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  • BLDC & Micro drill project.

    I always wanted a 12,000 RPM drill press. I now have a 400 Watt BLDC motor with a ER11 spindle. The drill press is based on a industrial riveting machine that has moved on to better things. Here it is before its been cleaned up and before the spindle is mounted.





    I'm mounting electronics in the base before body work and paint and that lead to the following...

    As seems to be typical with import electronics, not very much documentation comes along with it. What I have is the model number on the controller... a HX-WS400

    I have bench tested the controller and it seems fine.

    The controller looks like:




    The issue is how to control the start and stop of the motor. I could interrupt the 48 volts to the controller but that seems too crude.

    The speed control pot will stop the motor when the wiper is brought to ground, but I want to preset the speed and turn the motor on and off. The controller uses the GND-VR-(+)5V terminals at present.

    The EN(able), PWM and F/R terminals are unused, and I suspect incompatible with the pot operation of the controller. My inclination is to break the +5V supply which should disable the controller... but I want to find out if anyone has actual experience with this type of control instead of my guess work.

    When the motor is stopped by the pot, the VR terminal is pulled to ground, in effect removing all control voltage. That’s why I think that simply breaking the +5V line to the pot would have the same effect. I just hate to assume....
    paul
    ARS W9PCS

    Esto Vigilans

    Remember, just because you can doesn't mean you should...
    but you may have to

  • #2
    I'm not familiar with that particular controller, but I'd think the ENABLE input would allow you to start and stop the motor irrespective of the pot position. It would seem that it is there to do exactly what you are thinking about. Could not hurt to try, anyhow....

    Comment


    • #3
      Not seeing the potentiometer here, but would wiring a switch in parallel do the job? When the switch is closed you'd effectively be shorting the pot, therefore giving an instant zero velocity command.
      Last edited by hojpoj; 01-08-2016, 08:08 AM.

      Comment


      • #4
        Be a bit careful about wiring a switch in parallel with the pot. If the pot is connected between +5 Volts and Ground and the wiper is set to the highest speed position, the +5 V end, and your switch shorts it to ground, then you may blow a fuse or the power supply. A SPDT switch (Single Pole Double Throw) would be better. Place it between the pot's wiper and the speed control terminal on the electronics. One side of the switch goes to the pot's wiper, the other side goes to Ground, and the center swinger goes to the control terminal on the electronics. Add a medium sized capacitor between that center swinger on the switch and ground to avoid a ragged transition when the switch is toggled. A 1 or 10 uF capacitor at around 10 or 16 Volts DC rating should work fine.



        Originally posted by hojpoj View Post
        Not seeing the potentiometer here, but would worrying a switch in parallel do the job? When the switch is closed you'd effectively be sHorton the pot, therefore giving an instant zero velocity command.
        Paul A.

        Make it fit.
        You can't win and there is a penalty for trying!

        Comment


        • #5
          If using a pot, breaking the +5v line to it will stop the motor, but the EN would be the better choice.
          Max.

          Comment


          • #6
            The speed pot set at zero, or the input grounded, might still apply power to the coils of the BLDC motor to hold it in position. The EN input might "tristate" the drivers and not apply power to the motor. You probably should also have a power on/off switch as well.
            http://pauleschoen.com/pix/PM08_P76_P54.png
            Paul , P S Technology, Inc. and MrTibbs
            USA Maryland 21030

            Comment


            • #7
              I think that motor controller needs a pulse/clock signal and works like a stepper motor driver. The absence of pulses should stop the motor keeping it energized to hold position and the enable should free the motor.
              Helder Ferreira
              Setubal, Portugal

              Comment


              • #8
                Originally posted by MaxHeadRoom View Post
                If using a pot, breaking the +5v line to it will stop the motor, but the EN would be the better choice.
                Max.

                Kinda what I thought as well, but it functions without using the EN input now... so if the EN gets a +5 signal does that stop it???

                As far as the pot goes, I wasn't to clear when I stated "The controller uses the GND-VR-(+)5V terminals at present."
                The pot is wired to +5V and GND with the wiper going to VR, provident a 0 to 5 signal to the VR terminal.

                The system can be set up for PW control, but the pot must then be disconnected. I figured the converse might be true.

                I guess I'm going to just lift the +5 lead and see what happens.

                I do have a main power switch that controlles the 48V supply which is seperate from the contrller.
                paul
                ARS W9PCS

                Esto Vigilans

                Remember, just because you can doesn't mean you should...
                but you may have to

                Comment


                • #9
                  Originally posted by ironmonger View Post
                  so if the EN gets a +5 signal does that stop it???
                  Function Description:
                  Speed mode:

                  1. The default speed potentiometer, can be directly through the rotary potentiometer speed
                  2. Analog control, VR pin is connected to a voltage signal input terminal, GND pin to ground (voltage range 0-5V) (NOTE external voltage signal control necessary to remove the potentiometer control to take effect, whether the person can not control)
                  3. You can use an external PWM signal input speed control, external PWM input requirements: level 3.5-12V VPP, frequency 1K-10KHZ, suitable for MACH3 spindle speed control, (note the external PWM signal control necessary to remove the potentiometer control It takes effect, whether the person can not control).
                  Motor Run / stop control (EN):
                  Control terminal EN relatively GND-off can control the motor to stop and run. EN pin is floating the motor is running, when the GND terminal is connected motor stops.
                  Motor forward / reverse control (F / R):
                  Control F / R and + 5V-off operation can be controlled direction. When the F / R and + 5V is not connected, the motor is running counter clockwise, otherwise the motor running in a clockwise direction

                  //------------------------------------------------------------------------------------------------------------------------


                  From a webpage selling a HX-WS400 based kit.

