Migbot Prusa i3 Unofficial Support Thread

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gwc2795

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kaffemustasj

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gwc2795

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kaffemustasj
So I measured the voltage coming of the voltage regulator and it was 2.33V, this was no good, so I changed it out with a voltage divider. The sensor now reads 3.2V.
However, how I've ran into another problem.
When I try to home the Z axis, the sensor lights up and triggers, but the Z axis keeps on lowering. This means the sensor and printhead slams into the printbed and keeps on trying to lower.

So I've tested with M119. The problem is that the sensor is always open, it never shows as triggered. This is although the voltage drops from 3.3V to 0 when a metal object is placed under the probe.

I had the exact problem when I added the sensor to my Migbot. I disconnected the sensor from the pin and measured the pin voltage on the pin the sensor connects to and found it was supplying 5V. I tested various resistance values to find one that took the pin voltage to <0.2V when I connected it to ground. In my case that value was 680 ohm. I used that as the resistor that connects to the pin and ground in the voltage divider. A 1K resistor allows the voltage to rise to ~4V from the output of the sensor. The sensor I have is normally closed and opens when the bed is sensed. Before the changes to the voltage divider resistance values mine tried to go through the bed.

Yeah, I'm guessing that's my problem. I measured 5V coming from the motherboard pins without the sensor connected.
When the sensor is connected to the board I'm reading 4.7V with a drop to 2.3V when the probe is triggered.
I've used a 15k ohm and a 10k ohm resistor in the voltage divider.

Could you draw your circuit in paint or whatever, so I'm sure I understand how to duplicate your connections?

Best I can draw. Hope it helps

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gwc2795

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CrackinX
I'm having an issue as well with my Auto leveling in almost the same way as above, I have my sensor hooked to 12V and a V divider so the signal wire outputs about 4.5V, it is Normally closed so outputs 4.5V when NOT triggered. I have the endstop inverted in the firmware pullup disabled and all that. My issue is that when hooked up does nothing triggered or not it always reads as open. Power is hooked direct to 12V and Negative is direct to ground, 4.5V signal is hooked to the pin on the board that is not outputting 5V, hooked back up old endstop and everything is working fine there so it is something to do with the proximity sensor. Please help.

Oh for reference this is my sensor [www.amazon.com]

Measure the voltage from the shell of the USB connector and the output of the sensor when you trigger the sensor. The voltage is going to read about 12V if the sensor is working.

Quote
CrackinX

Quote
gwc2795

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CrackinX
I'm having an issue as well with my Auto leveling in almost the same way as above, I have my sensor hooked to 12V and a V divider so the signal wire outputs about 4.5V, it is Normally closed so outputs 4.5V when NOT triggered. I have the endstop inverted in the firmware pullup disabled and all that. My issue is that when hooked up does nothing triggered or not it always reads as open. Power is hooked direct to 12V and Negative is direct to ground, 4.5V signal is hooked to the pin on the board that is not outputting 5V, hooked back up old endstop and everything is working fine there so it is something to do with the proximity sensor. Please help.

Oh for reference this is my sensor [www.amazon.com]

Measure the voltage from the shell of the USB connector and the output of the sensor when you trigger the sensor. The voltage is going to read about 12V if the sensor is working.

I think it is the other way around, it is 0V when triggered and 5v with the divider normally.

Quote
kaffemustasj

Quote
CrackinX

Quote
gwc2795

Quote
CrackinX
I'm having an issue as well with my Auto leveling in almost the same way as above, I have my sensor hooked to 12V and a V divider so the signal wire outputs about 4.5V, it is Normally closed so outputs 4.5V when NOT triggered. I have the endstop inverted in the firmware pullup disabled and all that. My issue is that when hooked up does nothing triggered or not it always reads as open. Power is hooked direct to 12V and Negative is direct to ground, 4.5V signal is hooked to the pin on the board that is not outputting 5V, hooked back up old endstop and everything is working fine there so it is something to do with the proximity sensor. Please help.

Oh for reference this is my sensor [www.amazon.com]

Measure the voltage from the shell of the USB connector and the output of the sensor when you trigger the sensor. The voltage is going to read about 12V if the sensor is working.

