How will this setup hold up?

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  • blado
    Member
    • Dec 2009
    • 39

    #1

    How will this setup hold up?

    Hi folks. I have almost finished my Rigged Insanity. Looks good, really happy with it. I just want your input to ensure this won't melt, blow up or anything else tragic.

    I have two Turnigy 5000 mah 20c hooked in series for 14.8volts.
    Hooked to a Swordfish 120 amp.
    Using a 7xl pulso motor, around a 2000 but cant be sure.
    Using .150 drive cable with a 40 X 52 prop or 42 X 53 I think.

    Does this sound like a decent setup?

    Thanks in advance
  • electric
    Fast Electric Addict!
    • May 2008
    • 1744

    #2
    hmm. My first reaction is the C rating on the batteries. I know, as an example, you can "puff" a 25c rated battery in a SuperVee with a x445 prop. So I question whether the batteries are up to the task.

    There is an FEcalc program you can use to run the numbers and calculate about where you will be on speed and amp draw as I recall. I usually just start with a small prop and run a data logger to get my amp draw and work my way up.

    Others who are smarter than I will surely comment shortly...

    Comment

    • U1Racing
      Member
      • Apr 2011
      • 62

      #3
      if i were you i would at least run 40c batts. my p-spec hydro heats up a 40c battery in about 2 laps. how big is your boat?
      too much power not in the FE racing dictionary

      Comment

      • U1Racing
        Member
        • Apr 2011
        • 62

        #4
        just looked up the specs and i would go with at least 30c minimum batteries for the 26 inch boat but the rest of your setup sounds like it will holdup
        too much power not in the FE racing dictionary

        Comment

        • blado
          Member
          • Dec 2009
          • 39

          #5
          That's great thanks. I will look at buying those batteries then. I don't want to take any chances.

          Comment

          • Simon.O.
            Fast Electric Addict!
            • Oct 2007
            • 1521

            #6
            A 7XL on 4S is going to stress that esc, especially if the packs are not up to the game.
            As soon as the load comes on the V drops and the Amps go up and the speedie either cuts out or lets the smoke out ! Been there done that, more than once !

            Good packs are one thing but a decent size speedie is another.

            You may get away with it.
            See it....find the photos.....sketch it it....build it........with wood

            Comment

            • electric
              Fast Electric Addict!
              • May 2008
              • 1744

              #7
              I would agree on the ESC, should work, but it is kinda pushing it. Just start with a small prop. The other thing I forgot to ask is what are you using for your connectors? Deans? You might have an issue if you are. Again, not required to go to bullet connectors, but kinda on the edge if you used deans. What will happen with the deans is the solder will melt during the run and that will be it for the day. That is what caused me to switch to the bullets.

              The other thing to look at hard is how long are your wires from the esc to the motor. Should be short as possible. I once had a 180 esc hooked up to a neu motor and the wires were the standared 3 inches or so long, incredible heat build up. I cut them shorter and the heat issue went away. That convinced me of what others have told me about how important that is.

              I read somewhere that one of the sources of failure for an esc(and there are many) is that those wires get super hot and that heat gets transferred back to the esc. Not sure how big an impact it has, but it why not get it right.

              Hope that helps..

              Comment

              • blado
                Member
                • Dec 2009
                • 39

                #8
                I recently picked up some 5.5 bullets from MPG, a member here last week so I should be safe with them. I have made the wires short as you mentioned also. I think my saving grace is I won't be racing. This is a hobby/project for me. I hope to be on "wot" for no more than 30 seconds at a time. Thanks again for the input.

                Comment

                • electric
                  Fast Electric Addict!
                  • May 2008
                  • 1744

                  #9
                  The ironic thing about these boats is they run the coolest and best WOT. Anything less heats them up. Kind of counter intuitive to a degree, but true.

                  You know, in the end, you are just trying to eliminate as many failure points as possible to get the reliability up so you can have fun. The good news, is that any deffciency will make itself known, the downside is it usually means $"s and time. I have been doing this about 3 years now and am still learning a lot of things, but I gave learned if you play it "safe" you get a whole day of trouble free running fun.

                  I have done the blow things up routine and eveyrthing on the edge, which was interesting to a degreee, but it got expensive, and really, running a boat for like 2 minutes and then watching it up flames is really not all that much fun.

                  If you can spring with some type of device(there are few at different price ranges) to measure the amp flow (peak and average) it would be a good investment. This really allows you to prop up and see how that effects the amp pull which is the whole thing to watch because it causes failures to the (batteries,esc, and motor). Once I got that things got easier. No guessing.

                  Comment

                  • blado
                    Member
                    • Dec 2009
                    • 39

                    #10
                    Ok, I have a set of 5000mah 40c batteries on order. For argument sake, in a month or so I will let you know how it all works out. Thanks again.

                    Comment

                    • U1Racing
                      Member
                      • Apr 2011
                      • 62

                      #11
                      the 40c batts will be much safer and better performing, and will also run cooler in any boat, especially a rigger
                      too much power not in the FE racing dictionary

                      Comment

                      • blado
                        Member
                        • Dec 2009
                        • 39

                        #12
                        Electric, do you know of any brand names for that recorder you spoke of? It might be worth looking into. Thanks

                        Comment

                        • electric
                          Fast Electric Addict!
                          • May 2008
                          • 1744

                          #13
                          Sure,
                          Here are a few with different price points:
                          1. http://www.offshoreelectrics.com/pro...?prod=dh-wu100 (Good basic tool, easy to use, will give you some basic information about peak amps etc)
                          2. http://www.offshoreelectrics.com/pro...PRV4-LEADS-150 (This is what I am using, very good tool. This thing will give you volts, amps and has many attachments you can add later if you wish. The best one is the GPS for speed. You plug it into your computer after your run and you can get a full re-play of your run with the voltage and amps etc. Oh, you can also order the lcd screen and then see data while you are out in the field running) You really can do no better than this one.
                          3. http://www.hobbyking.com/hobbyking/s...dProduct=10343 I tried this one out to. Pretty cool if you can find it in stock.

                          In the end, I sold off the other two tools and just use item #2. It will give you more data about your boat than you could dream of.

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