Mamba Monster's Issues/Not Working
05-14-2008, 07:37 AM
#16
Tech Regular
05-14-2008, 08:03 AM
#17
I have asked you nicely that if you really want to attack me take it to the PM. I dont see anything arrogant here. But please PM to tell me that I am a jerk or what ever you wish to. The thread is not the place. Thank you.
05-14-2008, 08:23 AM
#18
RURC: I can see how your posts can be taken as being arrogant by reading them on face value. You need to remember that when posting messages online there is no context to how you are saying what you are saying. So in general, making that comment in person while laughing about it may be taken as a light hearted jab, versus a serious tone about it.
Think of the net as a place where everyting has a serious tone when you don't use the JK or smilies.
My MMM should be in in the next couple of days, maybe today. Is there anything anyone wants me to look at specifically on the ESC itself. Maybe see if there is a difference between what RC Monster got versus the preorder from CC direct?
Think of the net as a place where everyting has a serious tone when you don't use the JK or smilies.
My MMM should be in in the next couple of days, maybe today. Is there anything anyone wants me to look at specifically on the ESC itself. Maybe see if there is a difference between what RC Monster got versus the preorder from CC direct?
when they sense arrogance specially in forums. The Schumacher guys loves me 
over there at the Speed Passion thread.
05-14-2008, 08:52 AM
#20
RURC: I can see how your posts can be taken as being arrogant by reading them on face value. You need to remember that when posting messages online there is no context to how you are saying what you are saying. So in general, making that comment in person while laughing about it may be taken as a light hearted jab, versus a serious tone about it.
Think of the net as a place where everyting has a serious tone when you don't use the JK or smilies.
My MMM should be in in the next couple of days, maybe today. Is there anything anyone wants me to look at specifically on the ESC itself. Maybe see if there is a difference between what RC Monster got versus the preorder from CC direct?
Think of the net as a place where everyting has a serious tone when you don't use the JK or smilies.
My MMM should be in in the next couple of days, maybe today. Is there anything anyone wants me to look at specifically on the ESC itself. Maybe see if there is a difference between what RC Monster got versus the preorder from CC direct?
05-14-2008, 08:57 AM
#21
RURC: I can see how your posts can be taken as being arrogant by reading them on face value. You need to remember that when posting messages online there is no context to how you are saying what you are saying. So in general, making that comment in person while laughing about it may be taken as a light hearted jab, versus a serious tone about it.
Think of the net as a place where everyting has a serious tone when you don't use the JK or smilies.
My MMM should be in in the next couple of days, maybe today. Is there anything anyone wants me to look at specifically on the ESC itself. Maybe see if there is a difference between what RC Monster got versus the preorder from CC direct?
Think of the net as a place where everyting has a serious tone when you don't use the JK or smilies.
My MMM should be in in the next couple of days, maybe today. Is there anything anyone wants me to look at specifically on the ESC itself. Maybe see if there is a difference between what RC Monster got versus the preorder from CC direct?
I doubt that there will be a difference with your MMM. Castle has not had the time to do anything but build them. I am almost positive that they have made no changes in less than a week. When I worked for Audi over in manufacturing they had a saying,' We dont make one bad part, we make 10,000 of that same part, and we still have to use them.' I am sure that those numbers are not Castles but it takes time to relay a line with updated parts. If in fact this even is a Castle problem. It may be a programming issue also. These things have so much going on in them rithg no one knows.
05-14-2008, 10:21 AM
#22
Castle just called me at 1:10 on Wed the 14 of May. It seems that my thought on magnetic field collapse causing a voltage spike are correct. For the internal BEC problem. Also I have been confirmed that poor batteries are also to blame. As I was told the BEC problem is going to show itself within the first like 10 minutes of usage generally. If you dont have a problem dont send it in, it will be returned to you. The future of this problem will be take care of at Castle. As I understand it there will be a upgraded component installed to prevent this from happening. But like I said if yours is working it should be fine. Again they told me that this problem should show itself within the first 10 minutes.
05-14-2008, 10:30 AM
#23
Castle just called me at 1:10 on Wed the 14 of May. It seems that my thought on magnetic field collapse causing a voltage spike are correct. For the internal BEC problem. Also I have been confirmed that poor batteries are also to blame. As I was told the BEC problem is going to show itself within the first like 10 minutes of usage generally. If you dont have a problem dont send it in, it will be returned to you. The future of this problem will be take care of at Castle. As I understand it there will be a upgraded component installed to prevent this from happening. But like I said if yours is working it should be fine. Again they told me that this problem should show itself within the first 10 minutes.
