Additionally, I don’t see a difference in the specs between these 2. Yet one is listed as LTV-217-G and the other is LTV-217-C-G
The C-G is in stock while the other is back ordered until October.
Would the C-G opto work?
I looked at the manufacturers specs on the ltv-217 and was confused when I saw their CTR chart.
it showed C at 200-400 but in a note below the chart said B, C and no marking were with a CTR of 50-600.
CTR is the ratio of input diode current to the output current. I have no idea what kinds of current this optocoupler sees and I expect it to be very little. But we also don’t know what the LED diode current is so info from Ray would be helpful. MRRF is a big deal so I can see why he’s not been in the support forums. Hopefully soon.
Yeah, I saw that CTR chart too and was confused by the 2 measurements.
Thinking I’ll wait for @raykholo to weigh in on: if he agrees with the diagnosis of the issue and what his suggested solution is.
I appreciate all of your help thus far.
@donkjr @dougl thank you both for all of your efforts once again. It appears that we are at the assumed conclusion that the opto needs to be replaced. I sincerely appreciate all the time you have spent to help me. I am blown away by your kindness, understanding, patience, and willingness to help me out.
Here’s to hoping I’ll be joining you in the world of mods shortly!
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good to see Ray is helping and that he has a 2nd pin to use for Laser Fire control(L). Hope it works.
It might sound strange but take a empty paper towel roll, put it to your ear and aim it around the inside of the laser cutter and see if you can locate the direction of the hissing noise.
Is part of this thread missing? I don’t see any posts by Ray?
@dougl I will try that. Is the hissing the motor?? You had mentioned this earlier on. I’m so confused why it stops if I press “stop” in Lightburn and yet I can still run commands, jobs, jog, send to origin and home?
@donkjr he is posting on the c3d forum with me. He had me try a new test, results are posted over there. I’m not totally sure what the results will point him to, but I’m guessing it will confirm a bad opto.
@donkjr he told Dylan of another connection to wire the L and ground wires to and it’s called FET and has screw terminals. Since he didn’t mention changing the config he likely split the signal from the processor over to two separate drive circuit( one optocouple driven and one FET driven ).
It seems to be working for Dylan except that even with the L connected to the FET output when the C3D is unpowered, the laser fires. BUT, when the C3D is powered, Dylan was able to control the laser with GCode as we would expect.
@Dkwells it does seem strange that even with the control of the Laser Fire( L ) signal being moved to the FET output on the C3D that your machine fires the laser when the C3D is unpowered. THAT is just really odd since there should be only a very high impedence to ground put on the L when the C3D is unpowered.
Can you make sure there is no connection(s) at all between the LPS and the C3D except for the one Ground wire and the L wire? Make darn sure all the other wires in the control panel are connected where they need to be connected and not connected to other places. The GFI trip is a sign of ground loop or some current flowing where it is not supposed to be flowing and that could be what is throwing this off.
Also, can I ask if the laser fires when the C3D Laser Fire( L ) line is not connected to the LPS and the K40 is powered On?
@dougl sorry about the delay in my response.
I agree. I am confused by the results… I don’t think this is the permanent solution, so at least there’s hope that all will be resolved back to a normal state. Definitely not comfortable leaving this issue in a state where the laser can fire if the board is not powered on.
I checked all connections to the C3D board and they all trace properly. X and Y plugs trace accordingly, endstop ribbon cable traces back to the mechanical switches, and the L and G wires are routed properly. No connection between the LPS and the C3D board other than the G and L wire. All other wires appear to trace properly as well.
If I remove the L wire from the board, the laser does not fire at power on.
Does the laer fire with the C3D board unpowered AND USB cable is disconnected from the computer?
Pretty much the only wire I use on that connector is the L wire which is connected to a PWM output on my board. I do use the GND to make double sure there is a common ground but the key is that L connection for laser control.
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