Yes the frame can twist but if it is standing on a solid flat surface then it will be stable and braced against the forces generated by the axes moving. I would imagine a frame built from extrusions would also conform to the surface it was standing on unless it had only three feet. If it was totally rigid it would rock but it would need to be extremely stiff to do that without being a box frameby nophead - Mendel90
The J-Head shouldn't melt at 240C, I run them up to 255C for the white ABS the kits are made from. I think you must not have the right thermistor if you replaced it. Thermistors don't normally fail when they are cemented in unless molten plastic gets into the cement. They then read high and the hot end temperature falls. PEI melts at 217C so you can easily melt it if you crash the nozzle into itby nophead - Mendel90
There is no difference between G0 and G1 in the version of Marlin I use. Both should move to the bottom. In standard G code G0 is a travel move to get there as fast as possible and G1 is a coordinated move where the axes are kept in sync for cutting. I think in CNC G code they each maintain a separate feed rate. What firmware are you using?by nophead - Mendel90
No Idea but AFAIK all slicers have Z=0 to mean nozzle on the bed and go upwards from that. The firmware maps that to physical locations. I don't know of any machines where the axis is inverted. Obviously some move the nozzle up and others move the bed down but the gcode should be the same with Z increasing from 0. What do the first few Z values in the gcode look like?by nophead - Mendel90
Perhaps it is PLA that has leaked and then cooked for a long time. Without a picture I am just guessing. The exhaust putty is like grey cement. It is rock hard once cured and there shouldn't be any excess. It is only around the resistor and the thermistor. I use those hot ends at 255C for ABS, so 200C is no problem at all. If the hot end is not starting to separate at the join but leaking justby nophead - Mendel90
Other than perhaps the belts being very slack, I can't think what would reduce the size by so much in both x and y. Tighter belts stretch slightly so will have a slightly bigger pitch but I don't think it normally makes so much difference.by nophead - Mendel90
I don't know about the latest Marlin but the Z speed should be capped to 4mm/s by this line The homing speed is defined separately.by nophead - Mendel90
The 10R resistor is needed to get the 12V rail to be close to 12V. Without it the PSU throttles back to keep the 5V from being too high and then the 12V rails drops when the bed is on. I would keep it in circuit. I use the 5V standby rail to power my RPIs and then use GPIO to control the main PSU. Seeby nophead - Mendel90
I have printed E3D edge, which is form of PETG but it only needs 240C. I printed all the kit parts with ABS at 255C for the first layer and 250C for the rest, so J-Heads can definitely can handle that for thousands of prints, even in a chamber at 45C. I know their spec says less but with the more accurate thermistor that I use I have not found it to be a problem.by nophead - Mendel90
Ethyl acetate is a better solvent for PLA. I use that to clean the glass when printing PLA. One thing I have been meaning to try is to dissolve PLA in it an try 'PLA juice' as a bed adhesive like ABS juice made with acetone. So far I have not needed it as a hot bed for the first layer works well for me. I print ABS with a the J-head up to 255C. You can fit a E3DV6 to the standard Wade's block usby nophead - Mendel90
Yes PLA should stick to plain glass as long as it is free from grease. I run the bed at 100C for the first layer and 70C on subsequent layers. Extruder 220C for Prusament, which is what I am printing at the moment. Never used hairspray or an form of adhesive. Just plain glass for PLA.by nophead - Mendel90
Seems like the Z calibration is too low. Print an outline and adjust so it is exactly the first layer height as per the Mendel90 manual. When it is a lot too low you get a thin first layer rather that zero thickness because the pressure of the plastic is enough to lift the nozzle but it then doesn't lift enough for the second layer.by nophead - Mendel90
On Windows or Linux I don't expect to get a new terminal window if I run a command from the terminal. The output should just go to the terminal it is started from. Not sure what happens if I run it from the GUI. Some programs do open a new terminal then. I am not at home to try it. I can't think why you would get garbage. Perhaps it is a character set problem.by nophead - Mendel90
Not sure what you mean. I run it from a terminal window and it brings up a GUI and prints some commentary to the terminal I ran it from.by nophead - Mendel90
They are intended to be printed parts. They are not the same spacing as the off the self variety which I found to be very inaccurate.by nophead - Mendel90
It should carry on where it left off, so the worst would be a blob. Seems more like some lines of G code go missing. Have you been able to reproduce the effect at will? Possibly a faster PI might help but I still use RPI Bs to run my machines. I haven't updated Octoprint for a long time though as it does seem to get slower with each new release like most software. I try to stick with versions tby nophead - Mendel90
The MDF version of the machine is designed to be made by hand from rectangular sheets. In the UK I can buy MDF cut to size in B&Q. It is done on a saw that ensures perfect rectangles. You can then print the PDF drill templates and tape them over the top, prick though the crosses to mark the holes and then centre punch them. You do need a coping saw to cut out the gantry after drilling the hby nophead - Mendel90
Don't forget to anchor it at the spool end. I.e. like the original dust filter.by nophead - Mendel90
I don't know, my Mendel90s still work fine with the original lead screws. I would start by installing the PTFE tube that stops the filament dragging on the print head. If the filament is hard to pull it can lift the carriage. Even if it doesn't it pulls towards the centre at the edges of the print and increases backlash, that is why it is in the design.by nophead - Mendel90
Is the Z axis sitting down on both nuts? If for some reason the Z bars are leaning such that when you level the bed only one nut is bearing the weight, then the Z motion could be erratic.by nophead - Mendel90
It's hard to say without watching it go wrong or a better description. It seems to get offset in both X and Y simultaneously and also seems to get smaller and taper back out to the correct size. I can't think of anything that would do that but perhaps I am interpreting the pictures incorrectly. Is the carriage firmly attached to the rails? Sometimes the carriage can break at the back where the tby nophead - Mendel90
Have you got a picture of what the part is supposed to look like. It looks like the top is shifted in both X and Y? Are you sure the filament isn't dragging on the print head? Do you have it feeding through the PTFE tube. If not it can lift the print head and cause layers to not attach properly and also cause X shifts. Can't explain a Y shift as well though.by nophead - Mendel90
No there isn't anyway to query what is on screen in OpenSCAD. You will need to figure it out from the BOM files.by nophead - Mendel90
Yes the extra / will definitely break it. It won't include the configuration so nearly everything is undefined.by nophead - Mendel90
Running views sturdy_E3D should get the configuration from scad/conf/sturdy_E3D_config.scad and build correct views into sturdy_E3D/views.by nophead - Mendel90
This is why it homes upwards: No I don't know why it doesn't stop either if M119 reports H when the bed is fully forwards.by nophead - Mendel90
Sometimes, due to a build up of hole clearances it is possible the carriage hits the left bar clamp before the switch activates. In that case loosen the two font bar clamps, one at a time and slide the left one forwards and the right one backwards. Odd you would need to do this if the machine had been previously working though.by nophead - Mendel90
The Y axis switch is attached to the front right Y bar clamp. You would need to push the bed towards the back to see it. So if the X switch is working does homing move towards it and stop when it hits it? Note that the switches only stop the axis motion during homing. After that it knows the position and limits movement in firmware, so should not be able to hit the switch again.by nophead - Mendel90
They should change to H if they are pressed while M119 is typed. The switch should open and the input pulled high. >I didn't make any changes to the firmware, loaded it straight up from the USB. Not sure what you mean by that. It should have had firmware already installed and be ready to use. Did you load new firmware via USB using the Arduino IDE? If so where did you get it from?by nophead - Mendel90