Thicker rods won't eliminate imperfections in the Z axis due to leadscrew wobble, it might help a bit, but if the leadscrews don't run straight, the Z-nuts won't ride on the same place inside the nuts, when the leadscrews turn, this will result in non linear motion in the Z direction. I used 16mm hardened steel rods on my repstrap, in the hope that it would improve quality. It probably did sinceby Ralf - General
I did a remake of my nozzle tonight, and from preliminary testing, it seems as it has fixed my problem with shrinking first layers. The tip is now protuding ~6mm from the heater block, and as an added feature I made a PTFE heat shield, to keep the heat inside the nozzle, and away from the print. The edge of the PTFE is ~120 degrees when printing at 230 degrees.by Ralf - Printing
Interesting.. How pointy did you make it? I have problems with the bottom ~3mm of my prints shrinking, the more infill, the more shrinkage. Also pointy features like gear teeths tend to curl up, not to mention overhangs.. I have been suspecting that my hotend was too blunt, so I was actually about to write a post about it.. I also have a rather flat hotend, with ~2.5mm from the heater bloby Ralf - Printing
I have done a bit of testing on layer bonding. I printed the same piece at 210 and 230 degrees, at 230 degrees the parts was of course strongest. When the parts was dipped in acetone, the strength of the parts printed at 210 degrees came to par with the parts printed at 230 degrees, but I didn't really saw any increase in strength on the parts printed at 230 degrees. Edit: I might add that I haby Ralf - Reprappers
It looks like wobble in your z-axis leadscrews, if you google "reprap z-axis wobble" you will find a lot of posts about what causes it, and different ways of getting rid of it.by Ralf - General
Or if they are tilted to one side, the bed doesn't move perpendicular to the x axis.by Ralf - Reprappers
1. The 0.5 calibration cube should come out as 20x20x10mm, the interesting part here is the wall thickness, it should be the same as what is in your g-code. In slicer generated g-code this would be something like: ; perimeters extrusion width = 0.62mm Depending on your settings, and nozzle size, the goal here is to calibrate e-steps, to make the printer actually print the width stated in the g-by Ralf - Reprappers
What if you try to shield the extruder from the heat? It looks like that the extruder assembly is getting a good deal of the heat from the lamp. This could lead to insonsistent filament supply, explaining the less that optimal surface finish on the top layer.by Ralf - General
Apart from the possibility to exchange nozzles, there are a coupple of reasons why I have made it in two pieces. I think that Stainless steel for the nozzle would work fine also. But machining nozzle and tube in one piece reduces the margin for errors quite a bit. And my lathe is too big and clumsy to drill a 0.35mm hole without breaking the drill bits, leaving them embedded in the workpiece.by Ralf - Plastic Extruder Working Group
Been wondering the same thing, I am also running Marlin. So after reading your post I put my osciloscope on the hotend resistor, and @128 actually means 100% at least on my machine. So if your hotend drops in temperature @128 (100% dc) you need to either put in a smaller resistor, print slower, or raise the supply voltage a bit, ofcourse staying within the limit of the electronics.by Ralf - Plastic Extruder Working Group
After having read countless posts on all-metal hotends, and problems assosiated with them, i thought it might be usefull for someone if I posted my design. It hardly gets any simpler, only drawback is that you properly need a lathe to make it work, and the extruder base plate needs to be made of aluminium. This is version 2 of it, made with 6mm threaded rod: The feeder tube is made from stainby Ralf - Plastic Extruder Working Group
What if you swap the motor connections from the X and Y axis? Also check endstop switches.by Ralf - General
Interesting question.. I have been struggeling with bad layer adhersion, for quite some time, and I think that I have finally solved the problem, but I dont really know, as I haven't found any strenght data on parts printed on other printers to compare with. It would be interesting to have a set of standard parts, and some standard methods of destroying them. So you would know how the parts priby Ralf - General
I have never seen anything like that on my printer, but assuming you use a resistor heater.. What if some of the resistor windings have shorted with the hotend, that could send noise up to the electronics via the heater circiut.. Should be easy to check with a multimeter. Just a thought..by Ralf - General
I've had a great deal of issues with TB6560 and missed steps, with Sprinter/Marlin firmware on Arduino. In the first build I used NEMA23 motors, so the polulo's weren't quite powerfull enough, so I bought a 25€ 3-axis TB6560 driver board of eBay and wired XYZ to this. The problem with this was that Sprinter and Marlin toggles the step pin for only 1-5uS, and the TB6560 wants something around >by Ralf - Controllers
On my first "RepRap" build I have a 300x260x6mm bed heated with nicrome wire, hold in place by kapton tape, ~10mm rockwool and a 1mm alu sheet. I found that ~240W was about right. It heats to 110 degrees in approx 10 minutes. Below 200W I couldn't sustain 110 degrees. But I think that 3mm alu is too thin for a bed that big..by Ralf - General
Spot on.. I measured with a dial indicator, which showed approx 0.1mm movement up and down within the first second after the heater turned on or off. Reason.. The glass plate I am printing on is missing a corner, so I rearranged the attachment to 3 point instead of 4, and away from the broken corner. Then I set the bed temp check interval to 0.5 sec, and now the movements is in the order 0.01by Ralf - General
I have been having "fun" the last coupple of days trying to get some decent quality out of my new prusa. Very long story short, I wanted to upgrade the printer, so I ordered a heated bed, and some alu pulleys from T3dP3d. For a start I did the first coupple of test prints with the HBP hooked up to my bench PSU, and the prints looked fine. Then I took the printer apart, upgraded the belts, and hby Ralf - General