Another great vid! The big problem long term is the heat created inside the internal BEC. Sure, a stock esc may output the amperage required, but amps are what create torque and create heat. On a trail run, many of the lower cost ESCs will either overheat or completely fail from the constant load that rock crawlers present. It's not so much "if", but "when".
@@RCReviewChannel yes, either measure the temp giving 1 second bursts every 5 seconds (or whatever duty cycle you choose) or simply watch the amp stability and voltage output over a few longer cycles. It won't be pretty for any of them except maybe the mamba and axe. Not sure what the axe really has inside, but the mamba is pretty stout BEC.
HolmesHobbies Hey guys i’ve got a dual BR Mini TorqueMaster- Holmes Hobbies with a 10 a Castle Creations BEC and I keep going through servos so i’m looking at buying the Savox Servo - Sav-Sb2290Sg. The BEC is probably about 3 -4 years old would it still be working correctly
You're AWESOME!!! You must be reading my mind lately. You saved me a munch of money and aggravation. Now I know what I need for my servo needs and do I need a Bec for my traxxas line up of vehicles. You are my Top RU-vid channel!!! Thank you so much 👍👍👍👍👍👍👍👍👍😀
I hate to be "that guy", I really do BUT...there is a *fundamental flaw* here that means you can take these numbers and toss them in the trash! You are measuring only *1* side of the equation therefore missing how much total *power* these ESC's can put out. It's what causes people to get brownouts when a servo stalls. Amperage may shoot up to 5 amps, but voltage may dip to 3 volts. Generally in these type of circuits, amperage goes *UP* as voltage goes *DOWN* . One cancels out the other. You need to measure both input *voltage and amperage* and calculate total *wattage*. Watts = voltage x amperage. Watts is total power output. So that ESC putting out 4 amp could be at 6 volts and put out 24 watts. (6x4=24) While the 5 amp ESC drops to 4 volts and only puts out 20 watts (5x4=20) and actually has LESS output! Edited for "bold" formatting.
I’ve been around awhile and I’ve said it before, the realist and the rawest. If the RC companies cages were rattled before you’ve got them damn well shaking in their boots now!, lol. Well done. Thank you.
Amps shown in test do not mean that your BEC circuit can handle those amps as you do not know how much safety margin manufacturer gives at rated amps. 1080 result would make me very nervous for this servo as it is set to 7,4V according to video description but can only put out 4,5A that is close to 4,4 at AE-5 set to 6V. So massive voltage drop for 1080 and AE-5 is rated to 3A so that is overloaded in this test as well. Measured amps drawn from the BEC do not give any indication about how much it can handle.
This is the sort I've testing I love! Nice to know that the 1080 internal BEC can do a pretty good job out of the box. In the test for the Power HD LW-20MG you did, it drew 4.3a so I'm happy my 1080 can cope. If someone is installing a more power hungry servo, why not spend a few more $$ and get an external BEC anyway :)
Great test! Thanks for doing this! I think it would be good to run the test again, and measure the voltage from the BEC at the same time, as this may drop as the BEC approaches the max current output. You never know it might make for some interesting results!
Super helpful as I was on the fence about needing a BEC or not. I'll still probably go that route so I have the ampere overhead to add light bars, winches etc down the road, but to be able to upgrade my servo right off the esc is great to know!
Have you considered doing a new version of this or your servo tests?I find these kind of tests really informative sorting the bs from the real data. Thanks!
aa might be a 2year old vid but been watching your youtube for a long time was a main for nitro's but ever since X-maxx's came out they just seem the best all rounder for me since i was one for worrying about the ESC's or lipo batteries catching a light 🔥but i think we all can agree on they gotten way better then they used to be ;p
The weird thing is I’ve read a spec sheet for an xl5 HV that rated it at 1amp also! I was really surprised and reassured seeing it pull 3.5amps since I’m running stock still. Thanks so much for all your valuable info.
I assume that you left the Castle BEC at the default voltage (6v). It would be interesting to use the Castlelink to set the voltage to 7.4v and see how many amps it can provide!
