Forum Top Banner Ad

Collapse

Ebay Classic organs

Collapse

Announcement

Collapse
No announcement yet.

Leslie o-ring contact point

Collapse
This topic is closed.
X
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Leslie o-ring contact point

    What is the correct contact point for the o-ring and the slow motor armature? Should it be on the rounded tip or the vertical side of the armature?
    Farfisa Mini Compact V1, Fender Rhodes 73 Mk. 1, Hammond B2, Hammond L-102 "El Choppo", Hammond M-101, Hohner Cembalet CF, Hohner Cembalet N, Hohner Favor Combo, Hohner Pianet L, Hohner Pianet T, Hohner Symphonic 30N, Leslie 145, Leslie "430" (former 130 cab with horns and light show added), Nord Electro 3, and an entire village of guitars and harmonicas.

  • #2
    Yes, you want the tip to slip past the o-ring, but not too far. I sometimes tweak the position of the drive wheel or vary the number of shim washers on the slow motor long screws to optimize this.
    I'm David. 'Dave' is someone else's name.

    Comment


    • #3
      It's trial and error. I adjust for the rotor to sit fully within the stator.

      Since the slow motor's adjustments allows for the shaft to come in at an angle, I adjust to get the shaft to be as perpendicular to the tire's outer edge, trying to get the shaft to meet the tire to start slowing down the speaker rotors without being too tight up against the tire to be able to move into position and achieve chorale, and then be loose enough to exit chorale when going into fast.

      Best to have a tire in good condition with enough meat on there. If you notice wear on the tire and it looks like the sidewalls of the tire is wearing, then the adjustment is not right and the shaft is sitting at the wrong angle and coming in too tight up against the tire and the rubber wears out prematurely. Get new tires and have spares.

      Keep the shaft clean and dry, no oil, no caked rubber.

      Click image for larger version

Name:	leslie-slow-motor.jpg
Views:	464
Size:	66.7 KB
ID:	661169

      Comment


      • #4
        There's more than one adjustment here, from my point of view. One adjustment is the engagement angle with the two nuts you loosen and tighten. However, you can tweak the shaft position relative to the drive wheel both by adding or removing shim washers on the two long screws holding the motor together or by moving the drive wheel up or down slightly on the fast motor shaft.
        I'm David. 'Dave' is someone else's name.

        Comment


        • #5
          Yes the long screws allow the shaft's distance from the tire to be adjusted. Important to take note of the three nuts (one at the plate and the two on the motor) on each screw so the screw doesn't stretch at those points. Don't over tighten them as they can break or strip thread.

          If you think it's easy to find the proper length and size of screw with the same thread pitch, think again.

          Keep track of all star washers. They are tiny and easy to get lost.

          Need to adjust each nut accordingly, not just one and keep track of what's going on with both nuts at the motor, the one that shifts the motor's angle and the nut that locks the screw in place. So it's actually six nuts for the two screws (for the two slow motors, top and bottom rotor one long screw each).
          Click image for larger version  Name:	motor schematic pnt.jpg Views:	0 Size:	50.9 KB ID:	661186
          Use proper wrenches and sockets, stay away from pliers and other quickie methods of working with these parts.

          Keep the nuts from getting marred and out of square. Respect the parts of the motors.

          Click image for larger version  Name:	s-l640.jpg Views:	0 Size:	57.6 KB ID:	661184
          Last edited by Goff; 07-22-2019, 04:54 PM.

          Comment


          • #6
            Hang the whole stack from an upside down table leg corner by resting the arms over them.
            Improvise an AC on/off.I use a Combo preamp pedal or a wall AC outlet...
            With a wrench to fine tune, and some 220 grit sandpaper, run that o-ring 'fast' to smooth out a nice rounded surface with lots of 'dull' for grab.
            Grab the wheel and test how much surface comes in contact with the slow motor shaft.Does it drop away when off is selected?
            Does it jump when enabled? Bounce incorrectly when it does so? You'll get it perfect eventually.
            You don't want shiny......oil and other contaminants will never allow the proper silent grab.
            Now you're ready to install
            A100/251 A100/147 A102/222 B2/142 BV/147 BCV/145 M3/145 M102/145 M111/770 L101/760 T222/HL722 M111/770 no B3/C3!

            Comment


            • #7
              David - I never thought about the actual vertical adjustment of the slow motor, just the angle. Obviously I'm asking this question because my slow motor is only making contact at the tip. I tried giving the spring a little stretch today and that actually seemed to help. But there are two shim washers on each long screw, tomorrow I might experiment with taking one away and see if that improves it even more.

              Pete - the wheel got that treatment a few months ago, but I think working on the vertical adjustment is the missing puzzle piece I've been looking for!
              Farfisa Mini Compact V1, Fender Rhodes 73 Mk. 1, Hammond B2, Hammond L-102 "El Choppo", Hammond M-101, Hohner Cembalet CF, Hohner Cembalet N, Hohner Favor Combo, Hohner Pianet L, Hohner Pianet T, Hohner Symphonic 30N, Leslie 145, Leslie "430" (former 130 cab with horns and light show added), Nord Electro 3, and an entire village of guitars and harmonicas.

