Differences between high end ESC's and cheap ones for Lehner motors?

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  • srislash
    Not there yet
    • Mar 2011
    • 7673

    #91
    Originally posted by dmitry100
    But how much more can a 6 inch cable possibly tighten though past 5-6mm ?
    One could play with it. You would see the wear on that washer on the drive dog if it sees some pressure. I run 4-5mm gap on the Fantasm and also run 7” of cable. Mine has been good.
    Of course there is always wire drive. No shrinkage there I believe

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    • TRUCKPULL
      Fast Electric Addict!
      • Apr 2007
      • 2969

      #92
      You could also paint the rear of your strut with a black permanent marker and see if there is a rubbing from the drive dog.

      Larry
      Past NAMBA- P Mono -1 Mile Race Record holder
      Past NAMBA- P Sport -1 Mile Race Record holder
      Bump & Grind Racing Props -We Like Em Smooth & Wet

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      • TRUCKPULL
        Fast Electric Addict!
        • Apr 2007
        • 2969

        #93
        Originally posted by jim82
        Gotcha. My situation is different with the motor mounted it will slide through the mount. I'm going to have to figure something out or just keep using without one. All my other boats have one
        Jimmy
        How large is your hole for the shaft in the mount?
        If large enough or if you can make it large enough to clear a 8mm thrust bearing.

        The 8mm thrust bearing would center itself on the shaft, and then the 5mm collet would be tight up against it.
        https://www.offshoreelectrics.com/pr...rod=boc-f8-16g

        Larry
        Past NAMBA- P Mono -1 Mile Race Record holder
        Past NAMBA- P Sport -1 Mile Race Record holder
        Bump & Grind Racing Props -We Like Em Smooth & Wet

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        • RaceMechaniX
          Fast Electric Addict!
          • Sep 2007
          • 2821

          #94
          Originally posted by dmitry100
          Do LMT motors not like a decent 5mm+ gap between the drives and drive dog?

          There was something I read about how it is a big no no with LMT in particular... Is that true? Or did I misread that

          Something about it ruining the bearings or motor shafts
          You can run thrust forces on an LMT just like any other motor. There are a couple good reasons to reduce it or run a square drive.
          1. LMT's using smaller bearings compared to Neu's and TP's and smaller bearings cannot handle high thrust forces.
          2. LMT's use a very fine pitch thread to secure the output side end cap to the can. Particularly if the motor is not supported on the rear you run the risk of pressing hard enough to break the threads. It's actually a combo of the motor being cantilivered and the thrust forces that generally cause the threads to fail. Lesson here is to support the rear of the motor.
          3. If you do run a thrust bearing with a LMT, you need to have the bearing push against the end plate not against the ball bearing. The flanged ball bearing is facing the wrong way for the thrust force so it will just push the bearing towards the wire end.

          I do recommend using a rear motor support for all LMT motors, that should go for almost all larger motor beyond a spec size motor.
          No big concern letting the motor take up the thrust forces, but know you will have to change your bearings more often.
          I would stay away from the thrust bearing that directly transfers the forces the front ball bearing. Either make a plate that can take the forces or leave out the thrust bearing.

          The gap at the drive dog is dependant on what cable you are running and how long it is. 3/16-1/4" gap works for most boats.
          Tyler Garrard
          NAMBA 639/IMPBA 20525
          T-Hydro @ 142.94mph former WR

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          • dmitry100
            Fast Electric Addict!
            • Mar 2015
            • 1264

            #95
            Tyler, shaft shifting ... is that a concern at all when not using thrust bearings on LMT's? like in kfxguy's case -- his LMT motor shaft shifted.

            thrust bearings just sound like something that will blow up at high rpm -- everyone is recommending the ones on OSE but what RPM are they rated at? All the ones I've seen so far on google are 20k maximum.
            Last edited by dmitry100; 04-23-2018, 04:54 PM.

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            • RaceMechaniX
              Fast Electric Addict!
              • Sep 2007
              • 2821

              #96
              The 5mm Tamiya ones work fine up to 40k. Travis’ shaft slipping is due to the rotor getting really hot which breaks the bond between the shaft and magnets. This is pretty rare.
              Tyler Garrard
              NAMBA 639/IMPBA 20525
              T-Hydro @ 142.94mph former WR

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              • dmitry100
                Fast Electric Addict!
                • Mar 2015
                • 1264

                #97
                Tyler, if 1 castle edge ESC had 4 caps total in the front of the near the phase conductors and the another ESC only had 2 in the front. Could that possibly cause some throttle sync issues -- like causing one motor going faster than the other. Even after going through all of the throttle calibration this is the only thing different between the controllers. Can't think of anything else that may be causing this. Switched sides of the ESC's and its definitely the controllers, not an issue with the motors.

                I guess I'll solder on the other 2 caps and see if it makes a differences. Figured since the 2 extra caps are near the phases and all... maybe it can make it behave differently?

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                • RaceMechaniX
                  Fast Electric Addict!
                  • Sep 2007
                  • 2821

                  #98
                  The caps should not make a difference like you suggested. I would check the software level, timing and start power. It's not uncommon for the ESC's to vary a little bit even with identical software. It's a known issue with guys running twin Castles. Usually in the water, it's not too noticeable once the boat gets going.

