I am having problems with my ESC cutting in and out. I am using the Viper 20 on a DKM Lutzow running direct drive 380's. When the pump is hooked up the ESC will completely cut out and reset then come back on a few secs later.. If I unhook the pump the esc will only cut out slightly but not fully reset. This only happens when running at full speed. Havent had any problems with half power or less. I have gone through all of the wires and everything seems fine. I have also hooked up my Viper 40 and it has the same problem. Any thoughts or suggestions would be great. Electrical info: I am using NIMH 7 and 8 cell bats. I run the positive/red wire from the bat to a bus bar and then from there one wire goes to the esc and one goes to a switch that activiates the pump, then out to the pump. The negative/black goes from the bat to an on/off switch then to the bus with two wires from the bus going to the esc and one to the pump.
A few questions to help diagnose the issue: What drive motors are you using, and what is their amp draw with load? (without load if not possible to determine draw with load) Are your motors capped? (capacitors added to the terminals-drive and pump) What radio frequency: 75MHz or 2.4GHz? What pump and pump motor are you using, and what is it's amp draw under load? What is the capacity of your battery pack in Ah or mAh? What size props are you using? How many seconds is full speed for your rule-set? First guess, I think you might be drawing too much amperage for your battery pack (discharge rate too high for that pack), or you are taxing your ESC to it's limits and a safety cut-off is kicking in.
The batteries are 7 cell 4600mah and 8 cell 5000mah. I dont really know any of the information regarding the motors. I got them in the strike hardware kit. I dont believe I have any capacitors on it. I dont currently have anything to test the amp draw. I have the small strike pump. I am using a Hobbyking 2.4ghz 5 channel. The props are also from the strike hardware kit. It doesnt matter whether it is in the water or not. Will do it either way. MWC Lutzow is 24 secs. The first couple times I ran it, I had no issues. I will try to get some more of the information when I get the chance.
Are you using oilite bushings on your stuffing tubes or the telescoping brass? The bushings tend to be a bit tight which make the motors work a bit more and draw more power. Some folk have had good luck running a needle file or 1/8" bit through the bushings and opening them up a bit. If you can get your hands on an ammeter, knowing the current draw of your motors under different conditions is very useful in figuring these things out.
Ken, thats a bit hard for me to quantify, but I'll give it a try. Note: The following is just my experience and opinion. Others may hold different views. YMMV. Generally I've found that asking myself 'does this seem reasonable?' is a good guide. If they're not connected to the motors and you have just enough grease to lightly lube/seal the bearing surfaces of the bushing that the shaft contacts, the shafts should spin fairly freely (wheel collar on the inside end, prop on outer, it should be able to be given a nice spin that doesn't stop immediately). That 'free-ness' will decrease once the stuffing tubes are packed full of grease, if you're into that. I freely admit mine are not stuffed to any sort of limit. The shaft shouldn't rattle or play side to side in the bearing, if it does, they are too open. If your bushing is loose (haven't fit it tube the stuffing tube yet) you should be able to slide and spin it freely on a prop shaft.
Actually Nick that is very helpful. Wisconsin is my first build and I just installed the shafts this weekend. They essentially were free spinning until I packed the stuffing tubes with marine grease. After following this blog, I was concerned that something similar waould happen to my ship.
I would cap your motors. 0.001 micro-farad capacitors are what I use--be sure to get the flat ceramic disk kind. Interference from the brushes can cause receiver problems even with 2.4GHz systems. Last year my Kirishima went full auto on the stern gun when I turned on the pump. I capped the motors for the next sortie and the problem went away. Looking at the Strike website, assuming you are using one of their 6V motors, your pump is drawing more than 9 amps at 9.6V (V increase = A increase for DC, IIRC). Let us assume your drive motors are the same can, and you are getting similar load on those. Now, let's round each motor up to a 10A draw--so 20A for drive and 10A for pump. That is putting you at a 6C discharge rate on your eight cell pack (out of juice in 10 minutes with all motors running). 6C is not really excessive for NiMH, but if they are cheap cells, it might be too much. Also that 20A drive is pushing your ESC to it's rated limit. Keep in mind this makes a whole lot of assumptions, and I am rusty in my electrical theory--bottom line: test current draw in Amperes with an ammeter or multi-tester. This will really help iron out the issue by giving you good data. Borrow one or spend $40 on a decent one. Nick, Thanks! I was starting to worry about my bushings a little. I will have to pull the shafts and apply the needle file on my current build.
I am going to try to test the amps this weekend. As soon as I find out I will post. Thanks for the info and tips.
I have been using the RCE220 for years now with no issues on any of the ships. www.teamdelta.com/products/prod2.htm