I think it is the other way around, it is 0V when triggered and 5v with the divider normally.

Yea, that's how it's supposed to be.
But I don't know if I understand the drawing correctly. Dosen't the circuit mean that the signal wire is always grounded, i.e. the signal wire always reads equal to zero?

Quote
CrackinX

Quote
kaffemustasj

Quote
CrackinX

Quote
gwc2795

Quote
CrackinX
I'm having an issue as well with my Auto leveling in almost the same way as above, I have my sensor hooked to 12V and a V divider so the signal wire outputs about 4.5V, it is Normally closed so outputs 4.5V when NOT triggered. I have the endstop inverted in the firmware pullup disabled and all that. My issue is that when hooked up does nothing triggered or not it always reads as open. Power is hooked direct to 12V and Negative is direct to ground, 4.5V signal is hooked to the pin on the board that is not outputting 5V, hooked back up old endstop and everything is working fine there so it is something to do with the proximity sensor. Please help.

Oh for reference this is my sensor [www.amazon.com]

Measure the voltage from the shell of the USB connector and the output of the sensor when you trigger the sensor. The voltage is going to read about 12V if the sensor is working.

I think it is the other way around, it is 0V when triggered and 5v with the divider normally.

Yea, that's how it's supposed to be.
But I don't know if I understand the drawing correctly. Dosen't the circuit mean that the signal wire is always grounded, i.e. the signal wire always reads equal to zero?

I didn't provide a drawing, someone else did with a different sensor. but with a resistor in line on the signal and then another to ground it acts as a voltage divider lets 5V through the signal and the rest to ground. [drive.google.com]

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kaffemustasj

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CrackinX

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kaffemustasj

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CrackinX

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gwc2795

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CrackinX
I'm having an issue as well with my Auto leveling in almost the same way as above, I have my sensor hooked to 12V and a V divider so the signal wire outputs about 4.5V, it is Normally closed so outputs 4.5V when NOT triggered. I have the endstop inverted in the firmware pullup disabled and all that. My issue is that when hooked up does nothing triggered or not it always reads as open. Power is hooked direct to 12V and Negative is direct to ground, 4.5V signal is hooked to the pin on the board that is not outputting 5V, hooked back up old endstop and everything is working fine there so it is something to do with the proximity sensor. Please help.

Oh for reference this is my sensor [www.amazon.com]

Measure the voltage from the shell of the USB connector and the output of the sensor when you trigger the sensor. The voltage is going to read about 12V if the sensor is working.

I think it is the other way around, it is 0V when triggered and 5v with the divider normally.

Yea, that's how it's supposed to be.
But I don't know if I understand the drawing correctly. Dosen't the circuit mean that the signal wire is always grounded, i.e. the signal wire always reads equal to zero?

I didn't provide a drawing, someone else did with a different sensor. but with a resistor in line on the signal and then another to ground it acts as a voltage divider lets 5V through the signal and the rest to ground. [drive.google.com]

So what you've drawn now works for you?
On the input of the Z-min on the motherboard there's to connections. Did you connect the sensor output to one of the Z-min inputs, and nothing else on the other Z-min input?

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Ironsights
I also bought the Electron Prusa i3 Sixth Gen, I am currently assembling it and the LCD screen ONLY turns on, when plugged into my computer via USB. Any insight would be nice.

Also if there a website I can go and get replacement parts, rather then deal with these people, I would appreciate it.

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dburas

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Ironsights
I also bought the Electron Prusa i3 Sixth Gen, I am currently assembling it and the LCD screen ONLY turns on, when plugged into my computer via USB. Any insight would be nice.

Also if there a website I can go and get replacement parts, rather then deal with these people, I would appreciate it.

Sounds like your not getting 12 volts from the power supply. Maybe wire issue or need to check the 110/220 volt switch. I know mine was set on 220 which I needed 110 where I live. You should see the switch thru a small hole on the side of the power supply.

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Ironsights

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dburas

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Ironsights
I also bought the Electron Prusa i3 Sixth Gen, I am currently assembling it and the LCD screen ONLY turns on, when plugged into my computer via USB. Any insight would be nice.

Also if there a website I can go and get replacement parts, rather then deal with these people, I would appreciate it.

