I need to decide on what type of motor control I'll be using, any suggestions on battle proven gear? needs to handle following setup: each controller handles 2 550 size motors running on 12 volts, direct drive.
I use and recommend the Mtroniks range of electronic speed controls. They are waterproof, reliable and available in various amperage ratings. Wow, that sounded just like a commercial...They are good though. I buy mine direct from the UK, from www.huntersystems.co.uk to avoid middle-man price markups. They're still not cheap, but IMO they're worth it.
I second the recommendation for MTronics. I've used them in several different ships & am happy. Price isn't bad, even from 3rd-party (i.e. Hobby People). Compare vs. plain standard servo, 2 switches, & wire. For about $20 more (not counting time & effort) you get full proportional fwd & reverse - a very tiny share of the total cost of the ship. Waterproof is a very useful attribute in an ESC. Also, be sure to get one with instant reverse, if you can get it. Some units have delayed reverse. Measure your motors' stall current & double that for your ESC's rating. Follow the directions exactly as printed. Proboat is another make that several people like. I saw another one recently - smaller than MTronics, waterproof, & rated for 80A - but I don't remember the brand. Hopefully, the guy who had it will read this & chime in. JM
And most of them were Mtronics... Enough of them ate it that many people swore them off. Not to be totally negative, the Mtronics Marine 15 in my I-boat is still going strong and I have no intention of getting rid of it
I'll bet that most of those fried ESC's were underrated for the current they faced (especially while starting or reversing). MTroniks has an excellent reputation in the WWCC. They have never failed during battle. Proboat ESC's developed a habit of cutting power a few minutes into battle, leaving the victim to drift or sink at the mercy of others. We never could find out why, and they are not used here any more. I have not heard any other club complain of this problem.
Using a fuse or self-resetting circuit breaker rated at 5A less than the the controller's rated max is good insurance for any speed control. The only ESC failure I have had was self-inflicted by reverse polarity. This will cause the magic smoke to escape from almost any ESC.
It's very likely, Carl. I used a 15A one to run two 400's in my 26 sec I-boat. Brian K (who also had no problems) used two 15A ones, one for each 550 in his 24-sec Vanguard. Still, for most of them in use (at Nats) to fry...
It's a servo with a micro switch on either side. Moving the servo controls the microswitches...one of which provides power for forward, the other for reverse. Its simple, and cheap. I can build 3-4 MAGs for the price of one ESC, and have heard of MAG failures only on very rare occassions. I've seen more ESCs cook then heard of MAGs failing. Mike D
If you are talking about mine, it is a Team Associated/LRP AI Runner+. You have to be careful, though, as some of their range are not waterproof. The AI Runner si supposed to have a conformal coaing and they say it can be run under water. Wreno
Actually, I have seen quite a few of the mag switches fail. In fact, they have problems more often than ESC's in the NTXBG now that the bugs are worked out. Keep in mind that you have to size the ESC to the STALL draw of the motors, not the normal draw. A lot of guys try to run 2 or more 550's on a 20A rated ESC. After all, they only draw a couple of amps each at full speed, so there is plenty of reserve, right? Then their ship gets mossed, and the motors stall out and draw 89A or more each (check the specs on the Mabuchi site), even if new. Are you really surprised that a 20A ESC fries when you suck over 160A through it? The other common issue is failure to cut the red wire and using a separate RX battery. When batteries get low, the RX battery will discharge through the ESC, going the wrong way, and kill the ESC. Of course, if the directions had been followed, and the red wire clipped, the ESC would still be thriving instead of dead. There is an article on ESC's, lessons learned, on the ntxbg.org web site. With the exception of a waterproofing failure on an ESC I inherited with one ship, I have yet to have an ESC fail me, though I have seen quite a few Mag Switch failures. They have so much more to go wrong... However, use what you are comfortable with. Wreno
I've yet to see an ESC fail when they've followed my tech tip: http://ntxbg.org/KnowledgeBase/?category_id=45&menuaction=phpbrain.uikb.view_article&art_id=12 For the record, I've fried a couple myself early on, and watched a few other people fry some, which is where that article came from. If it's mentioned in there, somebody's done it. The Proboat ESC in Dallas is now 4-5 years old and doing fine, and the Mtroniks eco20 that was for propulsion has been on turret rotation duty for about that long. Properly taken care of, these things LAST quite a while. On the other hand, we've had the MAG switches are failing left and right in the our club ships for mostly mechanical reasons like switches failing, screws coming undone, CA cracking, servo's dying... etc. But they are proving to be a maintenance nightmare when trying to maintain the 8 club transports with them, so the NTXBG is taking the hit to convert them all to ESC's to keep them operational. I will say I've seen the Proboat's "shutdown" in Espana. It's actually a voltage drop causing a reboot which then activates the failsafe on the throttle (cause you have the throttle not at neutral when the reboot occurs). It should be rectifiable with a nice sized Capacitor both on the receiver and the on the Proboat's supply plug to keep the voltage levels good preventing the reboot. I suspect it's better with 7.2v packs instead of the 6V packs. Although with Espana, I put in an Mtroniks because the Mtroniks has finer level motor control, and I didn't need the extra 40A capacity of the Proboat on a ship with 280 motors.
