What is your impression of Prusa reliability based on? We have three (or is it four?) of them at the makerspace and they break down much more often than my self-designed printers. Reliability isn't just using a specific controller or power supply. These are complex machines that ultimately have a lot of user interaction. That user interaction is a huge factor in the reliability of the machine.by the_digital_dentist - General
I emailed them about the nozzles- here's what they said: Great questions and observations. We’ll try to answer your questions with as much information as we’re comfortable sharing. Questions 1 & 2: To retain the diamond, the brass body housing was deformed around the polycrystalline diamond tip. We have patents pending on the detailed method that addresses your retention question and theby the_digital_dentist - Tech-Talk
I wonder how they manage the difference in thermal expansion coefficients of the diamond and brass that it's mounted in...by the_digital_dentist - Tech-Talk
rq3: This looks quite similar to your extruder:by the_digital_dentist - Tech-Talk
I looked at the drawings and can't figure out how the gears are arranged inside the gear box. The output shaft position makes it look like the worm gear is on the output shaft and the motor shaft drives the disc gear, but that wouldn't work... Have you tried it in a printer? What does the print Z quality look like?by the_digital_dentist - CoreXY Machines
That looks like ringing, caused by flexibility in the mechanism and the moving mass of the extruder carriage, not the vertical banding that people think is coming from the gears in the BondTech extruders.by the_digital_dentist - Tech-Talk
Take a look at this thread at Duet forums, then look at your prints- do you see any of the "woodgrain" or vertical banding in your prints?by the_digital_dentist - Tech-Talk
Very nice! Can you post photos of the finished print? Does retraction work?by the_digital_dentist - Tech-Talk
The center of the bed is still the best place to put prints to ensure that they will stick. The history part of it goes back to when people had crappy unflat/flexible beds on stupid 4 corner "leveling" systems. Also, they tended to use underpowered heaters that would heat up the center of the bed and not much else. Cheap printers are still built that way. If the slicer didn't put parts on the cenby the_digital_dentist - Slic3r
Slicers automatically locate parts on the center of the bed because historically that was the place they were most likely to stick long enough to complete the print. If you're trying to make room for other parts, just put them on the bed too and let the slicer auto arrange them.by the_digital_dentist - Slic3r
If the youtube video mechanism were applied to a 3D printer the Z axis print quality is 100% dependent on the quality of the rack and pinion and worm gear, and their bearings. What sort of bearing will the printed rack slide on in the gear box that will have no slop and accommodate the dimensional variations from 3D printing the rack? Yes, you could 3D print the parts, but every minor error in thby the_digital_dentist - CoreXY Machines
I made the left hand threaded nut using a small piece of steel and a left hand threaded tap. The nuts were soldered to 5mm diameter brass tubes that fit tightly in the gears and into bearings that were embedded in the printed ABS housing. This blog post has some pictures of the snakebite extruder showing the bearings, etc. The housing is actually three printed parts with bosses to ensure alignmenby the_digital_dentist - Tech-Talk
I just found this post - my browser hadn't indicated any new posts for a couple years. I worked on something similar to this, but not nearly as elegant, a few years ago using cheap plastic gears and counter rotating nuts. That was back when really crappy hot-ends and extruders were all that was available. My design worked for 3 mm filament (I used 6-32 nuts). I thought that the counter rotatioby the_digital_dentist - Tech-Talk
Melting motor mounts is your first intro to the joy of PLA filament. I advise you too reprint any PLA parts in your printer with either ABS or PETG as soon as possible, and remember how PLA behaves at warm temperatures when you're selecting filament for future print projects. PLA will melt in a hot car, too. So unless you can guarantee your prints will never be left in a hot car, don't use PLA.by the_digital_dentist - Printing
If the motors are hot the current is set too high.by the_digital_dentist - Printing
If the board has 25V caps, it isn't a 24V board. If they claim it is, they are lying or they don't know anything about electronics, and you shouldn't be buying their stuff.by the_digital_dentist - Reprappers
