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Java - everyone loves it and it works well everywhere. Maybe.
Re: Flexidrive is Flex3Drive Early Birds - 4 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 - 4 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? - 4 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? - 4 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? - 4 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 - 4 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
Re: Z-axis suddenly going nuts - 4 years ago
Perhaps there is a bad connection in the motor and one coil briefly loses continuity. The only way I can think it can move or vibrate when stationary is if the current changes. If it isn't the driver and it is specific to one motor, the only thing that can change inside the motor is the continuity of the coils. If it loses contact that would judder the rotor and the vibration could conceivablyby nophead - Mendel90
Re: Z-axis suddenly going nuts - 4 years ago
Knocking sounds and pauses in motion are usually a sign that the driver it overheating and momentarily shutting down. Is the chip hot? It will burn your finger if it is hot enough to shut down.by nophead - Mendel90
Re: Z-axis suddenly going nuts - 4 years ago
It vibrates when stationary? What sort of frequency is the vibration? I can't think what would cause that because in series they both see the same coil current, so should have the same forces applied to the rotor. To be vibrating you would think the current must be modulated, but that would affect both equally and would come from the driver or the PSU. I can't think of a fault in the motor thatby nophead - Mendel90
Re: Polycarbonate is brittle or I am doing something wrong? - 4 years ago
Polycarbonate sheets can be bent cold without cracking, so it should not be brittle, quite the opposite. I know that PET is brittle if it is printed with absorbed moisture, it needs to be dry, perhaps PC is the same.by nophead - Printing
Re: Z-axis suddenly going nuts - 4 years ago
The Z motors are more likely to be affected by low voltage because they are in series, so only get half the voltage but the full current, so they have the same torque as X and Y but a lower top speed. The Z motors make a high pitch noise simply because they run at a high step rate and are well coupled to the axis and the base for sound. The other axes have belts to isolate the step vibration froby nophead - Mendel90
Re: Z-axis suddenly going nuts - 4 years ago
If the axis isn't level and is only supported by one nut they other side can make a vibrating noise due to the nut rattling on the threaded rod. I don't understand how motors could be fading fast like that. They would have to be losing magnetism very quickly or the windings getting so hot they have shorted turns, or the ball bearings have dried out and are failing. They are standard bearings, soby nophead - Mendel90
Re: Z-axis suddenly going nuts - 4 years ago
I am at a loss to explain it. I think logically you have eliminated everything apart from ripple on the PSU and the motors. I have never known stepper motors to slow down with age. The max speed is mainly a function of the winding inductance, which is dictated by the number of turns, so hard to see how it could change. If the magnets lost some strength I think that would affect torque rather thanby nophead - Mendel90
Re: Z-axis suddenly going nuts - 4 years ago
Seems close enough to me and it with the bed off it should definitely be enough. If the motor current is set too high then they could warm up and increase in resistance but you said they run cool. The other things that could affect it are the jerk and acceleration settings but if you haven't reloaded the firmware then I can't really explain it. It is odd that it can home OK, because the homingby nophead - Mendel90
Re: Z-axis suddenly going nuts - 4 years ago
In my experience motors and drivers don't degrade over time but power supplies do wear out eventually. The capacitors dry out and you get more ripple on the supply lines. That could be hard to detect without a scope but the average voltage might go down. It should be about 12.2V when the bed is off and about 11.8V when the bed is on.by nophead - Mendel90
Re: Z-axis suddenly going nuts - 4 years ago
The Melzis supplied were set to 1.25A but current affects torque, so with no load on the screws there should be plenty of torque to spare. When one motor stalls it stops generating back EMF, so there is more voltage for the other. If that is spinning it implies there is not enough voltage for both but there is enough for one and voltage affects the maximum speed. Try explicitly moving them at 4by nophead - Mendel90
Re: Z-axis suddenly going nuts - 4 years ago
