Anyone interested in a differential IR Z probe for deltas? January 29, 2015 05:08AM |
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Re: Anyone interested in a differential IR Z probe for deltas? January 29, 2015 10:46AM |
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Re: Anyone interested in a differential IR Z probe for deltas? January 29, 2015 12:47PM |
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Re: Anyone interested in a differential IR Z probe for deltas? January 29, 2015 01:09PM |
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Pointy
I am definitely interested Dave, as you know.
Size is going to be the key thing, I am using a version of AndyCarts CPIIIs sprung effector, and there is limited space to fit one. I had this crazy idea, which probably isn't feasible due to noise or interference, but is it possible to separate the sensor part from the main PCB? You could then have a tiny PCB mounted on the bottom of the effector with just the sensors, and then mount the main PCB on the top with a short cable connecting the two.
Just an idea.
Regards,
Les
Re: Anyone interested in a differential IR Z probe for deltas? January 29, 2015 01:47PM |
Registered: 10 years ago Posts: 14,682 |
Quote
Pointy
I am definitely interested Dave, as you know.
Size is going to be the key thing, I am using a version of AndyCarts CPIIIs sprung effector, and there is limited space to fit one. I had this crazy idea, which probably isn't feasible due to noise or interference, but is it possible to separate the sensor part from the main PCB? You could then have a tiny PCB mounted on the bottom of the effector with just the sensors, and then mount the main PCB on the top with a short cable connecting the two.
Just an idea.
Regards,
Les
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dougal1957
Or have the board waisted so that it could fit on one corner of the effector (Narrow part) Maybe that would work.
Re: Anyone interested in a differential IR Z probe for deltas? January 29, 2015 03:11PM |
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Re: Anyone interested in a differential IR Z probe for deltas? January 29, 2015 03:45PM |
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Re: Anyone interested in a differential IR Z probe for deltas? January 29, 2015 06:21PM |
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Re: Anyone interested in a differential IR Z probe for deltas? January 29, 2015 07:34PM |
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dc42
I am aware that some people use FSRs under the bed supports, but I was under the impression that this was not so easy when a heated bed is used. I presume this is because of the extra weight of a heated bed and/or temperature sensitivity of the FSRs.
Re: Anyone interested in a differential IR Z probe for deltas? January 30, 2015 02:51AM |
Registered: 9 years ago Posts: 395 |
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dc42
I am aware that some people use FSRs under the bed supports, but I was under the impression that this was not so easy when a heated bed is used. I presume this is because of the extra weight of a heated bed and/or temperature sensitivity of the FSRs.
Re: Anyone interested in a differential IR Z probe for deltas? January 30, 2015 03:05AM |
Registered: 10 years ago Posts: 327 |
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dc42
Les, how much depth is there between the bottom of the effector plate and the tip of the nozzle on your build?.
Re: Anyone interested in a differential IR Z probe for deltas? January 30, 2015 03:17AM |
Registered: 10 years ago Posts: 1,159 |
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Pointy
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dc42
Les, how much depth is there between the bottom of the effector plate and the tip of the nozzle on your build?.
I have 8mm from the bottom side of the effector to the tip of the nozzle.
Regards,
Les
Re: Anyone interested in a differential IR Z probe for deltas? January 30, 2015 05:45AM |
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Re: Anyone interested in a differential IR Z probe for deltas? January 30, 2015 07:54AM |
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dougal1957
Les you may have to modify the effector design slightly to add a mounting plate on one of the corner's to take whatever dave comes up with (It would need to have provision to move the probe up or down to suit the hotend as well)
Re: Anyone interested in a differential IR Z probe for deltas? February 06, 2015 02:30PM |
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Re: Anyone interested in a differential IR Z probe for deltas? February 06, 2015 03:22PM |
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Re: Anyone interested in a differential IR Z probe for deltas? February 08, 2015 11:20AM |
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dc42
The problem I am up against with designing an IR probe suitable for a wide range of delta printers is that the height of the effector plate above the nozzle varies so much. On the Mini Kossel, the complete IR probe and electronics would for comfortably below the effector plate. On some other printers there is too little space there, so the board would need a very narrow waist that fits in the effector cutout between a pair of parallel rods, with the sensors below and the rest of the electronics and connectors above. But there is no standard height at which to put that waist.