                  Rob

                  Comment


                  • #10
                    Thanks Rob. Just what I wanted to know.

                    I was going blind following links last night, and never found that one :>)
                    paul
                    ARS W9PCS

                    Esto Vigilans

                    Remember, just because you can doesn't mean you should...
                    but you may have to

                    Comment


                    • #11
                      By the way, that's a great idea using one of those motors for a HS drill press. Got me thinking about making a sensitive drill press.

                      Comment


                      • #12
                        Originally posted by Forestgnome View Post
                        By the way, that's a great idea using one of those motors for a HS drill press. Got me thinking about making a sensitive drill press.
                        The 12,000 RPM brushless DC motor was chosen for its torque at lower speeds and the obvious fact that it has no brushes to wear out. With a low speed of around 1000 RPM and the fact that a .125" drill bit should spin around 3000 RPM this motor should work out quite well. The ER11 collets are available on fleabay, watch for the ones using a .008mm TIR ~.0004", there are others that are around .016mm TIR ~.0006"... read the specs. Who knows if either of them are anywhere near that figure, but soon I will be able to verify their accuracy.

                        The last mechanical bit is to figure out the feed mechanism. The slide on the first pic had a metric feed screw in a bronze nut similar to what you would find on a cross slide. I have converted it to 3/8"-10 LH ACME , and have to thread and build a lead screw next. I wanted some predictable amount of down feed. Picture a giant micrometer barrel sticking out the top.

                        While I have no experience with high speed drills, I am told by someone who does that feed pressure will be something that I don't have to worry about...

                        I will also have a fixture to hold a dial indicator to assure that I don’t punch though into a chamber when it's being used to drill for a scope mount. The dovetail, which is quite massive for the load it will carry, has two bronze pin gibs that are visible next to the 3/8" bolt sticking out of the side of the column in the first pic.
                        paul
                        ARS W9PCS

                        Esto Vigilans

                        Remember, just because you can doesn't mean you should...
                        but you may have to

                        Comment


                        • #13
                          Whew, that was a close one. After seeing your cool post I got all sweaty & extremely excited about getting a 400W BLDC motor for my toolpost grinder project & sh!t canning my cheapo 24V DC brushed scooter motor. Fortunately, reality kicked in & realized I only have $32.50 in the motor & already have a nice variable 32 VDC power supply. Guess I'll have to stick with plan A for now & when the cheapo motor goes T.U. see how much the BLDC rigs have done down.

                          Please post lotsa pics & info about your project, we all could use one of them things! Come to think about it I wish I had one of those; I'd be making me a cool little CNC micromill out of it!
                          Last edited by DICKEYBIRD; 01-08-2016, 11:36 AM.
                          Milton

                          "Accuracy is the sum total of your compensating mistakes."

                          "The thing I hate about an argument is that it always interrupts a discussion." G. K. Chesterton

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                          • #14
                            Running

                            A little paint, a couple of tie wraps and a power cord. The ENable contact worked as described by MrSleepy. Thanks Rob




                            Now onto the ACME parts.

                            I decided to purchase the motor, driver power supply and the bracket as a single lot. I estimated that this project would get finished much sooner by having all the parts on hand. Considering that I ordered the big bits on Christmas eve, this has gone very quickly for me.

                            I have seen small BLDC controls for less if you want to do a little more yourself. I bought one of these to experiment with converting an automotive alternator to a motor... back burner project... but I do have the hall effect sensors on hand :>)

                            @DICKYBIRD This would make a great tool post grinder. I have also wanted a small cnc router to make casting patterns as well. The Micro drill was required to drill some small holes in my welded AR lower project.. well maybe not required, but welcomed.

                            I need more horizontal surfaces to pile stuff on... and to finish a few projects that need to get moved up a notch...
                            Last edited by ironmonger; 01-08-2016, 01:54 PM.
                            paul
                            ARS W9PCS

                            Esto Vigilans

                            Remember, just because you can doesn't mean you should...
                            but you may have to

                            Comment


                            • #15
                              that is really really neat. What a stout DP! I'm presuming all the controls are in the old front panel at the bottom? Those complete motor+spindle deals are really cool, saves alot of fiddling around.

                              I'd avoid the super cheap collets on eBay though, for obvious reasons. I made an ER25 collet chuck for my lathe and some of the collets are fine (less than 0.0005 run out on a gauge pin at the nose), others are marginal and a majority of them have wayward grind marks on them. I'll need to replace a couple of them with the partial refund I got from the seller.

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