Best posts made by Adrian52

@fred-y Thanks for this idea - it seems to work. I made this:

using the two holes on the motor side of the extruder. This leaves a nice gap on the molex connector side for the plug to fit properly.
This is how it looks in situ:

I am using the default sensitivity on a v3 smart effector, and found that it needed an extra -0.04 on the probe offset. Seems to work well though - a 19 point G32 gave a 0.010 fit.

The mount pictured was printed with the new setup - I was fine tuning the thread diameter - 12.3mm was good for me. I havent pushed the new setup yet - seems promising though.

@3dmntbighker I have put a new version on thingiverse, 3649565. I have increased the play, and made the bolts screw in from the side. This is easy for the bottom bearing, but you need a 7mm bolt for the upper bearing to fit between the vertical bolts. Their spacing is determined by the holes on the PCB.

I have done more experiments with the gap between sensor and top bearing, and have concluded so far that a 5mm spacer is probably ok. I realised that my initial results were essentially single points for the max and min - with repeated runs, the picture is not so clear, but I think 5mm is better than no spacer.

The percentages I get are still high, but quite reproducible - for the 5mm spacer, the average is about 270%, with the min not below 259, and the max not above 287 on 4 runs of at least 500mm extrusion. The relationship between sensor distance and average percentage reported is very linear - I have 12 points in my dataset now, with a least squares linear fit r squared of 0.998. The slope is 23.0 - the average percentage increases by 23 for each mm of gap between the sensor and bearing surface.

@jay_s_uk I find the easiest thing is to set a minimum layer time. The cat on the left is 20sec minimum, and the middle one is 10sec minimum. To check that its the time not speed of printing, the one on the right is one of two printed together with 20sec minimum.

I have posted a design on thingiverse for mounting an Orbiter 2 extruder on the Smart effector. (https://www.thingiverse.com/thing:5239585)
The magballs are moved out by 12mm, but maintaining the 55mm arm separation so you don't need to alter the carriages. This is enough to give access to the whole 250mm bed of my kossel XL with the extruder mounted horizontally just above the hotend. A prototype in pla seems to work fine, with a 19 point G32 giving mean deviation around 0.02. Print quality seems really good, although still optimising (still using my old input shaping settings). Have now printed it in carbon fibre petg, which should be stiffer, but not sure if that is necessary.
Enjoy.

Have done a test print of the 693zz version in pla.
As you can see, the jaw tends to drop somewhat when the filament goes through. Do you think it needs some extra support? - maybe a plate that goes on the bottom? Or perhaps it would be better in petg? For my printing, I think the 4mm slots for the bearings could do with a tiny bit more tolerance. Great idea though - I am about to order a laser monitor on the strength of it.

Those changes seem to work OK

I used 0.1mm gap on each side of the bearings, and added 1mm to the base of the jaw to make the spring stronger. I didn't have room for washers, but the bearings rotate quite freely.

@3dmntbighker I have just put the files on thingiverse, 3618968

I have some preliminary results on the effect of changing the working distance of the sensor. The sensor Web page suggests 5 - 60mm for glossy surfaces, and 20-40mm for white paper. I printed some spacers to go between the top and middle sections of the indirect sensor, and checked the results after printing about 700mm of filament. I have been using A0, and 5mm measuring interval. With no spacer I got 72%(48), 149%(100), 243%(163) for min, average and maximum, normalised to average =100 in the brackets. With the 10mm spacer, I got 180(49), 370(100), 390(105). With a 15mm spacer, it was 472(97), 487(100), 505(103), and the 25mm spacer 575(81), 708(100), 749(106). I need to do more tests, but it looks like a longer working distance may be better - the 15mm spacer result is quite good. Perhaps this is worth investigating with direct sensing too.
I am still getting the sensor reported as v1 after sending M591 D0 A0, sometimes reverting to v2 after a number of M591 D0 s (it is a v2 sensor)

