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conny_g

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Everything posted by conny_g

  1. Laser cut a drilling template and did some drilling for a few hours - 57 holes through 19mm MDF is quite time consuming. Also added a 3rd hole on the top side (not on the photo, did that later). As a first version of the bottom holes I did shape the area of a 120mm fan, which results in 57 holes and 4.500 mm^2 of opening, which is half of what a 120mm fan has. The idea is: if the airflow is enough with that, without a fan, I am happy and it's done. If the airflow is not enough I can choose to either drill more holes (2-3 times as many) or add a fan on the bottom side of the cabinet to push air in. While the 2nd fan on top pulls the air out. Resulting in twice the pressure and probably enough airflow. Another print test to check "level 1" of the above is running just now.
  2. Started another 10 hours print right after this one to see if the temperature stays stable in the long term. And it does, even after 7 more hours the temp stays at these values. Interesting that you can see that I lowered the extruder temperature to 190 C instead of 200 C - the temperature in the cabinet decreases by 0,5 C. Summary for all who want to build something like this: 120mm fan with high static pressure (3mm H20 = 30Pa) on top of the cabinet. I used this: https://www.bequiet.com/de/casefans/270 2,5-3mm H2O of pressure are the ones with the highest available in the regular PC fans area. There is just industrial ones like this with >7 mm H2O: https://noctua.at/de/nf-f12-industrialppc-3000-pwm But they have 40dB. Inlet and outlet holes of at least 4.000mm^2. One of them larger, more in the area of the fan >10.000mm^2. Ideally inlet/outlet would be the same area the fan has = 10.000-11.000mm^2, but my experiment shows that either inlet of half or outlet of half are already working. But both half or less does not work, that were my earlier experiments. Inlet/outlet ideally positioned diagonally across the box, i.e. in at the front, out at the back, to ensure flow across the hole cabinet I thought a moment about retrying the 2 50mm fans. But if you compare their technical data to the 120mm, they are too weak to achieve the same result and temperature will be higher: Air flow: 120mm: 120m^3/h 2x50mm: 23m^3/h Static pressure: 120mm: 2,7mm H20 2x50mm: 1,2mm H20 120mm: https://www.bequiet.com/de/casefans/270 50mm: https://www.blacknoise.com/datas/downloads/datasheets/TData_BSF50_122012_de_en.pdf Both are silent fans, the 120mm produces 29dB and the 50mm only 16dB of noise. I think I will try another one of Bequiet with 16 dB next that has half the RPM and some 30% less static pressue and airflow, but still much more than the 50mm. https://www.bequiet.com/de/casefans/718
  3. Now we're getting there!! In the diagram you see the test with the fan "off" as dashed lines and the newest one with the carton door with ventilation slit as solid lines. Now the "exhaust" cabinet where the heat is pulled to goes 2 degrees above the printer cabinet, the printer cabinet stabilizes at 28 C and the 2nd extruder (which reflects the top of the inside of the cabinet) is at a max of 32 C - which is almost 6 C lower than before. The exhaust line is now above the cabinet line which means there is more heat pulled outside than stays inside - that's perfect. So clearly the air inlet is the most important bottleneck for now and is way too small, I need to drill additional holes into the bottom and then it works as it does here and absolutely hits the goal that I was planning for - to stay around 30 C. The area of the carton slit is some 20x530mm = 10.600mm^2. If I use 500mm of the width to drill a grid of 10mm holes with 10mm space in between I get 16 holes in each row. And I need 4 rows to meet a total of 11.300 mm^2 - that's what I am going to do tomorrow.
  4. Here’s my carton test door with ventilation slit. Nice what you can do with a laser cutter ?
  5. It seems your ventilation is a whole dimension stronger. But likely also much louder? Good idea to place a carton at the front and test with variations of ventilation holes. Before I buy the expensive duct vents I should do that. And regarding active cooling... that's all too much hassle and I think it's not that much heat to be removed, a reasonable airflow should really do it. In the end I think it's not too much more heat a good desktop processor would produce. And the case fans can handle that as well, just that there is better ventilation holes in the case.
  6. No noise cancelling materials - foam or similar. Just the wood cabinet is enough, works perfectly well, no foam needed. It's built from 19mm MDF material, so it's quite heavy and I think that is essential so that the printer vibrations do not make the cabinet a speaker ?. The doors are 16mm and have 6mm glas inserts. Needs good hinges to carry the weight. And 160+ degrees hinges are helpful.