I'm thinking of resurrecting an earlier idea I had, which is to use a solenoid-activated mechanical probe. The solenoid I have in mind weighs 12g. It can be mounted above the effector in all cases, and the probe extended downwards as necessary for different printers. Sensing contact of the probe with the bed could be done either using an optical pickup to detect when the probe has been pushed in a certain amount, or by using a cheap microcontroller (e.g. attiny45) to sense the change in inductance.
I would provide two output options:
1. Stepped analog output compatible with my Ormerod differential IR sensor. This provides an indication of when the trigger point is approaching, to allow the firmware to reduce the speed.
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dc42
2. Digital output emulating a normally-closed microswitch that opens when the probe is triggered, for use with Marlin and similar firmware.
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dc42
I would probably design the board to require +12V, 12V ground, output, and signal ground wires. The 12V and 12V ground wires are typically already available from the hot end cooling fan (provided it is wired to a permanent 12V supply), and the output and signal ground wires are present already on the Mini Kossel kit with mechanical Z probe.
I could also provide the option of terminating all the hot end wires on the board as I do on my Ormerod board, with or without thermostatic control of the fan.
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dc42
How does this sound?
Re: Anyone interested in a differential IR Z probe for deltas? February 08, 2015 04:43PM |
Registered: 10 years ago Posts: 14,682 |
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dougal1957
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dc42
I would probably design the board to require +12V, 12V ground, output, and signal ground wires. The 12V and 12V ground wires are typically already available from the hot end cooling fan (provided it is wired to a permanent 12V supply), and the output and signal ground wires are present already on the Mini Kossel kit with mechanical Z probe.
I could also provide the option of terminating all the hot end wires on the board as I do on my Ormerod board, with or without thermostatic control of the fan.
Yes Please This would make wiring a breeze as long as the sockets/plugs you use are readily available (Or even supply them with the board at additional cost)
Re: Anyone interested in a differential IR Z probe for deltas? February 09, 2015 02:40AM |
Registered: 10 years ago Posts: 1,159 |
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dc42
Quote
dougal1957
Quote
dc42
I would probably design the board to require +12V, 12V ground, output, and signal ground wires. The 12V and 12V ground wires are typically already available from the hot end cooling fan (provided it is wired to a permanent 12V supply), and the output and signal ground wires are present already on the Mini Kossel kit with mechanical Z probe.
I could also provide the option of terminating all the hot end wires on the board as I do on my Ormerod board, with or without thermostatic control of the fan.
Yes Please This would make wiring a breeze as long as the sockets/plugs you use are readily available (Or even supply them with the board at additional cost)
The connectors I use are Molex KK series, which are widely available. Unlike some other connectors used on hot ends, it is not difficult to remove the crimp pins from the housings after they are inserted. When I supply Ormerod hot end boards, I include the mating connector shells and crimp pins too. However, the customer still needs to connect the wires from the hot end loom, for which I recommend a crimp tool.
Re: Anyone interested in a differential IR Z probe for deltas? February 28, 2015 03:20AM |
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Re: Anyone interested in a differential IR Z probe for deltas? April 07, 2015 07:39PM |
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Re: Anyone interested in a differential IR Z probe for deltas? April 08, 2015 03:33AM |
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Re: Anyone interested in a differential IR Z probe for deltas? April 11, 2015 11:57AM |
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dc42
I have done some preliminary design work on the board, and the size is coming out at 25mm wide by 20mm high. The bottom edge of the board needs to be between 1mm and 2mm above the nozzle. So the minimum space needed will be about 20mm height between the tip of the nozzle and the underside of the effector. I may be able to reduce this by a couple of mm if I use a smaller connector than the Molex KK.
Re: Anyone interested in a differential IR Z probe for deltas? May 07, 2015 04:45PM |
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Re: Anyone interested in a differential IR Z probe for deltas? May 07, 2015 05:19PM |
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Re: Anyone interested in a differential IR Z probe for deltas? May 07, 2015 07:33PM |
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Re: Anyone interested in a differential IR Z probe for deltas? May 08, 2015 03:42AM |
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Re: Anyone interested in a differential IR Z probe for deltas? May 08, 2015 04:16AM |
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Re: Anyone interested in a differential IR Z probe for deltas? May 08, 2015 05:43AM |
Registered: 10 years ago Posts: 14,682 |
Re: Anyone interested in a differential IR Z probe for deltas? May 08, 2015 12:16PM |
Registered: 10 years ago Posts: 14,682 |