Brown-Out Issues?
08-09-2013 | 08:38 PM
#16
Because the esc has only so many amps to send the receiver and servo at the same time, usually 5amps at 6v. When the pack is fresh it's easily doable, but after a few minutes when the voltage has dropped a little the savox servos are known to pull high amps basically using what is available not leaving much for the receiver.
If your at full steering and powering out of a turn, the voltage drop from the motor digging deep and the servo pulling higher then normal amps(savox is known for this) then the receiver "browns out"
If your at full steering and powering out of a turn, the voltage drop from the motor digging deep and the servo pulling higher then normal amps(savox is known for this) then the receiver "browns out"
Bolded because its the correct answer I highly doubt any thing else could cause what your having problems with. Dont add a cap or any other bandied setup, just run what will for sure fix the problem.
08-10-2013 | 02:40 AM
#17
Tech Master
Joined: Feb 2013
Posts: 1,065
From: SanDiego
Spektrum and Savox are not friends, they are enemies 
Every time somebody asks me about radio problems and I ask what radio and what servo they answer Savox and Spektrum
I can't figure out why with the tons of Savox issues threads people still buy them, 'cheap' is not an answer if you want to race
4WD SC is THE most demanding power wise of any class
Every time somebody asks me about radio problems and I ask what radio and what servo they answer Savox and Spektrum
I can't figure out why with the tons of Savox issues threads people still buy them, 'cheap' is not an answer if you want to race
4WD SC is THE most demanding power wise of any class
08-10-2013 | 05:16 AM
#18
Spektrum and Savox are not friends, they are enemies
Every time somebody asks me about radio problems and I ask what radio and what servo they answer Savox and Spektrum
I can't figure out why with the tons of Savox issues threads people still buy them, 'cheap' is not an answer if you want to race
4WD SC is THE most demanding power wise of any class
Every time somebody asks me about radio problems and I ask what radio and what servo they answer Savox and Spektrum
I can't figure out why with the tons of Savox issues threads people still buy them, 'cheap' is not an answer if you want to race
4WD SC is THE most demanding power wise of any class
I run Savox in all my cars, never had a glitching issue. But I use a decent radio (Airtronics) and decent ESC's (ie NOT A CASTLE) and I test the amp draw of the servo before I install it to make sure it's appropriate for the job.
Spektrum DSM is 7 or 8 yr old tech, Castle ESC's are well known for internal BEC issues (strange that the solution is a BEC they sell for an extra $20-$30)
08-10-2013 | 06:52 AM
#19
Well, I'm getting desperate. If my LHS has an external BEC, I'm buying it. What I don't understand is why this problem is cropping up in the last 3 weeks or so. Why not the 6 weeks before that?
08-10-2013 | 07:15 AM
#20
Just for kicks, adjust your steering end points. I had a similiar problem my SCTE (savox servo, rx8, futaba tx/rx) and it was a 2 part problem. Item 1: at full lock (like diving into a corner) the steering linkage was binding a bit, making the servo work harder and pulling more amps leading to a mild brown out. Item 2: the bec in my RX8 was starting to fail, repaired by Tekin.
After each step it got better but didnt always go away until both issues were addressed.
After each step it got better but didnt always go away until both issues were addressed.
08-10-2013 | 07:22 AM
#21
Also recheck your end points for your steering on the radio, make sure the servo isn't trying to travel further then necessary to achieve full steering, if you turn the wheel all the way and the servo is buzzing real bad it could be causing an extra high amp load aswell.
08-10-2013 | 08:28 AM
#22
I think the end points are ok, just reset them w/the new servo. At least I have a couple of things to try: 1. Orange Rx, 2. External BEC
Better than when I posted this stuff yesterday.
Better than when I posted this stuff yesterday.
08-10-2013 | 09:06 AM
#23
The havok pro has a 3 amp bec
The max amps at locked according to the specs of both of these servos are above 3.2 amps
Normal amp draw is under 1 amp, but at full steering & full throttle they will approach or go above the max amps of the internal bec.
A Main Hobbys advises for both of these servos.
*NOTE: Certain combinations of receiver and ESC have been found to cause "Brown Out" issues when combined with Savox servos. An external BEC, or BEC stabilizing receiver capacitor may be needed for efficient, glitch free operation in low voltage electric applications.
Normal usage with any brushed will increase the amp draw as the brushes break in.
I use a castle bec, I prefer it to a capacitor as the valve of my truck is around $600 & to me the $20 bec that produces 10 amps makes me feel better.
I have many friends that use either with no problem.
And yes I have an amp meter I have put inline to check this.
Hope this helps
TM
The max amps at locked according to the specs of both of these servos are above 3.2 amps
Normal amp draw is under 1 amp, but at full steering & full throttle they will approach or go above the max amps of the internal bec.
A Main Hobbys advises for both of these servos.
*NOTE: Certain combinations of receiver and ESC have been found to cause "Brown Out" issues when combined with Savox servos. An external BEC, or BEC stabilizing receiver capacitor may be needed for efficient, glitch free operation in low voltage electric applications.
Normal usage with any brushed will increase the amp draw as the brushes break in.
I use a castle bec, I prefer it to a capacitor as the valve of my truck is around $600 & to me the $20 bec that produces 10 amps makes me feel better.
I have many friends that use either with no problem.
And yes I have an amp meter I have put inline to check this.
