How much current can a Futaba 608FS handle?
12-15-2009, 05:57 PM
#2
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RE: How much current can a Futaba 608FS handle?
I'd like to expand this question to include other Futaba Receivers and Digital Servos. Will the 14 channel and 8 channel 2.4GHz receivers handle 6.4 volts OK? Will the Brushless 451 and the S3152 handle 6.4 Volts from the A123 batteries? This information seems to be elusive, and it shouldln't be.
JC
JC
12-16-2009, 01:35 AM
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RE: How much current can a Futaba 608FS handle?
I have run 12 high torque digital servos on a 40% aerobatic plane (150cc) into a 6014FS with no issues. I run 5 digital servos on my pattern plane into a 6008HS with no issues. I use 6 digital servos on my thermal duration gliders with 608FS receivers with no issues.
I use unregulated 5-cell NiMH packs in most all set ups. These are at near 7.1 volts when freshly charged. Again, no issues. I will be running unregulated 6.6 volt A123 on a few planes soon. Again, I do not expect any issues.
I run the 3152 in the 5-cell NiMH which like I said see over 7 volts on a fresh charge, no problems.
Futaba generally recommends not more than 6 volts, but real world experience of many, many, many pilots shows that 5-cell NiMH and the A123 packs are working fine with no known issues.
I use unregulated 5-cell NiMH packs in most all set ups. These are at near 7.1 volts when freshly charged. Again, no issues. I will be running unregulated 6.6 volt A123 on a few planes soon. Again, I do not expect any issues.
I run the 3152 in the 5-cell NiMH which like I said see over 7 volts on a fresh charge, no problems.
Futaba generally recommends not more than 6 volts, but real world experience of many, many, many pilots shows that 5-cell NiMH and the A123 packs are working fine with no known issues.
12-16-2009, 06:43 AM
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RE: How much current can a Futaba 608FS handle?
FWIW,
I only use unregulated A123's on all my aiplanes/Helis, but I can tell you of a few guys at my field flying (helis) FASST R617's and R608's on unregulated 7.2 volts LiPos for about 2 years now, we only regulate the Gyro/servo to 5.4 volts.
Me personally, I will not go above the A123's. Also keep in mind that the new 4 and 6 channel rx's from Futaba are good for 8.4 volts.
Regards,
Doug.
I only use unregulated A123's on all my aiplanes/Helis, but I can tell you of a few guys at my field flying (helis) FASST R617's and R608's on unregulated 7.2 volts LiPos for about 2 years now, we only regulate the Gyro/servo to 5.4 volts.
Me personally, I will not go above the A123's. Also keep in mind that the new 4 and 6 channel rx's from Futaba are good for 8.4 volts.
Regards,
Doug.
12-16-2009, 09:04 AM
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RE: How much current can a Futaba 608FS handle?
I have been running the S3152's with 5 cell eneloop NIMH batteries now for several hundred flights. I've not experienced any problems at all.
12-16-2009, 09:13 AM
#6
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RE: How much current can a Futaba 608FS handle?
The servos are more of an issue with the higher voltage than the Rx's. I have one pair of JR 791 Retract servos that will not tolerate 6v. I run mainly 2cell LiPo Rx packs. I use 6v Regulators and sometimes 5v Regulators. 2cell LiPos charge to 8.4v. If it weren't for the servos, I would run 8.4v, unregulated. The JR 8711 servos will tolerate that.
12-16-2009, 02:20 PM
#7
RE: How much current can a Futaba 608FS handle?
Thanks for the replies. While I think JC was asking about voltage, I was wondering how much current the receiver power bus can handle.
Silent AVR8 have you measured the current draw on your digital servos or do you know anyone who has? It would be interesting to know how much current those digital servos are drawing in violent maneuvers.
-Ed B.
Silent AVR8 have you measured the current draw on your digital servos or do you know anyone who has? It would be interesting to know how much current those digital servos are drawing in violent maneuvers.
-Ed B.
12-16-2009, 04:12 PM
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RE: How much current can a Futaba 608FS handle?
ORIGINAL: Flyfast1
Thanks for the replies. While I think JC was asking about voltage, I was wondering how much current the receiver power bus can handle.
Silent AVR8 have you measured the current draw on your digital servos or do you know anyone who has? It would be interesting to know how much current those digital servos are drawing in violent maneuvers.
-Ed B.
Thanks for the replies. While I think JC was asking about voltage, I was wondering how much current the receiver power bus can handle.
