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mrjohnk

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Everything posted by mrjohnk

  1. I had an object crash yesterday too. I had placed these by hand and simply got two parts too close to each other. The skirt of the second one cut right across the top of the first item (printing one at a time). Luckily the first model is only a few millimeters tall and my bed springs have some travel, so the print head was able to mow over it, just making a fresh deep melted track-like impression on the first part. I just moved them further apart and the problem is solved.
  2. I see a set of gcode macros in the configuration area. I would like to add to this macro list to set the fan speed. I'm working on ABS now and would like to control the fan more closely instead of simply on or off. What is the proper way to control the fan speed for Netfabb short of editing the resulting gcode directly? Thanks. -John
  3. I would welcome some help on materials. Even though I'm fairly new, I did notice a huge difference between printing with the white PLA that came with my UM verses the orange "JET" brand PLA I'm currently using. The orange blobs up a lot and doesn't print the same dimensional shapes as the white does. The parts just don't fit together with the orange as they do with the white without a lot more clean-up and modification.
  4. Maybe even try temperatures all the way down to 190 degrees. That has helped me on similar situations. It will just take some experiments to balance the temperature that the whole job can deal without having layer separation, bed attachment issues and still getting nice detail on the finer parts of the model. At a lower temperature, the filament doesn't just freely ooze out of the hot end and actually has to be pushed out, giving more control for those smaller more detailed areas. Also be sure to check that your minimum speed in the expert settings isn't speeding up your minimum layer time setting. -John
  5. I've been tuning on this the past few days. I use a variety of methods to help off-set this. I do try to keep a small bit of card stock in my hand (like a business card) so that I can catch the ooze right before the job begins. I also have taken to using two skirt runs around each part with a slightly larger distance from the model. That usually is enough to get any globs to stick around the outside. Lastly, I've seen that lowering the temperature helps a lot too. I have one job I run at 185 degrees that doesn't ooze at all, but sometimes has adherence issues. Generally, temperatures between 190 and 200 degrees help to reduce the ooze. But, if you are printing larger and faster, you'll need those higher temps. In my case, I was printing objects that are about 5 mm in size at very slow speeds, so oozing and temperature control become more critical on the small parts. -John
  6. I agree too. If you are getting within 0.5mm, you are doing well. I've taken to using a drill press after my parts are done to widen the holes to the correct size after the printing is done. Even though my CAD models show close fits, the holes are always a little smaller than the mating part. You could spend some time figuring out how much shrinkage you are getting and keep adjusting the model to accommodate for that, but something tells me that even the same model printed out will have variances from one to the next due to temperature and humidity and some other variables I'm probably not thinking of, but you would be closer to what you need. -John
  7. I too am fairly new, but I normally leave my filament where it is and just let the machine cool down. It helps to keep the hot end primed for the next print and will pick-up where you left off after re-heating. Now, if you plan to change filament, then, yes, you do need to heat up the hot end to get it to let go of the currently loaded filament. -John
  8. As an update, I was able to get through this without much fuss. I just grabbed a couple of the longer bolts that were left over from the assembly and used those. They worked great. I think if you could just change the instructions and kit to use these longer M3 bolts, it would solve most of the issues. You have to be a bit careful not to go too long as one of them is very close to the sliding axis that runs from front to back above one of the steppers. Luckily, the substitute bolt extends all the way through the switch and hangs out the other side, but does not impede the axis motion.
  9. Thanks for the tip. Your suggestion worked and I now have solid filled walls.
  10. I'm trying to convert from Netfabb over to Cura, but having one small challenge. In my model, which is a small case for electronics, I have a wall that is 1.23mm wide. In Cura/Printrun, it prints this as two thin walls (inner and outer) instead of just one thick wall. The two thin walls are fairly weak and flex all over the place. The same model from Netfabb produces a solid thick wall. I'm using 100% infill and even increased the infill overlap to 35%, but still not working. I also bumped the wall thickness up to 1.6mm. Any suggestions? Full disclosure: I'm a new UM owner (and new to 3d printers) in general and I'm at the end of my first week. I seem to be getting better results for my projects from Cura instead of Netfabb.
  11. I see the views on this thread going up, but no responses. I'm interpreting that to say that I hooked up my heated bed correctly despite blowing up the power supply. Perhaps the power supply was simply not up to the challenge of a real load.
