is there any reason why you can't work around using one?
Shawn
01-09-2007, 09:22 PM
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RE: elevator servos on a y-harness?
Im trying to figure out how im going to use one reciever two batteries on my 35% 260 and fit everything on the one reciever.ill have a choke servo throttle servo two on each wing one on the rudder one on each elevator .
01-09-2007, 09:23 PM
#6
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RE: elevator servos on a y-harness?
If you don't have a computer radio where you can mix the two elevator halves, I'd suggest using two programable servos.
Even if you overcome the signal loss or tother short coming of Y-harnesses, you won't have anyway to match the elevator halves other than mechanical linkages or arm adjustment. Either of which will not allow you to match the travel of the halves to be equal at neutral, full up and full down (unless you are very, very, very very lucky
).
What servos are planning on using?
.........Mark
Even if you overcome the signal loss or tother short coming of Y-harnesses, you won't have anyway to match the elevator halves other than mechanical linkages or arm adjustment. Either of which will not allow you to match the travel of the halves to be equal at neutral, full up and full down (unless you are very, very, very very lucky
).What servos are planning on using?
.........Mark
01-09-2007, 09:25 PM
#7
Senior Member
RE: elevator servos on a y-harness?
ORIGINAL: profile540
Im trying to figure out how im going to use one reciever two batteries on my 35% 260 and fit everything on the one reciever.ill have a choke servo throttle servo two on each wing one on the rudder one on each elevator .
Im trying to figure out how im going to use one reciever two batteries on my 35% 260 and fit everything on the one reciever.ill have a choke servo throttle servo two on each wing one on the rudder one on each elevator .
01-09-2007, 09:34 PM
#12
Senior Member
RE: elevator servos on a y-harness?
Do you have the transmitter yet? If so, which one? (Sorry for all the questions but the more info, the easier it is for us to help you with the best set up [sm=thumbup.gif] )
01-09-2007, 09:53 PM
#14
Senior Member
RE: elevator servos on a y-harness?
ORIGINAL: profile540
i have a 9c.
i have a 9c.
Borrow a Hitec programmer if you don't have one. Use GOOD QUALITY "Y" harness in each wing half (See note below) and "Y" the two aileron servos together. Then program the aileron servos to match each other in one of the wing panels. Then do the same to the other wing panel.
Ch 1 - Rt aileron
Ch 2 - Elevator #1
Ch 3 - Throttle
Ch 4 - Rudder
Ch 5 - Elevator #2 (mixed to Ch 2)
Ch 6 - Lt Aileron (mixed to Ch 1 )
Ch 7 - Choke servo
Ch 9 - Battery #1
Batt input or Ch8 (depending on receiver) - Battery #2
Note: What I did to make sure I had the best quality "Y" with the least amount of connectors (i.e. eliminate signal and /or voltage loss), is order custom "Y" harnesses from Radical RC or another good quality supplier. the "Y" harness is built to the exact lengths to make sure you only have one connector at each servo and then to have the male part of the Y just long enough to stick out the wing enough to plug it into a short HD connector at the receiver. If this doesn't make sense, let me know and I can go into more detail.
Hope this helps.........Mark
P.S. I also have a 9C. If you'd like you can send me your campac and I can load my set up from my radio. Then you just plug in the servos and tweak the throws. It's not hard to set up. Just use the manual and take your time.
01-09-2007, 09:57 PM
#15
Senior Member
RE: elevator servos on a y-harness?
" Then program the aileron servos to match each other in one of the wing panels "
(program neutral, full up and and full down to match each other with NO binding).
(program neutral, full up and and full down to match each other with NO binding).
01-09-2007, 10:06 PM
#16
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RE: elevator servos on a y-harness?
thanks this helps alot.....................each battery has its own switch right?i didnt know you could run two batteries on the recieve like that untill recently..........
01-09-2007, 10:25 PM
#17
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RE: elevator servos on a y-harness?
ORIGINAL: profile540
thanks this helps alot.....................each battery has its own switch right?
thanks this helps alot.....................each battery has its own switch right?
Glad to be of help.
Right, each battery must have it's own switch. The bus bar in the receiver (i.e. the positive or negative terminals) are all interconnected throughout the channels. (I just found this out a few years ago myself [X(] )
Also, one thing to mention while I'm thinking about it, some dual/multiple output chargers may give you problems if you charge the batteries at the same time. Most switches only break positive wire going to the battery. During charging, the negative wire is actually connected to the charging battery through the switch wire, into the receiver bus bar and then to the other charging battery. This wire can sometime give a false signal to a peak charger and shut off (or not even let the charge begin.) A friend of mine had this happen with the Hobbico Mark 2 charger. All you would need to do is unplug one of the switches wire going into the receiver to charge it. Just remember to plug it back in before flying.
01-09-2007, 10:32 PM
#18
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RE: elevator servos on a y-harness?
That makes sense i have a sirus quad charger i wonder if it will do the same ill know when i try it.I thought if you hooked up two batteries to the recieve it would give to much voltage to the system.......guess not.
01-09-2007, 10:41 PM
#19
Senior Member
RE: elevator servos on a y-harness?