Sounds like your not getting 12 volts from the power supply. Maybe wire issue or need to check the 110/220 volt switch. I know mine was set on 220 which I needed 110 where I live. You should see the switch thru a small hole on the side of the power supply.

Currently it is switched to 110V, I live in the US. Rather then dealing with these people, is there one I can just go buy and get here, rather then trying to explain to them and they tell me "No no, its the screen, screen bad, we send again"

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dburas
Okay, like typically someone would say, I have a quick question. If it was asked before, I do apologize and please direct me to the answer, or just answer it again.

Here is the situation. I bought an Electron Prusa i3 Sixth Gen which is a Migbot from the famous 3dprintersonlinestore and I am using Cura (newest version). I can print (finally) fine with the printer BUT it won't use the entire print bed, only about 50%. I have checked the firmware and the perimeters are set to the correct bed size. 3dprintersonlinestore (Gary) told me to zero out the offsets, I asked where they were, he responded just place the objects on the bed where they can print (really, F*ing genius), NO that is not a fix.

My question is, where are these offset settings in Cura that need to be zero out ?? Why is my printer thinking the bed is in a different position ? It is the standard size bed 225 x 225. The G28 and G29 is set for auto level. The firmware checks out good for the size bed. Like I said, the unit prints fine, just not utilizing the entire bed correctly.

  // these are the offsets to the probe relative to the extruder tip (Hotend - Probe)
  #define X_PROBE_OFFSET_FROM_EXTRUDER 12
  #define Y_PROBE_OFFSET_FROM_EXTRUDER 60
  #define Z_PROBE_OFFSET_FROM_EXTRUDER -0.8

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CrackinX
this is the power supply i replaced the crap one with. Works well. [www.amazon.com]


Does anybody happen to have any insight on my issue with the proximity sensor?
I have double, triple and even quadruple checked everything and it all seems to be right, yet will not work.

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Ax

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CrackinX
this is the power supply i replaced the crap one with. Works well. [www.amazon.com]


Does anybody happen to have any insight on my issue with the proximity sensor?
I have double, triple and even quadruple checked everything and it all seems to be right, yet will not work.

I've really no clue on this one.. I bought the 2nd Migbot without auto levelling and ended up getting this, which is the same sensor that's on my first Migbot, ie what's sent with it. No need to step-down the Voltage, just wire it up and go. It basically worked out cheaper to do it this way than adding on the sensor and printed part. Only thing I can suggest is to head over to Tom's YouTube and check the Auto Levelling video..

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CrackinX
this is the power supply i replaced the crap one with. Works well. [www.amazon.com]


Does anybody happen to have any insight on my issue with the proximity sensor?
I have double, triple and even quadruple checked everything and it all seems to be right, yet will not work.

Quote
Ironsights

Quote
CrackinX
this is the power supply i replaced the crap one with. Works well. [www.amazon.com]


Does anybody happen to have any insight on my issue with the proximity sensor?
I have double, triple and even quadruple checked everything and it all seems to be right, yet will not work.

The picture of that PSU shows 115V, assuming I should not get it?

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dburas

Quote
Ironsights

Quote
CrackinX
this is the power supply i replaced the crap one with. Works well. [www.amazon.com]


Does anybody happen to have any insight on my issue with the proximity sensor?
I have double, triple and even quadruple checked everything and it all seems to be right, yet will not work.

The picture of that PSU shows 115V, assuming I should not get it?

That PSU will work perfect for you.

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Ironsights

Quote
dburas

Quote
Ironsights

Quote
CrackinX
this is the power supply i replaced the crap one with. Works well. [www.amazon.com]


Does anybody happen to have any insight on my issue with the proximity sensor?
I have double, triple and even quadruple checked everything and it all seems to be right, yet will not work.

The picture of that PSU shows 115V, assuming I should not get it?

That PSU will work perfect for you.

Not that I doubt you, or the resources, but the difference of 5V from 110V to 115V, is not going to affect the board, as far as burn it out? Correct?

