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  • Hendey electrical question

    I brought home a 12x30 Hendey lathe made in 1945. The motor is 3 phase
    220 volt, 1150 RPM. I'm trying to decide whether to go with a rotary phase converter or a VFD to wire it into 220 house current. Any advice would be appreciated.

    By the way, the move was made a great deal easier by renting a hydraulic lift bed trailer.

    steamwhistle

  • #2
    Hendey electrics

    Hi, all,

    I guess my question wasn't specific enough, as I see it got no answers.

    How about this. Is a 3hp VFD or 3hp rotary phase converter adequate for medium duty work on a 3hp 3 phase Hendey lathe (12x30)? Input is 220 one phase. Is the power loss on a VFD greater than that of of a RPC? The RPC, by the way, would go through a Westinghouse motor controler, if that makes any difference.

    all donations appreciated

    steamwhistle

    Comment


    • #3
      Well it depends.those old 1200 rpm motors,some will start easier than others.On a 3hp motor I wouldn't go with smaller than a 5hp RPC 7-1/2hp might be even better.

      On the VFD,remembering that single phase input usually de-rates the VFD 5hp would be absolute minimum,but there again 7-1/2hp would be more like it.

      With the RPC you can use your factory motor starter without much trouble assuming it can be wired to the correct coil voltage.

      With the VFD you probably won't even need the factory switch gear.Everything needed is included in the VFD.Fwd/Rev,current limits,accel/dccel etc.
      I just need one more tool,just one!

      Comment


      • #4
        Since you are inplying that the motor is a 3hp 3 phase motor, a VFD is what I would use.

        A reasonable VFD is the Teco FM50. The one you want is the FM50-203C.

        http://www.factorymation.com/s.nl/it.A/id.198/.f

        Cost is $185 and no derating needed as it is rated for single phase input. The Teco has a 2 year warranty.

        The variable speed on the VFD is so nice on a metal lathe you will wonder how you got anything done with fixed speeds.

        Comment


        • #5
          Yes.. and Hitachi also makes a very nice SJ200 3hp vfd that doesn't require derating - but.. more money than Teco...

          Personally, I like braking resistors on a lathe. If that's important to you, check that the VFD you chose can add one without the use of an external "braking unit" ($). DC injection braking can be used, but IMO, it's a poor subsitute (when used alone) and has the potential to damage your motor.
          Last edited by lakeside53; 08-20-2009, 11:56 AM.

          Comment


          • #6
            Originally posted by lakeside53
            Yes.. and Hitachi also makes a very nice SJ200 3hp vfd that doesn't require derating - but.. more money than Teco...
            The Hitachi is *very* nice, and the vectorless drive will give good torque at low speeds. I have one on my mill and regularly use large drills at 10hz with no problems.

            Personally, I like braking resistors on a lathe. If that's important to you, check that the VFD you chose can add one without the use of an external "braking unit" ($). DC injection braking can be used, but IMO, it's a poor subsitute (when used alone) and has the potential to damage your motor.
            With the mass of the spindle and chuck on that Hendey he'll almost have to have braking resistors, otherwise the VFD will end up freewheeling for a long time. Fortunately, all that's needed (usually) is a big-ass resistor, something lowish ohms and high watts. Poking around you can usually find surplus power resistors in aluminum cases that will do the job well (my SJ100 has had a $5 200W tubular ceramic wire wound on it for almost 10 years now). I would avoid any VFD that required buying their 'special' resistor, and some actually have the switching transistor built into it to require buying theirs.

            Comment


            • #7
              If the Hendey is a gear head, braking resistors shouldn't be necessary. There is a spindle clutch lever on the apron that engages and disengages the clutch on the headstock input sheave, and I do believe that somewhere in there, there is a mechanical brake that would also be operated by the apron mounted clutch lever. There should also be a clutch lever by the QC gearbox.
              Harry

              Comment


              • #8
                Hendey VFD

                Thanks for all the very helpful info. The lathe is a gear head job with a huge gearbox and two hand clutches that disconnect the motor drive from the gears. The Teco fm50 looks like a great VFD, but while examining the Teco link I noticed the Teco CV 7300 series which has CV 2003-h1, a VFD with sensorless vector control. What 's the advantage of this feature? Any opinions on the Teco CV 7300.

