Re: [Emc-users] Using laser time of flight sensor to home mill

On Thursday 10 August 2017 00:01:38 Kirk Wallace wrote: > On 08/09/2017 11:33 AM, Dan Bloomquist wrote: > > ... snip > > > You made me look. :) My wheels have no markings so taped a piece of > > paper and made pencil mark. I mounted a .0001" dial indicator. I > > can't see any backlash, just my

Re: [Emc-users] Using laser time of flight sensor to home mill

On 08/09/2017 11:33 AM, Dan Bloomquist wrote: ... snip You made me look. :) My wheels have no markings so taped a piece of paper and made pencil mark. I mounted a .0001" dial indicator. I can't see any backlash, just my wheel is sloppy. The wheel is 6 1/2" in diameter and to get a .001" move,

Re: [Emc-users] Using laser time of flight sensor to home mill

On Wednesday 09 August 2017 21:26:33 Jon Elson wrote: > On 08/09/2017 10:38 AM, Dan Bloomquist wrote: > > I know how accurate this thing is. The idea is that I can > > start up without hunting switches. > > Why is that such a big deal? LinuxCNC now can do all axes > with the press of ONE button!

Re: [Emc-users] Using laser time of flight sensor to home mill

On 08/09/2017 12:53 PM, Dan Bloomquist wrote: Ok, so maybe I'm over thinking this. So I should just mount switches in the centers, make sure I'm jogged close to a known side on start up, and just home on them. Yup, that's how it is set up on my Bridgeport. The X trip bar is in the center, and

Re: [Emc-users] Using laser time of flight sensor to home mill

On 08/09/2017 10:38 AM, Dan Bloomquist wrote: I know how accurate this thing is. The idea is that I can start up without hunting switches. Why is that such a big deal? LinuxCNC now can do all axes with the press of ONE button! I really don't see the need for exotic and possibly finicky

Re: [Emc-users] Using laser time of flight sensor to home mill

Hi, What is your mill? Does it have stepper motors or servo motors? What position feedback (ie. encoder, scale...), if any, do you have? thanks Stuart On Wed, Aug 9, 2017 at 1:41 PM, Dan Bloomquist wrote: > andy pugh wrote: > >> On 9 August 2017 at 18:40, Kirk Wallace

Re: [Emc-users] Using laser time of flight sensor to home mill

andy pugh wrote: On 9 August 2017 at 18:40, Kirk Wallace wrote: For an absolute position sensor, I'm thinking that a section of tape from a tape measure glued to the slide would work well in conjunction with a screw dial or pointer. Maybe something like I found

Re: [Emc-users] Using laser time of flight sensor to home mill

Kirk Wallace wrote: On 08/09/2017 10:07 AM, Chris Albertson wrote: One use I can think of for a low precision sensor is that you should be able to home faster. The motor can run at full speed until it gets close then slow just before it hits a mechanical switch. For this use case 10%

Re: [Emc-users] Using laser time of flight sensor to home mill

On 9 August 2017 at 18:40, Kirk Wallace wrote: > For an absolute position sensor, I'm thinking that a section of tape from a > tape measure glued to the slide would work well in conjunction with a screw > dial or pointer. Maybe something like I found on eBay.

Re: [Emc-users] Using laser time of flight sensor to home mill

Ok, so maybe I'm over thinking this. So I should just mount switches in the centers, make sure I'm jogged close to a known side on start up, and just home on them. I don't want to have to bounce off the limits, my X is almost a half a meter away from the center. (35" between limits). And I

Re: [Emc-users] Using laser time of flight sensor to home mill

On 08/09/2017 10:07 AM, Chris Albertson wrote: One use I can think of for a low precision sensor is that you should be able to home faster. The motor can run at full speed until it gets close then slow just before it hits a mechanical switch. For this use case 10% error is good enough. My

Re: [Emc-users] Using laser time of flight sensor to home mill

- From: "Chris Albertson" <albertson.ch...@gmail.com> To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> Sent: Wednesday, August 9, 2017 1:07:43 PM Subject: Re: [Emc-users] Using laser time of flight sensor to home mill One use I can thi

Re: [Emc-users] Using laser time of flight sensor to home mill

One use I can think of for a low precision sensor is that you should be able to home faster. The motor can run at full speed until it gets close then slow just before it hits a mechanical switch. For this use case 10% error is good enough. On Wed, Aug 9, 2017 at 9:40 AM, Stuart Stevenson

Re: [Emc-users] Using laser time of flight sensor to home mill

Hi, Positioning the laser with magnets seems like an invitation to disaster. The laser WILL get bumped or jiggled out of position. Hopefully, the out of position would result in the machine not moving instead of moving to the wrong position. Using the laser to establish rough position (therefore

Re: [Emc-users] Using laser time of flight sensor to home mill

s@lists.sourceforge.net> Sent: Wednesday, August 9, 2017 11:38:28 AM Subject: Re: [Emc-users] Using laser time of flight sensor to home mill Dan Bloomquist wrote: > > So it occurred to me to us a laser range finder. Then lcnc would know > where the table is without having to move on boot

Re: [Emc-users] Using laser time of flight sensor to home mill

Dan Bloomquist wrote: So it occurred to me to us a laser range finder. Then lcnc would know where the table is without having to move on boot. It does not have to be accurate like to mm as I probably never have to mill to the limit switches, and even then

Re: [Emc-users] Using laser time of flight sensor to home mill

On 08/08/2017 09:42 PM, Dan Bloomquist wrote: I have not set homing up on my mill yet, I've been mulling it over. A switch is not satisfying unless there is a way to keep from hunting for it, can't imagine... So it occurred to me to us a laser range finder. Then lcnc would know where the

Re: [Emc-users] Using laser time of flight sensor to home mill

On 9 August 2017 at 02:42, Dan Bloomquist wrote: > am I missing something fundamental that makes it a bad idea? If you never need to re-start a job after the machine has shut down then I think that it could be made to work. The development branch of LinuxCNC has support for

Re: [Emc-users] Using laser time of flight sensor to home mill

The sensors are about as accurate as cloth tape measure. So if you don't mind a home switch that gets you to within about 1/8 inch of where you need to be use it. They work really well for some kinds of automation and measuring the level of liquid in a tank. Light moves at about one foot per

Re: [Emc-users] Using laser time of flight sensor to home mill

On Tue, Aug 8, 2017 at 9:42 PM, Dan Bloomquist wrote: > I have not set homing up on my mill yet, I've been mulling it over. A > switch is not satisfying unless there is a way to keep from hunting for it, > can't imagine... > > So it occurred to me to us a laser range finder.

Re: [Emc-users] Using laser time of flight sensor to home mill

On Tuesday 08 August 2017 21:52:35 Jon Elson wrote: > On 08/08/2017 08:42 PM, Dan Bloomquist wrote: > > I have not set homing up on my mill yet, I've been mulling > > it over. A switch is not satisfying unless there is a way > > to keep from hunting for it, can't imagine... > > If you have

Re: [Emc-users] Using laser time of flight sensor to home mill

On 08/08/2017 08:42 PM, Dan Bloomquist wrote: I have not set homing up on my mill yet, I've been mulling it over. A switch is not satisfying unless there is a way to keep from hunting for it, can't imagine... If you have encoders with index, that can set the home position to an exact encoder

[Emc-users] Using laser time of flight sensor to home mill

I have not set homing up on my mill yet, I've been mulling it over. A switch is not satisfying unless there is a way to keep from hunting for it, can't imagine... So it occurred to me to us a laser range finder. Then lcnc would know where the table is without having to move on boot. It does