                  -Tyler
                  Tyler Garrard
                  NAMBA 639/IMPBA 20525
                  T-Hydro @ 142.94mph former WR

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                  • dmitry100
                    Fast Electric Addict!
                    • Mar 2015
                    • 1264

                    #99
                    But they should not vary to the point of flipping over the boat due to the torque roll right?

                    Thats the kind of difference I am seeing... kind of frustrating. Why on earth would they be so different from each other.

                    When I pulled data logs from the run on water after the cat flipped - I noticed that the "Throttle In" had a max of 2.1ms for one and around 1.7ms for the other. The Max "Power Out" was 80% and 100% for the other. With around 20 amps in difference between the 2 (since I was testing it on 3s only).

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                    • RaceMechaniX
                      Fast Electric Addict!
                      • Sep 2007
                      • 2821

                      #100
                      Then you are not calibrated correctly. Are you using fixed end points or auto adjustable ones?
                      I assume you are using a Y splitter for the lead connection and not trying to use a servo mixing function on an additional channel.
                      Try calibrating both ESC's simultaneously using a one battery to power up both ESC's.
                      Tyler Garrard
                      NAMBA 639/IMPBA 20525
                      T-Hydro @ 142.94mph former WR

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                      • CraigP
                        Fast Electric Addict!
                        • May 2017
                        • 1464

                        #101
                        Some of the ESC’s have a programmable throttle response. Could that be the difference?

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                        • TRUCKPULL
                          Fast Electric Addict!
                          • Apr 2007
                          • 2969

                          #102
                          Dmitry

                          Are you running a ?S2P setup?
                          With the two Red battery wires ( and the two Black wires) on the ESC"s connected together, giving you the 2P connection?

                          I had a diagram on here somewhere showing this wiring connection,
                          In my diagram it has a Plug in between the two ESC's in the Black wire.
                          I have found that with Castle 240 Hydra ESC's you have to program them individually.
                          This is why there is a plug in the Black wire between the two ESC's

                          Larry
                          Past NAMBA- P Mono -1 Mile Race Record holder
                          Past NAMBA- P Sport -1 Mile Race Record holder
                          Bump & Grind Racing Props -We Like Em Smooth & Wet

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                          • dmitry100
                            Fast Electric Addict!
                            • Mar 2015
                            • 1264

                            #103
                            I'm running both ESC's with their own battery packs connected separately.

                            Larry, what is the purpose of having a plug that connects the 2 black power wires of both ESC's?

                            Tyler, Both of the controllers are connected with a Y connector for the throttle port of the receiver. With both red wires from BEC pulled out. I have tried calibrating them with both Auto Calibration and Fixed EndPoints and still experience the same issue.
                            I'll try calibrating them both up with just 1 pack and see how it goes...

                            I think perhaps I'm not doing something right during calibration, maybe because of the pistix. Followed the instructions for setting up the Fixed Endpoints but maybe it's not taking effect.

                            Is there any particular way of doing fixed endpoint calibration with a pistol? from what I understand I have to power up both ESC's with both FWD/BRK Endpoints on my Futaba 4PLS transmitter set at 40% and the trigger in full throttle and then I would increase the FWD Endpoint until I hear a beep (at 84%) and release the trigger in neutral. From there on, increasing the BRK endpoint would not make any beep even at the full 120% -- pulling the trigger after this... the ESC would arm itself.

                            Castle sure could of made throttle calibration a bit little less complicated. Even my swordfish's worked without any issues like this.
                            Last edited by dmitry100; 04-27-2018, 04:29 PM.

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                            • TRUCKPULL
                              Fast Electric Addict!
                              • Apr 2007
                              • 2969

                              #104
                              Originally posted by dmitry100
                              I'm running both ESC's with their own battery packs connected separately.

                              Larry, what is the purpose of having a plug that connects the 2 black power wires of both ESC's?
                              You say you have each battery running to it's own motor.
                              So you are NOT running your batteries in a 2P configuration.

                              I run my twin setup in a 6S2P configuration.
                              The batteries are 6S-5000mah, In a 6S2P configuration, each ESC sees the same 10,000mah battery power.

                              When racing when turning right the outside motor gets more load, therefore running down the outside battery more then the inside battery.

                              Toward the end of the race the boat will want to turn Left, seeing that the inside battery has more power left in it then the outside battery does.

                              The plug in between on the black wire is so you can disconnect the two ESC's from each other when programing.

                              Larry
                              Attached Files
                              Past NAMBA- P Mono -1 Mile Race Record holder
                              Past NAMBA- P Sport -1 Mile Race Record holder
                              Bump & Grind Racing Props -We Like Em Smooth & Wet

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                              • dmitry100
                                Fast Electric Addict!
                                • Mar 2015
                                • 1264

                                #105
                                Larry, So your point is that these Castle ESC are that much more sensitive to lipo voltage differences than others?

                                I'm just trying to sync up both controllers so that both motors more or less spin equally. Because as of right ... on the bench ... one motor would be spinning at 5-10k RPM and the other would would be barely moving or at a complete stop.

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