Greetings list members; With all the talk or ARM vrs AVR vrs all others etc. I have a question for those who might be able to point me towards a workable solution.
Back in the early 80's my uncle purchased a HAAS 5C programmable indexer. This is the hardware that basically was the original foundation of the HAAS machine tool empire. The unit was built on a 5C indexer casting and assy made to spec by Yuasa and HAAS mounted a unipolar stepper motor inside a finned cast Aluminum cover. The unit was connected to the control box via 10 foot plastic coated 3/4" flex with a large 7 pin round Amphenol connector. Programming was all done via front panel numeric key pad. Storage allowed up to 3 programs of 99 lines each. Subroutines and loops were possible. Use with manual machines used a remote start button, which would single step through the program. Connection to CNC equipment was via 4 wire connection to provide a cycle start signal and a cycle complete status return signal. A single M code was required. Unit had to be manually zeroed during setup and care was required to compare dial on indexer with display position while running production as it was an open loop system. Sadly the control has died, and looking inside the box shows this was built almost 100% discrete components and of the few IC's that are used most have been out of production for a decade or 2. HAAS basically told me I was SOL and that they don't have any staff left who understand this dino hardware, and won't try because key components have been un-obtainium for many years. The indexer is very well built and just by not connecting certain pins the motor can be driven Bipolar, that is the great news. However I will need to build a controller/driver/power supply unit to run this. - - - Now I will say that for my Hurco KM3 kneemill conversion to LCNC I will let LCNC drive it directly. But Hurco #1 which still uses the OEM control will need the blind cycle start / cycle complete interface with all 4th axis programming done in the indexer control. I also have manual mills and drill presses etc. where I will require the stand alone functionality. Using LCNC for the stand alone control seems like using a nuke to blow up an ant hill. I tried using an Arduino to run an automated bullet lube sizer machine and it was a dismal failure. Not sure if the stepper drive or stepper PWS was causing the issues with the Arduino but when I drove the system via LCNC it worked exactly as programmed. The Arduino would sometimes fail to set the correct direction and the unit would try to start in reverse near a hard stop - so it would rip teeth of the belt. Plus the quality of the pulse stream was hideous. Others, however have apparently been successful using and Arduino for a stepper indexer - but once bitten... I'm trying to use this in an industrial setting, not like someone trying to spin Nema 17's on there desktop with a Pololu A4983. I need a solution I can trust. I am a Machinist first - though for some reason I seem to be hired for computer and electronic type jobs more than I make chips. I have no formal training in electronics so its safe to say I end up having to do constant research to be able to fix things as they go awry. The one problem I don't know how to solve is with a Arduino type system - is there a way to input the motion program, manually via keypad, into the controller and have that program stored in nonvolatile memory. I have several RPi's - and that is another disaster I intend to avoid - because it will work fine for a few months then suddenly the SD card is toast, wipe and reformat and it works fine in cameras or other devices. Given any length of time a Pi will eventually fail you. And remember this application requires stand alone capability - no network. Now - something completely different and more on topic There used to be a retrofit system called ProtoTrak used on Bridgeport type mills and lathes to allow manual, CNC assist, and in some cases full CNC control. I was wondering if LCNC could be configured to drive steppers in velocity mode using a feedback signal split off from the machines DRO scales to provide near functionality. Velocity mode was due to the fact that I would use something like O-ring type friction belts not a toothed belt - something that could be released easily when not needed - even between position moves, since the control is always tracking position from the DRO. It would require some type of soft key to enable/disable position holding. The ProtoTrak system used ballscrews and servos but when you switched to DRO mode it let the servos freewheel and there was very little drag. OTOH I have used CNC conversions others have done which retained handles and cranks. Even with the drivers set as non-enabled the parasitic drag of having to move the machine plus stepper m otor drag was considerable, even on those dinky small motors. Even if the system was limited to point to point positioning moves and single axis power feed (so as to not have multi-axis interpolation errors from a slipped belt) it could be a great help on manual equipment. I'm sure a few of you may have ideas to throw at me. Thanks. Greg, Out yonder in Yoder, CO ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