  7. Yes, you are absolutely right. The fans and holes are too small. Did the control test with fan off yesterday and to my surprise and frustration the temperature values don’t differ too much. Maybe 1 degree. It seems it has much more impact if the test was run right after another one or after 10/12 hours of break, the curves are very different in these cases. Means they are 2-3 C higher if there was a test right before, even if the starting temp is the same ~25 C. Logical, the hole cabinet stored heat and will absorb less right from the start. Looking into datasheets of fans some more I am finding that real house ventilation duct vents have 10-20 times the static pressure vs the best pressure optimized PC fans to get air through the 10cm holes in the wall. And for that they are 50dB mostly instead of 20-25 ? Thats the key issue here why not too much air is taken from the cabinet. It needs to be 5-10 times as much air to make a real difference. Thinking about making a test with a duct fan now ? Or with a vacuum cleaner, they are designed for strong pressure resp. suction ? Alternatively I build a small A/C into the cabinets, i.e. active cooling.... But on the other hand even this last print was successful. So it seems that the reduction of the feeder motor current brought the level of the filament temperature in the feeder to an acceptable level and there is no issue with the air temp of 35 C at all. I should just keep on printing and watch out for symptoms before spending more time on this.
  8. Not exactly "thrilled" by the result ? The 120mm fan did perform slightly better, but more in a negligible range. The cabinet temperature increased slower and stayed 2-2,5 C below the temperature with the 50mm fans. And the cabinet above increased slightly quicker and higher, so more heat was put there. But 2-3 degrees does not really make a big difference. Now it would be interesting to do a final test without any fan. (And btw, there is another difference in that last diagram: the temp curve of the 2nd extruder - gray line - is very different, goes up rather steep in comparison the the last test. That's probably because I had the 120mm fan in the cabinet to mix the air and avoid layering of the air temperature and that fan I used for the next test. And it seems there the temperature up in the cabinet at the height of the 2nd extruder was higher than for the thermometer at the bottom, 4 degrees of difference.) It seems that it needs more / larger ventilation holes to make this work with PC fans. The problem is obviously their low static pressure - their airflow decreases drastically with pressure they have to build up, that's at least telling me value of static pressure and the corresponding diagrams "pressure vs. airflow". But I don't really want to make the case that open, that will harm the noise reduction effect which is the key reason why I have them. Another option would be a test with a real 230V ventilation / duct fan. They seem to have higher air flow (2-5x of the 120mm) and like 100x the static pressure. That should also work with small holes for ventilation. But they are much noisier and much more expensive. The quiet ones (25db and less) are beyond 100 Euros. Or would anyone know a duct fan that is like 12V/24V and low noise, i.e. a small variant of the 230V building installation duct fans? I think I will do a final test without fan to know the difference. And if the 50mm or 120mm fans do make a notable difference I will just keep that until I run into any issues with longer prints. A temperature of 33-35 C does look doable at this time, will just collect more experience and react if necessary.
  9. Yes, there's a hole at the bottom back, underneath the sliding table for the cables going into the cabinet. It's not that big (50-60mm) and one of the next optimization steps. But first I want some indication that this principle works at all. Don't want to put lots of holes into the expensive & nice cabinets before having some proof of concept ?. So I am trying to approach it in small steps carefully. For this I now want to see the two lines to change their profile: the printer cabinet line needs to stay lower and the "exhaust cabinet" one needs to go steeper.
  10. 2 prints of this girl successful. But I am not completely happy with the temperature curve yet - see image. The "exhaust cabinet" temperature (the cabinet above the printers where the fans are sucking the heat) is not going really high and the temperature in the printer cabinets is not really much lower than before. I think so far the feeder current was the dominant driver as this generates more than 5 C more heat directly at the feeder. I think that this plus the +10C air temp caused the filament to become too soft to feed. So I am trying the other thing I had in mind. Put an enclosure on the two holes for the small fans, but use a 120mm fan with 2x the static pressure and 5x the airflow of the two small ones. (Hehe, that's fun: use a laser cutter to improve the 3D printer enclosure ?). If this has slightly better performance as an indication I would drill another hole for more airflow or even make a complete cut-out of 200x50 which is about the same area than a circle of 120mm diameter.
  11. I am back from vacation for a week now, but have a lot of work at the moment. Will take a few more weeks until I get to test the sensor. ?
  12. After 5 hours the temperature in the printer cabinet stabilizes at 31 C, the 2nd extruder shows 36 C, the cabinet above the printer it's 28,9 C. Print successful so far, 5 hours of 7 are done. So it seems the fans and lowering the extruder current did the job. But it feels kind of tight at the limit - the temperatures are not very much lower. So I will do another test with a 120mm fan which has double the air pressure and 5x the air volume than the two small fans.
