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http://reprap.org/wiki/Mendel90
Re: Prusa I3 R2 NicolaP -- Build Tips - 5 days ago
All the Prusa designs are open source so the parts STLs, etc should be online, probably on Github.by nophead - Discussioni generali - NO PROBLEMI DELLA STAMPANTE
Re: Resurrection - 4 months ago
It is worth checking there isn't a short between the heater and the thermistor as that will destroy most boards. We live in Tenerife in the winter, so +23C ATM. -1C in the UK.by nophead - Mendel90
Re: Resurrection - 4 months ago
Odd. Do they have different pullup resistors fitted? They should both be 4K7. A very low value could indicate the thermistor has been shorted to the heater as that blows up the input pin of the MCU.by nophead - Mendel90
Re: Resurrection - 4 months ago
Does it display the correct room temperature when cold? If not what does it display? Since the E3D has more thermal mass than a J-Head perhaps the thermal runaway protection is a false alarm due it not heating as fast as expected. I don't use it most of my machines because it is a PIA. I prefer to live dangerously.by nophead - Mendel90
Re: Resurrection - 4 months ago
Yes I wouldn't buy a Melzi today but it is probably something else wrong.by nophead - Mendel90
Re: Resurrection - 4 months ago
I think to get rid of the EEPROM error you just need to initialise it with M502 followed by M500.by nophead - Mendel90
Re: Resurrection - 4 months ago
I think I followed a YouTube video of one of the famous 3D printer vloggers. Perhaps Thomas Sanladerer or Teaching Tech. IIRC it was just a matter of downloading VSC, installing some plugins and then using the Marlin autobuild.by nophead - Mendel90
Re: Resurrection - 4 months ago
Very unlikely you would need to reprogram the board as the firmware stored in flash doesn't get forgotten in my experience. The recent version of Marlin I put on Github comes with support for Melzi with 1284p. I compiled it with Visual Studio Code using the Auto Build Marlin extension as that is the recommended way of doing it nowadays but it says it can still be compiled with Arduino. I didn'tby nophead - Mendel90
Re: Power Issues? - 1 year ago
Yes I saw that but haven't tried it. Note on my Github I also configured the bugfix branch for Mendel90 and it can be selected as Mendel90_bugfix. It also supports long file names on the SD card but Octoprint doesn't support that properly yet. I raised a couple of issues on the OctoPrint github. Odd that the "bugfix" branch isn't just the release with bugs fixed. It has new features and some cby nophead - Mendel90
Re: Power Issues? - 1 year ago
Yes PETG is very sticky. I think people print it on glue or similar 3D printing bed adhesion sprays, not to get it to stick, but to get it to release, when cold. I have never succeeded with it because it sticks to the nozzle so won't bridge because it rips up adjacent bridge lines it has just made.by nophead - Mendel90
Re: Power Issues? - 1 year ago
When using an E3D hot end I did need to increase the PID functional range to 20 when using it to print polycarbonate at 275C. I also changed THERMAL_PROTECTION_HYSTERESIS to 10. Marlin temperature control is a nightmare of complexity. On my old machines with my own firmware I simply used bang-bang and it works just as well, no tuning. It doesn't work on Marlin because it doesn't sample fast enouby nophead - Mendel90
Re: Power Issues? - 1 year ago
Have you got PID enabled for the BED? It is better than bang-bang because the fluctuations from bang-bang bang can cause the bed to flex. I don't see how minor voltage fluctuations can cause big changes in hot end temperature. Are you using the original Melzi we supplied or a different one? Perhaps voltage drops in the ground traces of the PCB are causing thermistor reading variations.by nophead - Mendel90
Re: Power Issues? - 1 year ago
I don't think it is a power issue. A small change in voltage would be easily corrected by the control. Perhaps the PID tuning is off as it looks almost like a sinusoidal oscillation.by nophead - Mendel90
Re: Tripteron patent deadline - 1 year ago
It has been on Thingiverse since 2016!by nophead - Polar Machines, SCARA, Robot Arms
Re: VENT YOUR PRINTER! DO IT NOW! - 1 year ago
Nightmare. I don't think I know anybody that has Moderna and been well after it. Myself I have had two Astra Zenica and a Pfizer booster and haven't' had an problems with my 3D printers, or any other side effects apart from sore arm and very mild headache.by nophead - General
Re: 1.75mm filament conversion in 2021 - 1 year ago
You can fit an E3D V6 but you lose some Z height as it is significantly longer and the fan duct won't fit. There are STLs on github for an alternative Wades block that loses less height and a shallower fan duct and a different fan bracket to clear the hot end fan. You also have to provide permanent 12V to the hot end fan by connecting the positive to the 12V heater connection and negative to tby nophead - Mendel90
