Alvin update - Thruster drivetrain

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  • wingtip
    Member
    • Dec 2004
    • 335

    #1

    Alvin update - Thruster drivetrain

    here is a pic of the flexible cable i will use (helicopter parts of course for all that know me ) for the side thrusters. basically the shafts come out of the wtc at the bow, hit a 90 degree box, then go straight up and flex to point to the stern and into the kort drives.... In the pic the flex cable spins inside the white tube, the brass tube is simply to retain the shape i bend the curve too so not to bounce around while rotating...the cable is 1/8 (3.2mm) diameter and is used for 30sized helis for special scale tail rotor applications to avoid "costly" lol 40,45,50 degree gearboxes....
    This stuff makes very sharp bends, the white tubing restricts the radius a bit but is more than adequite (spelling) for my needs

  • JWLaRue
    Managing Editor, SubCommittee Report
    • Aug 1994
    • 4281

    #2
    Dave,

    Interesting looking idea. This can

    Dave,

    Interesting looking idea. This can have a number of applications.

    Let us know if it works well running the props (kort nozzles) in both directions. I've seen some attempts at trying to do this with other products, and they seem to have difficulty in the 'reverse' direction....as in the flex cable essentially unwinds itself.

    -Jeff
    Rohr 1.....Los!

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    • wingtip
      Member
      • Dec 2004
      • 335

      #3
      certain flex cables are wound

      certain flex cables are wound in both directions so that it doesnt matter the direction of rotation... this particular one is wound it one way which is fine with me since my application they only have to rotate in one direction.... to change the thrust i am changing the ANGLE of the thruster, not reversing the prop..... I had the choice to use some double wound cable but it was big enough i was worried it wouldnt make the bend i needed.....

      Comment

      • wingtip
        Member
        • Dec 2004
        • 335

        #4
        after the carmel fun run

        after the carmel fun run and talking to pete, i have ordered my diving system... , i am going with the rcab system... so i ordered my bladder, pump motor, and check valve. Still working on a better schrader valve setup.
        i have also ordered the motor and gearbox for the dual shafts for the thruster drives that will connect to my cable pictured above.. and a few couplers to get started...

        below is a pic of the schrader valves i found locally at ACE hardware.. they are perfect for sliding on a bladder tube.. I just need to take to work and machine off 2 or 3 /16ths to allow room for the servo arm to depress the valve ...







        Edited By wingtip on 1108603095

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        • wingtip
          Member
          • Dec 2004
          • 335

          #5
          here is a pic of

          here is a pic of the completed rcab system and the controller board i made.. the blue box is the 12vdc input, the tall piece is the regulator that takes the 12v and takes down to 5vdc for the bladder pump motor...





          and below is the dual shaft single motor kit for the thruster drivetrain... i swapped out the 7.2 volt motor for a traxxas emax 14 volt motor so i only require one "wet" battery and a rx pack....

          Comment

          • themongoose_OLD
            Junior Member
            • Jan 2005
            • 26

            #6
            Hey Wingtip can you let

            Hey Wingtip can you let me know where you ordered everything from? I would like to do this also. I have a 1/48 scale fleetboat I'm working on. I have a blood pressure cuff but would need everything else. Any help would be greatly appreciated. Thanks.......Chris

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            • wingtip
              Member
              • Dec 2004
              • 335

              #7
              the bladder came from the

              the bladder came from the CMS/SafetyStore.com
              , the pump came from smartproducts.com, the controller board i made was mostly radio shack stuff...and is just slightly smaller than a credit card
              the dual shaft single motor gearbox is graupners, from their shark submersible..but ive had to kitbash it somewhat to work with my driveshaft and seals...

              Comment

              • anonymous

                #8
                Those smart pumps really do

                Those smart pumps really do the trick. I'm very pleased with mine. since they were only 5.95 I bought a few.

                Keep it coming and thanks for the tip on the larger bladders. those look great.

                Steve
                P.S. If you have a proper link for the bladders please post it. The one you posted didn't work. did a search too but did find it.

                Thanks




                Edited By U812 on 1108888716

                Comment

                • wingtip
                  Member
                  • Dec 2004
                  • 335

                  #9
                  http://safetystore.com/medanerparts.asp

                  for adult bladder i

                  http://safetystore.com/medanerparts.asp

                  for adult bladder i ordered




                  and the pump is http://www.smartproducts.com/air.html
                  The model # is AP-3PO1 It is their 6VDC 460ma @ 300 mmHg Micro air pump

                  Comment

                  • Guest

                    #10
                    Dave,
                    A failsafe system is recommended

                    Dave,
                    A failsafe system is recommended with the RCABS to turn the air pump on in case of loss of radio signal. Do you have a failsafe installed or planned?

                    Comment

                    • anonymous

                      #11
                      Wingtip thanks for the link.

                      As

                      Wingtip thanks for the link.

                      As for the fail safe. Art, the man who invented this wonderful system, I'm about to use the subsafe on a larger sub. However won't that just stop the pump or start it to surface? Depending how you have it set.

                      The problem I see with that is that if it inflates the bladder to surface when there's a radio signal loss you would need to have a micro switch or something like that to stop the pump from possibly blowing the bladder apart sending you to the bottom. Or are these bladders strong enough to hold.

                      Unfortunately on a small sub like the Kilo I built using Dave's WTC there's no room for one so the only option is to be careful or stick to a pool.

                      Thanks Art,

                      steve

                      Comment

                      • wingtip
                        Member
                        • Dec 2004
                        • 335

                        #12
                        as i mentioned in some

                        as i mentioned in some other threads my failsafes come from my PCM radio..... it has failsafes for every channel (all , i can program the servos to go to a pre programmed postion upon signal loss and doesnt require ANY additional space other than the rx itself.... so i dont have to buy a subsafe device for each indiv channel... i saw one fail at the fun run anyways. what a waste of space....
                        so, i could program it to just fill the bladder, or i could just program it to tilt the thrusters up and give full up thrust, or any combination of sequences i like... thats the nice thing on having a $600+ helicopter radio lol.... (on 75mhz of course)
                        But yes, i have already thought bout the failsafes...i tested it on my bladder lastnight by shutting the tx off and it instantanously started pumping like instructed.... just need to put in the safet switch to not over fill it.......
                        i got my thruster gearbox and stuffing tubes glued in tonight... and the pass thru's for the bladder... just need to order my main motor and gearbox for the stern prop and put in battery terminal pass thrus and the wtc will be finished....

                        Comment

                        • Guest

                          #13
                          As far as the pump

                          As far as the pump bursting the bladder, it has never happened to me with a latex or Neoprene bladder. The pump just labors without being able to put in enough pressure to burst it. I have not tested the thin plastic bladders, such as the ones sold by Electronic Goldmine. Has anyone inflated one of those to the maximum pump pressure?

                          Comment

                          • anonymous

                            #14
                            No Art. Not yet. I

                            No Art. Not yet. I may try it with one. They seem pretty tuff though. They're not that thin really.

                            I'll check with Dave Welch too to see what he has to say.

                            Thanks for the input Art.

                            Steve

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