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Cassie.

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  • #56044
    Amy jane September
    Participant
      @amyjaneseptember49770

      The furnace was from one of my bin diving escapades. Not hot enough for pottery, I don't think, (1000 degree celcius max), although it has been used for casting bronze bushes.

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      #56049
      ashley needham
      Participant
        @ashleyneedham69188

        AmyJ. Is there ANYTHING you can buy in NZ, or do you have to make everything yourself?? Bronze bushes for the car eh???? rose

        Ashley

        #56059
        Amy jane September
        Participant
          @amyjaneseptember49770

          Hi Ashley

          The bushes were for an oddball band saw, much easier to just cast new ones, right on the machine, than to try and locate replacements. (besides, my car is only 32 years old, far to new to require replacement bushes…lol)

          We can get most things here, but you may have noticed that I don't much care for paying for them!

          cheeky

          #56167
          Amy jane September
          Participant
            @amyjaneseptember49770

            Well, here we go.

            dscf6416 (640x360).jpg

            dscf6417 (640x360).jpg

            dscf6420 (640x360).jpg

            dscf6422 (640x360).jpg

            dscf6423 (640x360).jpg

            Yay!

            #56168
            Banjoman
            Participant
              @banjoman

              Hello Amy jane,

              That looks very, very nice indeed — congratulations on a succesful build! The large scale makes her look quite at home in the water, too!

              Are you happy with how she runs and handles?

              /Mattias

              Edited By Banjoman on 27/02/2015 09:06:05

              #56179
              Amy jane September
              Participant
                @amyjaneseptember49770

                Hi Mattias, Thanks for the kind words.

                She's very simple compared to your fine model, but yes, I'm quite pleased with her! The speed is quite scale like as you can see from the wave pattern in the bottom photo (she has no throttle, so the motor is just on or off) and she steers well.

                I had to play with the prop size quite a bit, was over proped, so ended up with a 35mm two blade. She is running on 7 cells. (I don't have an amp meter, but my feeling is she is pulling about 10 or a little more amps). I need to make up some more battery packs. Sadly the only nicads I can get around here are AA's, so I'll have to double them up to get a decent run time.

                Thanks for looking in

                Amy jane

                #56181
                ashley needham
                Participant
                  @ashleyneedham69188

                  AmyJ. good work. Great photos, lovely colour sea and the sky blue boat looks very pretty.

                  A more unusual shape than normally aired on the forum, and an unusual build to be sure.

                  Super.

                  Next one please.

                  Ashley

                  #56185
                  Amy jane September
                  Participant
                    @amyjaneseptember49770

                    Thank you sir.

                    Next one?

                    A toss up between an electric/gravity powered stern wheeler, or a fast sailing trimaran.

                    -but not for a while

                    smiley

                    #56192
                    Kimosubby Shipyards
                    Participant
                      @kimosubbyshipyards

                      Hi Amy,

                      fast sailing trimaran, though a gravity stern wheeler sounds good too. Question if I may, which propeller did you end up using? I'm just making some of various sizes for our Commodore's challenge this year, boats powered by elastic band drives, and find it hard to decide between three and four blades, cutting them is no problem, but seek your opinion.

                      One of my devices will be a side wheeler, both at the stern, but using floppy blades to slap and stroke the water rather than have paddle bars.

                      I just love the way you improvise and get your projects finished, very inspiring. Must visit NZ some time, it's on my list.

                      Aye, Kimmo

                      #56194
                      ashley needham
                      Participant
                        @ashleyneedham69188

                        Kimmo. a rubber band engine needs loads and loads of blade area to provide resistance to the unwinding. Too little and the motor just exhausts itself in seconds.

                        But depends upon the course of course. something short and you will then need to treat it like a normal motor and go for revs etc.

                        Have to thing about winding it up as well, and a 2 blade prop is handy for this!

                        Below. 20m of best glycerin lubricated flight rubber, 50mm 5-blade prop.

                        Ashley

                        ashleyboat2#2

                        #56196
                        Andy C
                        Participant
                          @andyc56856

                          Once again Amy J, a great build. Looking great on the water.

                          Andy.

                          #56200
                          Amy jane September
                          Participant
                            @amyjaneseptember49770

                            Hi Kimmo.

                            The Tri has a slight lead at the moment…

                            I ended up using a 35mm two blade.

                            My opinion is: The most efficient would be a REALLY big single blade prop with a counter balance, which of course would be totally impractical. I think the most sensible option would be a two or three blade, as big a diameter as the model would allow, with lots of pitch. As Ashley rightly points out, rubber motors are high torque engines, and the prop will need lots of bite to stop the motor unwinding too fast. The other option is to gear the prop up if a smaller prop is required.

                            Here's a notion, what about a geared up prop, and some sort of clock type escapment to control rate of rubber unwinding, perhaps with some sort or servo operated over ride for a throttle… (way too complicated, I know, Just a thought)

                            I am Intrigued by you paddle idea, I'd like to know more please.

                            Now that is an interesting model Ashley. Rubber full length of the hull, v drive and tractor prop, unless I'm horribly mistaken? Do tell more…..

                            Thanks for the encouragement Andy, always welcome!