Silent AVR8 have you measured the current draw on your digital servos or do you know anyone who has? It would be interesting to know how much current those digital servos are drawing in violent maneuvers.
-Ed B.
Emcotec did some measurements a couple of years ago and showed that a giant scale aerobatic plane had an average current load of just over 3 amps with peaks in excess of 20 amps during snap rolls, etc. That was with 14 digital servos.
Fromeco measured several helis doing hard 3D with digital servos and got an average of 3 amps as well with spikes to 6 amps.
I have calculated my giant scale Extra at an average of 3.4 amps, so it is in line with what Emcotec got. And this is for the very high torque digital servos we use in the big planes.
Point is that unless you are fully stalling your servos due to improper installation you really do not have to worry much about current draw. Let me put this another way, I am not aware of anyone who has ever "blown" or damaged a receiver due to an over current situation.
Keep in mind that stall current for most high torque servos is in the 3 to 5 amp range and that full deflection under load is NOT the same as stalled.
12-17-2009, 12:15 PM
#9
RE: How much current can a Futaba 608FS handle?
ORIGINAL: Silent-AV8R
Emcotec did some measurements a couple of years ago and showed that a giant scale aerobatic plane had an average current load of just over 3 amps with peaks in excess of 20 amps during snap rolls, etc. That was with 14 digital servos.
Fromeco measured several helis doing hard 3D with digital servos and got an average of 3 amps as well with spikes to 6 amps.
I have calculated my giant scale Extra at an average of 3.4 amps, so it is in line with what Emcotec got. And this is for the very high torque digital servos we use in the big planes.
Point is that unless you are fully stalling your servos due to improper installation you really do not have to worry much about current draw. Let me put is another way, I am not aware of anyone who has ever ''blown'' or damaged a receiver due to an over current situation.
Keep in mind that stall current for most high torque servos is in the 3 to 5 amp range and that full deflection under load is NOT the same as stalled.
ORIGINAL: Flyfast1
Thanks for the replies. While I think JC was asking about voltage, I was wondering how much current the receiver power bus can handle.
Silent AVR8 have you measured the current draw on your digital servos or do you know anyone who has? It would be interesting to know how much current those digital servos are drawing in violent maneuvers.
-Ed B.
Thanks for the replies. While I think JC was asking about voltage, I was wondering how much current the receiver power bus can handle.
Silent AVR8 have you measured the current draw on your digital servos or do you know anyone who has? It would be interesting to know how much current those digital servos are drawing in violent maneuvers.
-Ed B.
Emcotec did some measurements a couple of years ago and showed that a giant scale aerobatic plane had an average current load of just over 3 amps with peaks in excess of 20 amps during snap rolls, etc. That was with 14 digital servos.
Fromeco measured several helis doing hard 3D with digital servos and got an average of 3 amps as well with spikes to 6 amps.
I have calculated my giant scale Extra at an average of 3.4 amps, so it is in line with what Emcotec got. And this is for the very high torque digital servos we use in the big planes.
Point is that unless you are fully stalling your servos due to improper installation you really do not have to worry much about current draw. Let me put is another way, I am not aware of anyone who has ever ''blown'' or damaged a receiver due to an over current situation.
Keep in mind that stall current for most high torque servos is in the 3 to 5 amp range and that full deflection under load is NOT the same as stalled.
Thanks. That's very helpful information.
-Ed B.
12-19-2009, 03:46 PM
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RE: How much current can a Futaba 608FS handle?
Here is the official answer from Futaba:
Thank you for your recent e-mail.
That has a rating of 10 amps surge and 8 amp continuous.
We hope you find this information helpful. Should you have any further questions or concerns, please do not hesitate
to contact us at this email address. (Please be sure to copy all previous emails into any future questions.)
Sincerely,
John G.- PS9004
Product Support Lead Technician
Futaba Programming Technician
Great Planes Model Distributors
www.futabarc.com
Thank you for your recent e-mail.
That has a rating of 10 amps surge and 8 amp continuous.
We hope you find this information helpful. Should you have any further questions or concerns, please do not hesitate
to contact us at this email address. (Please be sure to copy all previous emails into any future questions.)
Sincerely,
John G.- PS9004
Product Support Lead Technician
Futaba Programming Technician
Great Planes Model Distributors
www.futabarc.com
12-19-2009, 07:42 PM
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RE: How much current can a Futaba 608FS handle?
And I can tell you from extensive field experience that those ratings are on the conservative side. Which is good, the rating should be lower than the actual limit.
