MHZ XCAT 1400mm (55") build.

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  • Jesse J
    scale FE racer
    • Aug 2008
    • 7116

    #31
    Rich, I think I know what the problem is: no windshield! The dudes can’t see anything!
    So, the motors being far apart makes any little difference between the motors 10x more pronounced.
    How stiff is your tie rod at the back of the motors?
    I’m also wondering how your electronics are unified? Can you share a pic or a schematic to show how this is wired?
    Also, comfort yourself by the the fact that when you see a video on YouTube and it looks amazing.. you can bet there are some tuning hours behind it!!
    Keep trying little tweaks, one at a time and you’ll get her dialed!
    "Look good doin' it"
    See the fleet

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    • Rich
      Senior Member
      • Jan 2008
      • 551

      #32
      Originally posted by Jesse J
      Rich, I think I know what the problem is: no windshield! The dudes can’t see anything!
      So, the motors being far apart makes any little difference between the motors 10x more pronounced.
      How stiff is your tie rod at the back of the motors?
      I’m also wondering how your electronics are unified? Can you share a pic or a schematic to show how this is wired?
      Also, comfort yourself by the the fact that when you see a video on YouTube and it looks amazing.. you can bet there are some tuning hours behind it!!
      Keep trying little tweaks, one at a time and you’ll get her dialed!
      Lol I bet they cant see with a white windshield! The tie rod is stiff and I have the servos wired with a y harness. Unfortunately the gears stripped one the starboard side motor so it's going to be on the shelf till I get more...
      24 R/C vehicles and still counting...What budget?

      Comment

      • Jesse J
        scale FE racer
        • Aug 2008
        • 7116

        #33
        "Look good doin' it"
        See the fleet

        Comment

        • srislash
          Not there yet
          • Mar 2011
          • 7673

          #34
          Rich, I finally watched the second to last vid on my big screen. So I immediately thought ‘what servos are you running’? And was going to suggest a filter/capacitor in the lines from Rx to servos, But then I see you had an issue with a drive so is it possible that one was fighting the other an$ then clearly enough to break one side? Now this brings m3 to an issue that I had with my SW 300’s in my HPR. I had them set at a soft start and they would never really sync up. Dang thing would waggle around till it was up on plane and then go. The fix was ESC’s set to HARD start. Her is much better now. Just brainstorming.
          Shawn

          Comment

          • Rich
            Senior Member
            • Jan 2008
            • 551

            #35
            Originally posted by srislash
            Rich, I finally watched the second to last vid on my big screen. So I immediately thought ?what servos are you running?? And was going to suggest a filter/capacitor in the lines from Rx to servos, But then I see you had an issue with a drive so is it possible that one was fighting the other an$ then clearly enough to break one side? Now this brings m3 to an issue that I had with my SW 300?s in my HPR. I had them set at a soft start and they would never really sync up. Dang thing would waggle around till it was up on plane and then go. The fix was ESC?s set to HARD start. Her is much better now. Just brainstorming.
            Shawn
            Ok I must have deleted my post like 3 times because doing an edit on your phone causes you to push the wrong buttons....I have 2 promodeler 630in/oz servos which I think is plenty. I think it was an issue with the motor alignment because it got better when I put shims on the tie rod. I think the fact that the props are rotating in is causing the lower units to bow towards each other since the outboard is mounted to the hull with plastic and not metal. When I got the outboards I did notice that the gear mesh was tight. I also noticed that the starboard side motor (the one the blew the gears) did use more power than the left. I charged both sides in parallel (2x 6s packs 8000 mah each) the left took 5700mah and the right took 9000mah. Definitely something going on there. I ordered some gears but I won't see them for 3 weeks. I guess ill just focus on the MHZ Alligator with this outboard until I get the gears assuming I don't have Ice on the lake!
            24 R/C vehicles and still counting...What budget?

            Comment

            • Rich
              Senior Member
              • Jan 2008
              • 551

              #36
              Well since the outboards can't handle 12s, I decided to convert my xcat to twin inboards. Here is the first run: https://www.youtube.com/watch?v=TJyzrPNwWu8

              Question, I noticed the hull spins out in tight turns, I am thinking that I need to move the lipos more aft. What do you guys think?
              24 R/C vehicles and still counting...What budget?

              Comment

              • Jesse J
                scale FE racer
                • Aug 2008
                • 7116

                #37
                Rich, how long is the rudder? Post a few pics to help us assess.
                "Look good doin' it"
                See the fleet

                Comment

                • Rich
                  Senior Member
                  • Jan 2008
                  • 551

                  #38
                  The rudder is 6 inches long and about 3.5 of it is below the hull.20210418_074223.jpg

                  Are you thinking it's too small?
                  24 R/C vehicles and still counting...What budget?

                  Comment

                  • Rich
                    Senior Member
                    • Jan 2008
                    • 551

                    #39
                    I think we have a winner! I moved all lipos back to get the cg in the 29-30% range and bam! It runs great!
                    24 R/C vehicles and still counting...What budget?

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