                            Aj

                            Edited By Amy jane September on 28/02/2015 21:35:59

                            #56201
                            ashley needham
                            Participant
                              @ashleyneedham69188

                              AmyJ. You have it on the nose. tractor prop so the gears could be as far back as poss, and so maximising rubber length. All rubber motors really need to be UP geared. I think about 5;1 on mine . The torque on that much rubber has to be felt to be believed. With no gearing the thing would shoot off like a dragster for 10 feet and then run out of steam. About 120 yards I reconed is about the run i got from it. IOt comfortably outpaced several boats on its debut! (for a bit, anyway)

                              The stand has winding gear built in, so you just dock the boat, make sure the drive engages (dogs) and wind the handle 8 or so times (2.5;1 gearing ….I cant remember properly now, I should have to consult the magazine that had the boat featured (my first feature, oddly enouigh)

                              4mm ply hull, draught aboutr 20mm. Small keel to counter tourque. What rubber band boats also need is some sort of govenor, would make a big difference to performance.

                              Ashley

                              #56202
                              Kimosubby Shipyards
                              Participant
                                @kimosubbyshipyards

                                Amy and Ashley,

                                I should really put this on another thread, will do after this quick reply.

                                Currently using a 50mm self cut 3 blade prop, geared 3:1 from the band gear. The elastic band (flight stuff) has rings each end so winding is done off the boat using a convenient nail as one end and a winder (self made) giving 3.5:1 wind ups. Once the band has enough tension unclip both ends and re-attach to hooks on the boat. Need to invent a stop/go on the prop.

                                The blades on the paddle wheel slope backwards, so that on entry they are angled ahead and stroke the surface of the water before raising again. there are 6 blades and they are very thin plasticard, so bend and flop a bit. They also act as a control on the elastic band power. I intend to gear that up as well, reading Ashley above, I'll make that at least 5:1 or more.

                                I'll start a new thread on band powered water craft, Kim

                                #56509
                                Len Morris 2
                                Participant
                                  @lenmorris2

                                  Hi Amy,

                                  Well done on Cassie, she looks brilliant and very sea worthy. Rubber motors? Yes you need and escapement mechanism to get any sense out of them. In my view, big props just delay the pain of a short run until later. Unfortunately, escapements tend to be big and try as I might I never really got any success out of them with mi rubber powered subs when I was a lad, but things might have changed.Good luck on your next project.

                                  Len

                                  #56561
                                  Amy jane September
                                  Participant
                                    @amyjaneseptember49770

                                    Thanks for that, Len.

                                    I had pictured a ratchet and spur type escapement, with opposing springs on an arm, rather than a pendulum. You're a clever engineer, what do you think?

                                    Aj

                                    #56766
                                    Len Morris 2
                                    Participant
                                      @lenmorris2

                                      Hi Amy,

                                      Sounds complicated but could work. Depends on the space to have to install it and the junk pile gubbins you can find to make it. However, how about this! Had to replace the cigarette lighter socket in mi car last week. Had to take out the ashtray module to do it. A totally stupid unnecessary design and a complete waste of the worlds resources. Instead of just opening it manually you have to press a button! The thing then slides out at a graduated pace. The thing is pushed out by a big spring but is retarded from a snap action by a small gear driven silicon loaded clutch. A stand alone unit about 15 mm diameter and 10 mm deep. Easily removed for another more purposeful life! I think there could be some mileage in this for rubber motors.

                                      Len

                                      #56770
                                      Amy jane September
                                      Participant
                                        @amyjaneseptember49770

                                        Hi Len

                                        Thanks for that, I'll give the escapement idea some more thought, when I have the spare brain space!

                                        Your little clutch sounds interesting, a mini torque converter! (I never ceases to amaze me how complicated some people can make what should be a very simple thing. (Too many marketers involved in the design process I suspect..) A couple of years ago I had a late-ish ('95) model Honda Accord. The blasted thing used to chirp and beep like a cage full of canaries, drove me twinky. After a monumental battle I found the beeper and cut one of the wires… stopped the the beeper all right, and the air conditioning and electric windows to boot! ……So, not to be beaten I reconnected the beeper – and pumped it full of silicone rubber! Silence. Now I drive a 1983 Mitsubishi Mirage. It has winders on the windows, points in the distributor, and a carburetor, and it never gives me a moments trouble….(God help me though if I ever hit anything bigger than a bumble bee…)

                                        smiley

                                        #60122
                                        Amy jane September
                                        Participant
                                          @amyjaneseptember49770

                                          Hi all

                                          Just thought I'd post a couple of pics of Cassie out playing in a bit of a chop. Not as rough as I wanted, but she was having a grand old time.

                                          dscf6594 (640x360).jpg

                                          dscf6596 (640x360).jpg

                                          dscf6598 (640x360).jpg

                                          dscf6599 (640x360).jpg

                                          No fuss at all…

                                          #60124
                                          Bob Abell 2
                                          Participant
                                            @bobabell2

                                            Brave little ship

                                            But she`s not making much headway?

                                            Bob

                                            #60141
                                            Amy jane September
                                            Participant
                                              @amyjaneseptember49770

                                              A bit deceptive, Bob. She's getting along well, but in a following sea the waves are overtaking the boat!

                                              #60142
                                              Bob Abell 2
                                              Participant
                                                @bobabell2

                                                I really do admire your nautical knowledge, Amy

                                                A very good answer

                                                Like a loco with the wind behind it?

                                                Bob

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