I was wondering what people have been using to Auto-Level their build platforms. I have been thinking of probing with voltage on the nozzle and grounded metal shims on the edge of the build platform. I have also recently been looking into using the FSR but the max temperature of 70c won’t work out. What do you think I should start experimenting with?
I’ve never got around to putting auto leveling on either printer. Once I got the beds dialed in properly, and fitted the micrometer based height adjustment bit, it just doesn’t change enough to make it worth the effort to me at this point. A little blue locktite on the corner height adjustment screws to keep them snug, a bit of time with a dial indicator and a feeler gauge, and it doesn’t require even touching for months at a time.
If I were going to go that route, I’d probably either do the swing down probe servo type, or the magnet probe. The voltage one seems problematic to me just because of the added bed mass and the nozzle cleanlyness issue. That being said the Mini looks lik eit’s going to ship with that sort of a system, so chances are its a fairly reliable way to go.
You could also try using a proximity sensor. I uploaded a sensor holder for the Taz to thingiverse. You can check it out here: http://www.thingiverse.com/thing:617615
Techsavvy34
How does the Proximity Sensor work? doesn’t it need to sense metal? also how would you go about wiring it to a taz4 ( where would you get the + , - 5v from )
There are inductive proximity sensors that sense metal and capacitance proximity sensors that can sense nonmetal materials. Some people use the inductive sensor with a Printinz printer plate since the new ones have a metal layer in them. You get the 5v from the endstop connection but depending on what sensor you have sometimes 5 volts isn’t enough power. When I was experimenting with the sensors I noticed that if I used 12 to 24 volts the sensor had a greater sensing range then when 5 volts was used. I would wire the proximity sensor to the 24v power supply and connected a 5v voltage regulator to the signal wire then connect the signal wire to the endstop. You have to use a voltage regulator or resistors to convert the signal back to 5v if your using more than 5v to power your sensor. If you don’t do this chances are you’ll fry your board.
I was wondering if you could help me out with my Proximity Sensor. I have the power and ground wire wired up to the main power supply of my printer because I wasn’t getting enough from the end-stop. Then I have the signal wire from the sensor going to the INPUT pin of the LM7805. The ground of the LM7805 goes to the same ground I used for the Proximity Sensor and then the OUTPUT pin goes to the signal wire of the z-min end-stop. When the sensor gets close enough to build plate the red LED turns on but the M119 code does not show triggered. Any tips how to fix this?
You might have to wire the ground from the z-min port to the proximity sensor’s/power supply ground. If it still doesn’t work after that I would try changing the logic of the endstop/sensor in the firmware.
This sounds like a promising route. I was considering adding a flip-down style limit switch one, but a proximity sensor might be simpler. Would this sensor - http://www.amazon.com/Tubular-Inductive-Proximity-Approach-LJ18A3-8-Z/dp/B005HKXKOG/ref=sr_1_1?ie=UTF8&qid=1420347475&sr=8-1&keywords=LJ18A3-8-Z%2FAX (the one you linked, Techsavvy34) work well with the taz’s glass bed?
No that sensor only works on metal. You need a capacitance proximity sensor to detect glass. I would also choose one that has a detecting distance of at least 8mm.
Still can’t get the probe to work. I am using the one found here ( http://www.ebay.com/itm/271444612857?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT ) as I was able to get it closer to my nozzle. I know it is possible to get it working because I saw it used in this thread ( http://umforum.ultimaker.com/index.php?/topic/7136-exploring-marlin-bed-auto-level/?p=68402 )
I also have a one of the cylindrical probes which I might try wiring up, but I am going to see if I can get this one working first.
Do you have a multimeter? Check the input voltage of the sensor, you are hooking it to the 24V right, so you should measure 24V.
The link that you provided is a normal open sensor, same tipe of sensors that are used on Taz, so no need to change the firmware. Check the output voltage of the sensor without any metal close to it, it should be “active”, meaning same voltage as the input. Now get a piece of metal close to the sensor and check the voltage again, it should be 0V.
NPN Sensors are good for sinking current, and not sourcing it, i think you should actually use a PNP sensor.
Instead of using a voltage regulator, try usinga voltage divider circuit with resistors.
Another thing, a inductive sensor is good to detect metal, and not glass, one capacitive sensor would work better on Taz I think.
Vitor Henrique
If you are wiring up a NPN sensor, you should not use the output of the sensor as input of the voltage regulator, you should connect you Vcc to both the regulator and the sensor, your sensing lead to the ground of the voltage regulator. Check this:
This makes more sense, working as a transistor almost. I will give it a try, thank you for your help.
let us know how it goes 
I am going to wire this up tomorrow been busy. I was wondering if I should have the ground pin of the voltage regulator connected to ground and the sensor lead or only the sensor lead.
I think the correct way to wire is the following (I did not test the circuit)
Pay attention to your voltage regulator and sensor pinout, mine was generic.
Still no luck. Could it be by any chance the wire-taps I am using? I am using these smaller ones and I was wondering if they can’t withstand the higher voltage. Below are 2 pictures of where I have connections made. Another picture is added of the wire-tap I am using and a red wire tap which I can use instead that is rated for 600V.
Those wire-taps can easily stand 24V.
You need to see if your voltage regulator is working. Put it on a bread board, wire it up, and measure the voltages. Which voltage regulator are you using?
After that, wire the sensor as my diagram on a bread board and use a large piece of metal to test the circuit.
I also already mentioned, your sensor is not suited to sense glass, I think a capacitive sensor is more likely to work. But again, but your circuit on the bench and test it first, before wiring to the Taz. and measure the voltages, that what we can figure it out what is wrong. Without this information is impossible to guess.
unfortunately I’m stuck at my apartment at school and won’t be able to access any of my tools at home, this is what makes this whole process a lot more annoying.
Okay so I got my multimeter shipped from home and did some measuring of the voltages. The input going into the sensor is 24V and it is outputting 24V when no metal is sensed. When sensed the voltage drops to 0V. This sensor is a NPN type sensor just so others are aware. In order to get this working how should I got about wiring the output to the z-min pins? I am no longer going to use the voltage regulator so I am looking into using resistors. Any help on how to do this would be great.
PS I appreciate all the support so far, it’s really great to have a place to go and gain some knowledge.