Re: Printing in the air - 2 years ago
Z_MAX_POS should be where your limit switch is, i.e. 188.5mm and the homing directions should be 1 and the switch defined to be a max limit. This is what my config looks like for a recent version of Marlin #define X_HOME_DIR 1 #define Y_HOME_DIR 1 #define Z_HOME_DIR 1 // @section machine // The size of the print bed #define X_BED_SIZE 200 #define Y_BED_SIZE 200 // Travel limits (mm) after hby nophead - Mendel90
Re: Corners not sharp after switching to 2GT belts - 2 years ago
I am struggling to see much difference on the top but the bottom looks like the original was printed with the first layer a little bit further from the bed so getting slightly thinner extrusion. The infill on the top layer is the opposite direction, so these are not from the same g-code and possibly not the same slicer. The acceleration would affect corner sharpness. I set that in firmware bit Iby nophead - Mendel90
Re: Corners not sharp after switching to 2GT belts - 2 years ago
Not sure what you mean by 20 tooth being lower resolution. 20 times 2 is 40mm, the same as 16 times 2.5 is 40mm. You shouldn't need to change any settings. Your left hand cube has three outlines but the right only has two. If the inner outlines are done first I could imagine it would lead to more rounded corners. Other things that can affect it are the nozzle diameter, the plastic's viscosity, aby nophead - Mendel90
Re: Y-Axis partly Waves/Ripples - 2 years ago
So this object was printed with the long sides parallel to the Y axis and the end at the front of the bed has waves? I would suspect one of the linear bearings has failed. Perhaps if you move it by hand with the power off you can feel it.by nophead - Mendel90
Re: Replacement board for my Mendel90 - 2 years ago
Sorry I didn't see your post about ripples when you posted it. I doubt changing the controller will make any difference.by nophead - Mendel90
Re: Back after a long break - 2 years ago
Good to here it's working again. It is a lot easier when you have another printer to repair the first one!by nophead - Mendel90
Re: Back after a long break - 2 years ago
If it is PLA you are printing you could try a higher temperature for both the filament and the bed for just the first layer.by nophead - Mendel90
Re: Flexidrive is Flex3Drive Early Birds - 2 years ago
What is the point of owning a 3D printer if you don't make things with it? And if you then do then why not make another better 3D printer? I hope Flex3Drive is still in business because I am designing a multi-head printer around it and can't find a source for the parts elsewhere. It seems to be the way to make the smallest lightest direct drive extruder. I can fit four of these in a small prby nophead - General
Re: Printing ABS in a closed box failing - 2 years ago
QuoteOhmarinus Sooooo meanwhile I've gotten to the point where a better sacrificial tower has improved the print quality drastically. Layer minimal time didn't work wonders because somehow Cura doesn't add in a retract when moving the nozzle away and it only moves the head 2cm away so it still keeps radiating heat onto the piece. I don't think radiation from the nozzle is significant. The heat dby nophead - Printing
Re: Mendel90 - 3 point leveling system? - 2 years ago
I have switched to picture clips instead of bulldog clips. They only grip at the edge, so should not be able to bend the glass to conform to the PCB. However I never had a problem with the bulldog clips, they just covered more of the bed. I also have a 1mm aluminium sheet between the PCB and the glass to spread the heat but it does slow the heat up process. I don't think it affects flatness becaby nophead - Mendel90
Re: Mendel90 - 3 point leveling system? - 2 years ago
So what happens if you turn the glass upside down? If you remove the bulldogs clips is is still bent? I have never known glass to be permanently bent, although it can be bent slightly with enough force, it always springs flat. My last sheet was probably 5 years old but I recently broke it and replaced it. It was still flat before it broke. Are you measuring it when cold or hot? Hot sheets canby nophead - Mendel90
Re: Mendel90 - 3 point leveling system? - 2 years ago
Not sure I understand. If the PCB had a 0.5mm dip in the middle why wouldn't the glass still be flat with a gap underneath it? The glass should be stiff enough to remain flat when it is only fastened at the edges.by nophead - Mendel90
Re: Z-axis suddenly going nuts - 2 years ago
Good to hear you got it working in the end. I don't like the idea of the slicer overriding firmware limits. I prefer the firmware to set the limits to protect the hardware from errant slicer settings. I still don't understand how it could home correctly at 4mm/s but not jog at the same speed. And a motor that can self oscillate is spooky. I don't think it is easy to see what the fault is as theby nophead - Mendel90