Gyro on nose steering question
08-10-2015, 07:03 AM
#4
I have not made a gyro selection yet just gathering information. I have been using gyros in my jets for 3yrs now but never on the nose steering. My normal set up is run a dual rate on the nose steering ch. lots of travel to taxi out and turn into the wind then click to a lower rate for take off run. this has worked for many years. I have a new jet that has been very difficult at times to keep straight so i was looking for something else to help. does the gyro see the low rate and therefore restrict its own movement or is the D/R not a factor in the gyro travel. I have used servo slow before on one jet with a sensitive elev but never on steering although i know someone who sets his up that way.
Thx Vin...
Thx Vin...
08-10-2015, 07:23 AM
#6
I had a 1/9 scale F-15 from FEJ that was very difficult to take off. The main problems were a main gear stance that was too narrow and a nose gear steering system that was too sloppy. Even after modifying the main gear mounts to angle the gear outwards and replacing the POS FEJ nose gear unit with a Robart one, it was very difficult. It wasn't just that the nose steering was sensitive, but that because of the overall geometry of the gear system and the "looseness" of the gear (both mains and nose) the plane would wander during the take off roll and any input to correct it was likely to cause it to "wheelbarrow" with predictably disastrous results.
I put a single axis JR G500a gyro on the nose steering *only* (not the rudders) and that fixed the problem. I actually had the rate on the gyro turned up fairly high, but because the gyro put the input in so quickly and removed it so quickly when the plane reacted, the overall result was that the plane tracked *much* straighter without it. I still used low rates on the nosewheel during take off runs to avoid over steering from my inputs to correct an overall drift that may be caused by wind, or initial lineup, etc.
The gyro was the only thing that made the takeoff run reliable enough to make the plane a daily flyer...
Bob
I put a single axis JR G500a gyro on the nose steering *only* (not the rudders) and that fixed the problem. I actually had the rate on the gyro turned up fairly high, but because the gyro put the input in so quickly and removed it so quickly when the plane reacted, the overall result was that the plane tracked *much* straighter without it. I still used low rates on the nosewheel during take off runs to avoid over steering from my inputs to correct an overall drift that may be caused by wind, or initial lineup, etc.
The gyro was the only thing that made the takeoff run reliable enough to make the plane a daily flyer...
Bob
08-10-2015, 07:34 AM
#7
My Feedback: (57)
I have not made a gyro selection yet just gathering information. I have been using gyros in my jets for 3yrs now but never on the nose steering. My normal set up is run a dual rate on the nose steering ch. lots of travel to taxi out and turn into the wind then click to a lower rate for take off run. this has worked for many years. I have a new jet that has been very difficult at times to keep straight so i was looking for something else to help. does the gyro see the low rate and therefore restrict its own movement or is the D/R not a factor in the gyro travel. I have used servo slow before on one jet with a sensitive elev but never on steering although i know someone who sets his up that way.
Thx Vin...
Thx Vin...
Great minds...
That has been modus operandi for many years as well, and has worked perfectly even for the "squirrely" ones. Can you just reduce your takeoff travel even more or is it a different issue causing the problem, i.e. not centering, loose cables, sloppy trunion, etc.?
08-10-2015, 07:43 AM
#8
I'm using 30% exponential mixed in with rudder to steering mix on my Rafale and it has mitigated the narrow track gear - steering dilemma. Have you tried this yet Vin?
Flew over SVF yesterday around 5 pm what the hell you bunch of babies the weather was perfect.....it's a dry heat ;-)
Flew over SVF yesterday around 5 pm what the hell you bunch of babies the weather was perfect.....it's a dry heat ;-)
08-10-2015, 07:58 AM
#9
If you do install a gyro on the nose make sure you put a mix on it to make the gyro gain zero when gear is retracted or else it will still make corrections on the steering servo. Depending on the aircraft it might not be able to move when the gear is up so it will burn it out.
Even with steering disabled when gear is up the steering servo will continue to make corrections unless you install a mix to make gyro gain zero.
Even with steering disabled when gear is up the steering servo will continue to make corrections unless you install a mix to make gyro gain zero.
08-10-2015, 09:03 AM
#10
[QUOTE=rhklenke;12082419]I had a 1/9 scale F-15 from FEJ that was very difficult to take off. The main problems were a main gear stance that was too narrow and a nose gear steering system that was too sloppy. Even after modifying the main gear mounts to angle the gear outwards and replacing the POS FEJ nose gear unit with a Robart one, it was very difficult. It wasn't just that the nose steering was sensitive, but that because of the overall geometry of the gear system and the "looseness" of the gear (both mains and nose) the plane would wander during the take off roll and any input to correct it was likely to cause it to "wheelbarrow" with predictably disastrous results.
