SOLVED: Proximity Switch adjustment and oozing filiment?

[Telstar]

The problems with this printer just never stop.

Over a year and I have only be able to successfully print one benchy, a couple of temperature towers and a few tiny other projects, When started trying to print bigger projects, I thought a Klipper upgrade might help, but it was full of problems as well.

Thought I had that all sorted out when suddenly had filament oozing issues, so I had to disassemble the printing head, check the parts and reassemble. I found nothing that would indicate a problem in the extruder; no filament to clean out and the passages were clear.

This DID NOT fix the filament oozing issues. It continues to “pee-out” a constant, slow stream of PLA when the head is heated to 210C. I don’t get it.

Also now the print head rams into the print surface when I try to Z calibrate and I have to hit the emergency stop on the Kilpper screen.

I followed the Sovol video tutorial on how to disassemble the printing head to the letter. Seems though, they kinda forgot to tell you that this will hose your Z axis sensor calibration, as the proximity sensor has to be removed and it doesn’t return to the same position with the simplistic instructions they provide.

Also, the printer is now homing HARD on the X and Y axis. I tried restoring the Klipper screen to factory settings, but it’s still noticeably firm when it hits the end. It was never like this before I disassembled the extruder; that shouldn’t have affected it!@

I am pretty much at a loss as how to proceed.

I know the proximity switch needs to be a specific distance from the print bed, but what is the point of reference you use to set this switch?

Looks like I’ve poked some holes in my PEI sheet and probably ruined a couple of new nozzles by ramming them into the print bed.

What am I going to have to do? Buy yet another extruder assembly just to get a properly adjusted probe?

[Lion]

I don’t use Klipper, so I can’t help with that. I have an SV06 & a SV06+, I posted some probe pics for the Plus, so it should give you a general idea for the SV06.

Auto Home crashes into bed

Hello, Had to buy a new sensor and after I’ve installed the new one I can’t get the printer to work right. Whenever I try to calibrate it, it has to do an auto home first and it always crashes into the bed so I have to power it off. The sensors red light is on, it is mounted correctly and at the correct height. I flashed the firmware and I reset the eeprom several times. I’ve had the problem before and fixed it but that was a while ago and I can’t recall exactly what I did.

[Telstar]

Thanks Lion. Mine is a SV06 + with the Klipper screen, so the hardware should be exactly the same regardless.

I don’t think Klipper is at fault here, just the probe position. Just to be sure, I am going to reflash the firmware on the Klipper Screen and the mainboard to start.

So, I assume you have the Z offset set for 0.30mm for a .40 nozzle?

Does the probe light go off when it stops moving after setting the Z height?

I tried adjusting the Z offset to 0.30mm and then sliding probe down until the LED went off. Then I raised it to where it just came back on and tightened the screw.

This was after I ran the Z axis up to the top and leveled the two Z lead screws to make sure the Y axis was set correctly.

However when I started bed leveling after adjusting the probe, it started punching down into the PEI sheet. I just can’t figure out where exactly the level the probe should be adjusted to in order to avoid damage.

Pretty scary when the machine starts driving the nozzle down really hard and I have to scramble for the emergency stop button, which really takes too long to operate.

[Lion]

I took a measurement after I auto homed using old 1st layer tests.

Once you get the probe set as close as you can…set your z offset, do it just like when you 1st got the printer…follow the manual.

[Telstar]

Many thanks for your taking the time to do the measurements; I truly appreciate it!

Hopefully I am just about out of the Woods!

[Telstar]

Lion,

Many thanks! I think I have the sensor issue sorted out with your help. I was trying to make it too complicated, but I used your photo as a reference and withing 3 tries, had the sensor calibrated.

I simply lowered the probe below the tip of the printing nozzle with the screw on top of the bracket, which basically is the very first possible thread on the screw that catches and homed all axes. I then did the Z tilt calibration and then the Z offset.

The first attempt was obviously off; the tip was way too far from the bed, so I turned the screw a couple of turns and ran all the way back through the above procedure. Again, I thought it a bit too high, so a couple of more turns and through the Z tilt and Z offset and that time it looked within reason.

The problem with this sensor is that it relies on gravity to keep it in the proper position; it simply hangs through a hole in the bracket and there is no resistance to keep in firmly in place. So I marked where the tube exited the bracket, unscrewed the screw and put some thread lock on the screw, Put it back in, adjusted to the scribed line and ran the whole calibration again. It worked fine. Just to be sure, I took some white water based glue and ran a bead down between the sensor mount and the tube to be sure it doesn’t go anywhere. This glue can be removed at a later date without many problems, so I recommend it instead of something like super glue which will be impossible to break later on.

I guess you could put a small spring (like from a fountain pen) over the shaft of the screw, but I didn’t think of that until just now. Anyway, it’d done…

The oozing problem turned out to be something really stupidly simple; I am using SunLu
Black PLA and was using 210c nozzle and 70c bed temperatures on the default PLA profile in the printer. All I had to do was lower the nozzle to 200C and the bed to 60c and most of my issues with oozing and bed adhesion went away.

I still may have some retraction issues because when the print head has to travel a longer distance, the filament tends to not extrude immediately when it should be printing.

Anyway, here is a 300 x 300 bed level test I just printed and, except for some missing filament in places, it appears to be good.

Hope my post of shame helps others. Look for the simple fixes before you start tearing your extruder and machine apart. I tend to jump to the most complex reasons BEFORE I investigate the more simple issues, but sometimes you have to ride that pony to get it drilled into your head.

[Lion]

Cura Retraction Settings