Hi, The limit switch wiring may be picking up electrical noise. You can try adding a bypass capacitor from the input to GND or additionally add a resistor in the path right before entry to the input.
https://hackaday.com/2015/12/09/embed-with-elliot-debounce-your-noisy-buttons-part-i/ the 74HC14 in the schematic is not strictly necessary, but can but used to "square up" the input signal (while inverting it). The value of R2 and C1 in the image determine how much filtering will occur. Too much filtering will affect switch performance. Not enough and you can still get the nuisance interrupts from voltage spikes caused by motors in the system. : Additionally, you can add a debounce filter to the HAL file http://www.machinekit.io/docs/hal/rtcomps/#sec:Debounce http://www.machinekit.io/docs/man/man9/debounce/ Jeff On Tuesday, July 21, 2020 at 10:39:00 AM UTC-7, Mason Millner wrote: > > We are using momentary hinge limit switches ( > https://www.amazon.com/URBESTAC-Momentary-Hinge-Roller-Switches/dp/B00MFRMFS6/ref=sr_1_3?ie=UTF8&qid=1535482225&sr=8-3&keywords=limit+switch) > > and our spindle ( > https://www.amazon.com/Koolertron-Spindle-Milling-Converter-Engraving/dp/B074XTKJTJ/ref=sr_1_9?ie=UTF8&qid=1535482152&sr=8-9&keywords=spindle+cnc) > > is operating from its own power supply. > The machine is fairly rigid. No limit switches are triggered from until > material is being cut. The bamboo does vibrate quite a bit as it spans 65" > supported only on the ends, but we have been able to successfully cut this > dimension previously (on a 3-axis Techno machine). > > > On Tuesday, July 21, 2020 at 1:12:01 PM UTC-4 [email protected] wrote: > >> You didnt mention what type of limit switches you're using or how your >> spindle works. The Y axis itself shouldn't be under any special stress >> while cutting but the spindle generally takes a hard hit as soon as a tool >> enters the cut. Is the spindle motor powered by the same power supply your >> switches are on? Supply could be dropping low. Is the machine not ridgid >> and vibration tripping the switches? >> >> On Tue, Jul 21, 2020, 8:54 AM Mason Millner <[email protected]> wrote: >> >>> Hi All, >>> >>> We are developing a 4-axis CNC to mill bamboo poles and are currently >>> running tests in just three axis (x, y, z). We can dry-run g-code files >>> successfully, however we receive limit switch errors (primarily on joint 1) >>> when we begin cutting material. We suspect that the error is occuring in >>> the y-axis and that possibly our drivers are causing a problem (either they >>> are too small or not tuned adequately).. It is difficult to tell what is >>> going on and how the machine is configured from the information given. >>> >>> We have the z-axis running on the long x-axis, running on two shorter >>> dual y-axes. >>> >>> The axis shaft is a ½” (12.7mm) , also the motor shaft is ¼” (6.35mm). >>> we are using polyurethane insert couplers (these have regularly been coming >>> loose though). >>> >>> The motors are NEMA 23s with 3A rating/phase controlled by Pololu >>> TB67S249FTG drivers on a Cramps 2.2 cape on the Beaglebone Black. The >>> drivers have a current limit of 1.6A and are further limited to %90 for >>> safety. The Current limit for the board and drivers are defiantly a bottle >>> neck, but the motors have enough power to operate. [Could this be the >>> problem?] >>> >>> Any help or recommendations would be greatly appreciated. If more >>> information is needed please let me know. I'm fairly new to the machine >>> development side of this project. Thanks. >>> >>> -- >>> website: http://www.machinekit.io blog: http://blog.machinekit.io >>> github: https://github.com/machinekit >>> --- >>> You received this message because you are subscribed to the Google >>> Groups "Machinekit" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/machinekit/790379d8-160b-4fed-9fa2-d03cbe160926n%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/machinekit/790379d8-160b-4fed-9fa2-d03cbe160926n%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/machinekit/88d28691-1bcb-4773-83db-980560508e9bo%40googlegroups.com.
