<p>I currently use a BLtouch 3.1, which is known to stop operating at about 35-40 °C. In fact, when I preheat the bed at 100 °C close to the probe, I sometimes get issues with the pin not retracting correctly.</p>
<p>I would like in the future to enclose and heat the printer chamber, therefore I need a probe capable of operating at higher temperature. My target is 100 °C.</p>
<p>As of now, I'm aware of this solution:</p>
<p><a href="https://hightemp3d.com/products/remoteht-bed-level-probe-3d-printer" rel="nofollow noreferrer">https://hightemp3d.com/products/remoteht-bed-level-probe-3d-printer</a></p>
<blockquote>
<p>This high temperature probe uses a mechanical switch in combination
with a servo motor to probe the bed. The servo motor is outside the
enclosure and retracts the probe pin by pulling on a steel string
inside a spring guide tube.</p>
</blockquote>
<p>Microswitches are known to work at high temperatures (that's what the link above uses), but usually need a servo or other mechanism to extend/retract them when needed. Servos typically don't operate at such high temperature, not to mention that they are usually not very accurate.</p>
<p>I saw a <a href="https://www.thingiverse.com/thing:4138933" rel="nofollow noreferrer">Hall filament sensor</a> which uses Hall effect sensors &quot;<a href="https://sensing.honeywell.com/honeywell-sensing-ss39et-ss49e-ss59et-product-sheet-005850-3-en.pdf" rel="nofollow noreferrer">ss49e</a>&quot; and which could be easily <a href="https://www.youtube.com/watch?list=PLC-4S0aWJmLgpsTpdV56nfbFBFBC1jijn&amp;v=-UwGZgZvYmw&amp;feature=emb_title" rel="nofollow noreferrer">modified to be used as bed probe</a>. Those Hall effect sensors are rated up to 100 °C but at that temperature they have up to 8% shift of the null value and +3/-9% change in sensitivity. The linked project uses two of them in differential mode so the temperature compensation should be much better, but it is not clear how much better. A <a href="https://3dua.info/topic/21-datchik-diametra-filamenta/?page=2" rel="nofollow noreferrer">discussion</a> about it on a Russian forum does not talk about this.</p>
<p>Are there other options operating at 100 °C?</p>

[{'answer_id': 15636, 'author': 'blalor', 'author_id': 20406, 'author_profile': 'https://3dprinting.stackexchange.com/users/20406', 'pm_score': 2, 'selected': False, 'text': '<p>Have you considered using or adapting Prusa’s P.I.N.D.A. V2 or SuperPINDA? Seems that within some bounds they’ve solved the temperature compensation issue.</p>\n<p>The older P.I.N.D.A. V1 sensor seems to be temperature-sensitive. See more information in <a href="https://help.prusa3d.com/en/article/p-i-n-d-a-superpinda-sensor-testing_2091" rel="nofollow noreferrer">P.I.N.D.A./SuperPINDA Sensor testing</a> article of Pruse Knowledge Base.</p>\n'}, {'answer_id': 15671, 'author': 'FarO', 'author_id': 2338, 'author_profile': 'https://3dprinting.stackexchange.com/users/2338', 'pm_score': 1, 'selected': True, 'text': '<p>There are various designs which can be made to work at 100 °C.</p>\n<p>For example this <a href="https://www.thingiverse.com/thing:4390007" rel="nofollow noreferrer">solenoid probe</a> uses a solenoid to lift a plunger during print, letting it drop during probing. The design uses a rare earth magnet which usually loses strength at 60-80 °C, but there are high temperature versions or a ferrite magnet will do. It also uses an Attiny13, rated 80 °C, but there are higher temperature versions of the chip. It is likely that it would work out of specs at 100 °C too, but it uses an optical endstop, which is the limiting factor with 85 °C typical.</p>\n<p><a href="https://www.thingiverse.com/thing:4689074" rel="nofollow noreferrer">This other design</a> uses a solenoid to push up and down a tactile switch. I see no reason why the solenoid would not work at 100 °C, maybe only the external wires may require replacement to withstand the temperature. There is no electronics limiting the operating temperature.</p>\n<p>Other <a href="https://www.thingiverse.com/thing:3593971" rel="nofollow noreferrer">designs</a> with a servo are limited by the temperature range of the servo, which is typically 50-60 °C max. I think they would work fine up to 80 °C since they are not operated continuously and they are loaded with little force, but there is no guarantee.</p>\n<p>Another <a href="https://www.thingiverse.com/thing:2752968" rel="nofollow noreferrer">design</a> working perfectly and with an even lower total weight is based on a microswitch and... the user placing the probe in position manually. It can probably be automated by mounting it on a hinge and by using something on the side of the bed to move it in an upright position and in a tilted position, where it could be held by (ferrite) magnets.</p>\n'}]
['https://3dprinting.stackexchange.com/questions/15605', 'https://3dprinting.stackexchange.com', 'https://3dprinting.stackexchange.com/users/2338/']