  13. Mounted 2 pieces of 50mm fans in one cabinet for a test. That should extract some 24 m^3 per hour of warm air to the the cabinet above it - that has holes to the outside anyway (IKEA already has these type of cabinets open for any electric devices you might put there). As the warming of the cabinet was very slow - 10 degrees in 2 hours - I would hope that's enough to keep the temperature down enough for PLA.
  14. This is what happens to the feeder with PLA if the environment temperature is too high: The filament is torn and it starts to wrap around the feeder wheel... Wanted to print some quick mounting bracket today and for that change the filament to silver. And somehow it wouldn’t move at all. So I dismantled the feeder and found this. But also found that the feeder motor was rather hot even with the cabinet door open, checked the motor current and it was set to 1.200mA which is unnecessary much. I think to remember that they recommend 1000mA. My 50mm Fans arrived, will add them to the cabinet this weekend and test. Have a plan B with 120mm fan if that does not work.
  15. I was planning with one or two ultrasilent 50mm fans per cabinet with 12m^3 / h each, that should do it. The increase in temperature was very slow, so there does not seem to be much air I have to remove to keep the temp down. Would mount it/them on the top or top back side, back bottom there is already a hole for the cables where cool air can be pulled in. http://www.blacknoise.com/site/de/produkte/noiseblocker-it-luefter/nb-blacksilentfan-series/50x50x10mm.php Thanks for the tipp with the temperatur controller, looks like a good option. Was thinking about something I can integrate in Cura / G-Code or Octoprint like a self-made circuit attached to the Raspberry Pi (Octopi) that would be controlled by an Octoprint plugin that looks for a certain thing in the G-Code, which is configured in Cura in some way. But the Cura part is even optional, it's not much effort to open Octoprint and set the fan temp. But maybe simple solution first and nice second and your proposed controller for the start... ?
  16. After the 2nd try these learnings: After a few hours the temperature stabilizes at 35 C air (outside UM) and 40 C 2nd (unused) nozzle Together with the heat from the feeder motor the PLA is too soft for the feeder and the prints fail for underextrusion resp. "non-extrusion" So I need ventilation for PLA.
  17. Ok, the first thing that was happening after 2,5-3 hours is that the feeder stopped feeding. The thermometer in the cabinet showed 32 C and the 2nd extruder had 38 C. So it's very well possible that the 32-38 C air temperature plus the feeder motor temperature (it's a BondTech) made the PLA too soft to be extruded. As the PLA is in the printer unused already for 2 months I forwarded it by 50cm and restarted the print. My expectation is, though, that the same will happen and it will stop feeding at some point.
  18. Just testing this, longer print in PLA. After some 2 hours of printing the temperature in the cabinet reached 30 degrees, now let's see what happens in the remaining 3 hours. With that slow increase of temperature there will not be much ventilation required to keep it down. Some two 40mm fans on the back top of the cabinet pulling the warm air outside should be far enough.
  19. No extraction / cooling yet. As the ones who print ABS (me not yet as most tries failed) close their cases to increase the temperature I am assuming / hoping that the printers do not mind a slightly increased temperature. In case this is not true for PLA and other low temp materials I can still add ventilation. Did the first short test print today and the noise reduction is phenomenal: The Synology disk array in the cabinet next to the printers is louder than the Ultimaker!
  20. Here’s my new printer cabinets to keep noise in my office down and to store them in a neat & tidy way. Made by my favorite furniture maker. PSU, cables, Raspberry Pi with OctoPrint are stowed in the drawers underneath the printers. The printers can slide out for filament change or other maintenance. The doors have gaskets so the noise can’t escape.
  21. Don't have much time at the moment, but I left a few points here how I did it, have a look:
  22. @foehnsturm fyi, the parcel arrived a few days ago, thank you! Will take a while until I have the time to do the mod. Currently too much work, projects already in progress and also family vacation to be done.
