Throttle servo glitching
05-03-2009, 04:11 PM
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Throttle servo glitching
Have a Fuji 64 setup with an RCEXL ignition.
Used the RCEXL because with the stock Fuji ignition I was getting total radio signal loss.
Using a Spektrum DX7 and AR 7000 RX.
Now with the RCEXL while I'm not getting total radio loss, I am still experiencing a glitchy throttle servo at low throttle settings.
the servo is a Hitech 82MG.
It is mounted on the left side of the motor box utilizing a nylon pushrod to the throttle lever. No metal whatsoever.
The ignition box is mounted on the right side of the motor box.Around 5-6 " away from throttle servo.
Ignition battery pack is mounted on the top of the motor box.
The glitching occurs mainly at low throttle settings when engine is first started.
When I run the engine up it disappears and most times doesn't return when i back off the throttle.
I have the two RX packs mounted on either side of the fuel tank which is about 4 inches back from the firewall.
The throttle lead runs across the top of the tank into the RX. Doesn't run along any other wiring.
Used the RCEXL because with the stock Fuji ignition I was getting total radio signal loss.
Using a Spektrum DX7 and AR 7000 RX.
Now with the RCEXL while I'm not getting total radio loss, I am still experiencing a glitchy throttle servo at low throttle settings.
the servo is a Hitech 82MG.
It is mounted on the left side of the motor box utilizing a nylon pushrod to the throttle lever. No metal whatsoever.
The ignition box is mounted on the right side of the motor box.Around 5-6 " away from throttle servo.
Ignition battery pack is mounted on the top of the motor box.
The glitching occurs mainly at low throttle settings when engine is first started.
When I run the engine up it disappears and most times doesn't return when i back off the throttle.
I have the two RX packs mounted on either side of the fuel tank which is about 4 inches back from the firewall.
The throttle lead runs across the top of the tank into the RX. Doesn't run along any other wiring.
05-03-2009, 05:15 PM
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RE: Throttle servo glitching
SodBuster,
I use RCEXL ingitions flying for a major ARF importer in my area and I too experienced some servo glitching for no apperent reason.
Changed servos and it went away. You may need to change to a different servo and or switch to a JR Signal Amplifier/Choke on the offending throttle servo and see if that helps also.
Good Luck
JDS
I use RCEXL ingitions flying for a major ARF importer in my area and I too experienced some servo glitching for no apperent reason.
Changed servos and it went away. You may need to change to a different servo and or switch to a JR Signal Amplifier/Choke on the offending throttle servo and see if that helps also.
Good Luck
JDS
05-03-2009, 07:34 PM
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RE: Throttle servo glitching
All,
I don't know if metal gears has much to do with it as better resolution. I replaced a 3 pole non metal 94102 airtronics servo thats solid as a rock anywhere else with a 5 pole HS985 coreless metal gear servo. So I don't think metal gears has anything to do with it. The radio is an RDS8000K 2.4 radio. Battery placement, ignition placement. Everything looks good but was getting some glitching during engine runs. Replaced the servo per the above and all worked great.
Later with another set up this time a 3MM TOC 53 in a composite 330L plane and using the same 94102 Airtronics servo no problems. The previous plane was a smaller 26cc Edge 540 where everything was sort of bunched up forward. The 330L is a much bigger plane and the ignition and batteries were much further away from the throttle servo.
Also I dont remove the carb spring on my gas engines and use a cable set up ah la QQ Somenzini via his Yak 54 86". This works good and causes no glitches. Both the above engines use Pull to open the throttle with 2mm du-bro clevis with a 2mm bolt and fiber lok nut.
Another plane (VQ Cap10b 1.20 size) using a Zenoah G26EI would glitch with the same radio as above and was narrowed down to a smartfly dual adjustable regulator using Dual Sky 1500 MAH Lipoly 2S batteries. Installed a JR amplified Y harness on the batteries and all noise went away.
So conclusion: Servos can cause glitching, Batteries can cause glitching, Elec Accy's can cause glitching. And close proximity to one another is more the problem than the quality of the above components.
