I did look both here and in electronics and haven't seen this question. If it is a repeat I apologize... I am toying with using a Viper25 in my USS Indianapolis. I am setting up a radio box similar to the one depicted by Brian Kohler on the MWC site. I hear ESC tend to get hot. Would putting it in the radio box be a bad thing (tm)? I know they are water proof but I figure if I have the room in there may as well do it. I still have my BC micro switches for that but was pondering getting a Mtroniks from Strike Models..
I agree, if its waterproof then use as intended. You could just velcro to the top of the box. Marine goop works better for holding down velcro than the glue it comes with, in my experience. I am getting the banebots 12/45amp version that is not waterproof. Since the unit will run the standard 500 motors well below its max it should stay cool enough in the radio box. If not I will add an aluminum heat sink to it. I have heard that since ESC are designed to run much higher voltage that the heat dissapation is less when running with lower voltages like 5V or 6V so it may not get that hot. Only testing will tell.
My waterproof Mtroniks esc sits in the bottom of the hull, next to the pump. The spray from the pump primer hole hits it right in the middle. Cooling is not a problem.......
Mine is the same as Darrens. The ESCs generally get hot is you limit speed allot with it. If you use gears and props that get you close to speed or on speed you shouldn't have too many heat issues. J
Mine also sits in the bottom of the hull where it will get wet quickly. The only time I have had them fail is when I plug them in backwards!
For the MTroniks - put it in the bottom where the water can help cool it and you will be fine as to heat - they are designed to be waterproof and installed this way. If you are new to ESCs, I strongly suggest you read the manual and the article "ESC's Lessons Learned: in the NTXBG.org knowledgebase. Know what to do with the red wire in the servo connecion. Also, make sure your ESC is sized to the stall load of your motors. While the Viper series is supposed to have some overload protection, keep in mind that 550 style motors can draw over 85A EACH ad stall. So, Jadfer. even the Banebots 12/45 might even be a bit strained on a full stall (85A is higher than the the 45A max rating, right?) even though the normal draw, with clear props. might only be 1-2A on the bench. If it fries when your ship gets mossed, or hits a rock, do not blame the ESC. The specs indicate overcurrent protection, so you may be OK. Let us know how it works out. You can waterproof many non-waterproof ESCs with Scotchkote, of course. Cheers,
I learned about stall current after my last post here but alas most of these motors I have seen for our hobby don't have any specs. I am trying something new for waterproofing based on a suggestion from an electronics vendor. I sprayed the ESC with a silicon spray 3 coats each side and wasn't satisfied so I put some marine goop on it. I am not sure if there are any chemicals in the goop to damage the unit so if there is I spent $30 to replace it which is the same I would spend if the silicone spray didnt work. I am hoping the plastic gear I have in the ship will break before any potential 85 amp stall current builds up in the ESC. In this instance I am using it for a single motor - single prop Baden so the weight is low also. see ya
Motor specifications are sopmetimes hard to locate. For regular common Mabuchi types, however, look here:www.mabuchi-motor.co.jp/en_US/product/p_0304.html - you should be able to find what you want and identify your motor. I have not found a good source for Johnson or Wah Ming motors. Maxxon specs can be had, gut navigating the labyrinth can be tough. With an MTroniks ESC, there is no need nor deisre to cat it further - it is already fully sealed. In fact, adding additional coating will merely degrade the heat-sink's ability to dump heat. As for the stall current - 85A+ is the stall current of 550's (aka Speed 500s) each. A 555 or 545 is much lower, like 6-10A (the RPMs are also lower, which can be a good thing) and are a similar size format Whether you want or need a motor that big..... In Big Gun, for the Indianapolis, I would say absolutely way overkill. As noted, 2ea geared Speed 400s (aka 380s) will push a Rubenesque Richelieu well overspeed. I seem to recall we measured it at about 49kts in our scale, which is about 23sec/100' or 4.9km/h actual speed. Also keep in mind that, at startup, the motor draws a surge which can be much of its stall draw momentarily. Cheers,
Well I am starting to do the wiring and I am coming back to this. The thought of using an ESC is getting mighty tempting. Since the MTroniks have a stall fail safe would it be better to go higher on the ESC rating? If one was using 550s with reduction gears (that was what came in my cleveland running kit) and since the stall amperage of the 550's are 85 +- would the 40 be better? I am thinking the higher rating the least likely the failsafe would kick in if I was mossed. This would also be for my second project a class 5 dn (either bulged Tennesee or Iron Duke). Since there is no weight difference between the two I do not see why not. However, my premise is that the lower rated ESC also has a lower failsafe. I can not find any info on that on the MTronik site. I just noticed that Strike models also has a 75 but I don't see that on the MTroniks site. On another note, does anyone know the weight of the viper 75? Is it 55g like the rest of the viper esc?
Higher rating is always better but if you are using gears , you should be ok, I used gears in a sodak and a Arizona and was able to run 15 amp mtroniks with no problems for years. i didn't burn one out until I went direct drive. That was too much for it.
We dont raun anywhere near as fast as you fast gun guys so sucking loads of amps isn't really an issue. Getting weeded up will be a pain but in my boat I've got a viper 25Amp esc and have had it for years now and it handles everything except the pumpI had 4 X 380's then took the outers out and now just run the inner props with the 2 X 380 style Mabushi motors. I also put fuses in the leads to the engines so that if one motor weeds/stalls I wont allow it to pull over 10amps (we use 380 style motors not the big ones) Like Darren and Wreno said, my ESC sits in the hull between the motors where the water pools to cool it. Never been an issue. You can get resettable fuses too if you're inclined just to reset it rather than find why it blows. Cheers
