Another Hare-Brained Idea

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  • Dr. Jet
    Fast Electric Addict!
    • Sep 2007
    • 1707

    #1

    Another Hare-Brained Idea

    So I have a new pond to run my boats where I don't have to deal with a lot of floating reeds. Most of the people are there to fly RC float planes, but boats are welcome, and smaller boats are even more welcome. One of the club members approached me the other day when I was running my 1:20 Short Circuit and asked about a good hull candidate for club members to race and stir up boating interest in general. The requirements were that they be reasonably quick, but not insanely so, easy to get on the water, small, and cheap. I have all sorts of hulls that fit those requirements and the 1:20 scale hydros would be perfect; BUT WAIT!........ There was one more requirement.... They had to handle rough water when the wind came up.

    That got me to thinking (uh oh! ). What do I have in my inventory that fits all of those requirements? All the hydros are out. The twin cats are out due to the complexity. The single cat is a possibility, but when flipped, that's it. A self-righting, V-hull boat is what's needed. I have the Geckos, but the self-righting feature is kinda iffy with them now that they run the lighter weight LiPos. What is really needed is something with a flood chamber for positive self-righting. I suppose I could put a flood chamber in the Geckos, but that's a lot of ex post facto work.

    Pre-molded composite hulls would be the best option for simplicity's sake. They are easy to get on the water with a minimum of work, and even more so when the manufacturer has a package deal with much of the hardware included or sometimes already installed (my Geckos and other MHZ hulls came that way at the time). The Germans have some hulls that will meet those aforementioned needs, but shipping is expensive. What to do?? How about yet another wood build? Now, I realize I already have a lot of irons in the fire that I need to finish up first. But both of the 1:20 scale hydro designs are complete with just some final tweaks needed to the running models. The same applies to the single-step hydro. I wanted to build a final prototype of the twin cat, but I really should do more hull tuning work on the single version before I finalize the plans for the twin. I already have the Micro Scat Cat Twin running, and propeller tweaking is in the works. The rigger project will be next on the bench; THEN, I can think about building another wood project from the ground up.

    I can still do a lot of the preliminary design work on the new project as time allows. I don't need workbench space; my computer has plenty of room for all the ongoing projects. This new project should be something really easy to build, with a low parts count. I should do it such that there is no part longer than 12" in order to make it easy to find building materials. And it will get a flood chamber! An added benefit is that the diminutive size will accommodate the lengths of special "homemade" strakes that I can produce. I always like doing something a bit on the "different" side, and this should be no exception. I think I will design something that employs the well-tested power system of the little stepped hydro with the 2030 inrunner (3100 Kv), a straight shaft, and a de-tongued 26 mm CNC aluminum prop. I think I'll be able to have enough room for a 2040 motor, but that would no doubt be overkill in a 12" hull.

    Hmmmm... I have an idea!!

    Oliver Seiss (Hydro & Marine) has been making and selling essentially the same list of hulls for decades now. I have some of his cat and hydro hulls in my inventory and the construction quality is quite good. On his site he has listed the perfect hull for my proposed project. It has the ability to install a flood chamber, it is a stepped V-hull, so it should do well in rough water, and it is a bit quirky in appearance. At well under 500 mm, it already fits the definition of "Mini".

    My plan? I've ordered one, and I will install running gear using stuff I already have in my parts inventory. I have an assortment of 2040 motors with water jackets that should work in a hull designed around a Speed 400 brushed motor. Yeah, shipping was a little pricey, but I ordered a bunch of other parts to amortize the shipping over a greater number of items. I'll build it "quick and dirty" to see IF I like it. If I do, I'll scale it down to make a 12" version out of wood. I'll forgo a lot of the sexy compound curves and simplify some things, but the heritage will be obvious.


    Stay tuned....
    Last edited by Dr. Jet; 03-09-2020, 01:32 PM. Reason: Cut-and-paste doesn't keep all the punctuation...
    A nation of sheep breeds a government of wolves
  • NativePaul
    Greased Weasel
    • Feb 2008
    • 2759

    #2
    Length for length a decent rigger will maintain at least the same speed in rough water as a decent mono will.
    Paul Upton-Taylor, Greased Weasel Racing.