Before you get too deep into the project, you might want to calculate the time required to heat up the bed based on size, material, and power applied. See: In general, it's not a good idea to use DC power to heat the bed, especially if it's 300x300mm or larger. A heater doesn't need DC or regulated voltage, so it's better to use AC switched with an SSR. You won't need a big power supply or fatby the_digital_dentist - General
I run wiring to the hot-end inside a horizontal drag chain that makes a large loop so that the wires don't have to bend sharply anywhere. Some commercial printers do similar and include filament feed tubes inside the drag chain. The particular drag chain I used sags quite a bit, but works OK so I haven't bothered to swap it out. Unfortunately there's no spec for that type of behavior, so you justby the_digital_dentist - General
No, the dual layer PC doesn't do anything to stiffen the frame, but the frame is pretty rigid (4040 t-slot). Direct drive extruder. Most of the electrical connections to the mechanism are at the top of the printer, so putting electronics there helps keep cables short. My original plan was to make the electronics and XY stage as a module that could be dropped onto different size Z axes/frames. Pby the_digital_dentist - General
I like double walled PC for the sides- in my printer it fits inside the t-slots in the frame (with old electronics): It has some nice optical properties as well as being a good thermal insulator: I like the electronics on top- I can access them without bending over whether the machine is running or not.by the_digital_dentist - General
45-50C chamber usually works well for me.by the_digital_dentist - Printing
The pulse waveform from the controller can be distorted by the time it reaches the driver, especially if the cables are long. Also, in my experience, you can't really trust specs on Chinese made electronics, especially if they don't tell you how the testing was done, so the drivers may not perform exactly as specified.by the_digital_dentist - CoreXY Machines
Shifting layers at 45/135 degree angle indicates that one of the motors is not keeping up with the input. Check cables and connectors between controller and drivers. Also, check jerk and acceleration settings- either or both can cause layer shifting if they are set too high. Is there a reason you're not using the drivers on the Duet board? You may need to tweak the timing parameters for the exterby the_digital_dentist - CoreXY Machines
We were talking about driving the motor in full steps, not the driver. Microsteps are what makes the motor run quietly. Driving the motor with full steps will be noisy. Interpolated or not, 256:1 is microstepping. It doesn't matter if the input to the driver is full steps, the motor is driven in microsteps which is specifically what we were talking about not using. Hey, why not add X0 and Y0 toby the_digital_dentist - Mechanics
Motors are only quiet if you use microstepping, Trinamic drivers will be as noisy as any other if you're driving the motor in full steps. Homing the Z axis at the end of a print is potentially disastrous. You might want to home X and Y to get the print away from the extruder, but leave Z where it is until after the print is removed from the bed. There's no need for a separate gcode file to homeby the_digital_dentist - Mechanics
Correction: with 0.04 mm full step resolution, 0.1 mm layers doesn't work. Try 0.12 mm... If you drive the motor in full steps, yes, you'll always be on a full step multiple point, and you'll still need to specify layer thickness in full step multiples. There's a minor problem if the full steps don't exactly match up with the positions of the bed and nozzle for the first layer. For example, ifby the_digital_dentist - Mechanics
I've seen a ring of phosphor bronze(?) blades pushed down into some hot-ends, presumably to help grip the PTFE tube. They also have the little plastic piece at the entrance to the hot-end with the little lock ring. My printer has a very short Bowden tube (maybe 70 mm total length). I managed to get the extruder to push out the tube once or twice, but always from the extruder side, never the hot-eby the_digital_dentist - Mechanics
16:1 ustepping is used mostly to make the motor run "quietly". When you are printing, for maximum print quality, you usually want the layer thickness to be a multiple of the Z axis whole-step resolution. 0.0025 mm per ustep is the same as 0.04 mm per whole step. That means you want to print in layers that are multiples of 0.04 mm, so 0.1mm is OK, 0.2 mm is OK, but best not to print in 0.25 mm lby the_digital_dentist - Mechanics
The the wayback machine:by the_digital_dentist - General