Hello LCNC users hive mind; I am finally getting to the actual wiring stage of my LCNC retrofit of my 1987 HURCO KM3. The point of this message is to say what I have planned and if anyone notices that I’m heading for a cliff, a wall, a Magic smoke event you can yell at me now, or if anyone has been down this road, tips would be appreciated.
The Hurco KM3 is a Bridgeport Vari-drive style clone knee mill with the Iron being made by Kondia in Spain (Manual machines were also sold in the USA under the Clausing name). The servos are big ElectroCraft 4 brush DC units set for 1:1 direct drive with encoders and tach feedback. These are driven by a CMC / Randtronics Servomate unit. Each axis amp is fed 60VAC and has a healthy bridge rectifier. These I believe are set for velocity mode using +/- 10V signals. I believe a single servo power signal enables the entire 3 axis amp panel. With the MAX II control rapids were 250IPM, the MAX32 would jog at 400IPM and do 300IPM in AUTO. I have the Mesa 5i25 / 7i77 combo and after just re-reading the manual I’m a bit confused as the word “field” is used for many different things and I’m feeling like I am stuck out somewhere in left field. It appears field can mean GPIO, or it can be a 8-32VDC power source, or ??? I am un-clear. The existing limit switch system uses Prox sensors for X & Y and a roller microswitch for the Quill on Z. The knee is manual only. These prox switches have a working voltage of 5VDC, the documentation fails to say what the steady state is when not tripped. Much of the hardware actually uses 120VAC as control voltage, however some devices use 24VDC. Since I have removed the blazing fast 8086/8087 card racks and the massive supporting power supply I have ordered both 5VDC and 24VDC power supply units. These new power supplies will provide the 5VDC for the 7i77 logic and encoders, and the 24V will provide “Field” power and provide power for relay sources. Here is where things get messy – the servo amps take input from the limit switches so that when you hit a limit, motion towards the limit is disabled but motion away from the limit is allowed. Not only that, there are inputs from the control to kill motion if you approach a soft limit. I may have to bypass these hardware functions, it is yet to be seen. The spindle speed will continue to be manually set via vari-drive crank. I intend to use a Huanyang 2.2Kw VFD to drive the spindle motor and report spindle at speed. I won’t have a spindle encoder initially, however I would love to add one eventually if possible. I don’t know if I should use the RS-485 module for control or I should just hardwire in for +/- 10V. Once upon a time, long ago and far away at the Los Angeles convention center while attending the WESTEC Machine tool show I saw a retrofit kit which replaced the vari-drive pulleys with 8mm pitch toothed belts and swapped out the OEM motor for a wide range 5hp inverter rated motor. This setup still had the Hi/low back gear but for all speeds within a range it was fully programmable. Coolant pump is 3ph also but I am going to try just using a run capacitor with 230VAC 1ph. Spindle brake and Mist coolant will also need to be wired in. I also have a control pendant with handwheel, axis switches etc. As much as I hate the idea, I will run this machine via PC keyboard and the jog pendant initially till I can plan out the wiring and layout for a proper control console. Also this machine is going to have to make some money to buy the extra bells and gizmos. I have a 8” rotary table I want to convert for an “A” 4th axis. I will need the mill functional for that project. PC main board will be a HP DC7700 CMT mATX with a Pentium D 945 (Dual core running at 3.4 GHz) 4GB ram. Not sure, but I will likely use the onboard Intel 965 chipset video. I have several Radeon 5450 cards I could use if offloading the video will help things. Any advice is appreciated. I've done small stepper systems but this is my first foray into big iron. Thanks All. Greg, out yonder in Colorado ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
