Broken P.I.N.D.A Probe Replacement
Hola,
So I recently printed the pinda protection hat, and I could not get it off. Long story short, I broke the probe. I don't want to buy it from the Prusa shop because their shipping prices is only for rich people. So I looked around and found this probe: https://goo.gl/2vhFoc The minimum voltage is 6 volts and the Rambo only does 5v. So I wanted to use this step up converter: https://goo.gl/cbzg28 and supply the probe with 12v. I'm wondering if the increased voltage will change the output voltage. If I do this I also need to know which one of the three wires is the positive, negative, and signal. Deos the output voltage for this probe work for the Rambo? Please let me know if I should buy these parts to replace the regular pinda probe.
Thanks for any help,
Brandon Esser
😉
Re: Broken P.I.N.D.A Probe Replacement
hi brandon,
first i think you need the npn version of the probe, not the pnp version. ❗
then you've asked for the output voltage:
➡ there is none, the emitter of the npn transistor inside the probe is connected to GND (usually the blue wire) while the collector is connected to the Z-Endstop pin at the rambo (usually the black wire).
at the pin used for the z-endstop, there's a so called pull-up resistor enabled inside the atmega2560 microcontroller (@ the rambo).
when the probe is triggered, the transistor will switch through and the pin at the rambo board will change its voltage from +5V (as provided through the pullup-resistor from the rambo) to approximately 0.5V, when the transistor is fully switched through.
this circumstance will not change, even if you provide another supply voltage to operate the probe.
💡 by the way: for the all the LJ8... inductive probes, there's a trigger distance of 2mm given. but these 2mm are only valid for detecting full metal (iron based). at other metals, or alloys, the triggering distance is expected to be shorter. so i don't know if the probe will be able to trigger above the calibration points of our mk42 heatbed (only a small 35µm thick copper disc-structure inside the layout of the heatbed pcb).
anyway, i've ordered myself a few of the LJ8 and even LJ12 probes, to analyze and test them. maybe they show a similar voltage dependency of the sensitivity like the genuine probe (as explained inside the thread about my i3 mk2 clone). but i expect about a month until they'll arrive here (ordered them in china).
dem inscheniör is' nix zu schwör...
Re: Broken P.I.N.D.A Probe Replacement
I have just come across a proximity sensor which has the correct working specs and physical dimensions. The given information is the following:
4mm sensing range
3% repeat accuracy
1000 samples per second
5V input voltage
NPN normally closed output - requires external pullup resistor
8mm body by 35mm length
1M cable with locking 2.54mm connector
Not sure if providing the link would get me banned from the forums and this post deleted...
http://www.xagyl3d.com/oc2/XAGIPS8X4-5V
Re: Broken P.I.N.D.A Probe Replacement
sorry to revive a long dormant thread, but did you have any success using the replacement part you listed?