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Retrofit of Hercus CNC Lathe

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  • Retrofit of Hercus CNC Lathe

    Since the other thread progressed from a gloat thread to something more substantial I decided to start a new thread about the retrofit.

    Previous thread here:

    http://bbs.homeshopmachinist.net/showthread.php?t=34521

    Today I installed the Z axis motor. Fits good. Enough movement to allow belt tensioning. Heres pics of the lathe without the chip guard and lead screw. Sorry about the pic. Had my aperture a bit too open.



    Here are the motors I am using for X and Z. SimpleServo motors made by ACTech/Lenze. 200 watts (~1/4HP) with brake, 3000 RPM rated, 4500 Max, 2000 line encoders. The drives run off 120v and take step/dir inputs as well as analog. Drives are tuned through a pc with a serial port.



    This might be the motor I use for the spindle. Kollmorgen AC Brushless, Resolver feedback. About 1HP. 1900RPM max. The drives are Superior Electric Slo-Syn SS2000 drives. Analog input. The smaller unit is the power supply that runs the drive. It provides buss voltage and logic power. Its awful bulky so I am not sure. Again, too big of aperture so lack of depth of field.



    Took apart the tool turret as well tonight and figured it out. Really neat mechanism and very well made. The housing is cast iron. Where the turret rotates the bearing surface is hand scraped. The turret is pretty simple to control. Runs off 24v dc. Two wires for motor. three internal microswitches. One senses turret locked, one senses home and one senses each position. The way it operates is this. Power is applied to the motor to make it turn clockwise looking at the face of the turret. The shaft turns gearing which pulls a conical pin back that unlocks the turret. The turret is now rotates clockwise. When the in-position switch closes the control stops the motor and reverses it. This causes the conical pin to seat which locks the turret in place and also brings it into alignment. The lock microswitch closes and tells the control to turn off the motor. The home switch in the turret activates when tool #8 is in position.

    Should be real easy to make work. Just a little h-bridge chip and a little micro controller. Maybe something like the arduino that everyone is talking about.

    My friend managed to figure the pinout on the keyboard. Looks like everything maps to pretty much normal ACSII on the 8 bit parallel output. Might try one of these Teensy micro controllers to get the computer to see it as a normal keyboard. http://www.pjrc.com/store/teensypp.html Supposedly there is info how to make windows treat it as a HID USB device.

  • #2
    It would be a good idea to upgrade the spindle drive motor with that 1hp version you have as the standard 3/4hp is a little under powered for serious turning, especially screwcutting. Hercus did offer an optional 0.75kW (1hp) motor with upgraded spindle drive board but I have only ever seen the standard motor fitted.

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    • #3
      Actually the motor in the late is .55kw but it is a 180v motor and they are running it on 90v. So you dont even get the performance that it is good for.

      I think I have figured out what I am doing for the spindle now. I have a compumotor 750w brushless motor that will fit in there if I modify the amphenol connectors that connect the encoder and motor power leads to the motor. The drive that was intended for the motor is toast and the one I hoped to use with it dosnt have the voltage to run the motor at anywhere full power. The motor needs 240v and the drive would only put out about 120v.

      So I found a Glentek drive on ebay that should do the trick:

      http://cgi.ebay.com/ws/eBayISAPI.dll...m=330323927179

      I still need 240v for the motor so I am going to use the transformer that was in the machine to up the 120v to 240v. Hope the transformer will be enough.

      I got the X axis Servo mounted today. Took a bit of figuring. Milled out the existing mount to drop the centerline of the motor lower and made an adapter plate to mount the new servo to the old servo's holes. It all still fits in the old box. Need to order new pulleys now and figure out the belt length needed.

      http://farm4.static.flickr.com/3361/...24f26eee_b.jpg

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      • #4
        Made some more progress on the lathe in the past couple weeks. The connectors for the servo motors showed up. I build a heatsink to hold the drives and made ducting to get air moving through them. Got the power wired up to the drives. Bad news. One of the drives is bad. When I first hooke up power everything seemed normal. But when I enabled the drive it started running without an input. Not good. Disconnect and reconnected the drive and now its pretty much dead. All the lights come on and stay on. No response to the computer either. The other drive works fine though, even with the same cables and motor. This sucks...

        But I have a couple mitsubishi drives and motors. One 200w and one 400w. So for now I am going to use them even though the 400w is way overkill for the Z axis. Thats over 1/2HP.

        I also got the glentek servo drive running with the compumotor motor I have. Had to adjust the timing of the encoder to get it to commutate right though. Now it seems to work good. At 208v input it runs at about 2900 RPM and on 240v it runs at 3200 RPM. Belted to the spindle thats about 3300RPM max in high belt and 1200RPM max in low belt. Incredible starting torque. Spins up in a fraction of a second.

        The pulleys showed up from SDP-SI yesterday. Machined them out and got them mounted. Had to figure out how to mount the new spindle motor. The power and encoder connection are large amphenols and with the motor mounted to the original mount the connectors fell smack in the middle of a bed rib. So I needed to move the motor back about 3/4" to clear the rib. Took the old end bell off the old motor and used that to make an extension/adapter. Also had to extend the shaft a bit since the shaft would only pass about 1/2" into the pulley.

