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General Mach Discussion / Re: program run screen
« on: April 08, 2014, 05:05:55 PM »
Try re-selecting the screenset.
Regards,
Ray L.
Regards,
Ray L.
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Thinking that a mechanical switch or optical sensor is going to be more trouble free than a proxy sensor is folly. Any sort of contamination that will interfere with a prox sensor will be at least 100x as good at interfering with a mechanical/optical device. There are some accurate and repeatable mechanical switches out there be prepared to pay about $50 for one. They work well when covered from direct contamination and are simple to wire up but still require a mechanical actuator making installation more difficult. I did some testing a few months ago on three different micro-switches that are commonly used on home brew DNC machines. I put together a rig so I could very precisely measure where the switch actuated and released. You can find the paper I wore on it in the documentation section of my website.
Optical sensor can be very accurate but get dirty very easily and are very sensitive to temperature (one that works great at 70F may not work properly at 40F). If the machine is in a relatively temperature environment and can be kept clean it is a good choice. It still needs a precisely aligned actuator/flag so it is harder to install.
A proxy sensor is sealed, has no mechanical actuator and is easy to mount. They are used on a whole lot of industrial machines as well. In the next few weeks I'm going to set up to test prox sensors shielded and unshielded with different target types to see what the accuracy and repeatability is like.
Well, Im trying to match servo motors output shaft size to the readily available ball screw size. This is determined by what is included in the cnc retrofit kit(s). Some are 8mm, and some are 1/4" Of course, a nema23 size frame in the mid range power and wattage wize is about right for a small mill(bf20). So, making everything match up physically, and electronically is actually a bit complicated. My router works great on stepper motors, but it seems like servos are the way to go when making heavy hogging cuts. The router loses steps if pushed too hard. When I mention heavy hogging,, I mean in terms of a 300 pound bench mill,, so I know, not real heavy,, but presumably much deeper than the aluminum framed router can handle.