I absolutely love your videos you always give great information that's accurate please keep them coming I would love to go crawling with you one day LOL
Thanks for all the research with servos and everything. It really helps to know what you're getting for your money. Not a big deal but I just looked up *traxxas 2269 bec but the part number is actually 2262. Great content keep it up guys.
Man this channel is so awesome. Thank you for all your efforts. This stuff is so helpful. But i think you would have to use a much higher amp user( sorry, english is not my first language) because if that servo only pulls around 5 amp, none of this Devices will Show if it can put out more. That castle bec for axample claims up to 10 amp Max output. And if a 1 amp rated Esc gives almost 5,what would for example the axe Esc be caoable of?
You'd have to find a servo that drew that kind of current. He's already used the Savox 2290 which is the most power hungry servo they've tested and it only takes 5a
Thank you for guys like you to help US save money, or build it right the first time! One thing I'd like to see you monitoring the voltage output when your doing the amp test on the BEC's along with the amp drawl. That way we can see the voltage sag as well when the BEC is getting pushed to its amperage limits. Course I'm probably one of the few people that would ask that..... after all what we experience in the form of "brownouts" or "glitches" from the voltage inconsistencies because of high loads. Course if you check out the video of my charging station on my channel, you'll see I'm a bit of a electrical nerd, who likes data. Considering I do alot of industrial electrical and robotics troubeshooting/repairs I'm very into that kinda stuff.. just not the serious math 😂🤣
One other consideration for BEC and amp draw be it an external one or the internal one of an ESC is the combination of all electronics being powered by the BEC. I had a combination of one servo that was a little too power hungry with only a receiver being powered by the ESC in a touring car that had problems on these lines. The built in BEC of the ESC wasn't up to the task of providing power to the servo as well as the receiver. What would happen is the servo would cause the BEC to brown out (voltage would drop too much to try and keep up with amp draw) which would cause the receiver to glitch out from lack of power. I could negate the problem somewhat with a capacitor, but even then I would run into brown out situations (the combination was a Savox servo, Spektum receiver, an a Speed Passion receiver on 50C 4000mah 2S LiPo). I ended up replacing the servo with a different brand that had similar specs but lower current draw to fix the problem.
the one advantage I found with a external BEC is heat!!! ESC’s with built-in BECs are Linear type and Linear BEC reduces the voltage from the main Lipo to 5V by converting the excess voltage into heat. This is not a very efficient way of voltage converting
I was using the traxxas blue coreless servo and found while the esc handled it, it got HOT. After moving to a castle bec for servo power I noticed much lower temps.
You should make a jig that will hold the tires that way your getting the real amp draw with the use of a motor as well. Nice work tho. Should set up the castle bec to a base 6.0v lock the wheels turn the wheels to one side full lock and see what the system is drawing.
PoorManRC from what I know the internal bec over heats. And he needs to test with the wheels bound up in rocks. It will pull even more amps with the use of the motor.
@@CasperRc81 That is true. He's admitted that these aren't real world tests... But testing everything the exact same, does make an accurate control comparison.
I usually do some turning while moving forward, and see how much the throttle "drops off" when I'm activating the servo from left to right. The Axe system I currently have keeps up pretty good . I do have a bec on standby(Hey Ok brand) in case I want to use it to keep the temps down on the esc , it's only rated for 5 amps and I've had it turned up to 12v when adjusting it. The version 2 Axe system claims to be able to make 6.0 amps @ 7.4v to the servo, which is one amp more than the original or version 1.
Notice how the servo does not "pull" and make noise during the XL5 test. Must see the voltage at that time. Makes sense that although is shows around 3.5 amps, it is really does not pull much. On the Castle Micro X the 3.9 amps make the servo scream!
very interesting, i have a new bronco and you were right after a few charge ups the servo is starting to die :( so the stock ESC is generating 3.5 amp is that good enough for the upgraded servo from traxxas ?
Cool tests! Showing the amp draw is on the esc's bec outputs is only half the story. Be good to know what the voltage is dropping to. Receiver browning out and/or shutting off from low voltage isn't good for one thing.