I put a single axis JR G500a gyro on the nose steering *only* (not the rudders) and that fixed the problem. I actually had the rate on the gyro turned up fairly high, but because the gyro put the input in so quickly and removed it so quickly when the plane reacted, the overall result was that the plane tracked *much* straighter without it. I still used low rates on the nosewheel during take off runs to avoid over steering from my inputs to correct an overall drift that may be caused by wind, or initial lineup, etc.
The gyro was the only thing that made the takeoff run reliable enough to make the plane a daily flyer...
Bob[/QUOTE
Hi Bob...I'm kind of dealing with the same thing as your 15. I can go down the runway but anything other than a very minor correction she will wheel barrow. The jet is a 1.35 HE 162. I have the steering cables like guitar strings and I am doing reasonably well with it but to make this a little more dependable I feel like a nose gyro would be a good idea. I was thinking of a simple rate gyro on the nose only. What type of gain setting did you end up with on your 15?
thx Vin...
I put a single axis JR G500a gyro on the nose steering *only* (not the rudders) and that fixed the problem. I actually had the rate on the gyro turned up fairly high, but because the gyro put the input in so quickly and removed it so quickly when the plane reacted, the overall result was that the plane tracked *much* straighter without it. I still used low rates on the nosewheel during take off runs to avoid over steering from my inputs to correct an overall drift that may be caused by wind, or initial lineup, etc.
The gyro was the only thing that made the takeoff run reliable enough to make the plane a daily flyer...
Bob[/QUOTE
Hi Bob...I'm kind of dealing with the same thing as your 15. I can go down the runway but anything other than a very minor correction she will wheel barrow. The jet is a 1.35 HE 162. I have the steering cables like guitar strings and I am doing reasonably well with it but to make this a little more dependable I feel like a nose gyro would be a good idea. I was thinking of a simple rate gyro on the nose only. What type of gain setting did you end up with on your 15?
thx Vin...
08-10-2015, 09:28 AM
#11
Hi Bob...I'm kind of dealing with the same thing as your 15. I can go down the runway but anything other than a very minor correction she will wheel barrow. The jet is a 1.35 HE 162. I have the steering cables like guitar strings and I am doing reasonably well with it but to make this a little more dependable I feel like a nose gyro would be a good idea. I was thinking of a simple rate gyro on the nose only. What type of gain setting did you end up with on your 15?
thx Vin...
thx Vin...
I'm not exactly sure what the final setting was, but I'd guess it was around 50% - in rate mode only, not heading hold. The gain was fairly high in that you could move the nose side-to-side and see quite a bit of movement in the nose steering servo. I eventually sold the plane though, so I can't check it...
I had pull-pull steering as well, and the cables would go slack when the gear was up, so I didn't need to worry about turning the gyro off when the gear come up. Actually, I was using an 8-channel RX in the plane, so I could not adjust the gyro gain in flight (not enough channels) - I just did a couple of experiments on the ground to set it where I needed it and then left it there.
Bob
08-10-2015, 09:29 AM
#12
Hi Vin,
Back in the old days of single channel, rate only gyros, the nose gear steering was a "go to" application. In your case, I would think about a relatively cheap single channel gyro (Futaba 401 or even cheaper), in rate mode on just the nose (with an adjustable gain channel but you could even do without that). That way you are decoupled from the 6 axis gee whiz gyro set up process, if you are using one.
In my experience you can crank the gain up very high, as the normal slop in the nose gear linkage kind of filters out any high frequency oscillation. Maybe with your guitar strings might need a bit lower gain. You can either adjust that with a spare channel or a screwdriver, just do some taxi tests.
As someone said, take care that you know exactly what is happening when airborne (retracted) but in these days of zillion channel radios you can probably just set it up to turn the gain off when retracted.
As Bob indicated these things can cure a lot of ugly steering problems.
Back in the old days of single channel, rate only gyros, the nose gear steering was a "go to" application. In your case, I would think about a relatively cheap single channel gyro (Futaba 401 or even cheaper), in rate mode on just the nose (with an adjustable gain channel but you could even do without that). That way you are decoupled from the 6 axis gee whiz gyro set up process, if you are using one.
In my experience you can crank the gain up very high, as the normal slop in the nose gear linkage kind of filters out any high frequency oscillation. Maybe with your guitar strings might need a bit lower gain. You can either adjust that with a spare channel or a screwdriver, just do some taxi tests.
As someone said, take care that you know exactly what is happening when airborne (retracted) but in these days of zillion channel radios you can probably just set it up to turn the gain off when retracted.
As Bob indicated these things can cure a lot of ugly steering problems.
08-10-2015, 10:06 AM
#13
You will always get the what do you need a gyro for guys. I use a Futaba GY240 for the nose wheel only. I run 100% gain and I do not use heading hold. I do not have it on a mix switch all my planes have cable steering that is loose when retracted. Been running that way for many years. I have it on 3 of my 5 jets.
