Futaba 12 FGA Throttle setup
11-15-2008, 08:42 PM
#1
Senior Member
Thread Starter
My Feedback: (4)
Join Date: Feb 2002
Location: Klamath Falls,
OR
Posts: 277
Likes: 0
Received 0 Likes
on
0 Posts
Futaba 12 FGA Throttle setup
I found something really wierd about the throttle setup for the 12 FG. After setting the end points top and bottom, I noticed that with the throttle stick pulled all the way against the stop on the bottom, the trim lever would have no effect on the throttle servo. It was as if the T3 trim lever was turned off, I could see it moving up and down the scale on the display, but it didn't move the servo at all. After an hour of looking at the manual... (last resort) I accidently discovered that there is a dead band at the bottom of the throttle control. From the stop up about 5-6 clicks on the ratchet nothing happens, no servo movement. But once past that, the servo moves, and the trim works too. I'm not sure what the purpose of this is. It's like the lower 15% of the stick throw is void of any input. And this is the stock, brand new airplane default throttle setting.
I did find a way to fix it though, and the fix made other features that weren't working suddenly come to life. Inside the Model Menu, is AFR. AFR is an old friend of mine from my 9Zap. Inside the AFR menu, change the function selection on the second page from ELE to THR, go back to the first page and adjust the offset. This will get rid of the dead zone, so that the stick will start effecting the movement of the servo arm as soon as you start to advance it. I put in +20 on mine. This makes it so that the trim lever works now while the stick is on the stop as well, so you can adjust idle as you need.
Before making this change to the AFR offset, I could not get the Throttle Cut, or Idle down features to work.... AT ALL. Now with this dead band gone, they work perfectly.
Hope this helps somebody else. It sure wasn't something you could deduct reading the manual.
I did find a way to fix it though, and the fix made other features that weren't working suddenly come to life. Inside the Model Menu, is AFR. AFR is an old friend of mine from my 9Zap. Inside the AFR menu, change the function selection on the second page from ELE to THR, go back to the first page and adjust the offset. This will get rid of the dead zone, so that the stick will start effecting the movement of the servo arm as soon as you start to advance it. I put in +20 on mine. This makes it so that the trim lever works now while the stick is on the stop as well, so you can adjust idle as you need.
Before making this change to the AFR offset, I could not get the Throttle Cut, or Idle down features to work.... AT ALL. Now with this dead band gone, they work perfectly.
Hope this helps somebody else. It sure wasn't something you could deduct reading the manual.
11-15-2008, 09:13 PM
#2
My Feedback: (26)
Join Date: Sep 2002
Location: Springfield, MA
Posts: 212
Likes: 0
Received 0 Likes
on
0 Posts
RE: Futaba 12 FGA Throttle setup
Capgains
Are you sure the servo was not up against a mechanical throttle stop in the carburator?
I have a somewhat different issue with the throttle stick on my 12FGA. If the stick is all the way to idle and I apply left rudder the idle will increase significantly. This does not occur with right rudder. I checked to make sure I hadn't set some rudder to throttle mixing by mistake. It may occur at higher settings also. I'll have to check it out.
Are you sure the servo was not up against a mechanical throttle stop in the carburator?
I have a somewhat different issue with the throttle stick on my 12FGA. If the stick is all the way to idle and I apply left rudder the idle will increase significantly. This does not occur with right rudder. I checked to make sure I hadn't set some rudder to throttle mixing by mistake. It may occur at higher settings also. I'll have to check it out.
11-15-2008, 09:54 PM
#3
RE: Futaba 12 FGA Throttle setup
ORIGINAL: Capgains
I found something really wierd about the throttle setup for the 12 FG. After setting the end points top and bottom, I noticed that with the throttle stick pulled all the way against the stop on the bottom, the trim lever would have no effect on the throttle servo. It was as if the T3 trim lever was turned off, I could see it moving up and down the scale on the display, but it didn't move the servo at all. After an hour of looking at the manual... (last resort) I accidently discovered that there is a dead band at the bottom of the throttle control. From the stop up about 5-6 clicks on the ratchet nothing happens, no servo movement. But once past that, the servo moves, and the trim works too. I'm not sure what the purpose of this is. It's like the lower 15% of the stick throw is void of any input. And this is the stock, brand new airplane default throttle setting.