Just seems like you are trying to run them a little too fast. That is exactly what they would do. And other than the supply voltage being too low I can't see what else would cause it.by nophead - Mendel90
Re: Z-axis suddenly going nuts - 4 years ago
I noticed you changed the X & Y steps per mm in gcode. Is it possible you loaded some g-code that changed the Z motion parameters? I noticed in your video that the Z acceleration sounds lower than normal. The firmware I supplied did not have EEPROM enabled but it would remember new settings until you powered it down or pressed the reset button. Or have you loaded a version with EEPROM enableby nophead - Mendel90
Re: Z-axis suddenly going nuts - 4 years ago
When the motors are wired in series, if one stalls the other tends to keep running. If they are wired in parallel then if one stops they both tend to stop, but you get half the torque that way. What happens if you change line 8 of your start gcode to G1 Z0.05 F200? I can't see how that file ever printed correctly because the bed temperature will not be set.by nophead - Mendel90
Re: Z-axis suddenly going nuts - 4 years ago
What is actually happening on the video? At first there is a loud whine and no movement then repeated stop-start movement. The closest I can get with my machine and Octoprint is repeated 0.1mm movements but they are not as close together as yours. When you print the Z speed in your example is 9000mm/m but it is capped by the firmware, in my case 4mm/s. When you move with OctoPrint the Z speedby nophead - Mendel90
Re: Z-axis suddenly going nuts - 4 years ago
I wonder if the power supply is failing. Have you tried measuring the 12V rail? I have never known a stepper motor to fail. The only moving parts subject to wear are the ball bearings and the Z axis doesn't do much mileage compared to X and Y. I had a weird fault on my first DiBond machine a few months ago where it would print some layers with far too much plastic. It took me ages to work out wby nophead - Mendel90
Re: Z-axis suddenly going nuts - 4 years ago
Perhaps it needs a little oil or light grease on the lead screws and the bearings if it is sticking and stalling the motors. That would make them buzz. Have you updated the firmware at all? You could have slicer settings that are too fast for Z but the firmware previously capped it. A loose connection on the Z motor wiring could cause them to stall and buzz.by nophead - Mendel90
Re: Problem when reanimating Mendel90 - 4 years ago
When the terminals are loose and drop some voltage they get very hot and can affect the PCB solder joints. It's a good idea to look at the back of the board and perhaps re-solder them. Hard to see how tightening them could make it worse otherwise.by nophead - Mendel90
Re: Problem when reanimating Mendel90 - 4 years ago
Check that the ground connection on the Melzi terminal is tight. Classic sign of it being a bad connection is the bed current flows down the USB lead and causes a disconnect.by nophead - Mendel90
Re: Mendel90 issues after replacing controller - 4 years ago
I don't think my version of Marlin contains the string " Debug communication ". If the message is from Pronterface I have not idea how it could tell if a motor was working or not unless it was a more advanced stepper driver with a serial link. What do the motors do when you try to move them?by nophead - Mendel90
Re: New thermistor for Orcabot 0.43?? - 4 years ago
Why are you asking about Orcabot in the Mendel90 section of the forum? Mendel90 is a specific machine that uses a different hot and and a different thermistor.by nophead - Mendel90
Re: Printer stops - 5 years ago
It shouldn't matter where you measure the 5V as they are all connected together. I think the easiest is on the jumper that selects between regulated power and USB power. Most likely all your problems are bad power connections. If the PSU ground is not good it causes bed current to flow down the USB cable and that will cause the USB connection to drop out.by nophead - Mendel90
Re: Printer stops - 5 years ago
Perhaps monitor the 12V in at the terminal screws and see if the power dips or has excessive ripple on it. Could be the PSU going bad due to the capacitors wearing out. Also check the 5V rail is actually 5V.by nophead - Mendel90
Re: Are newer printers better? - 5 years ago
The X bearings are a tight fit in the X ends so they are held rigidly once snapped in. Yes the third bearing mount is designed to float in the Y direction, so that it won't bind if the X rod spacing is not exactly right. I have only printed the parts in ABS, so I don't know how they would last in other plastics. In theory it doesn't need to flex if everything is perfectly aligned.by nophead - Mendel90