Race Prep on my Crew Hull

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  • Steven Vaccaro
    Administrator
    • Apr 2007
    • 8723

    #16
    Nice Job.
    Steven Vaccaro

    Where Racing on a Budget is a Reality!

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    • longballlumber
      Fast Electric Addict!
      • Apr 2007
      • 3132

      #17
      Now for the big one, this technique can be applied to any boat you need to cut a flex cable to the proper length.

      First item is to address the position of the drive dog. I start by gathering a mix of props you “think” could possibly be used on this flex shaft and boat. I have an X440/2, X440/3, 45X55, M445, X447. The X447 may never be used, but it helps to make sure you have everything covered. Oddly enough, the hub for the M445 is longer than the X447 making it the longest. The X440/2 was the shortest. The goal is to make sure you have enough thread for all of the props, and mark where the drive dog needs to set. I mark the edge and I also remove the set screw and mark the hole for the set screw.
      Attached Files

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      • longballlumber
        Fast Electric Addict!
        • Apr 2007
        • 3132

        #18
        Next, using a grinding stone in my dremel, I grind a flat spot on the stub shaft. This spot is just big enough so the set screw will have a flat surface to compress against. After installing the drive dog and confirming that all of your props fit correctly with ample amount threads I disassemble and use a permanent form of loctite. In most cases I would use RED, but I didn’t have any on hand, but I did have retaining compound. I a small amount of retaining compound on the shaft at the point the drive dog gets assembled and rotate so that it’s coated well. I also put some on the set screw and tighten everything up. I want this to be a permanent assembly; once together I don’t want it coming apart.

        Oh, as you can see in the last picture, I put a slight chamfer on the leading edge of the drive dog using my belt sander... It's all about minimizing resistance in the water!
        Attached Files

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        • longballlumber
          Fast Electric Addict!
          • Apr 2007
          • 3132

          #19
          Now comes cutting the flex shaft to the correct length. As you remember before our motor alignment with the shaft/stuffing tube has already been set, make sure you have the flex collet loosened so our flex can travel all the way into the collet. Run your cable thru the strut and into the flex collet until it stops. What the flex shaft is getting stopped by is the motor shaft, meaning it can’t go in any further. With the flex shaft fully installed go the back of the boat and measure how much needs to be cut off. This is very important; when measuring, you will need to measure from the back of the strut to the leading edge of the drive dog. Mine was right at 4”. Hold on, because cutting off 4” off the flex shaft would make it too short. You want to take 5/32” to 3/8” off of that dimension. This will build in a preset gap at the strut. Remember the golden rule; measure twice and cut once and you can always remove material, but can’t add…
          Attached Files

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          • longballlumber
            Fast Electric Addict!
            • Apr 2007
            • 3132

            #20
            Now that I have the correct dimension and my flex cable marked, I use a cutoff wheel and my dremel to cut the flex shaft. I use my belt sander to clean up the cut end and put a chamfer on the end. Slide in the flex making sure it’s seated completely in the collet and check to make sure you have the proper gap!

            Later this evening I will be soldering the end of the flex and finish getting this boat ready to run at tomorrow’s practice.
            Attached Files

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            • longballlumber
              Fast Electric Addict!
              • Apr 2007
              • 3132

              #21
              Originally posted by Steven Vaccaro
              Nice Job.

              Thank you Sir...

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              • Rumdog
                Fast Electric Addict!
                • Mar 2009
                • 6453

                #22
                Great thread, Mike. Should help a lot of guys get their Motley's really ripping!

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                • longballlumber
                  Fast Electric Addict!
                  • Apr 2007
                  • 3132

                  #23
                  Originally posted by Rumdog
                  Great thread, Mike. Should help a lot of guys get their Motley's really ripping!
                  Thanks Rum, I appreciate you comments... Half the fun for me is actually working on the boats, not just running them.