No, your voltage won't change (assuming the batteries are not somehow hooked up in series as apposed to in parallel).
In other words, if you have two 6 volt batteries (let's say each rated at 1800 mah) and you plug each into the reciever at two separate inputs, you still have 6 volts (batteries are working in parallel with each other), but now you have a total of 3600 mah of flying time, PLUS the needed safety of dual batteries and switches (i.e. if one battery or switch fails, the other one should still be able to power the receiver and servos).
Just remember that before every flight check both batteries with a volt meter and then check both switches. To do this, turn on ONLY ONE switch and wiggle the sticks to make sure the servos move. Now turn off that switch and turn on the other and check for servo power again. If all is okay, turn the other switch back on and go fly.
In other words, if you have two 6 volt batteries (let's say each rated at 1800 mah) and you plug each into the reciever at two separate inputs, you still have 6 volts (batteries are working in parallel with each other), but now you have a total of 3600 mah of flying time, PLUS the needed safety of dual batteries and switches (i.e. if one battery or switch fails, the other one should still be able to power the receiver and servos).
Just remember that before every flight check both batteries with a volt meter and then check both switches. To do this, turn on ONLY ONE switch and wiggle the sticks to make sure the servos move. Now turn off that switch and turn on the other and check for servo power again. If all is okay, turn the other switch back on and go fly.
01-09-2007, 11:29 PM
#20
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RE: elevator servos on a y-harness?
Do you notice any lag between the 2 elevator servos when they are plugged into ch2 and ch8 ? Im trying out some 5955's and was planning on just getting a HD Y and plugging it into ch 2..after programming of course..
01-10-2007, 12:06 AM
#21
RE: elevator servos on a y-harness?
ORIGINAL: SBerkheimer
Not sure how much I agree with this, the bottleneck is still going to be the single connector feeding two high current servos.
personally I think that all "Y" connectors should be banned. Is there any reason why you can't work around using one?
Shawn
ORIGINAL: Rcpilet
Plug the Y-harness into the RX and run a seperate extension out to each servo.
If you plug one servo extension into the RX and run it all the way down into the tail and THEN plug in your Y-harness-----it's possible you could be starving both servos for power and signal. This is because your asking only one extension to carry all the signal and power to run both servos---and your asking it to do it over a very long distance.
Better way is to use a heavy duty Y and plug it right into the RX. Then run a seperate extension down the fuse to power each servo. That way the Y only has to carry the signal and power a short distance before it gets split out into each individual servo extension. The Y will carry the voltage and signal that short distance.
It's just like a battery lead. They don't necessarily need to be huge 10ga wires, because it's only pushing the voltage a very short distance before it hits the receiver buss.
Plug your 50 gallon portable air compressor into a 200' extension cord and see if it will kick on when the pressure in the tank drops to 80PSI. It won't, because the voltage drop through 200' of extension cord is massive. Not even enough left to kick the electric motor on after 200' of cord and resistance.
Now plug the air compressor straight into the wall outlet and run a 200' air hose. What changed? It kicks on when you need it. AND--you don't suffer any pressure drop through 200' of air hose.
[sm=idea.gif]
Plug the Y-harness into the RX and run a seperate extension out to each servo.
If you plug one servo extension into the RX and run it all the way down into the tail and THEN plug in your Y-harness-----it's possible you could be starving both servos for power and signal. This is because your asking only one extension to carry all the signal and power to run both servos---and your asking it to do it over a very long distance.
Better way is to use a heavy duty Y and plug it right into the RX. Then run a seperate extension down the fuse to power each servo. That way the Y only has to carry the signal and power a short distance before it gets split out into each individual servo extension. The Y will carry the voltage and signal that short distance.
It's just like a battery lead. They don't necessarily need to be huge 10ga wires, because it's only pushing the voltage a very short distance before it hits the receiver buss.
Plug your 50 gallon portable air compressor into a 200' extension cord and see if it will kick on when the pressure in the tank drops to 80PSI. It won't, because the voltage drop through 200' of extension cord is massive. Not even enough left to kick the electric motor on after 200' of cord and resistance.
Now plug the air compressor straight into the wall outlet and run a 200' air hose. What changed? It kicks on when you need it. AND--you don't suffer any pressure drop through 200' of air hose.
[sm=idea.gif]
Not sure how much I agree with this, the bottleneck is still going to be the single connector feeding two high current servos.
personally I think that all "Y" connectors should be banned. Is there any reason why you can't work around using one?
Shawn
If you push the signal through 1 servo extension thats 36" long and run it all the way to the back of the plane before you install the Y--then you'll see serious signal/power degradation.
Given his original post and the information contained in that post--I gave him the right answer. He indicated that he wanted to run dual elevator servos off a single channel and wanted to know if he could use a Y. Yes, he could use a Y, but now that we have all the particulars and specifics from profile540--that changes the answer completely. He could do it, but it really wouldn't be the best setup given the other equipment he has selected. (i.e. RX and programable servos)
Now that we know he is using Hitec programmable servos and a big enough RX to handle all the servos and batts--it makes absolute sense to rig it the way OnTheEdge has outlined in posts 14 and 15.