        Now the machine is pretty much mechanically finished. Its all electrical now. Need to get a motherboard for the computer section. A BOB as well. Need to come up with a way to control the tool changer as well. Might be able to do this through Mach with a "brain".

        I have also decided to run the thing on 240v instead of 120. The new spindle drive needs it for the motor. Even if I used the old motor it still needed 240v to run the correct drive for the motor. Unfortunately the Mitsubishi servos I have are 100-120v in, not the normal 240v so I found a couple drives off ebay. I will use the 400W until I can find a 200 watt motor and drive to replace it.

        I did disasseble it and clean it up. Looks a lot better. There was still bluing under the headstock where they scraped it into alignment with the bed!

        I cant imagine how much this machine must of cost when it was new. There are three resolvers in the machine and those things sell for $1500 each nowadays.

        New Drive motor:


        Backside with new X axis motor and new cable guide.



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        • #5
          Glad I found this. I will be picking up one of these in a couple of weeks. I haven't seen it yet, but the guy says the control panel is mounted above the bed. Thing is about 6' tall he says. Anyway, if it is anything close to what you have here, I will be pleased. Supposedly came out of a vo-tech with little use. His is a bit smaller, I would guess. Says it is 8" swing over bed, 4" over carriage, 12" center to center, with the tool changer, too!
          Paul in OKC
          PHDesigns

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          • #6
            Paul, Hercus call that their Industrial Version, it is fully enclosed with perpex splash guards, coolant system and machine light. Should be a good machine if you can get it working.

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            • #7
              Cool! I am looking forward to playing with it.
              Paul in OKC
              PHDesigns

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              • #8
                There is mention of a version of the machine with coolant capability. That must be the one you have. I may add a spray mist unit to it. I have another Bijur unit sitting new in the box.

                Made some progress on the lathe in the past week. Got all the limit switches and tool changer switches wired up to a bank of relays for isolation. Got to thinking about it and added three more relays and now have the tool changer fully controlled by relay logic. Two inputs, one sends the turret to home position and the other indexes it one position at a time. Really quick changer. About a second from tool to tool.

                Got the two 200-230 versions of the Mitsubishi drives off ebay and wired them up. Both work good. I can jog the axis's via the built in control panel. Also got the spindle drive mounted and wired in. Hooked it to a cnc4pc C6 step/dir to analog speed control board that used to be in my mill until I installed one of Peter Homanns Digispeed boards.

                Now I am waiting to get paid so I can buy a motherboard to go in there. Also need to figure out what I want to do for a breakout board. I think I can do all the IO on one parallel port since I am going to use a PoKeys 55T for the control panel interface.

                A friend who works down at FEI may be getting me one of the old miniITX boards they use in their electron microscopes so that may solve my mobo issue.

                Heres a couple pics of it so far. Axis drives are in the bottom left, spindle drive with its control in the bottom right. Relays and terminal strip down the center. +24v/12v/-12v/+5/-5v power supply top left. Top center is the limit switch breakout. Open area is where the mobo and breakout board will reside.



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                • #9
                  The guy I am getting mine from was on vacation last week. Will be getting with him some time this week to make arrangements to pick it up. He already gave me the manual. It has coolant, and the 3 jaw is pneumatic, apparently. Getting anxious! Thinking of it needing any wiring is not a good thought, as I am generally electrically challenged!
                  Paul in OKC
                  PHDesigns

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                  • #10
                    Well, picked mine up today. Will post a pic later, still on the back of the pick up. Did plug it in and turn it on. Got some lights, but no screen, and no power to move anything, so.....
                    Paul in OKC
                    PHDesigns

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                    • #11
                      Well, what is the trick to post a picture?
                      Paul in OKC
                      PHDesigns

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                      • #12
                        http://s606.photobucket.com/albums/tt146/phdesigns/
                        Link to pics, I hope!
                        Paul in OKC
                        PHDesigns

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                        • #13
                          Neat machine. I am curious how that power chuck works.

                          Does it do anything when you hit the on button on the control. The estop is missing there below the power switch but that should not stop it from booting up. But I could be wrong. The two connections should be connected together when estop is up.

                          I have the manuals for the machine but unfortunately there are no service instructions.

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                          • #14
                            Paul, is there anything on the screen, maybe just a curser? You may have to clear the multi bus, I have the instructions for this procedure.

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                            • #15
                              Originally posted by luthor
                              Paul, is there anything on the screen, maybe just a curser? You may have to clear the multi bus, I have the instructions for this procedure.
                              I have the manual, but said, no maintainance instructions. There is nothing on the screen at all. I have the estop button, it popped out when I turned the key. I have emailed Ultra Logic and the reply stated that the estop button must be in safe mode for the power button to work. I will get it back in today, and will have the little battery replaced in a day or two as well. Going to make it off board, at least for the battery holder. Any instructions that will help are certainly appreciated! Thanks.
                              Paul in OKC
                              PHDesigns

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