A little confused on BEC

[NitroBoy24]

Hey guys, I did a search to see if I could find any more information on BEC's and all I really got a snip at was that it helps send power to the servos/rx :confused:

The reason I am asking is because I am looking at dropping a brushless in my Mini Quake since I bought some aluminum cvd's a while back. I am looking at Kontronik controllers, specifically the Jazz 50-6-18 (50A cont./60A Bursts, 6-18 cells) and one of the Feigao 380/400 BL motors, probablly the 8T with a 51A max.

The Jazz I am looking at has Opto instead of BEC. Exactly what is the difference and is this going to screw me in the long run? The ESC is $130 which is just what I am looking for, but I don't want to end up having to upgrade because I wouldn't spend $40 more for a similar Jazz w/BEC. I run an Etec 2s 2400mah Lipo and dont plan on going over 2-cells.

So, I need help on the differences between "Opto" and "BEC" and what the pro's and con's of each are.

I plan on running a 40T spur and 19T pinion, a member on the boards has a program that will give you all kinds of MPH figures, feet per minute, etc if you enter the tire height, KV rating, spur/pinion, voltage, etc. With the gearing I mentioned above, without wind resistance, the vehicle being underload, etc it should 53mph and still have a lot of low end. I am running such a low gear ratio because A) A friend on one18th.com has a Trex (4500kv brushed motor) on this same spur/pinion setup with no low end problems and C) I dont want enough power to rip my differentials up until the Ball Diffs come out in may.

So, I just made this a BEC/Opto Question slash my Mini Quake update..Sorry about that, had to empty this out of my head!
Thanks a ton!
-John.

[tcolesen]

That controller isn't a very good choice a car, since it is made for airplanes. Another thing is the opto. Car controllers all have BEC, or they don't. I am not sure what opto is, but I think (Note: think) that it is so you can plug something into it and get BEC. Or, it could be something totally different.

[chilledoutuk]

i would not bother with a kontronik controller for a car as there are many better controllers out there that are better.
BEC stands for batterie elimiator circuit. and it does what it says it eliminates the need for a seperate power supply for your receiver and servo by regulating the voltage suplied to the controller down to an usable level such as 5v for the receiver.

The u-force has BEC

If your after a cheap sensorless controller that has BEC then there are many around The new hackers BEC works fine and so does the mtroniks.

The MGM controllers looked promising until this mid throttle breaking issue was reported. Hopefully they will get this resolved in software updates.

The mtroniks genesis sport with the latest softwate v1.04 is very impressive with very smooth throttle response also if mtroniks say the controller works with 10 cells or 4s lipo then that also means the BEC. Mtroniks tend to always be very conservative with there claims about there products in my experiance.

The new hacker Jeti made controllers have tons of power and a very nice machined aluminium casing but there not quite as smooth as the genesis sport controllers.

The best controller out there is the u-force but you do have to pay for this. I believe that once castle creations realease there sensorless controller and mtroniks releases there pro controller that the uforce will have real competition.

[NitroBoy24]

I think you guys are missing that this is for a 1/18 Truck, I do not need a controller that can handle over 150 amps, 60 in bursts is all I need.

The Kontronik esc's can be programmed to work with cars, boats, planes, gliders, etc. I might have to buy the Car Specific controller if it's going to be this big of a deal though.

I'm not going to spend over $300 on an esc, the truck cost me $130. So, the U-force is out of the question. If anyone knows of an esc that is in the 50-70A range and is under $200 then just let me know :)

Edit:
Just found a link to the MGM 80A esc for cars specifically and it looks good; best of all its cheap!! I heard problems about it braking when you let off the throttle, but I dont think it will bother me that much.

[starluckrc]

You can run the Feigao with the Mamba 25, so no need to spend much on an esc. I wouldn't recommend the 8 turn though. Most guys use the 12 turn. I haven't heard any feedback from the one guy running the 10 turn. I am getting ready to add a Mini Quake combo to my site soon, but you can email me for a special combo deal.

[NitroBoy24]

You can run the Feigao with the Mamba 25, so no need to spend much on an esc. I wouldn't recommend the 8 turn though. Most guys use the 12 turn. I haven't heard any feedback from the one guy running the 10 turn. I am getting ready to add a Mini Quake combo to my site soon, but you can email me for a special combo deal.

The only Feigao I would want to run on the Mamba is the 12 Turn, everything else that has higher kv is probablly going to pull too many amps for the Mamba to handle. And I know the 8T is too hot because Cooljoe at one18th tried it on the Mamba and had a lot of cogging. The 12 Turn is really a waste of money for me unless I buy a 3-cell lipoly pack, then I would have been better off getting the better esc and hotter motor. I have a 2-cell Etec that I am definitely going to be sticking with for right now.

Is there any way you could order the 9 Turn? That seems like it's going to be the right motor because it wont be stupid fast and still perform way over average on a 2-Cell lipoly. Who knows, I may go with the 10T since you have it in stock, without wind drag, the motor being weighted down, etc the 10T would hit 38mph on a 45T/19T spur/pinion, so around 34mph or so with real world factors, and that is still way fast! And if I really want more speed I could always drop it down to a 40T spur and drop a pinion tooth if needed.