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kaffemustasj

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CrackinX

Quote
gwc2795

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CrackinX
I'm having an issue as well with my Auto leveling in almost the same way as above, I have my sensor hooked to 12V and a V divider so the signal wire outputs about 4.5V, it is Normally closed so outputs 4.5V when NOT triggered. I have the endstop inverted in the firmware pullup disabled and all that. My issue is that when hooked up does nothing triggered or not it always reads as open. Power is hooked direct to 12V and Negative is direct to ground, 4.5V signal is hooked to the pin on the board that is not outputting 5V, hooked back up old endstop and everything is working fine there so it is something to do with the proximity sensor. Please help.

Oh for reference this is my sensor [www.amazon.com]

Measure the voltage from the shell of the USB connector and the output of the sensor when you trigger the sensor. The voltage is going to read about 12V if the sensor is working.

I think it is the other way around, it is 0V when triggered and 5v with the divider normally.

Given for my Migbot:
The S pin on the Z Min pin has 5V supplied it at all times by the motherboard
The max current provided is 5ma

Given for my Inductive Sensor:
Model #SN04-P2 Normally Closed
The sensor supplies voltage when metal is sensed

Problem:
The M119 command showed Z min was always triggered even when the metal bed was detected by the sensor
This caused the head to crash into the bed and gouge the surface.
The Sensor does not sink any voltage to ground when it is detecting the bed. The Sensor output drops to 0V but the Z min S pin still has 5V on it from the motherboard the sensor does not lower this voltage.

Solution:
Install a voltage divider comprised of a 1K resistor on the sensor output wire to the Z min S pin
Install a 680 ohm resistor from the Z min S pin to ground
When the output of the sensor goes low (bed detected) the 5V being applied to the Z min S pin by the motherboard is lowered to ~0.85V which the processor sees as bed detected. The 680 ohm resistor can sink the 5ma supplied by the motherboard but can not sink the 300ma supplied by the sensor so the processor sees 5V on the Z min S pin when the sensor does not detect the bed.

Edited 1 time(s). Last edit at 10/27/2015 03:54PM by gwc2795.

Quote
gwc2795

Quote
kaffemustasj

Quote
CrackinX

Quote
gwc2795

Quote
CrackinX
I'm having an issue as well with my Auto leveling in almost the same way as above, I have my sensor hooked to 12V and a V divider so the signal wire outputs about 4.5V, it is Normally closed so outputs 4.5V when NOT triggered. I have the endstop inverted in the firmware pullup disabled and all that. My issue is that when hooked up does nothing triggered or not it always reads as open. Power is hooked direct to 12V and Negative is direct to ground, 4.5V signal is hooked to the pin on the board that is not outputting 5V, hooked back up old endstop and everything is working fine there so it is something to do with the proximity sensor. Please help.

Oh for reference this is my sensor [www.amazon.com]

Measure the voltage from the shell of the USB connector and the output of the sensor when you trigger the sensor. The voltage is going to read about 12V if the sensor is working.

I think it is the other way around, it is 0V when triggered and 5v with the divider normally.

Given for my Migbot:
The S pin on the Z Min pin has 5V supplied it at all times by the motherboard
The max current provided is 5ma

Given for my Inductive Sensor:
Model #SN04-P2 Normally Closed
The sensor supplies voltage when metal is sensed

Problem:
The M119 command showed Z min was always triggered even when the metal bed was detected by the sensor
This caused the head to crash into the bed and gouge the surface.
The Sensor does not sink any voltage to ground when it is detecting the bed. The Sensor output drops to 0V but the Z min S pin still has 5V on it from the motherboard the sensor does not lower this voltage.

Solution:
Install a voltage divider comprised of a 1K resistor on the sensor output wire to the Z min S pin
Install a 680 ohm resistor from the Z min S pin to ground
When the output of the sensor goes low (bed detected) the 5V being applied to the Z min S pin by the motherboard is lowered to ~0.85V which the processor sees as bed detected. The 680 ohm resistor can sink the 5ma supplied by the motherboard but can not sink the 300ma supplied by the sensor so the processor sees 5V on the Z min S pin when the sensor does not detect the bed.

Ok so if I already have a 10k resistor on the sensor output and another 10k from sensor to ground to sink the voltage from 12v to 5v you're saying I have to add another inline and and the bridge to ground.

