How can I print these ridges..?
hi everyone
So for a long time Ive been printing the attached file on a Cubicon - .4 nozzle, with no problems. Its a part that fits on a servo, and so the little ridges inside the centre tube are important. No matter what I seem to do in Prusa Slicer, I just cant get them to be printed properly. Its almost but not completely smooth in there when the print is done 🙁
Im guessing that ever decreasing the layer height is not making any difference. Ive slowed down the infil speed to 40mm/s to see if that helped. But no luck. Any help greatly appreciated!
Andrew
PS Happy to send anyone the STL if they want to have a go!
RE: How can I print these ridges..?
Does slicing with "detect thin walls" selected in Print Settings help?
Post the STL and others are more likely able to help
RE: How can I print these ridges..?
@guy-k2
hey
It doesnt seem to want to let me upload the stl! Ill try zipping it and attaching it here!
RE: How can I print these ridges..?
@guy-k2
Im going to try that! And the zip is attached of the stl - thanks for your ideas!
RE: How can I print these ridges..?
I don't see thin wall detection help you much.
You could drop external perimeter down to 0.35 to 0.3, but that will also under-extrude the rest of the perimeters in addition to making those sharp teeth more prominent.
If that does not work, I would redo the STL to make those teeth more trapezoidal teeth instead of triangular. Basically thicken the inner points so they can be sliced with 0.45 mm extrusion width. That means a minimum size at the ends of slightly bigger than 0.45 mm
RE: How can I print these ridges..?
@guy-k2
I don't see thin wall detection help you much. -- It didnt work :((
You could drop external perimeter down to 0.35 to 0.3, but that will also under-extrude the rest of the perimeters in addition to making those sharp teeth more prominent. --- Im trying this now!
If that does not work, I would redo the STL to make those teeth more trapezoidal teeth instead of triangular. Basically thicken the inner points so they can be sliced with 0.45 mm extrusion width. That means a minimum size at the ends of slightly bigger than 0.45 mm -- Ive got my hopes on the last point you made. Thanks very much for all of this..
Oddly, the Cubicon could handle it very happily so it must be a slicer setting...
RE: How can I print these ridges..?
PS I have external perimeters set to .45 not .35 - maybe I should lower that?
RE: How can I print these ridges..?
Does printing slower have any effect? Should I slow down external perimeters speed? Its currently 25mm/s
RE: How can I print these ridges..?
Does printing slower have any effect
Not that much. I don't think going down from 25 mm/sec will appreciably change your results. The sliced tool path has very small undulations and that is how it is printing.
Going down to an external perimeter width of 0.30 mm makes the tool path more tightly follow your geometry. Give that a try. If that does not work, rework the STL geometry as I previously mentioned.
RE: How can I print these ridges..?
@guy-k2
I will. Thank you very much
RE: How can I print these ridges..?
Try deepening the ridges. I tried adjusting many slicer parameters and could not find anything that seemed to work, so I tried adjusting the CAD profile.
Here is a CAD drawing with different options and the corresponding PrusaSlicer output shown below. The starting point on the left is the hub from your STL. The middle version has slightly deeper ridges and it looks like it might work. The one on the right is deepened as far as it can go until each ridge intersects with the neighbor.
I ran with the default setting of the slicer with a 0.4mm nozzle. You may need to scale the resulting hub to make it fit tight on the servo.
Steve
RE: How can I print these ridges..?
@steven-p8
Hi Steve - thats fantastic that you did that.I can see what you mean thanks to the image.
So the solution is probably to remake the model.. I wonder why the cubicon slicer could handle it - a mystery
Im trying something as we speak - im going to scale up the part a tiny bit and see if enough plastic gets added to the ridges to grip on the servo..
A long shot - but i need 1000s of these!
Thanks again
RE: How can I print these ridges..?
The feature is below the resolution of the 0.4 mm nozzle, have you tried a 0.25 mm nozzle?
RE: How can I print these ridges..?
@tim-m30
I see what you mean - but I know I can print this on a different printer with a similar .4 nozzle
So Id really love to know whats different about the slicing that lets my old, ugly, noisy, slow, cantankerous Cubicon print this great, whilst my 4 quiet, fast, quickly turnaround, open source Prusas fail... 😀
Andrew
RE: How can I print these ridges..?
I have no doubts about the Prusa's ability to print with the required accuracy. The difference is the slicer. Is there any reason that you can't slice on the Cubicon and print on the Prusa?
Steve
RE: How can I print these ridges..?
@steven-p8
That is a good idea. My next experiment! And ill share what happens here