              Comment


              • #8
                I would buy the proper spring and replace them if they get weak. Since it takes so much time and effort, best to replace parts for longevity's sake rather than having to murphy the whole thing out of the cab, a repeat performance. Although some seem to feel the spring stretch is ok, it's a stylized approach and the spring will not operate within the motor system properly. A weak spring will end up making the slow motor rotor bang within the stator, making a noise each time the slow motor is used depending on if it's the lower rotor or upper as each motor is doing opposite direction work. In fact the slow motor springs for each rotor are not the same build, one is heavier wound than the other. One for down thrust, one for up. The proper new spring makes the slow motors ride quiet, like a Cadillac.

                Comment


                • #9
                  The spring is less than a year old, but being at a loss about anything else I could do, I figured it couldn't hurt to stretch it.
                  Farfisa Mini Compact V1, Fender Rhodes 73 Mk. 1, Hammond B2, Hammond L-102 "El Choppo", Hammond M-101, Hohner Cembalet CF, Hohner Cembalet N, Hohner Favor Combo, Hohner Pianet L, Hohner Pianet T, Hohner Symphonic 30N, Leslie 145, Leslie "430" (former 130 cab with horns and light show added), Nord Electro 3, and an entire village of guitars and harmonicas.

                  Comment


                  • #10
                    The spring on the upper slow motor does nothing other than keeping the rotor from clunking when it drops. That's its only purpose. The motor's magnetic field should be enough to keep the rotor where it's supposed to be, unless you've got it way off the proper adjustment angle. Start with the motor not turning the drive wheel at all and bring it in until it does.

                    As for Goff's point about the long screws, they are 6-32, and I keep them in stock to replace them if they are damaged.

                    I'm David. 'Dave' is someone else's name.

                    Comment


                    • #11
                      Originally posted by theseacowexists View Post
                      The spring is less than a year old, but being at a loss about anything else I could do, I figured it couldn't hurt to stretch it.
                      Actually the proper operation of the spring has been compromised by stretching it. Each spiral is calculated to give the spring its functionality.

                      Now you have a broken spring, it being a year old and the issue is not the spring unless it's the wrong spring gauge and wind that's been placed unknowingly in that position.

                      If the springs were all the same, then parts suppliers would not make an effort to display the springs in separate listings, one for up motor, one for down motor.

                      I discussed both springs with a professional spring maker in the business for at least 30 years. They took samples of the upper and lower springs, noted the winds and mainly the spring wire gauge to be different for each spring.

                      Compression springs.
                      When you put a load on the spring, making it
                      shorter, it pushes back against the load and tries to get back to its original length.

                      There are three basic principles in spring design:
                      •The heavier the wire, the stronger the spring.
                      •The smaller the coil, the stronger the spring.
                      •The more active coils, the less load you will have to apply in order to get it to move a certain distance.

                      Once the coils are warped, there goes the proper action of the spring.
                      And then assembly/disassembly trial and error taking the stacks apart repetitively is the result of guessing spring tension that will work, when a spring is stretched or not the correct spring gauge and wind. And it only adds to the wear and tear on the stacks, the screws and nuts with the chance that something else might break from fiddlin' with it too much. These motors are decades old.

                      Suppliers have these springs. Give them the business and save yourself some grief.
                      Click image for larger version

Name:	twg-usk.jpg
Views:	427
Size:	25.5 KB
ID:	661238:-)

                      Comment


                      • #12
                        After the first twenty motor stacks one does value a fresh spring kit......and know how to install it correctly.
                        When they are in a recording application noise isn't welcome.
                        Those kits are inexpensive,and replacement slow motors aren't 'the real deal'......
                        A100/251 A100/147 A102/222 B2/142 BV/147 BCV/145 M3/145 M102/145 M111/770 L101/760 T222/HL722 M111/770 no B3/C3!

                        Comment


                        • #13
                          There were two shim washers on the two long screws. Removing one washer from each screw gave the shaft enough height to properly engage the wheel. I can now run the Leslie on slow for as long as I want without losing the slow speed. Thanks for all the input everyone!
                          Farfisa Mini Compact V1, Fender Rhodes 73 Mk. 1, Hammond B2, Hammond L-102 "El Choppo", Hammond M-101, Hohner Cembalet CF, Hohner Cembalet N, Hohner Favor Combo, Hohner Pianet L, Hohner Pianet T, Hohner Symphonic 30N, Leslie 145, Leslie "430" (former 130 cab with horns and light show added), Nord Electro 3, and an entire village of guitars and harmonicas.

                          Comment


                          • #14
                            Here's one picked at random. This is about as low as I'd want to see. The position of the "wheel" can be moved up/down a bit on the armature. The "throw" of the slow motors varies, dependent on the spring, the shims, and how a given one feels like working.
                            You may only view thumbnails in this gallery. This gallery has 1 photos.

                            Comment

                            Working...
                            X