I see what you're saying, I was assuming the S pin would detect the 5v signal but it supplies 5v and detects a voltage drop to ground... That makes more sense.

Quote
CrackinX

Quote
gwc2795

Quote
kaffemustasj

Quote
CrackinX

Quote
gwc2795

Quote
CrackinX
I'm having an issue as well with my Auto leveling in almost the same way as above, I have my sensor hooked to 12V and a V divider so the signal wire outputs about 4.5V, it is Normally closed so outputs 4.5V when NOT triggered. I have the endstop inverted in the firmware pullup disabled and all that. My issue is that when hooked up does nothing triggered or not it always reads as open. Power is hooked direct to 12V and Negative is direct to ground, 4.5V signal is hooked to the pin on the board that is not outputting 5V, hooked back up old endstop and everything is working fine there so it is something to do with the proximity sensor. Please help.

Oh for reference this is my sensor [www.amazon.com]

Measure the voltage from the shell of the USB connector and the output of the sensor when you trigger the sensor. The voltage is going to read about 12V if the sensor is working.

I think it is the other way around, it is 0V when triggered and 5v with the divider normally.

Given for my Migbot:
The S pin on the Z Min pin has 5V supplied it at all times by the motherboard
The max current provided is 5ma

Given for my Inductive Sensor:
Model #SN04-P2 Normally Closed
The sensor supplies voltage when metal is sensed

Problem:
The M119 command showed Z min was always triggered even when the metal bed was detected by the sensor
This caused the head to crash into the bed and gouge the surface.
The Sensor does not sink any voltage to ground when it is detecting the bed. The Sensor output drops to 0V but the Z min S pin still has 5V on it from the motherboard the sensor does not lower this voltage.

Solution:
Install a voltage divider comprised of a 1K resistor on the sensor output wire to the Z min S pin
Install a 680 ohm resistor from the Z min S pin to ground
When the output of the sensor goes low (bed detected) the 5V being applied to the Z min S pin by the motherboard is lowered to ~0.85V which the processor sees as bed detected. The 680 ohm resistor can sink the 5ma supplied by the motherboard but can not sink the 300ma supplied by the sensor so the processor sees 5V on the Z min S pin when the sensor does not detect the bed.

Ok so if I already have a 10k resistor on the sensor output and another 10k from sensor to ground to sink the voltage from 12v to 5v you're saying I have to add another inline and and the bridge to ground.

I see what you're saying, I was assuming the S pin would detect the 5v signal but it supplies 5v and detects a voltage drop to ground... That makes more sense.

No you replace the 10k resistor on the sensor output with the 1K resistor and replace the 10k from sensor to ground with a 680 ohm.

Quote
gwc2795

Quote
CrackinX

Quote
gwc2795

Quote
kaffemustasj

Quote
CrackinX

Quote
gwc2795

Quote
CrackinX
I'm having an issue as well with my Auto leveling in almost the same way as above, I have my sensor hooked to 12V and a V divider so the signal wire outputs about 4.5V, it is Normally closed so outputs 4.5V when NOT triggered. I have the endstop inverted in the firmware pullup disabled and all that. My issue is that when hooked up does nothing triggered or not it always reads as open. Power is hooked direct to 12V and Negative is direct to ground, 4.5V signal is hooked to the pin on the board that is not outputting 5V, hooked back up old endstop and everything is working fine there so it is something to do with the proximity sensor. Please help.

Oh for reference this is my sensor [www.amazon.com]

Measure the voltage from the shell of the USB connector and the output of the sensor when you trigger the sensor. The voltage is going to read about 12V if the sensor is working.

I think it is the other way around, it is 0V when triggered and 5v with the divider normally.

Given for my Migbot:
The S pin on the Z Min pin has 5V supplied it at all times by the motherboard
The max current provided is 5ma

Given for my Inductive Sensor:
Model #SN04-P2 Normally Closed
The sensor supplies voltage when metal is sensed

Problem:
The M119 command showed Z min was always triggered even when the metal bed was detected by the sensor
This caused the head to crash into the bed and gouge the surface.
The Sensor does not sink any voltage to ground when it is detecting the bed. The Sensor output drops to 0V but the Z min S pin still has 5V on it from the motherboard the sensor does not lower this voltage.