JDS
I don't know if metal gears has much to do with it as better resolution. I replaced a 3 pole non metal 94102 airtronics servo thats solid as a rock anywhere else with a 5 pole HS985 coreless metal gear servo. So I don't think metal gears has anything to do with it. The radio is an RDS8000K 2.4 radio. Battery placement, ignition placement. Everything looks good but was getting some glitching during engine runs. Replaced the servo per the above and all worked great.
Later with another set up this time a 3MM TOC 53 in a composite 330L plane and using the same 94102 Airtronics servo no problems. The previous plane was a smaller 26cc Edge 540 where everything was sort of bunched up forward. The 330L is a much bigger plane and the ignition and batteries were much further away from the throttle servo.
Also I dont remove the carb spring on my gas engines and use a cable set up ah la QQ Somenzini via his Yak 54 86". This works good and causes no glitches. Both the above engines use Pull to open the throttle with 2mm du-bro clevis with a 2mm bolt and fiber lok nut.
Another plane (VQ Cap10b 1.20 size) using a Zenoah G26EI would glitch with the same radio as above and was narrowed down to a smartfly dual adjustable regulator using Dual Sky 1500 MAH Lipoly 2S batteries. Installed a JR amplified Y harness on the batteries and all noise went away.
So conclusion: Servos can cause glitching, Batteries can cause glitching, Elec Accy's can cause glitching. And close proximity to one another is more the problem than the quality of the above components.
JDS
05-03-2009, 08:49 PM
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RE: Throttle servo glitching
I went back today and re-ran all the wiring I just kind of stuffed up front and will give it a shot
IF THE RAIN EVER STOPS AGAIN!!
JDS, I agree with you. There's so many variables that can cause glitching it's ridiculous.
At least after changing the ignition out all I'm contending with now is the throttle not the whole system.
One thing I can tell you, NEVER use the stock ignition on a Fuji engine.........there's no grounding system on them from the ignition unit to the plug so the interference can be unbelieveable.
If the problem continues I'll try a different servo first, moving the servo second, and if all that fails, a choke.
IF THE RAIN EVER STOPS AGAIN!!
JDS, I agree with you. There's so many variables that can cause glitching it's ridiculous.
At least after changing the ignition out all I'm contending with now is the throttle not the whole system.
One thing I can tell you, NEVER use the stock ignition on a Fuji engine.........there's no grounding system on them from the ignition unit to the plug so the interference can be unbelieveable.
If the problem continues I'll try a different servo first, moving the servo second, and if all that fails, a choke.
05-03-2009, 09:07 PM
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RE: Throttle servo glitching
SodB,
Yeah I am developing a fav set up for gas.
ATX 94780 or 8611a all round the plane
7.4 Li-On on ignition on all my 3W IIS ignitions
7.4 Lipo with Duralite or MPI single 6.0 VDC reg on all 4.8 ignitions.
7.4 Li-On TBM, Duralite and Smartfly Super or Turbo regulator
Smart Fly EQ 10 for big stuff
Smart Fly Sport for small stuff
A123 on the SmartFly Sport so I dont need a regulator for that size plane
When I go back to the above I get absolutely great range on my RDS8K 2.4 and my Stylus on 72 MgHz.
Now I get to do all this over again for turbine.
jds
Yeah I am developing a fav set up for gas.
ATX 94780 or 8611a all round the plane
7.4 Li-On on ignition on all my 3W IIS ignitions
7.4 Lipo with Duralite or MPI single 6.0 VDC reg on all 4.8 ignitions.
7.4 Li-On TBM, Duralite and Smartfly Super or Turbo regulator
Smart Fly EQ 10 for big stuff
Smart Fly Sport for small stuff
A123 on the SmartFly Sport so I dont need a regulator for that size plane
When I go back to the above I get absolutely great range on my RDS8K 2.4 and my Stylus on 72 MgHz.
Now I get to do all this over again for turbine.
jds