@dc42 have done some more tests using a 20x20x4mm cube with 100%fill, printed at 60mm /sec, then varying the layer height or width to achieve specific filament movement rates. I print the first layer at 10mm/sec, so checking after 100 mm gives a 'slow' baseline for each test, and the total is a little over 700mm. Under these conditions I have no hiccups or missed steps.
For me, the monitor works well with filament movements up to 1.3mm/sec (max/min within 10% of the average) , but for 1.5mm/sec and 2mm/sec, the max/min range becomes very wide, often going negative on the min side. I get similar results with and without a 5mm spacer, although the actual numbers are higher with the spacer as previously observed.
The total extrusion reported by the monitor is very close (usually within 1%) to that shown by dwc or the slicer, even when the extrusion rate is above 1.5mm /sec.
I have also started to note the error rates for the monitor reported by M122. For tests below 1.3mm/sec, frame errors are 2000-4000, and pol errors high(20000-30000). Above 1.3mm/sec, frame errors are 20000 - 30000, but pol errors are below 10000. I have also noticed that the error count is not zeroed when you start a new print - I have been doing a reset after each test to zero things up.

Have now done some rolling back and forwards. M226 pause from gcode works for me in 3.1.1 and 3.2b2, but not in 3.2b3 or 3.2b3.2. Pause and resume working from dwc in all versions.

@the_dragonlord you could try the laser filament monitor with the indirect sensor setup - the original thread:
https://forum.duet3d.com/topic/10042/indirect-bearing-laser-filament-monitor-concept/96
I have found it very reliable, spookily accurate for the monitoring of length extruded, and more or less completely filament type independent.

So sad. I particularly appreciate DuetLapse, and Danal was so helpful to so many people.

@brunofporto realised later that one of the bearings was not fully seated, so your bearing gap may well be right. Still need a bit of tolerance for the outer part of the bearing, and I suspect that the jaw spring may need to be a bit thicker. Will try again - thanks for the design.

@t3p3tony I think it might be related to y direction travel between objects. With two simple 20x20x20 cubes displaced 40mm in the y direction but aligned in the x direction, I get a pronounced (18deg) slope in the - y direction on both cubes . Printing the same two cubes aligned in y but displaced in x seems to give straight sides.

https://vimeo.com/415279225
Is an effort with pla. Used detect - pause, with M226 in the gcode at each layer change. The extra frames have to be deleted before running ffmpeg again

I have seen an occasional failure of M122 to give a response in the DWC g-code console. With the current firmware and DWC (2.02rc1 and 1.22.3), M122 will cause a pause, disconnect, and immediate reconnect. This usually happens when I return to the printer some time after the print has finished. I can connect with YAT, and I get a response to M122 - this is the output: 0_1536068880847_20180904m122 from yat.txt
This output does not relate to the completed print, so presumably the M122 from DWC was processed to some extent. Interestingly, the DWC g-code console is still responsive to some commands - I can send an M999 reset for example. Have seen this with previous versions of firmware/DWC.

@brunofporto I finally got a sensor, and have fitted it. It seems to be working OK, although giving high percentages - 103 minimum, 147 average, 203 max, on a roughly 3000mm print. I have made the following changes to the design

1. The cutout for the board components needed an extra 1mm - maybe because I have the v2 sensor?
2. The jaw bearing is lowered by 0.3mm. The hinge only bends a little, but enough to grip the filament
3. The ptfe tube slot is widened to 4mm diameter. I was finding the filament was sticking because of compression of the tube. I also made 3 narrow cutouts 4.2 mm diameter in the slot to make the inside ridged - the tube seems to hold quite firmly without occluding the bore
4. I think I already mentioned giving 0.1mm clearance for the bearings, and 1mm extra for the hinge
5. I roughened the outside of the upper bearing with an emery board - feels a bit more grippy, and maybe seen better by the sensor?
   this is what it looks like
   

I could post my changes on thingiverse, but didn't want to steal your thunder

Will update as I get more experience with it.

@t3p3tony have now tried the two cubes without infill, without input shaping, with z hop=0, and with pa=0, and the slope in the - y direction is the same.

@Danal here is my first go

https://vimeo.com/415969620
Worked fine with M226 in the gcode file. Excellent. Will try detecting layer changes later. Great work.

There seems to be a linear relationship between the sensor distance and the average percentage reported:

This is the percentage value returned is on the Y axis, and the distance between the sensor and bearing surface on the X axis. Looks as though it would give 100% with contact! Also looks as though the minimum returned is a bit more sensitive to distance than the maximum.