Solution:
Install a voltage divider comprised of a 1K resistor on the sensor output wire to the Z min S pin
Install a 680 ohm resistor from the Z min S pin to ground
When the output of the sensor goes low (bed detected) the 5V being applied to the Z min S pin by the motherboard is lowered to ~0.85V which the processor sees as bed detected. The 680 ohm resistor can sink the 5ma supplied by the motherboard but can not sink the 300ma supplied by the sensor so the processor sees 5V on the Z min S pin when the sensor does not detect the bed.

Ok so if I already have a 10k resistor on the sensor output and another 10k from sensor to ground to sink the voltage from 12v to 5v you're saying I have to add another inline and and the bridge to ground.

I see what you're saying, I was assuming the S pin would detect the 5v signal but it supplies 5v and detects a voltage drop to ground... That makes more sense.

No you replace the 10k resistor on the sensor output with the 1K resistor and replace the 10k from sensor to ground with a 680 ohm.

Ok I'm following now, thanks a bunch.

So I can just use an fet transistor as a switch then power the gate with the sensor and connect the S pin to source and ground to drain, should effectively do the same thing.

Edited 1 time(s). Last edit at 10/28/2015 09:57AM by CrackinX.

Quote
CrackinX

Quote
gwc2795

Quote
CrackinX

Quote
gwc2795

Quote
kaffemustasj

Quote
CrackinX

Quote
gwc2795

Quote
CrackinX
I'm having an issue as well with my Auto leveling in almost the same way as above, I have my sensor hooked to 12V and a V divider so the signal wire outputs about 4.5V, it is Normally closed so outputs 4.5V when NOT triggered. I have the endstop inverted in the firmware pullup disabled and all that. My issue is that when hooked up does nothing triggered or not it always reads as open. Power is hooked direct to 12V and Negative is direct to ground, 4.5V signal is hooked to the pin on the board that is not outputting 5V, hooked back up old endstop and everything is working fine there so it is something to do with the proximity sensor. Please help.

Oh for reference this is my sensor [www.amazon.com]

Measure the voltage from the shell of the USB connector and the output of the sensor when you trigger the sensor. The voltage is going to read about 12V if the sensor is working.

I think it is the other way around, it is 0V when triggered and 5v with the divider normally.

Given for my Migbot:
The S pin on the Z Min pin has 5V supplied it at all times by the motherboard
The max current provided is 5ma

Given for my Inductive Sensor:
Model #SN04-P2 Normally Closed
The sensor supplies voltage when metal is sensed

Problem:
The M119 command showed Z min was always triggered even when the metal bed was detected by the sensor
This caused the head to crash into the bed and gouge the surface.
The Sensor does not sink any voltage to ground when it is detecting the bed. The Sensor output drops to 0V but the Z min S pin still has 5V on it from the motherboard the sensor does not lower this voltage.

Solution:
Install a voltage divider comprised of a 1K resistor on the sensor output wire to the Z min S pin
Install a 680 ohm resistor from the Z min S pin to ground
When the output of the sensor goes low (bed detected) the 5V being applied to the Z min S pin by the motherboard is lowered to ~0.85V which the processor sees as bed detected. The 680 ohm resistor can sink the 5ma supplied by the motherboard but can not sink the 300ma supplied by the sensor so the processor sees 5V on the Z min S pin when the sensor does not detect the bed.

Ok so if I already have a 10k resistor on the sensor output and another 10k from sensor to ground to sink the voltage from 12v to 5v you're saying I have to add another inline and and the bridge to ground.

I see what you're saying, I was assuming the S pin would detect the 5v signal but it supplies 5v and detects a voltage drop to ground... That makes more sense.

No you replace the 10k resistor on the sensor output with the 1K resistor and replace the 10k from sensor to ground with a 680 ohm.

Ok I'm following now, thanks a bunch.

So I can just use an fet transistor as a switch then power the gate with the sensor and connect the S pin to source and ground to drain, should effectively do the same thing.

OK so I found an N-channel MOSFET laying around which worked perfect!! no resistors needed. source to ground, drain to S pin, gate to sensor wire. invert x-min in firmware. TADA working bed sensor.