    Comment

    • willy43
      Junior Member
      • Aug 2015
      • 22

      #3
      How about a Sonicwake ??

      Comment

      • Dr. Jet
        Fast Electric Addict!
        • Sep 2007
        • 1707

        #4
        Originally posted by NativePaul
        Length for length a decent rigger will maintain at least the same speed in rough water as a decent mono will.
        Yeah, but it still looks like a 'rigger. It's not always about going fast, sometimes it's how you look attempting it.
        A nation of sheep breeds a government of wolves

        Comment

        • Dr. Jet
          Fast Electric Addict!
          • Sep 2007
          • 1707

          #5
          Originally posted by willy43
          How about a Sonicwake ??


          WAY too big, WAY too fast....
          A nation of sheep breeds a government of wolves

          Comment

          • Dr. Jet
            Fast Electric Addict!
            • Sep 2007
            • 1707

            #6
            A bit away from the topic of this thread, but I didn't want to start a new one for just a short note. I'm completing a lot of projects that have been languishing for a while and this is one that I've had in the works for 12 years. It is the BBY Micro Scat Cat Twin. It's gone through several upgrades and revisions over the years, but was never 100% perfect. Now it is; it looks good and goes like stink. If I get some good vids of it, I'll post links to them here.

            Just another thing finished up so I can work on the new project.
            Attached Files
            A nation of sheep breeds a government of wolves

            Comment

            • Dr. Jet
              Fast Electric Addict!
              • Sep 2007
              • 1707

              #7
              Back on Topic.....

              You've all heard me bellyaching about the limited supply of little props.

              Native Paul from the UK has come up with many great suggestions in the past, and in one thread where I was bellyaching about little props, he mentioned a 26mm Graupner prop that was pretty decent. It was unusual in that it fits a M2 threaded shaft, but I can deal with that.

              This was a year or so ago and I searched all around at the time and finally found a few in Germany. Shipping was prohibitive.

              Low and behold, I was wandering around the OSE Store, and what do you think I found??

              You guessed it. Steve has those 26mm props. I have some unhardened 304 stainless steel shaft. I might be able to cut some M2 threads on them.

              Or, there's always this option: https://www.ebay.com/itm/Model-Boat-...Bq4_b8wvhhJjeg

              It's entirely possible I could do this Hare-Brained project using all over-the-shelf hardware.
              A nation of sheep breeds a government of wolves

              Comment

              • Dr. Jet
                Fast Electric Addict!
                • Sep 2007
                • 1707

                #8
                Well, I bought Steve's entire inventory of 26mm Graupner props. I hope he can still keep a few in stock for future needs. My plan is to use a water-cooled Hacker B20 18L (3080Kv) and a 30A ESC with added water cooling in this Hare-Brained 12" stepped mono. I hope the 26mm will be enough for this setup on 2S. I'll be able to swap the 2mm shaft with M2 threads for a 2mm shaft with M4 threads in seconds, so I can always prop up if necessary, but I'm thinking the small prop is a good start.

                Stay tuned.......
                A nation of sheep breeds a government of wolves

                Comment

                • JimClark
                  Fast Electric Addict!
                  • Apr 2007
                  • 5907

                  #9
                  A 1/16th scale hydro would be perfect run on 2s lipo. you could get Mike L to laser cut kits
                  "Our society strives to avoid any possibility of offending anyone except God.
                  Billy Graham

                  Comment

                  • Dr. Jet
                    Fast Electric Addict!
                    • Sep 2007
                    • 1707

                    #10
                    Originally posted by JimClark
                    A 1/16th scale hydro would be perfect run on 2s lipo. you could get Mike L to laser cut kits
                    I have a 1/16 scale 2S boat in my inventory. In fact, it was THE HULL that got me into the whole 1958 Short Circuit fascination. I liked the double-entendre (triple-entendre) of that name. I thought the color scheme was rather striking and I could do all the decals on a black and white printer.