05-14-2008, 11:03 AM
#24
Here are the basic mechanics of a gauss failure.
When the field collapses it is just like the points on an older car, bam you get a huge jump in voltage. If the voltage is passing through a phase of the motor you have just increased that possibly several hundred times. That depending on the total number of windings in the motor. I would think that one of 2 things happened here on this. 1 Castle did not account for some very high wound motors. Or 2 Some part in the esc was faulty from the manufacturer of that individual part. 2 is the more likely one. Seeing that they said ' the problem should reveal itself within the first 10 minutes of use". To me this indicates a problem from the component manufacturer not a design issue. I did not pry into the exact line with them.
Now I dont how they can be held responsible for weather or not someone is using a battery that is capable of safely supplying the required current and an acceptable voltage. If the voltage drops the compensation is to draw more current. This causes more heat to be generated. Heat can cause tons of problems one of the most obvious ones is higher resistance. Once you go down this street it can be a never ending cycle till something gives or the request for the use has stopped. Either battery or the esc are going to have a problem under this situation. The hotter things get the higher the resistance and it just keeps in that circle.
I personally think that Castle's 75 amp continuous rating minimum for the battery is at least 40 amps too low. I will not put anything on the MMM that cannot sustain 160 amps continuous. I told them this while I had them on the phone and they are looking at it.
There is a lot going on in this little ESC and in the long run these little growing pains will be worth it.
05-14-2008, 01:16 PM
#25
One question keeps coming to my mind. If this is such an issue with an ESC designed for 1/8th; why wasn't it a problem when all these people were running modified Mamba Maxs? This is an ESC designed for 1/10th and not the stress of 1/8th yet few posted of issues.
05-14-2008, 01:27 PM
#26
I am seeing way to many of those running MMM that are way, way under battering them.
Guys you need to step up and go to the next level of battery. Just like you did when you first got a brushless. Going from nickel to lipo. Now you need to go from 120 to 160 amps to something that can handle 200 amps continuous. You are not playing with the big guns.
There is more current being used here than you think.
Guys you need to step up and go to the next level of battery. Just like you did when you first got a brushless. Going from nickel to lipo. Now you need to go from 120 to 160 amps to something that can handle 200 amps continuous. You are not playing with the big guns.
There is more current being used here than you think.
05-14-2008, 02:27 PM
#27
I personally think that Castle's 75 amp continuous rating minimum for the battery is at least 40 amps too low. I will not put anything on the MMM that cannot sustain 160 amps continuous. I told them this while I had them on the phone and they are looking at it.
05-15-2008, 12:43 PM
#28
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Last edited by Bernie Wolfard; 10-27-2010 at 02:36 PM. Reason: Not as accurate as it needs to be
05-15-2008, 03:57 PM
#29
Tech Adept
The load from the motor determines how much current is drawn from the batteries. Batteries don’t push current, hence you cannot have too large or too high a discharge battery. The ESC, between the motor and the batteries has two jobs. First, it run the motor by analyzing the motors back EMF then sending commutation pulses to the motor based on its analysis of the motor. This involves much more than knowing the position of the rotor, there are several complex algorithms that, by analyzing the back EMF, set the computation pulse advance to get the most power and efficiency of out any motor is it running.
Its second task is to control the speed of the motor to the users command. It does this with Pulse Width Modulation or PWM. PWM works by turning full throttle current on and off very fast. The portion of the pulse that is 'on' in relation to the part that is 'off' determines how much power the motor sees. I.E 50% on, 50% off the motor sees 50% power. The PWM switching rate is 13,000 times per second (13 khz). DC power sources, in this case batteries, do not like high current being switched on and off, they want to put out steady current. The ESC wants to see square waves, instant full on, instant full off. However, the battery takes time to go to full on and won't switch off immediately. This creates a sloped instead of a square wave. The caps on the ESC are there to get the PWM pulse back closer to a square wave. The reluctance of a battery to put out pulsed current also creates a side affect called 'ripple current.' The caps also control ripple current. The less capable a battery is of keeping up with the current demands of the motor the higher the ripple current. If the capacitor overheats or get completely drained from inadequate batteries the caps will burn or blow up and the ripple current cascades thought the power board burning up the ESC. The other primary cause of ripple current is resistance on the battery side of the circuit. A plug with too much resistance, long or too small battery wires, bad connections etc. will increase ripple current, possibly to catastrophic levels. I cannot prove it but my guess is that more of our ESCS are burned up from inadequate batteries than over current.
