Extrusion issue? Cooling Issue? Something else?
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I found these tests to be interesting:
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I have a T3P3 Kossel XL and I decided to make a new print fan duct. It should also work on the mini. It's not perfect but I believe it works better than the original.
Here's the STL files and the original SCAD file:
https://www.dropbox.com/s/uk8wdzlcvps34r4/kossel-fan-duct-mb-v1.scad?raw=1
https://www.dropbox.com/s/vp95ca5aprixyyn/kossel-fan-duct-mb-v1-bracket.stl?raw=1
https://www.dropbox.com/s/ues81fvlylgjkb6/kossel-fan-duct-mb-v1.stl?raw=1
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Short version: radial fan - good, axial fan - bad.
Long version: an axial fan at the sizes we use has almost zero pressure capability. Best wait to use it is without a funnel, but that spreads air all over the place. What is really needed is some small nozzle(s) to get high air speed, because the printhead will not stay in the same place for too long (see hair dryers). This requires pressure, so the best candidate is a radial fan, aka "blower".A turbine axial fan rotating at high speed will do it too, just like the above mentioned hair dryer, but who has one and who wants to hear jet take-off noise when printing?
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I've order a 50mm blower-style fan (like the E3D unit linked above). Now to think about how to mount it without re-doing the whole spider. Ideally I can just connect a new mount/funnel to the existing T3P3 spider using the same attachment points.
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I have a T3P3 Kossel XL and I decided to make a new print fan duct. It should also work on the mini. It's not perfect but I believe it works better than the original.
I've used a small Eiffel tower for fan tests on my first delta printer. Some guys have made a similar two-pronged nozzle for the blower-style fan on the MK2, to good effect.
John
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I find that I still sometimes have to rotate the model "into wind" to get the best cooling but it's really OK for most models. The problem I found with the original duct was that most of the air was blowing backwards through the fan (as mentioned above, axial fans struggle to blow air through a small outlet). So I reasoned that having 3 outlets would be good as the total outlet area was larger and the air is blowing at the model from 3 directions (well, that's the theory, anyway!)
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A colleague modified a blower nozzle that he created for the Prusa i3 MK2 to be used with my T3P3 Kossel Mini R3. I finally got it mounted and recalibrated the printer this week. The results are very good! With the stock cooling fan, I could not even complete the 3D Benchy (as shown above in this thread).
Main downside at this point is the fan is reducing my print area on one side of the bed. It looks like the fan can be tilted up more to get some of that back. To really reduce the issue, I'd have to go with mounting the blower above the effector.
Left side is from Prusa i3 MK2. Right side is from T3P3 Kossel Mini R3. The left rear corner of the boat is the only area that start to get a bit soft. The rear nameplate is a bit less clear. The chimney is not quite as nice. Both are printed with Prusa PLA. Both sliced with S3D v4.0 with .2 layer height and similar settings for speed, etc.
Note the area where the fan could be tilted up closer to the hot-end. Just needs to clear the rod ends.
John
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Grab a set of these. Saves a lot of room and they push some air. With my fan and nozzle, it is right at 50mm tall and fits under my effector mounted vertically. Working on a new mount to put both fans on there.
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Had the same problems.
After numerous itérations, I ended with this solution.
https://www.thingiverse.com/thing:2378545
With 100% PWM, I experienced delamination.
50% would be enough for bridging.And With 2 blower at 100%PWM, it becomes a little bit noisy…
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Yeah, the 40mm fan would certainly fit better. I'd guess the airflow would be good enough. The airflow from the 50mm blower-style fan is such that I can readily turn it down on most prints.
Tech-ration's solution is interesting as well!
Now that I'm investigating Haydn's effector for magnetic rods, I'll have to see what solutions work with that.
Thanks, guys.
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Grab a set of these. Saves a lot of room and they push some air. With my fan and nozzle, it is right at 50mm tall and fits under my effector mounted vertically. Working on a new mount to put both fans on there.
I ordered the set of two. Thanks for the link!