Interesting comment that a lot failed at NATS. I asked for details on the IRCWCC forum as to what specific motor/ESC combinations failed at NATS, and got various replies that basically, one or two failed in the last two years due to known problems (one was a wire pulled out and case broken). Almost all replies were that the MTroniks were stable, reliable (if installed and rated appropriately) and are in widespread use. If a bunch failed at MWC NATS, how about some details? Model of ESC Number and size of motors attached per ESC (and whether geared or not). Fuses? Wiring? Were you running the BEC or with a separate RX battery. If running multiple ESC's did you clip the red wire in all but one? Were the motors capped? Any other helpful observations. Lets see if we can diagnose the problem. Cheers,
I'd say a dozen of them (Maybe more) failed at the 2006 MWC NATS. Some of them burned up in spectacular ways. Smoke and flame pouring out of them, was pretty interesting to see. This turned a lot of people who were using them off and some of us who were not decieded not to go down that road. As to why so many failed, I can see two reasons. 1. It was the first year most of the people were using them. I'm sure a few burned out because of some error in connecting them. 2. Since I know some of them were connected correctly and so many new ones burned up I think we may have got a bad batch of them. One of the members bought a bunch in bulk and sold them in the spring. These seamed to be the ones that died. The ESCs that were in ships the year before failed at a lower rate. In 2007 I only saw a couple go up in smoke. Not sure how many were being used, out of the 50 guys battleing I'd guess 1/3 had ESCs. I think going forward their failure rate will be more normal. They should fail about as offten as the MAG set up. If you size, install and protect them correctly they should be good for several years, just like the MAG. It becomes the captains choice to pay more for easier speed setting and some battle advantages or go with the cheaper MAG.
Interesting, Bob. Well, we are at least narrowing the timeframe for tha mass failure you are reporting. For 2006 and for the couple of failures in 2007, if we can get the information I requested earlier from the captains who had problems, we might be able to diagnose the problems thay had. Alternatively, if you were one of the captains who smoked one (or more), and you know the reason why, how about letting us know what you figured out happened (to save someone else making the same mistake). It would be interesting to know how many were from having too much draw for the ESC, how many from using the BEC and a RX battery at the same time, using 2 BECs at the same time, a non-waterproof ESC getting wet, wired backwards, wired to a Mag Switch, not fused, etc. Cheers,
I have never run with them. From what I saw in 2006 no one had fuses in line with them. They were all the water proof kind. I think they were the 15 amp rated ones. It was typicaly 1 ESC powering two motors on a BB, BC or CA. One of the better fires was in a Houston Class CA with the 380 motors. Smoked right in the middle of battle, no moss on the props, nothing weird going on... It left black stuff all over the under side of the deck, melted all of his hoses. Lots of smoke came up through the deck and SS. Wish I would have had a camera. I'm sure one guy wired at least one up backwards. He held it up and let it pour smoke out, he smelled like burt electronics the next day. When he walked by me I thought my stuff had started to smoke.