The minimum discharge rating for cells used with a Monster Max is 75 amps continuous, burst to 150 amps. This is a minimum to keep ripple current low enough to make sure the batteries don’t damage the ESC, more is better. Also, the more capable the batteries the more torque the motor will produce.
To answer the question of why don’t NiMh batteries damage the ESC is the fact that these cells voltage drop quickly under load then climb back. The drop in voltage protects the system from the motor pulling too much amperage and creating too much ripple current.
With high power electrical systems, the battery is the most important part of the system. Saving money on batteries not only gives lower performance, it puts the ESC at risk. Choose your batteries wisely.
Its second task is to control the speed of the motor to the users command. It does this with Pulse Width Modulation or PWM. PWM works by turning full throttle current on and off very fast. The portion of the pulse that is 'on' in relation to the part that is 'off' determines how much power the motor sees. I.E 50% on, 50% off the motor sees 50% power. The PWM switching rate is 13,000 times per second (13 khz). DC power sources, in this case batteries, do not like high current being switched on and off, they want to put out steady current. The ESC wants to see square waves, instant full on, instant full off. However, the battery takes time to go to full on and won't switch off immediately. This creates a sloped instead of a square wave. The caps on the ESC are there to get the PWM pulse back closer to a square wave. The reluctance of a battery to put out pulsed current also creates a side affect called 'ripple current.' The caps also control ripple current. The less capable a battery is of keeping up with the current demands of the motor the higher the ripple current. If the capacitor overheats or get completely drained from inadequate batteries the caps will burn or blow up and the ripple current cascades thought the power board burning up the ESC. The other primary cause of ripple current is resistance on the battery side of the circuit. A plug with too much resistance, long or too small battery wires, bad connections etc. will increase ripple current, possibly to catastrophic levels. I cannot prove it but my guess is that more of our ESCS are burned up from inadequate batteries than over current.
The minimum discharge rating for cells used with a Monster Max is 75 amps continuous, burst to 150 amps. This is a minimum to keep ripple current low enough to make sure the batteries don’t damage the ESC, more is better. Also, the more capable the batteries the more torque the motor will produce.
To answer the question of why don’t NiMh batteries damage the ESC is the fact that these cells voltage drop quickly under load then climb back. The drop in voltage protects the system from the motor pulling too much amperage and creating too much ripple current.
With high power electrical systems, the battery is the most important part of the system. Saving money on batteries not only gives lower performance, it puts the ESC at risk. Choose your batteries wisely.
Also, it seems as if a drop in voltage would cause the motor to draw MORE current rather then less to sustain its rotation (power consumption). Am I off base here?
Thanks,
Larks
05-15-2008, 04:29 PM
#30
The motor is trying to pull more current, but the battery can't keep up... which is why the voltage drops to begin with. I don't think the current actually increases DUE to the dropping voltage. The current is a product of the load of the motor.
I'm assuming what Bernie is saying about the nimh.. is that their voltage drop and rebound happens faster than with an average lipo cell? So that when the voltage does drop... it is not "messing things up" the same as a battery that is slower to respond? The faster the reaction from the battery, the easier it is for the esc to keep that square sine wave.
Still not sure it makes sense
and how it would be any different that a good lipo that is starting to dump, and has some saggy voltage issues of it's own.
Also:
Seems that bigger badder caps... and perhaps an occasional replacement of the caps would be a good thing. One thing to watch out for... when you connect a battery to the esc, the caps charge... thus that nice spark pops. If you don't get a spark it's a sing that maybe the caps are dead.
BTW, thanks for the info Bernie
I'm assuming what Bernie is saying about the nimh.. is that their voltage drop and rebound happens faster than with an average lipo cell? So that when the voltage does drop... it is not "messing things up" the same as a battery that is slower to respond? The faster the reaction from the battery, the easier it is for the esc to keep that square sine wave.
Still not sure it makes sense
and how it would be any different that a good lipo that is starting to dump, and has some saggy voltage issues of it's own.Also:
Seems that bigger badder caps... and perhaps an occasional replacement of the caps would be a good thing. One thing to watch out for... when you connect a battery to the esc, the caps charge... thus that nice spark pops. If you don't get a spark it's a sing that maybe the caps are dead.
BTW, thanks for the info Bernie