01-10-2007, 12:28 AM
#22
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RE: elevator servos on a y-harness?
ORIGINAL: Josey Wales
Do you notice any lag between the 2 elevator servos when they are plugged into ch2 and ch8 ?
Do you notice any lag between the 2 elevator servos when they are plugged into ch2 and ch8 ?
01-10-2007, 04:18 AM
#23
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RE: elevator servos on a y-harness?
Are the "normal" receivers capable of handling all this current without a power box or power expander?
8-9 digital servos can draw a fair amount of current. As pointed out above, all this current is going through the same bus bar.
I fly Graupner/JR, are any receivers better than others in terms of accepting high currents?
I am building a 96" plane with a MVVS 58, using one aileron servo per wing, one elevator servo in each half, and one servo for the rudder.
These servos will be high torque, probably either JR 8511/8611 or Hitec 5955.
In addition there will be: 1 throttle servo, 1 choke servo and two servos for retracts.
Still not sure if I should use a power box, or just plug everything into the receiver. (I will be using two separate channels for the ailerons, as well as for the elevators)
Magne
8-9 digital servos can draw a fair amount of current. As pointed out above, all this current is going through the same bus bar.
I fly Graupner/JR, are any receivers better than others in terms of accepting high currents?
I am building a 96" plane with a MVVS 58, using one aileron servo per wing, one elevator servo in each half, and one servo for the rudder.
These servos will be high torque, probably either JR 8511/8611 or Hitec 5955.
In addition there will be: 1 throttle servo, 1 choke servo and two servos for retracts.
Still not sure if I should use a power box, or just plug everything into the receiver. (I will be using two separate channels for the ailerons, as well as for the elevators)
Magne
01-10-2007, 09:30 AM
#24
RE: elevator servos on a y-harness?
trying to get two elevators to perfectly match at all speeds and throws requires good rx and you will find that if you use any programmable types - you will likely end up with a mismatch -not much but some
the JR 9 and 10 are good at matching -use the built in mixes
some other brands/models simply don't track.
The best tracking is with the new DX7 - -it feeds info at the same time
a 7 channel radio will do any size model - add a couple of HD Y's and go.
but no y's on elevators - this just messes up tracking on larger planes.
you loose power n signal and if you uses a reverser you typically loose parallel tracking.
for small models with not much power needed - a y can be fine but using servos which hog power -you could really botch things up
One of the worst problems comes with trying to align things using a programmer
as soon as you use different referrence centers on paired servos - you change throws and on expo this usually shows up as lead /lag.
best bet
match a pair of servos with no programming by setting em facing each other on a table -both arms up in the air facing together
they should track exactly . (use the channels you intend to use)
Once this is proven--then install them and leave the fu---- programmer alone
work on the mechanical aspects - linkage and elevator horns.
the JR 9 and 10 are good at matching -use the built in mixes
some other brands/models simply don't track.
The best tracking is with the new DX7 - -it feeds info at the same time
a 7 channel radio will do any size model - add a couple of HD Y's and go.
but no y's on elevators - this just messes up tracking on larger planes.
you loose power n signal and if you uses a reverser you typically loose parallel tracking.
for small models with not much power needed - a y can be fine but using servos which hog power -you could really botch things up
One of the worst problems comes with trying to align things using a programmer
as soon as you use different referrence centers on paired servos - you change throws and on expo this usually shows up as lead /lag.
best bet
match a pair of servos with no programming by setting em facing each other on a table -both arms up in the air facing together
they should track exactly . (use the channels you intend to use)
Once this is proven--then install them and leave the fu---- programmer alone
work on the mechanical aspects - linkage and elevator horns.
01-17-2007, 03:25 AM
#25
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RE: elevator servos on a y-harness?
Thank you, Dick.
I have decided to use the Hitec HS5955 TG on all flying surfaces.
Rx will be a 10ch. JR R1000DS receiver.
Still not sure about the power box, whether it is required or not for this size of model. (????) (WS 96", MVVS 58, about 20 lbs.)
Batteries will be two TP 2100 mAh li-pos, regulated to 6 volts.
Regarding matching servos:
If I use a power box, (in which case it would be a Smart Fly Power Expander) then I have two options regarding the elevator servos.
1. Use two separate channels, and reverse one channel. (Servos in tailplane)
2. Use one channel from the receiver, and use two leads from the same channel on the power expander. Then reverse one of the two Hitec servos using the programming box.
Opinions anyone?
Regards,
Magne
I have decided to use the Hitec HS5955 TG on all flying surfaces.
Rx will be a 10ch. JR R1000DS receiver.
Still not sure about the power box, whether it is required or not for this size of model. (????) (WS 96", MVVS 58, about 20 lbs.)
Batteries will be two TP 2100 mAh li-pos, regulated to 6 volts.
Regarding matching servos:
If I use a power box, (in which case it would be a Smart Fly Power Expander) then I have two options regarding the elevator servos.
1. Use two separate channels, and reverse one channel. (Servos in tailplane)
2. Use one channel from the receiver, and use two leads from the same channel on the power expander. Then reverse one of the two Hitec servos using the programming box.
Opinions anyone?
Regards,
Magne