  12. I've been printing with PLA today just to get some printing experience under my belt. The printer is working very well on the standard power supply as I was able to get some belt tighteners and a new fan shroud printed and mounted to the machine. Liking Netfabb, Cura and PrintRun. I'm getting excellent resolution and great looking prints. Attached are some pictures regarding the heated bed I added. I used 12 gauge silicone insulated wire on the heated bed, however, the terminals on the shield are too small to accept the large cables, so as you can see in the attached picture, I spliced in some 16 gauge wire in the last few inches. They are soldered and properly insulated at the joints. The resistance is exactly 2.0 Ohms up to the heated bed circuit board. The power supply was tuned down to 22V (the lowest it would go), so that would be 11 amps load if I calculated that correctly. I had a picture of the cable from the power supply to the UM, but apparently 4 attachments is the maximum for this forum. It is simply a 16 gauge dual conductor cable with a type N DC power connector soldered to the end with heat shrink tubing. It plugs into the standard power port on the UM. It is open on the other end where I connect it to the power supply screw terminals for positive and negative. Let me know if you need any additional details. Hopefully the pictures are clear enough to see where I connected everything. Thanks. -John
  13. I finally got done building up my machine. It has taken about 5 evenings. In addition to the standard issue UM, I added a 400W power supply and heated bed with a glass top. Generally, I followed 3DTOPO's example http://www.thingiverse.com/thing:30655 for parts to use, but used borosilicate glass instead of aluminum. I've covered the glass with the kapton tape, installed the 4.7K resistor and hooked up both the thermister and power for the heated bed. I had tested all the standard parts yesterday using ReplicatorG on the included power supply before adding the new heated bed additions. All motors and switches worked. The heater came up to temp in the extruded. All was well. After adding the heated bed and new power supply, I tested again with ReplicatorG and was still able to jog around and everything was still good. I knew I needed to update Marlin to support the heated bed, so I got that together with the online Marlin builder and uploaded using the batch file. After loading that, it of course broke communications with ReplicatorG since the baud rate was faster. I lowered the Marlin baud rate to 115.2K to get ReplicatorG working again, however, this time, it didn't work. I could connect to the Arduino and generally send commands, but the machine simply didn't respond. I figured something was broke between ReplicatorG and the new version of Marlin I had loaded. Moving to the next step, I loaded up Cura and ran through the setup check which went fairly well, except testing the extruder. The heater block was only luke warm to the touch and the extrude kept running while testing, but just chewing a hole in the filament since there was just a cold extruder it was pumping into. Moving on, I loaded up PrintRun and noticed that it too could connect, however, not actually get the machine to do anything with the controls. At this point, I began to suspect the power supply. Upon inspection of the power supply, the LED was on, but dim and it was emitting a slight buzzing sound. I checked the voltage output and it was at only 4.7V. I disconnected it, along with the heated bed and went back to the power supply that came with the UM and was able to get PrintRun to operate the machine, so I was sure the 400W power supply was toast. So, I guess, after that long winded explanation, I'm looking to see if I did something wrong or the power supply I bought was just not any good. Thanks. -John
  14. I'm about half way through the build in my machine. Overall it is going well. Near the beginning of the build, I did encounter some issues related to the mounting of the end stop switches. Two of them had threads that were stripped out, therefore, would not tighten down snug. The inclination is to think that I overtightened them, however, I do recall that they never gave any resistance once the screw was fully inserted. I'm considering my options on how to move forward as the switches will not stay in place on their own at this point. My next plan is to grab some surplus course threaded screws and see if I can get that to link up without having to modify the holes in the wood. Are there any recommended remedies? I imagine this is fairly common. Thanks. John
  15. Ah, good point. Thanks. Perhaps a modified approach, assuming this doesn't work, would be to at least reduce the total angle to a 90 degree bend instead of the full 180. This assumes still putting the extruder drive above the machine.
  16. I'm just curious, does it make sense to suspend the feed unit above the printer, perhaps hanging upside down on the wall on a bracket to center it up above the machine, and let the bowden tube be relatively straight verses the high arch. I'm thinking this would reduce the feed friction, help to avoid breaking the feed material, and also reduce forces pushing on the extruder to help it move more freely. Full disclosure: I recently ordered my UM and I'm still awaiting its delivery. I thought this might make sense to do during the assembly process. Thanks. John
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