I'm entering into the electronics phase of my LEAD 1010 (with High Z mod) build. I have been planning on using limitswitches on the MIN (home) extents of each axis and then using limitswitches on the MAX extent of each axis instead of softlimits. So basically, I would have the following: *** 2 limitswitches on the X axis at the MIN (home) and MAX extents... *** 4 limitswitches on the Y axis at the MIN (home) and MAX extents of both Y1 and Y2 (which are actually connected together at Y1 because Y2 is a 4th axis rotary)... *** 2 limitswitches on the Z axis at the MIN (home) and MAX extents... Anybody think this is overkill? scott
yes it is overkill (-: only 1 side of Y needs limits, and rotaries usually go all the way round, there is no limit, unless you have a swinging table type. also wrong for Z.... Z home MUST be at Z+, the high end of Z
Hey David.... Yes, you are correct about Z... It should have read "2 limitswitches on the Z axis at the MAX (home) and MIN extents..." and probably could go without the additional limitswitch. I should've clarrified that the rotary axis would not have limitswitches... My thinking was to have a switch at the end of each extent of travel and not rely on softlimits. All four of the limitswitches on Y are connected in parrallel and plugged into the Y port as a single switch... Not putting limitswitches on both sides of Y will leave it vulnarable, don't you think?
No, unless something is very wrong Y is in parallel. 1 trigger will stop the machine. Heck, I've ran into the end of y lots without any limit switch and havent had any major damage. Just have to do a realignment. So yes 4 on y is overkill. Ill likely go with 2 limit switches on Y in the future. Ive never hit max on X or Z and dont think limit switches here would be that useful. Actually adding the additional wiring and switch itself may introduce futher issues to troubleshoot later on should something break. David knows best.
Hi Scott, Apart from the switches used to define the machine home position, for most machines soft limits alone work really well. For general running, hard limits are only normally hit if for some reason a stepper loses steps and then a command that moves the machine towards one of the extremes is sent. The other situation that I have hit hard limits is when I have been commissioning or testing the machine, and cut corners to unlock the controller without homing, and then did something silly! The latter case is easily avoided (although I have done it more than once....) If the power of the stepper motors is not enough to damage the machine if it did run into the end, then not having switches under that situation is noisy and unpleasant, but will not cause damage. It is worth considering on a per-axis basis if hitting the end could cause damage though if you have up-scaled any of the steppers or changed a lead-screw to a finer pitch. Evan