Hope this helps
TM
08-10-2013 | 12:32 PM
#24
Your novak's bec puts out 3a @ 6v.
Your savox can pull up to 5a running 6v at stall.
Your servo may be pulling 4 or so amps under a heavy load, if your end points are set too far it will pull 5a (or very close to it).
Either scenario is a problem.
Savox servos are a little less $$ than other good servos but not a good value IMO. Spend the extra $25 bucks next time. They are ok for buggies or other light 1/10 scale that do not run high amp draw power systems.
Or 1/8 high voltage, low amp power systems.
High amp draw SCT, fail. That and spectrum radio... fail of the year.
On reception, my friend showed up to the track with a lower end spectrum radio and could not drive as everyone was over powering his radio. He bought a low end Airtronics radio (MX-V) and problem solved.
Edit:
Ha ha... didn't see the second page. Will leave text as is though.
Your savox can pull up to 5a running 6v at stall.
Your servo may be pulling 4 or so amps under a heavy load, if your end points are set too far it will pull 5a (or very close to it).
Either scenario is a problem.
Savox servos are a little less $$ than other good servos but not a good value IMO. Spend the extra $25 bucks next time. They are ok for buggies or other light 1/10 scale that do not run high amp draw power systems.
Or 1/8 high voltage, low amp power systems.
High amp draw SCT, fail. That and spectrum radio... fail of the year.
On reception, my friend showed up to the track with a lower end spectrum radio and could not drive as everyone was over powering his radio. He bought a low end Airtronics radio (MX-V) and problem solved.
Edit:
Ha ha... didn't see the second page. Will leave text as is though.
Last edited by fq06; 08-10-2013 at 12:48 PM.
08-10-2013 | 05:00 PM
#29
Having problems w/my TLR SCTE 2.0
I was having what I thought were brown-outs. Anywhere from 2-4 minutes into a 5 or 6 minute race, I would start having issues. The truck would just basically stop. No go, no steering. Usually after heavy braking into a corner and then attempting to accelerate out of a corner. After a second or two it would start again w/o intervention.
I was using a cheaper Savox servo (SC0251MG). Added a glitch buster cap, no help. Went to a better servo (Savox SC1258TG), no difference.
Just for kicks, I removed the fan that was on my motor (Novak 4.5t 550). No difference.
Thought maybe my ESC (Novak Havok Pro) was having issues, went to my spare, no difference.
Thought maybe my receiver (Spektrum SR301) was having issues, went to my spare, no difference.
I'm back to thinking it's the ESC. I check the temps on it after having issues, but it's always in the middle of the 'acceptable operating range'. I'm kinda at a loss now. I don't have a spare motor to try, nor do I have another battery to try (using a new SPC 6500 mAh, 65c).
Anyone got any ideas?
I was having what I thought were brown-outs. Anywhere from 2-4 minutes into a 5 or 6 minute race, I would start having issues. The truck would just basically stop. No go, no steering. Usually after heavy braking into a corner and then attempting to accelerate out of a corner. After a second or two it would start again w/o intervention.
I was using a cheaper Savox servo (SC0251MG). Added a glitch buster cap, no help. Went to a better servo (Savox SC1258TG), no difference.
Just for kicks, I removed the fan that was on my motor (Novak 4.5t 550). No difference.
Thought maybe my ESC (Novak Havok Pro) was having issues, went to my spare, no difference.
Thought maybe my receiver (Spektrum SR301) was having issues, went to my spare, no difference.
I'm back to thinking it's the ESC. I check the temps on it after having issues, but it's always in the middle of the 'acceptable operating range'. I'm kinda at a loss now. I don't have a spare motor to try, nor do I have another battery to try (using a new SPC 6500 mAh, 65c).
Anyone got any ideas?
I'm using an Airtronics M11 radio with the Spektrum module so I tried replacing the receiver and still had the same problem from time to time. I tried using a Futaba, Hitec and finally a Savox steering servo and still had the same problem. The only conclusion i can come to is that the problem is with the ESC on my Orca Spark brushless system. I never had this problem when I was racing with a silver can motor. The weird thing is I use the same Savox servo and Spektrum receiver on my touring car and I never get these issues.
08-10-2013 | 05:32 PM
#30
I have a similar problem but not quite as bad and it's also not repeatable. It seems to happen randomly during the mains on a full drivers stand with my Tamiya M-05. On some race days it's fine and on others I get lots of problems. I get a combination of power loss and glitching where the steering just won't work like they way I want it to and I end up crashing all over the place. When my car stops moving with loss of power it will usually get going all by itself again after 5-10 seconds.
I'm using an Airtronics M11 radio with the Spektrum module so I tried replacing the receiver and still had the same problem from time to time. I tried using a Futaba, Hitec and finally a Savox steering servo and still had the same problem. The only conclusion i can come to is that the problem is with the ESC on my Orca Spark brushless system. I never had this problem when I was racing with a silver can motor. The weird thing is I use the same Savox servo and Spektrum receiver on my touring car and I never get these issues.
I'm using an Airtronics M11 radio with the Spektrum module so I tried replacing the receiver and still had the same problem from time to time. I tried using a Futaba, Hitec and finally a Savox steering servo and still had the same problem. The only conclusion i can come to is that the problem is with the ESC on my Orca Spark brushless system. I never had this problem when I was racing with a silver can motor. The weird thing is I use the same Savox servo and Spektrum receiver on my touring car and I never get these issues.