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                  • longballlumber
                    Fast Electric Addict!
                    • Apr 2007
                    • 3132

                    #24
                    Ok… I finally got things finished up last night. I needed to finish up the flex shaft. I know there are different theories on this but my preference is to solder the end of the flex. I use a Weller 200/260 watt gun (not an iron). Getting the end of the flex hot enough for the solder to flow can be difficult and the heavy duty gun seems to work ok. I am sure that some people use a torch, but that has its own set of difficulties. I also use Stay Brite brand solder. This stuff comes with its own acid flux and has a small amount of silver making it a little stronger than you typical 60/40 lead solder. Because of the small amount of silver it does have a higher melting point.

                    I mount my flex in a small vice. There are some nice V-groves the run length wise in the vice blocks that allow me to lay the flex cable in to hold, but it’s not so tight that I can’t rotate the flex too. This helps with cleaning and soldering.

                    First step is clean clean clean…. I first wipe down the end of the flex with acetone. Next, I use the acid flux (Stay Clean). It only takes a couple of drops as you rotate the flex. I keep a Q-tip on hand to help coat the flex. Remember this stuff IS ACID, so I keep a well dampened rag close by (water neutralizes acids).

                    Once you have the end of the flex cleaned I take the solder gun and start heating up the very end of the flex. It will take a little for the flex to get hot enough, but once it does I start feeding the solder along the flex. Don’t worry about how it looks. Make sure your solder is penetrating the cable. Once your satisfied let everything cool off.
                    Attached Files

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                    • longballlumber
                      Fast Electric Addict!
                      • Apr 2007
                      • 3132

                      #25
                      Once cool, I took the soldered end to the belt sander again. Smoothed everything out and put a chamfer on the cable end… PREST-O BANG-O we are done with the flex!
                      Attached Files

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                      • longballlumber
                        Fast Electric Addict!
                        • Apr 2007
                        • 3132

                        #26
                        Last couple of easy things… I reinstalled the servo, again, swapping out the Phillips head screws for more user friendly socket head sheet metal screws, and washers.

                        I will admit, I did cheat a little. I snagged my other AquaCraft Speed control and swapped it out with the new one. I wasn’t going to have time to solder on new 5.5 bullets last night. No worries, it’s the same controller.

                        It’s getting wet for the first time this afternoon after work!!!!

                        I hope everyone found one or two things useful in this thread. I will try and keep it up to date with my Eagle Tree Data. I am still working to understand using the Eagle Tree effectively, so bear with me…. Stay Tuned

                        Later
                        Mike Ball
                        Attached Files

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                        • maxmekker
                          Senior Member
                          • Jul 2010
                          • 412

                          #27
                          Great tread(even though I have a MG) Now go out and make a video :-)
                          Drammen rock City

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                          • Grimracer
                            Senior Member
                            • Nov 2008
                            • 662

                            #28
                            Nice Job Michael..

                            Now that you have seen the boat from start to finish everybody has an idea of what, at this time, has to be done in mass market and what tid bits still need work.

                            The things that Michael brought forward here are the same things I do to my boats less replacing the screws and drive system.

                            Some day with the help of our great customers we will get each and every boat better and better..

                            Something you have to please take time to understand.. I have been "Racing" RC boats for over 20 years.. as easy as it might seem to "just do it right" meaning make it like Michael did, Its a balance of cost... To me all the little issues are HUGE.. but have to be taken as a bump in the road and as we continue, we WILL align!

                            Regards

                            Grimracer

                            Go get em Buddy!

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                            • wparsons
                              Senior Member
                              • Aug 2010
                              • 461

                              #29
                              How'd the maiden go?
                              Light travels faster than sound, so people may appear to be bright until you hear them speak.

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                              • longballlumber
                                Fast Electric Addict!
                                • Apr 2007
                                • 3132

                                #30
                                Sorry,

                                I have been out of town for work. I will reply tomorrow about my runs last week.

                                Later,
                                Mike

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