Adjustable Mesh-leveling-friendly SN04 Auto-level Sensor Mount for A8 (no heatsink, no fan [yet])

prusaprinters

<p>Updated thing with fan shroud <a href="https://www.thingiverse.com/thing:3965895">here.</a></p> <p>Compatible sensor sled for use with the BLTouch/3DTouch <a href="https://www.thingiverse.com/thing:4266379">here.</a></p> <hr/> <p>My A8 came with the SN04 sensor and I have used several of the sensor mounts available on this site to try and make it more user-friendly. I had been using <a href="https://www.thingiverse.com/thing:3023583">fabal's excellent adjustable SN04 mount</a> for quite awhile until I upgraded my firmware to Marlin and got fixated on its ability to do mesh leveling.</p> <p>The main problem with that sensor mount, and in fact, with most of the ones I've seen, was that the sensor was mounted so far away from the nozzle and the A8's travel limitations kept the sensor from reading the front edge of the heat bed correctly (or other edges for other sensor mounts). It would read the edge several millimeters inside the actual edge.</p> <p>The second problem, not with the mount I was using, but with all the others that put the sensor in a good position, was that they weren't easily adjustable. After living with that sensor mount for so long I consider it now a standard to have an easily adjustable sensor mount. After some thinking and browsing I found <a href="https://www.thingiverse.com/thing:2319403">this one</a> which I meshmixed and used for awhile. However it lacked fine tunability but it helped me figure out what to do.</p> <p>So here is the results of my endeavors. I have managed to keep the wonderful adjustability with a simple M3 screw as found with <a href="https://www.thingiverse.com/thing:3023583">fabal's mount</a> and I have found a position that puts the sensor close enough to the hotend to read much more of the heat bed. A bonus is that it is designed to work in conjunction with the <a href="https://www.thingiverse.com/thing:2121279">Mistral 2.1a fan duct</a>, which I find exceptional.</p> <p>NOTE:</p> <p>There is no room for the extruder heatsink with this design but I've yet to find it offers any real cooling advantage or dust protection in my mild printing environments. I found it just blocks my view. YMMV. The extruder cooling fan has to be removed as well although I have not found the carriage or the throat tube gets hot enough to warrant concern. Of course, YMMV. I am working on adding a mount for a 25x7mm or 25x10mm cooling fan, because... why not?</p> <p>The key part is the sensor is now inboard enough that it can reach the right edge of the heatbed to get accurate readings if you're comfortable with moving the carriage to the brink of crashing with the right X-axis assembly.</p> <p>It would probably do better with a super small spring or maybe some soft TPU elastomers to add tension between the sensor sled and the sled base. It works alright as it is but it does bounce around sometimes (most notable as read below; CONS).</p> <p>TL;DR</p> <p>PROS-</p> <p>Works with common SN04 leveling sensor</p> <p>Sensor range covers the entire area of the hot bed.</p> <p>Fine tunable height adjustment by turning an M3 screw.</p> <p>Compatible with very efficient common fan duct model.</p> <p>CONS-</p> <p>Extruder heatsink removal mandatory.</p> <p>Extruder cooling fan has not been added yet.</p> <p>Can run into left Z-axis rod coupling during X-axis homing in certain situations (sensor wiggles out of the way though).</p> <hr/> <p>UPDATE:</p> <p>Crash with Z-axis rod coupling resolved on the <a href="https://www.thingiverse.com/thing:3965895">thing page that includes the fan shroud.</a></p> <h3>Print Settings</h3> <p><strong>Printer:</strong></p> <p>Anet A8</p> <p class="detail-setting rafts"><strong>Rafts: </strong> <div><p>No</p></div> <p><strong>Supports:</strong></p> <p>No</p> <p class="detail-setting resolution"><strong>Resolution: </strong> <div><p>0.15mm</p></div> <p><strong>Infill:</strong></p> <p>25%</p> <p><strong>Filament:</strong></p> eSun PETG <p>Silver</p> <p><br/> <p class="detail-setting notes"><strong>Notes: </strong></p> </p><div><p>0.4mm nozzle, 0.48mm width, seven top/bottom and four perimeters, 60mm/sec, 80% outline and infill speed, 220c hotend, 60c bed.</p></div> Materials ========= <p><strong>Hardware, Assembly, and Marlin Settings</strong></p> <div><p>Hardware:</p> M3 hardware throughout. I neglected to get measurements for all the screws involved, terrible form. FWIW I had to cut down an M3x10 for the mounting plate. The rest were standard sizes. I will try to get those lengths ASAP. <p>UPDATE:</p> <p>Sizes are available on the updated thing page listed above.</p> <p>Assembly:</p> <p>The mounting plate traps an M3 nut that the sensor sled base uses as a mounting point. There is also a caputured M3 nut used for the height adjustment and two recessed nuts are used to mount the SN04 to the sensor sled. Hopefully the pictures help.</p> <p>Marlin Settings:</p> <p>Other than the usual auto bed leveling adjustments required in Marlin's "config.h" file, this is the offset settings for the sensor mount's position:</p> <h3>define X_PROBE_OFFSET_FROM_EXTRUDER -30 // X offset: -left +right [of the nozzle]</h3> <h3>define Y_PROBE_OFFSET_FROM_EXTRUDER 0 // Y offset: -front +behind [the nozzle]</h3> <h3>define Z_PROBE_OFFSET_FROM_EXTRUDER 0 // Z offset: -below +above [the nozzle]</h3> <p>And once again for good measure, YMMV.</p> </div></p></p> Category: 3D Printer Parts