                    I powered it with an 11-Series NeuMotor (don't recall which one at the moment) to keep it light, as it was built for scale looks and not racing. I never finished it though. I still need to make the exhaust stacks, mount the steering wheel, paint and mount the driver, and make the removable cowl attachment points.

                    It's on my list of things to do....
                    Attached Files
                    Last edited by Dr. Jet; 03-26-2020, 04:33 PM.
                    A nation of sheep breeds a government of wolves

                    Comment

                    • Dr. Jet
                      Fast Electric Addict!
                      • Sep 2007
                      • 1707

                      #11
                      Originally posted by JimClark
                      A 1/16th scale hydro would be perfect run on 2s lipo. you could get Mike L to laser cut kits
                      Does Mike L make 1/16 scale kits? I thought he was making 1/10 and larger.
                      A nation of sheep breeds a government of wolves

                      Comment

                      • JimClark
                        Fast Electric Addict!
                        • Apr 2007
                        • 5907

                        #12
                        No but I bet he could rework one down to !/16th. Doug campbell has a couple of 1/16th scale kits and there are always Gary Findlay plans still out there
                        "Our society strives to avoid any possibility of offending anyone except God.
                        Billy Graham

                        Comment

                        • Dr. Jet
                          Fast Electric Addict!
                          • Sep 2007
                          • 1707

                          #13
                          The 1:16 Short Circuit above was from Garry Finlay's Plans. Some build photos are attached.

                          I don't know how well the hydros would do when it gets windy though. That's why I'm planning a V-hull for my Hare-Brained idea.
                          Attached Files
                          A nation of sheep breeds a government of wolves

                          Comment

                          • Dr. Jet
                            Fast Electric Addict!
                            • Sep 2007
                            • 1707

                            #14
                            Well, the hull I ordered from Germany has arrived and I'm re-thinking my power options. For this project, I want to use a water-cooled inrunner. The air-cooled boats are fine for sport running, but if you want to push things, water-cooling is a must.

                            In my inventory, I have a Hacker B20 12L (basically a 2040 motor) that I'm thinking is too small for this hull, but would be the perfect candidate for the shrunken 12" version I'm planning. I have an old Aveox 1005 1.5Y but with a Kv of 5500 rpm/V, it may be too hot for a V-hull. I need something more in the low 3000s with enough torque to spin a 29~31mm prop. I have an 1112/1.5D NeuMotor, but that's a 1200-Watt motor and belongs in a pylon racer or a big rigger.

                            What to do?

                            Pick a common 28mm inrunner with a Kv around 3200~3300. They're cheap and plentiful. Is that the solution for an "All-out" racer? No, but it will get you pretty close. I can always swap out for the appropriate 11-Series NeuMotor at a later date.
                            Last edited by Dr. Jet; 04-02-2020, 06:01 PM.
                            A nation of sheep breeds a government of wolves

                            Comment

                            • Dr. Jet
                              Fast Electric Addict!
                              • Sep 2007
                              • 1707

                              #15
                              I added an uber-thin sheet of carbon fiber to make the inner wall of the flood chamber, and sealed it with an epoxy and Cab-O-Sil mix. After that cured, I cut out that portion of the transom to allow water in and out and tested it for leaks. Finally, I provided a vent hole at the forward end of the chamber.

                              At last! A hull with positive self-righting.

                              I added a thicker sheet of carbon fiber plate to make a transom doubler for the rudder attachment hard point.

                              I used a bit of that G-10 I have on hand to make a super-sanitary looking mount for the turn fin. Monos have to have turn fins, right?

                              My experience with H&M hatch covers is they tend to warp a bit over time. Since my hatch was thinner than the recesses in the hull for it, I thickened the edges of the hatch with some stranded carbon fiber.

                              I'm going to use the factory-recommended 2mm straight shaft, but I have the ability to replace the small diameter stuffing tube that carries a brass bushing for the shaft with a larger diameter stuffing tube that will accommodate supporting the shaft with ball bearings instead.
                              A nation of sheep breeds a government of wolves

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