                I'm very grateful for all the good data.

                thanks

                Comment


                • #9
                  Originally posted by steamwhistle
                  The Teco fm50 looks like a great VFD, but while examining the Teco link I noticed the Teco CV 7300 series which has CV 2003-h1, a VFD with sensorless vector control. What 's the advantage of this feature?
                  "Sensorless vector control" (what I called "vectorless", not completely sure how it came out like that) gives better torque at low speeds than a VFD without the feature. It gives the AC motor characteristics a lot closer to a DC drive than not.

                  Comment


                  • #10
                    hendey torque

                    I read somewhere that sensorless vector control might give a smoother finish on work better than some other types of drives. Is this true?

                    Also, top speed on a 1945 Hendey is 1000 rpm. Can a VFD push the rpm's up at least a little before risking spindle or bearing damage, or should the lathe be kept to design rpm?

                    Thanks

                    Comment


                    • #11
                      Originally posted by steamwhistle
                      I read somewhere that sensorless vector control might give a smoother finish on work better than some other types of drives. Is this true?
                      I don't see how it would, really. The usual remark is that you can see the difference between single phse motor drive and 3 phase with folks theorizing that it's the torque change on the zero crossing that causes something of a visible effect in the work. But a VFD is generating 20,000 pulses to generate the profile of the 3 phase voltage, and a drive with sensorless vector drive isn't going to be generating significantly different pulses.

                      Also, top speed on a 1945 Hendey is 1000 rpm. Can a VFD push the rpm's up at least a little before risking spindle or bearing damage, or should the lathe be kept to design rpm?
                      If it's using roller or ball bearings in the spindle you should be OK to push the speed up a notch or 2 (maybe 80hz instead of 60), particularly if you can find a brochure advertising faster machines. A lot of the manufacturers of that time would simply change out the sheaves for different speed models, keeping everything else the same. I'd avoid going any faster and make sure that the oil system is happy with the higher speed.

                      Comment


                      • #12
                        If this is the first and the last 3 phase machine in your shop, go with the VFD. Otherwise, build a rotary phase converter. Build it once and you'll be able to power other 3 phase as you buy them.

                        Comment


                        • #13
                          hendey vfd

                          Thanks again for all the info. I might go with the cheaper VFD because low end torque is not a problem. Lowest speed with this unit is 19 rpm! with motor speed of 1150.

                          Comment


                          • #14
                            Originally posted by steamwhistle
                            Thanks again for all the info. I might go with the cheaper VFD because low end torque is not a problem. Lowest speed with this unit is 19 rpm! with motor speed of 1150.
                            The torque from the VFD I referred to is when you're varying the frequency of the generated 3 phase and has nothing to do with changing the gears on the lathe. If you're not going to use the frequency changing on the VFD you might well be better off with a rotary phase convertor, but with the cost of VFDs nowadays you have to scrounge most everything to beat the price.

                            Comment


                            • #15
                              vfd

                              Thanks again for all the advice. I went with the Hitachi x200-022nfu. The big Hendey is so slow and has so much grunt as it is, I figured I could live without the vector thing and that saved $100. I've read so much grousing about the TECO manuals, that I called up a Hitachi manual and read through it easily, so that was a big selling point. What I need a VFD for is controlling higher speeds as the speed options are wide apart in the upper ranges on this lathe. Don't need braking as I have a clutch lever with brake. I'll probably leave the thing on factory motor speed (1150) much of the time and set the gears for 400 rpm and dial up and down from there unless threading or doing heavy drilling, tapping etc. Will wire existing controls, which are intermittent push contacts, to the inputs. No switches between motor and VFD. Everybody's been very helpful and I appreciate it.

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