Running the 10T on the Mamba succesfully would be great, but since it maxes at 41A I wouldn't want to risk spending $70+ on a mamba to find out it cant provide enough amps for the motor. Also, out of curiosity, would it be possible for you to get in MGM controllers or is Icare.com the only US site that is going to for now? It would be nice to be able to order everything from one site :)

Either way, you will probablly be receiving a Feigao motor order from me shortly! Time for work, have to pay for all this somehow ;)

Edit:
I read the email I got back (probablly from you) saying its hard to order specific Feigao's unless a lot of people will commit. I will probablly go with the 10T then, I highly doubt any of the 1/18 people I know want to spend the money to get an esc that will work with a 9T, etc. Oh well :)

[TimisTim]

Why not just order a mamba esc/motor combo? They seem to be tailored pretty well.

[NitroBoy24]

Why not just order a mamba esc/motor combo? They seem to be tailored pretty well.

Mini Quake + Mamba = Cogging.

It's a 200 sized brushless trying to power a truck that comes with a 380 size stock, not nearly enough low-end power.

[TheSteve]

When it comes to 18th scale the only controller worth considering is the Mamba, nothing else will come close to providing the level of control. Even if you did mount a U-Force in an 18th scale it wouldn't be as smooth as the Mamba simply because the Mamba software is tailored to the motor/drive requirements of an 18th scale. Given the price of the combos you can't go wrong with one, get the 5400Kv or the 6800Kv if you're sure you want that much power and enjoy...

*EDIT* - while I wrote the above you posted with your actual requirements.
If you want more torque stick with the Mamba controller but get a little bit larger motor. I don't think you want any of the Feigao line though, go with something like a Model Motors MiniAC/12(300 sized brushless) - or a higher turn version. You can also try a larger spur/smaller pinion to get the required torque.

[NitroBoy24]

When it comes to 18th scale the only controller worth considering is the Mamba, nothing else will come close to providing the level of control. Even if you did mount a U-Force in an 18th scale it wouldn't be as smooth as the Mamba simply because the Mamba software is tailored to the motor/drive requirements of an 18th scale. Given the price of the combos you can't go wrong with one, get the 5400Kv or the 6800Kv if you're sure you want that much power and enjoy...

*EDIT* - while I wrote the above you posted with your actual requirements.
If you want more torque stick with the Mamba controller but get a little bit larger motor. I don't think you want any of the Feigao line though, go with something like a Model Motors MiniAC/12(300 sized brushless) - or a higher turn version. You can also try a larger spur/smaller pinion to get the required torque.

Trust me, people have tried everything to get the mamba to work and there is one way that will work. You have to rig an RC18T spur to fit the MQ and then use on of its pinions. The problem is you wont have a lot of torque and with the 5400 it wont see 30mph after it's been geared down so much; which in my opinion is a major waste of money. I'm pretty much going Feigao or brushed since the Feigao's are cheap and meet my power demands.

The MGM 80A or maybe the 60A version (when it comes out) is probablly what I'll go for. If the 80A will fit I'd like to get it, since I could put a more mild brushless setup in a 1/10 s/t if the time comes.

[starluckrc]

The Mamba 25 will run the 10 turn. Don't let the rating fool you on the motor or controller. The motor will pull very little average current, and the Mamba 25 is rated for 50 amps surge. It sees spikes much higher than that without a problem. I doubt your batteries can deliver that kind of current anyway. Castle warranties the controller in ANY 1/18 setup. Shawn and I have already discussed this in detail.

[OptimaMan]

Heck, I had the Mamba 25 run my TC4 with 3s lipo! no problems... just a little warm. BTW, I'd disagree with TheSteve about the Mamba 25 being the best controller for 1/18th. For my Mini T, I liked the 12.97 better.

[starluckrc]

Should have seen the 32.40k in mine....LOL!

[TheSteve]

Heck, I had the Mamba 25 run my TC4 with 3s lipo! no problems... just a little warm. BTW, I'd disagree with TheSteve about the Mamba 25 being the best controller for 1/18th. For my Mini T, I liked the 12.97 better.

Which Software/Hardware rev Mamba were you running?
The first rev hardware wasn't overly smooth, second generation hardware and the newest beta software is pretty amazing.

[NitroBoy24]

The Mamba 25 will run the 10 turn. Don't let the rating fool you on the motor or controller. The motor will pull very little average current, and the Mamba 25 is rated for 50 amps surge. It sees spikes much higher than that without a problem. I doubt your batteries can deliver that kind of current anyway. Castle warranties the controller in ANY 1/18 setup. Shawn and I have already discussed this in detail.

Interesting..I will have to take your word for it. Hopefully tomorrow I can order off the site.

The only thing that I'm worried about is amp draw under startup, but if it can handle 50A surges then I dont think it will matter since the 10T can at the most draw 41A. I will email you about the MQ Brushless Combo Price and I can help guinea pig a Mamba/Feigao10T setup but tell all what the results are.

Oh and Starluck, check your sites email for one from me asking about the combo deal. Or just email me at aze30evolution@gmail.com or pm me on it. Just wanted to make you sure you know you've got mail since tomorrow is Sunday and you may or may not check it :cool:
Thanks for the help guys,
-John.