I'm trying to find my way in this new world after a long break from RC cars since racing 12th scale road cars back in the mid 1980s. It looks like the kind of car I used to race is called a pan car now. I've bought a couple electric cars and just added an HSP 1/10 nitro rally car to my stable most recently. I've upgraded to an FS-GT5 TX/FS-BS6 RX combo and am working on installing a Dsservo DS3225SG to replace the stock steering servo, and decided to watch a few videos to demystify everything a bit, which led me here. My HSP 94177, being a nitro car, doesn't have an ESC and everything is now wired into the FS-BS6 receiver, but now I'm wondering if I should be using a BEC, or if a BEC is more important with electric motored cars where the motor might cause the voltage to sag low enough to keep the servo from working as it should? The other thing puzzling me at the moment is whether I have to remove a bunch of screws and remove the battery/receiver box to get the servo wire through the little hole at the bottom, or if I'm overlooking an easier way to get around the gap between the chassis plate and radio box being too tight to finagle the servo connector through the hole. I'm a little apprehensive about removing a lot of screws at once since I don't yet know what might unexpectedly fall apart into multiple pieces and become a pain to figure out how to reassemble. 😉 Then again, I guess that's how you learn and become more comfortable with the whole car, so I'll convince myself to "send it" momentarily. 😉😁👍
Savox SB-2290SG Black Ed. BL Monster Torque 50kg (Metal Gear) $294.95 NZD for that I can get 14 25kg servo's that don't require an external Bec! just for the record the only time I've stalled a servo is when both wheel are trapped between rocks I say if you had a Savox SB-2290 you'd break your steering with that crazy amount torque or maybe rip both your front tires from the rims?
Question: if the BEC states 10A but the servo needs 1.5A, does that mean that the BEC is going to send 10A or servo is going to draw what it needs only, i.e. 1.5A?
Thanks for sharing this. I've already watched your video when it aired. I might have a misconception in relation to servo amp draw and built in BECs... Will an amp hungry servo burn an integrated BEC? Or will the BEC just provide as much current as its limit allows (which is a built in safety feature)? This way the current will stay in a safe range? Or is the current the lesser problem while the generated heat is the dangerous issue? This is the main question. Example is my setup: Mamba Monster X 6s, integrated BEC has 8 A peak, voltage can be adjusted. My servo is a brushless one rated at max. 555 oz or 40 kg at 8.4 V. Planning to run it at 5.5 or 6 V on the integrated BEC. Torque would be around 31 kg at 6 V. Still crazy fast on 6 V. Will it burn out the integrated BEC? Does this combination NEED an external BEC? I ran this combination previously on an external BEC, which can put out 8.4 V at 8 A. It powered the servo directly, bypassing the receiver. I'm running this in an 8th scale truggy, not in a crawler.
Fantastic videos. Great info we all eagerly want to know. I have a question about the hobbywing 1080 crawler esc. It rated at 4.5 amps with your test. Was the esc programmed for the BEC to be at 6v or 7.4v in your test? Thanks again for taking the time to make such great content.
Really valuable and technical ! In my experience I think that also receiver can influence the amperage throughput. In fact in some cases changing receiver I've seen different performance with the same ESC & Servo. Do you have some information about this ?
So if I have a rather small servo but an upgraded esc and motor would I need a BEC or would the rampage be fine. I'm confused as to whether a BEC is for when it requires more or less amps
Am I wrong here but isn’t This amp test showing what the servo is demanding vs what the esc can put out? The 1080 is 3A output regardless of voltage settings, the test shows 4.5 amp draw, the esc is only capable of constant 3A so this is a problem and will eventually fry the esc. The castle BEC is good for 10A of draw so there will be no issues with the servo not getting the amperage it needs. My best suggestion is to ALWAYS run a external BEC for any high demand servo or pay the price later 🤷🏻♂️
Don’t get me wrong, I love the videos you put up but this video may confuse some people into thinking the internal bec is “putting out” more amps than It actually does. Also, the way an external bec works is different than the internal bec. Will the internal bec work? Sure, but for how long? If you want the very best power from your servo using an external bec shouldn’t be a question.
