On 5/25/2018 5:27 AM, 'rico kirstein' via Machinekit wrote: > > Hi, I'm currently setting up a rather large gantry of 3x3m. > It is for a storage and test system. > I was wondering if the Gantry component has a way to abort homing if the > deviation between the two motors is bigger than lets say 10mm after passing > one endstop. > It is driven by two 400W Servo motors and I'm pretty sure they would > overload before permanently damaging the gantry but I'd rather have some > safety check, should one of the endstops fail at some point. > It also would run into Hardstops and overload the motor should it happen in > search direction, triggering a Estop, but you'll never know before it > happens.
The gantry component will not directly do what you want, but you should be able to craft something using HAL. When the gantry component is homing (moving towards the home switches and all individual home switches are not in the same state), the offset values for each joint are updated: http://www.machinekit.io/docs/man/man9/gantry/ You should be able to trigger a fault if the offset values ever exceed a specified level, but be aware that the offsets are not "absolute", and include any initial racking from when the machine powered on. In other words, if you power up and there's a 2 mm rack in your gantry, that will be removed when you first home, and the offset value for one of the joints will be 2mm, meaning your 10mm limit would be an offset of either 8mm or 12mm, depending on direction. For your application (assuming the gantry is not racked but a home switch might fail) I'd probably capture the commanded position out of motion when any of the home switches trips and trigger a fault if the position moves more than your 10 mm limit without the other home switch activating. You could build this up with existing HAL components, but it might be easier to craft a simple comp or add it into the gantry component where you can piggy-back on the existing homing logic: https://github.com/machinekit/machinekit/blob/master/src/hal/i_components/gantry.icomp -- Charles Steinkuehler [email protected] -- 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]. Visit this group at https://groups.google.com/group/machinekit. For more options, visit https://groups.google.com/d/optout.
