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So I got a VFD...

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  • So I got a VFD...

    Hi guys,

    I've bitten the bullet and purchased a 3 phase motor and VFD for my mill/drill.

    The mill/drill is an RF30 clone.

    Haven't installed the motor or VFD yet, and I'm wondering what others have set their VFD's up to do.

    The VFD is a Transtecno TT100 series unit. Heaps of stuff that can be set, but I doubt I'll need anywhere near all the features.

    So, what's useful to set this thing to do?

    Obviously run/stop and forward/reverse. But what else would be useful?

    I've never used a VFD before, so I'm looking for ideas and advice.

    Thanks in advance fellas.

    Best regards

  • #2
    Off the top of my head:

    Well, on mine, there is a setting for TEFC style versus other style cooling, having to do with how much torque the motor can develop at lower percentages of rated power. The higher torque setting is nice if you the motor can handle it.

    Based on the motor, you might be able to set an overload condition where the VFD will stop trying to turn the motor. This is probably a good idea.

    An emergency stop would be nice, if enabled.

    Also, you probably can set lower and upper frequency, which will correspond to lower and upper speed of the motor. The upper speed does NOT have to match the upper plate speed.

    On many, the display can be frequency or RPM, I have found RPM more useful than frequency.

    Make sure you set the input power correctly (e.g. 110 or 220) correctly before powering up.

    There may be a setting for how to reverse. You might want to set it to "require a stop before reversing" to protect your mill.

    I feel like I am still missing something important though...
    Esoteric Garage


    • #3
      Originally posted by Tait
      I feel like I am still missing something important though...
      Potentiometer (or speed increase/decrease buttons) to adjust speed on the fly.


      • #4
        Does not look like it has a remote control panel, might want to build a small one with a pot for manual speed control, on off, fwd reverse switches.

        edit: wow i type slow on my tablet


        • #5
          It may require an additional resistor, but I have set mine to completely stop the motor in under 2 seconds. This is a great safety feature and is very convenient for quick tool changes etc.

          Do yourself a favor and see if your TV carrier has America One News Network (AONN). 208 on Uverse. It is good old fashion news, unlike the networks, with no hype, bias or other BS.


          • #6
            Set "accel" and "decel" to 3 seconds or so. Long times are tedious and slam bang starts and stops serve no good purpose. If you need instant reverse remember the FWD/REV times are proportioal to the sync RPM. Set the mechanical reduction to 300 RPM and dial the motor RPM down to 1/2 speed and the motor will instant reverse for all practical purposes.

            Remember duty cycle before you get nervous about installing and additoional coolong fan (someone is bound to rant about this). It take time for a motor to over heat under mild overload or full load at reduced RPM. Most machining operations take less than two minutes.

            Use your mechanical speed reductions. You cannot simply dial the speed down to 20 spindle RPM from in top belted speed and expect significant torque at the spindle. The motor develops HP in proportion to its RPM. Motor torque is almost constant over 10 to 70 Hz when running from a VFD. Some types of VFD's extend this range. These are facts of motor/drive physics.

            This is not rocket science. There's no need to rush. Spend an evening with the VFD and the motor temporarily connected on the workbench. Try several start/stop contrp; ideas and play with the speed reference pot. Diddle with the parameters. Familiarize yourself and de-mystify the dreaded VFD manual. You can't screw anything up. The drive has too many protective features unless you get downright reckless.
            Last edited by Forrest Addy; 12-06-2011, 08:27 PM.


            • #7
              motor on bench!

              Be SHURE to have the motor straped securely to the bench or it may end up in your lap or on the floor with a bent shaft. HTH. John


              • #8
                I just made the same leap on my mill. I was VERY disappointed when I first applied power because it sounded like the bearings on my $40 craigslist motor were toast. The whine was like a jet engine spooling up.

                I played with the base frequency and found that the default setting was causing the whine. I upped it a bit and the motor now runs smooth as silk and quiet as a mouse.

                The variable speed via a potentiometer ( variable resistor ) is VERY convenient, since it lets you dial the speed you want with almost never a belt change.

                At the end of the project, there is a profound difference between spare parts and left over parts.

                Location: SF East Bay.


                • #9
                  In case nobody said it, make sure you use a linear potentiometer, not the stereo variety.

                  One of my favorite features on mine is JOG for a whole multitude of reasons. The braking function is probably my second.
                  "I am, and ever will be, a white-socks, pocket-protector, nerdy engineer -- born under the second law of thermodynamics, steeped in the steam tables, in love with free-body diagrams, transformed by Laplace, and propelled by compressible flow."


                  • #10
                    My horizontal mill came with momentary start-stop pushbuttons and I wired these (with phone wire) to the appropriate VFD inputs. The only other feature I use is the 3 second ramp up/ramp down as mentioned earlier. My mill is a gear head with multiple speeds and feeds so I have found no need to fool with speed control via the VFD.

                    Tom - Spotsylvania, VA


                    • #11
                      A jog button is very handy. Set the jog freq. to give about 100 rpm on the spindle. Perfect for power tapping, moving a boring head or fly cutter a few degrees for alignment with the work piece, etc.



                      • #12

                        Hi guys,

                        Thank you all for the great responses, you fellas are fantastic.

                        A few votes for a jog button, so I'll include that for sure. I got some
                        gear together so I can have a play on the bench before I install everything.

                        I'll be sure to post again when I've had a play, and got the motor and VFD

                        Thanks again guys.