The key discovery here is the the manufacturer ratings are just guesses or conservative ratings. Some are rated too high, some are rated too low in regards to what they actually deliver pull after pull. As for longevity, it is a crapshoot. Who knows if any of them will last a week or 3 years on the same servo. We have a new test to measure and ESC's temperature pull after pull to stall and see how much it heats up and if it breaks. We'll do it for both an ESC and an external BEC.
Any chance you can run this test again using some of the more popular esc's? Specifically interested in the the Copperhead 10 using a direct power servo such as the 3Bros G11 or G14
With the new Fusion SE combos, how do we consider adding a BEC? Do the 2 in 1 motor options put out enough amps for upgraded servos or do we still need a separate BEC? Running a Traxxas TRX4 with the stock ESC currently. Thanks!
Dang..I wish the torque output versus the amps was visible. I'm really interested to see the actual real world difference in torque..between a mamba x and a hw1080 .. You didn't happen to log those numbers, did you?
I know this sounds like a stupid question but I’m going to ask anyway. How do you know when you need a external bec? I run mamba x with a power hd servo. Plus I have a bunch of lights. Everything seems fine I just don’t want to hurt anything. Oh and the truck is a trx4. Thank you!!
If your servo draws way more amps than your ESC can ever provide, then a BEC is needed. Or a more powerful ESC. In your case, your ESC provides about 8 amps and your servo draws about 5 amps. So you are way good. For folks who have a servo that draws 6-8 amps, and have a stock ESC that provides, 3-4 amps, then they need one. Our series of servo tests and ESC tests now actually show what these devices draw.
RC Review I’m so glad I came across your channel. I’ve only really been in the hobby for 3-4 months. I’ve learned so much from your videos. Thank you very much!!
Can you list out the perfect match setup for a beginner like me..from the r/c,battery,transmitter,esc,motor and servo..i want to restore my old karbon batt toys but i'm confused with load of each item i need too.. I'm considering using lipo batt..just a simple and cheap setup ..i really apprecited it..thank you
Wow great tests! Just bought a reefs 444 and running on the stock xl-5hv and was wondering if it was a waste of money considering the esc couldn’t put out more than 1 amp so would not be seeing any torque gain. Good to see the stock esc puts out 3.5. Wondering if the 1080 is the best upgrade to get an extra amp and perhaps better crawling speed modulation
Quick question; I have the Hobbywing 1080 esc for my TRX-4 which I have the Savox 1230 servo and the stock receiver, do I need or should have an external BEC also and thanks all the informative videos you put out, awesome job guys!
Was surprise by the result of axial stock esc almost the same result with the hobbywing 1080. Did you use the default output voltage of hobbywing1080(@6v) when you measure the current draws by the servo?
Good morning idol im your follower i have i questions and im asking favor i have plan to make rc boat can you pls give me idea what kind of motor. Servo .and some kit im using the measurement of boat is 40 inches long 10 inches wide
My project has 11 servos now, though 4 of them are not powered by the receiver, (powered by separate bec to via superscale 2020 unit) I am using a dumborc x6dcg receiver (with led outputs) and hobbywing 1080. I have added lights now but they don't work as expected and flicker a bit. I think I might need to add a bec, does anyone know how many amps I can draw throuh the recevier board before it gets too much?
Awesome idea! Keep the real testing coming. I'd love to see you guys get a motor dyno and start testing motors Btw that enduro body is hilarious. Worst rtr body ever.
That test doesn't tell you much because you're measuring draw which is p much load dependent. A better setup would be with a variable load, mapping voltage drop as you increase amp draw.
Please excuse the ignorance, but If these esc's only put out 3 4 and 5 amps do you need a servo that calls for larger amps? Would I ever get the speed out of the servo specs listed below if my esc only puts out 3.5 amps? Operating voltage: 4.8 - 6.8V Operating speed ( 5.0V ): 0.15 sec/60 degree Operating speed ( 6.8V ): 0.13 sec/60 degree Stall torque ( 5.0V ): 21kg/cm Stall torque ( 6.8V ): 25kg/cm If the above servo calls for an operating range of 4.8 to 6.8 volts how does my traxxas 3 .5 volt esc work with it?