  23. Hi Razanur, good work, congrats ? I had two different versions of a head initially as well, one version used the thumb screws to attach it to the side. The second version was an alternative head that allowed change a part of the head https://www.thingiverse.com/thing:945899 The 3rd version is the magnetic mount of https://magnetic-tool-changer.com/ (participated as beta tester there) That allows to attach/detach the laser head at any time, without screwing or anyting. Regarding color vs. photo resist. I am quite happy with the photo resist, it's very refined product and it's easy to expose it with the 150mW diodes which are cheap and available. The multi-Watt ones are much more expensive and harder to get in decent quality. Thought about trying the color method, but on one hand it's a bit of a mess to remove that much black color afterwards and on the other hand I am absolutely happy with the photo resist stuff. I belief it's more accurate than spray color and supports efforts of high resolution better than spray paint. Regarding the vector edging vs. pixel rastering I believe I can achieve higher resolutions with rastering as I can control the energy going into one pixel very precisely. And I can expose the exact image of what I want to do without having to convert it to vector edging, leaving the areas (unless I hatch it which is the same than rastering...). For that reason I don't experience much of an issue with the oval/rectangular shape of the dot. I have set it to 45 degrees vs. the raster direction and that way in essence it has the same size for X and Y, simply making the focus larger. Which I can compensate with reducing the energy (gaussian beam, effective dot converting the photo resist is then smaller). If you move in all directions you see the effects of the "bar" in one direction vs. the other. Then with the vector there is acceleration/deceleration ramps that change the energy going to the color/photo resist strongly so the lines are thinner/thicker, depending on the speed. Unless you go "full power'" anyway which will always create a large "effective" footprint (see the gaussian thing above). With the rastering every pixel is identical. And with the vector method I had strong oscillations in the corners as the laser is on while it't going around the corners. Depending on the speed, of course. After considering all this I stuck with the rastering approach. Tried the vectoring some time later and I didn't like it better, so still going with rastering now. The rastering takes long (3 hours for 1 side of Euro PCB), but I like the perfect result over the time factor. With the software + controller the vector approach is still possible. I have two modes built in, one is the "bitstream" mode, the sync signal given by printer starts the pixels being generated while the head moves along the defined path. And the "direct" mode where the sync signal actually controls the laser beam, sync on = laser on, sync off = laser off. That way I can vector any path directly with G-Code (just an amendment of the G-Code is needed: G01 X100 Y200 B1 -> the B1 is "beam on"). For simplicity I had started with the fan output originally as well, but I disliked that I needed to switch plugs or connection between fan or laser so I started to use the EXP3 port and can just leave the laser stuff connected. I don't have an issue with the firmware mod, it's making the solution more flexible and it's not a big /complicated mod. Even if you have to update the firmware from the repo again and resync the mod. For the "bitstream" thing you need an external controller and for that you need a sync signal. So there is not really a way around the firmware mod. I had tried to integrate the pixel generation in the firmware, but I got conflicts between the movement control (using interrupts) and the pixel generation (using ints as well). Possibly you can get that resolved, but I am quite sure that this will bring the poor Atmega to it's limits and I didn't feel like having to resolve all sorts of strange side effects changing the usage of the Atmega that much. So an external pixel controller was so much more safe and transparent. So for me all that is pretty much working and finished, currently. The most important next step is to unify the software parts in OctoPrint with a nice UI behind it. Currently it's just python command line scripts. And I am working on the drilling solution in a similar way. Magnetic attachment of the Dremel, python scripts to control the drilling. Also that would benefit strongly from controlling that with Octoprint. Already spent a few hours in the last months to delve into plugin development for Octoprint and I think am now ready to do the next step soon.
  24. @geert_2, I actually use this mount method already for a diode laser of 150mW for PCB exposure. But it could also be higher power for cutting or engraving. Ah, and I have used the 150mW laser for cutting paper stencils for SMD PCBs. Requires to paint the paper black with a laser printer to make sure the low power laser can cut it (black absorbs the energy better and makes sure the laser can pierce through the paper at all) and it cuts veeeeery slow (like 1mm per second), but it works. Still less work than putting the solder paste on the PCB manually.... don't care if the stencil takes 20-30mins to make. If you are interested, the whole process is: export the pads as Gerber, use a python script to convert the Gerber to g-code for the 3D printer, black the paper with laser printer (ideally two times for shiny surface = less absorbent, easier to distribute the paste), cut the stencil with the laser, spray the black surface with transparent lacquer to make it less absorbent. After drying for 1 hour you can use it as a stencil, even more than once. Engraving (not laser, regular engraving) I am not sure if that's going to work. The magnetic mount holds fine for light forces in Z direction, a few newton. But it will fall off with more force in that direction or even with lighter forces in X/Y. But of course the mount could be strengthened - it's just a bit more redesign. My motivation was to do as little as possible of (re)design on top of the Mark2 fixture to add the Dremel. And that succeded for this purpose. Regarding small drills and wobble. Have no experience yet, but the test in the video with 0.8mm drill bit was totally uncomplicated, no wobbling, no breaking of the bit. So I am not worried if it will work with 0.6mm - which is the smallest drills I use. So let's see the next tests after I finished the software part. I think the Dremels are quite good quality regarding wobbling. I tried a cheap $10 drill a few months ago and it's drill bit holder is a nightmare, wobbling like hell. Possibly one future iteration of this thing is to replace the Dremel flex extension with a decent quality DC motor with drill bit holder. Would make it more compact and it'd be still inexpensive.
  25. Cool ? Does it and how does it work with Bondtech feeders? http://shop.bondtech.se/en/extruders/qr-30-universal_lefthand.html
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