I did find a way to fix it though, and the fix made other features that weren't working suddenly come to life. Inside the Model Menu, is AFR. AFR is an old friend of mine from my 9Zap. Inside the AFR menu, change the function selection on the second page from ELE to THR, go back to the first page and adjust the offset. This will get rid of the dead zone, so that the stick will start effecting the movement of the servo arm as soon as you start to advance it. I put in +20 on mine. This makes it so that the trim lever works now while the stick is on the stop as well, so you can adjust idle as you need.
Before making this change to the AFR offset, I could not get the Throttle Cut, or Idle down features to work.... AT ALL. Now with this dead band gone, they work perfectly.
Hope this helps somebody else. It sure wasn't something you could deduct reading the manual.
I found something really wierd about the throttle setup for the 12 FG. After setting the end points top and bottom, I noticed that with the throttle stick pulled all the way against the stop on the bottom, the trim lever would have no effect on the throttle servo. It was as if the T3 trim lever was turned off, I could see it moving up and down the scale on the display, but it didn't move the servo at all. After an hour of looking at the manual... (last resort) I accidently discovered that there is a dead band at the bottom of the throttle control. From the stop up about 5-6 clicks on the ratchet nothing happens, no servo movement. But once past that, the servo moves, and the trim works too. I'm not sure what the purpose of this is. It's like the lower 15% of the stick throw is void of any input. And this is the stock, brand new airplane default throttle setting.
I did find a way to fix it though, and the fix made other features that weren't working suddenly come to life. Inside the Model Menu, is AFR. AFR is an old friend of mine from my 9Zap. Inside the AFR menu, change the function selection on the second page from ELE to THR, go back to the first page and adjust the offset. This will get rid of the dead zone, so that the stick will start effecting the movement of the servo arm as soon as you start to advance it. I put in +20 on mine. This makes it so that the trim lever works now while the stick is on the stop as well, so you can adjust idle as you need.
Before making this change to the AFR offset, I could not get the Throttle Cut, or Idle down features to work.... AT ALL. Now with this dead band gone, they work perfectly.
Hope this helps somebody else. It sure wasn't something you could deduct reading the manual.
11-15-2008, 10:10 PM
#4
Senior Member
Thread Starter
My Feedback: (4)
Join Date: Feb 2002
Location: Klamath Falls,
OR
Posts: 277
Likes: 0
Received 0 Likes
on
0 Posts
RE: Futaba 12 FGA Throttle setup
ORIGINAL: wingster
Capgains
Are you sure the servo was not up against a mechanical throttle stop in the carburator?
I have a somewhat different issue with the throttle stick on my 12FGA. If the stick is all the way to idle and I apply left rudder the idle will increase significantly. This does not occur with right rudder. I checked to make sure I hadn't set some rudder to throttle mixing by mistake. It may occur at higher settings also. I'll have to check it out.
Capgains
Are you sure the servo was not up against a mechanical throttle stop in the carburator?
I have a somewhat different issue with the throttle stick on my 12FGA. If the stick is all the way to idle and I apply left rudder the idle will increase significantly. This does not occur with right rudder. I checked to make sure I hadn't set some rudder to throttle mixing by mistake. It may occur at higher settings also. I'll have to check it out.
8178, Could you check something for me? Set your throttle all the way to the stop, and slowly advance it. Does it start moving the servo with the first ratchet click, or do you have 3-4 before the servo starts to move?
11-15-2008, 11:01 PM
#6
Senior Member
Thread Starter
My Feedback: (4)
Join Date: Feb 2002
Location: Klamath Falls,
OR
Posts: 277
Likes: 0
Received 0 Likes
on
0 Posts
RE: Futaba 12 FGA Throttle setup
Very strange. Well so far, I only have this transmitter powering one airplane, and it is with the 8 channel 2.4 ghz FASST setup. I'll try a second on the bench and see if I get the same problem. Thanks for checking that for me. [8D]
11-16-2008, 10:31 AM
#7
My Feedback: (16)
Join Date: Mar 2005
Location: spring valley ,
CA
Posts: 1,309
Likes: 0
Received 0 Likes
on
0 Posts
RE: Futaba 12 FGA Throttle setup
Just a thought??? did you assign the trim lever T3 to that position (throttel)??? You have to assign any of the trim buttons to a function on this radio.
11-16-2008, 10:49 AM
#8
RE: Futaba 12 FGA Throttle setup
To verify that I hadn’t done something to the model I was checking for you I did another test with a "new" model that I created this AM. With no changes to the throttle settings it has full movement and the trim works at idle. My TX is only a month old has v1.6 firmware and G3 2048 PCM. Not that it should matter, I tested both 2048 and 1024. As the 12FGA is new to me I assume a "new" model doesn’t copy any settings but I’m not sure.
