I know a lot of people will not use ESCs because they are afraid that magic smoke that makes the device work will succeed at escaping. What ESCs have you used / worked OR not worked on your boat & What was your setup (fuses,motors,voltage,water-cooling)?
Three common ESC mistakes are: They let the ESC overheat. ESCs, especially R/C Car/Truck ESCs assume that the device will not be cooped up in a water tight container or watersealed -- They assume a constant air flow over the "fins" (heatsink). Our ESCs MUST be watertight, but don't just shove them in a plastic box. Use one of the water cooling techniques to bring moving water to and from the ESC (without getting it wet!) They use an underrated ESC. The first thing you need to know about an ESC is: "Is this amp rating continuous or peak?" Remember, like amplifiers, "peak" typically means maximum possible current possibly at some sub-zero temperature. Continuous or RMS is the sustained current output with "standard" cooling. Further, don't forget about the stall current!! If your motor pulls 5Amps continuous, don't use a 6Amp MAX ESC! Figure out the stall current is for your motor & buy an ESC that will support it! They don't use a fuse. If your ESC is rated at 25A MAX, fuse it at 20A. Its better to blow a $.50 fuse than a $50 ESC!
I'm using a MCD Minicon Max to run my twin center motors. This is the first time I've used this product, so I'm not recommending it to any one, yet. But look at the specs: http://www.modelcontrol.com/maxminicon.htm 50 amp. Continuous current capacity, 120 amp., 5 seconds It's heatsink also accepts a watercooling tube. I also did one more step... I talked to people that have use each product that I was considering. This product came highly recommended from a friend who writes for a major boat hobby magazine. He said "unlike [some] other ESCs, this one performs at its rating levels".
I use a Viper marine ESC (20 amps) in Spahkreuzer and Luigi Cadorna. Spahkreuzer recently tested running current at 3 amps, stall 6 amps, and the commercially-made waterproof ESC sits in the bottom of the bilge, where it is frequently submerged. Cadorna's motors tested running current 2 amps, stall 4 amps, and again the ESC sits in the wettest part of the boat. Needless to say, I have never smoked an ESC by overheating it. I also like the Viper marine ESC because it's completely waterproof. I can drop it in the bottom of the boat without worry, and I've been sunk several times without ill effect. On the other hand, I have fried several ESCs by mixing receiver batteries with BEC. I toasted one ESC by running a servo test with a receiver battery, and I have seen several other ESCs melt down because of receiver batteries and BEC mixups. Other times, an ESC will let out the magic smoke for no apparent reason, or won't smoke but will act temperamental. Most recently one battleship skipper had every wire in his ship melt for no apparent reason. Also, with Proboat ESCs I have found that after several battles they start to shut down. We stopped using Proboat ESCs after several boats shut down in the middle of a fight.
I've let the smoke out of one Mtroniks Eco 15. Turns out I had miswired my main battery lead. They really don't appreciate reverse voltage. I keep them cool by placing them in the path of the stream of water coming from the primer hole in my pump.
I have a smokless Mtroniks Eco 15 too; its previous owner (apparently) used it with 25A+ stall race motors.
Just waterproof the esc, then mount it in the belly of the ship so that when the water comes rushing in, it cools the esc.
I'm thinking about doing this... but you still want to make sure you have done the math. Wires will burn, and if you run your boat on the test bench & it burns up... then you have a bunch of work replacing 1/2 your hull.
In my I-boat, the Mtronics 15 sits in a little pocket in the water channel. As soon as I get hit, water is cooling my ESC. With a hug and slug boat, that's pretty soon
If the boat "burns down" during the battle, it will make the battle more realistic. Just hope theres someone with scuba there to retrieve the remains.
Fireworks aside, there is no good reason to risk your time and money on an "unknown esc"! Do the math & figure out what current reqs you need before you get in trouble. I had a fire on one of my boats... I had used crappy wiring... It was pretty cool / realistic. I DID have time to jump in to the water and shut her down before I got flame, thankfully.
For all those ESCs that reportedly failed at NATS, it would be interesting if someone could give the details. 1) Model of ESC/rating 2) Type and number of Motor(s) controlled 3) Whether there was a separate RX battery involved 4) Gearbox? I would be willing to bet that most were running one or more 550 motor on a 15 or 20A ESC. Seems a lot of people do not believe the Mabuchi specs of stall draw on these motors (the new ones are 85A, some of the older surplus models are 89-90A, as I recall) And, to think, it is common to add stress to the motor with drag disks. Hmmm - intentionally drawing heavier electrical loads..... Been using ESC's from the beginning. In the process of swapping out my last personal MAG switch (came with the ship) before the next battle. For me they are more energy efficient, give you better control over your speed, take up less space, make wiring simpler, and are more reliable (less failure points than 3 discrete mechanical devices wired together). And, you just toss it in the bottom of the hull - no need nor desire for a water-tight box. Other people may have mileage that varies, of course. However, I do get a size with a rating higher than the stall rating of my motors. And, I read and follow the instructions on the BEC wire and capping the motors. Cheers,
What ESC would be recommended to run a pair of 550's? I'm going to be doing some experimenting with ESCs (only ever used MAGs), and am kinda looking for a one size fits all ESC. Since my two biggest ships (Courageous and Invincible) are both running 2 550s, that's probably a good place for me to start. I'd really rather not start off by getting the wrong controllers, and letting the magic smoke out because I bought the wrong things. As these are small gun ships, instant, 100% reverse is a must. I also want to look at using an ESC as my pump control. In treaty we regulate the pump flow, and after a year of using mechanical means to do so, I am looking for something simpler and more reliable. Any assistance and advice would be greatly appreciated.
I would take a standard Mtroniks40 & find the max continuous current (probably 40A) & put a slow burn 40A fuse on the +input.
Word of warning, I ordered an ESC from them a while ago and never recieved it and they wont answer the phone or return my calls.
I got mine, but rather much did not like it. Its not water proof & one went dead after sea trials. (no water, no reason.)
I've heard that the guy at MCD has had some medical issues that have kept him from filling orders or replying to inquiries. I don't know if he's back up to speed yet or not, but I have heard of plenty of others who have had similar contact/order problems, some for a very long time. JM
I've been using a Chinese clone of an ESC offered by Pro Boat to good effect. They are completely waterproof and will handle 50 amps forward/20 amps backwards. They can be had for around $35 - $40 off eBay. I have one in my Richelieu and in a Lutzow. The Richey uses two 550 motors geared around 2.5 to 1 turning 1 3/4" x 25 pitch props on 6 volts. The motors are wired in parallel to one controller. So far, I have had no problems with the ESC going up in smoke even with a stalled motor (a bb in one of the gearboxes). The ESC simply shut down the propulsion system to prevent damage, but maintained radio power for control. The only drawback to the ESC is it's half-speed reverse. Reverse is instantanious, but only runs at half speed. I've worked around that oddity by changing the props and adjusting the ESC's forward end points until the ship runs 24 seconds forward at 50% forward throttle. Not the best solution, but one that works for me. Overall, I'm satisfied with it. Especially the low cost. Recently, I picked up a Chinese made 100 amp forward/60 amp reverse ESC. It's going into a cruiser (can you say overkill?) for testing purposes. I'll let you know how it works after the MWC Region 3 regional battle in April.