11-16-2008, 10:54 AM
#9
RE: Futaba 12 FGA Throttle setup
ORIGINAL: SoCalSal
Just a thought??? did you assign the trim lever T3 to that position (throttel)??? You have to assign any of the trim buttons to a function on this radio.
Just a thought??? did you assign the trim lever T3 to that position (throttel)??? You have to assign any of the trim buttons to a function on this radio.
11-16-2008, 06:00 PM
#10
Senior Member
Thread Starter
My Feedback: (4)
Join Date: Feb 2002
Location: Klamath Falls,
OR
Posts: 277
Likes: 0
Received 0 Likes
on
0 Posts
RE: Futaba 12 FGA Throttle setup
Yeah, mine is that way as well. T3 is assigned to the throttle trim by default appearantly.
This just keeps getting harder to explain. I set up a test profile in the radio last night, and hooked up a new RX on the bench. I used a HS545 Hitec servo, which is a pretty good servo. This time it worked perfectly. The servo moves instantly, and the trim lever works from the idle stop. Maybe there is something wrong with the RX in the plane... or perhaps the servo in the plane. I don't tend to use a high quality servo for the throttle. This one is an HS300 which it the Hitec $12 special. Maybe it has some kind of problem with the signal?
This just keeps getting harder to explain. I set up a test profile in the radio last night, and hooked up a new RX on the bench. I used a HS545 Hitec servo, which is a pretty good servo. This time it worked perfectly. The servo moves instantly, and the trim lever works from the idle stop. Maybe there is something wrong with the RX in the plane... or perhaps the servo in the plane. I don't tend to use a high quality servo for the throttle. This one is an HS300 which it the Hitec $12 special. Maybe it has some kind of problem with the signal?
11-17-2008, 10:51 AM
#11
My Feedback: (11)
RE: Futaba 12 FGA Throttle setup
If you go into the "Function" selection inside the Linkage Menu, and then select the trim of the throttle channel, what mode is it set to? If it's to "ATL", then the trim won't work when the stick is moved away from one end. You may need to reverse the channel. "NORM" is trim that works in a linear fashion throughout the entire range of stick movement. "CNTR" makes the trim work when the stick is near the center.
Check the trim's mode, you may need to change it to "REVERSE" in the "ATL MODE" section, at the bottom of the trim page.
Your difficulty cannot be in the receiver, the receiver has nothing to do with how the channels operate. Their operation is totally governed by the transmitter's programming. The receiver just responds to the transmitter.
Check the trim's mode, you may need to change it to "REVERSE" in the "ATL MODE" section, at the bottom of the trim page.
Your difficulty cannot be in the receiver, the receiver has nothing to do with how the channels operate. Their operation is totally governed by the transmitter's programming. The receiver just responds to the transmitter.
11-17-2008, 03:08 PM
#12
Senior Member
Thread Starter
My Feedback: (4)
Join Date: Feb 2002
Location: Klamath Falls,
OR
Posts: 277
Likes: 0
Received 0 Likes
on
0 Posts
RE: Futaba 12 FGA Throttle setup
Hi Bax,
It is indeed ATL... I spotted that as a possibility. I'm really begining to think the problem is that cheap servo. I have read that there have been issues with Hitec servos and FASST. But for now, I think I have it figured out. Somehow, amping up the offset to the A sided, fixes the problem for this plane. Had 3 great flights with it yesterday.
While I have you on the line, I found another menu in which you could reverse individual directions under H/W settings. What is that for?
If I'm reading it right, you can reverse input for individual sticks, switches and trims, as opposed to reversing the entire channel, and the trims that go with it?
I looked into that to see if perhaps the T3 was reversed and only working off the top of the J3 throw..... no dice.
It is indeed ATL... I spotted that as a possibility. I'm really begining to think the problem is that cheap servo. I have read that there have been issues with Hitec servos and FASST. But for now, I think I have it figured out. Somehow, amping up the offset to the A sided, fixes the problem for this plane. Had 3 great flights with it yesterday.
While I have you on the line, I found another menu in which you could reverse individual directions under H/W settings. What is that for?
If I'm reading it right, you can reverse input for individual sticks, switches and trims, as opposed to reversing the entire channel, and the trims that go with it?
I looked into that to see if perhaps the T3 was reversed and only working off the top of the J3 throw..... no dice.
