Help with 3D Printing

[easyw-fc]

Awesome, thanks for that, much appreciated. I'll download the file and check it out. Out of interest, was it clear to you what the error was, or what was changed?

3D on Win doesn't say anything about what it repaired... I noticed that if I export the file to STL instead of OBJ, 3D doesn't find any errors at all...
You could try this path, instead of obj format.

M

[TheMarkster]

Interesting, but that's not where the print had the defects.

This is the repaired file, not the one he sent to the printer.

[chrisb]

Many 3D print services accept Step files as well. That avoids on your side the additional step of meshing.

[oldmachine]

Printed only the upper section of the Clasp/post… It printed fine. Photo attached (did not print it for good quality - print settings at end of post).

Regarding your part:
I ran your file through my Netfab app and it appears to be O.K.
Also checked O.K. in Simplify3D.

The problem with the Post/Clasp is most likely one or combination of these:

*Infill density and infill type.
*Layer height.
*Print Speed.
*FF material type.
*Number of shells.

Apart from part issues, these Printing tips may be of value:

Print the Post/Clasp separately (and glue it into place) that way you can focus on the problem.
When that’s dialed-in, if still wanting a one-piece print, your printer folks should be able to print two processes in one print job (if using something like Simplify3D. Most other software cannot do multiple (different) processes in one print.

Most likely will need Supports on curved surface - the is can result in rough surface. Consider sinking the part into printer software bed, printing it. Then, rotating 180 deg and printing the top curved surface.
Example images show this done in Simplify3D.

FYI
Print settings (for quickly printing on my Prusa i3):
FF material: PLA (eSun brand)
Layers: Top=2, Btm=2
Shells=2
Layer Height=0.2
Infill type: Rectilinear/Rectilinear
Infill density: 10%
Temperature: 230C
Print Speed: 2000mm/m

Other printer settings based on machine and experience.

[fosselius]

Printed only the upper section of the Clasp/post… It printed fine. Photo attached (did not print it for good quality - print settings at end of post).

Great job! If you check the image in the first post you can see that they printed with support, also for the "middle pin" (thats the rectangular thingie at the base), you can also see support in the "hole" under one of the "cogs".

What i find interesting is that the "middle pin" fails early where its "just" circular, there should be no difference between the failed layer and the ones above and below, also there are no artifacts in the outer shell at the same level..

I get a strong feeling that the "3D printing company" is not very good at what they are doing..
The ones i have used before i got my printer would find, repair and fix very broken files and even make modifications (with permission) to improve the "printability" of the part.

[meowdog]

hey, this really looks like a printer/slicer issue. What slicer are you using and what speeds are you running at. Fill rates etc. I know someone is going to knock this thread for not being a Freecad issue but so be it.

It looks like your print head is moving too fast in that area. Most likely due to the retraction length vs the travel speed. Depending on your slicer you can dial this in better. Your model looks fine. You can reduce your slicer speeds at that level, and that would certainly help. Most slicers sadly don't allow you to slow down for one "feature" sadly. However you can mess with your retraction length and speed also reducing jitter couldn't hurt if your slicer allows that. I know cura does.

Basically what I'm saying is that this isn't a problem with the model. Your model is fine. You just aren't extruding properly for that feature. Slowing down your print at that level may suck, and take double or triple the time but it will solve your problem.

[chrisb]

This middle thingy is higher than the rest so one layer doesn't take much time. There should be some time gap between layers.

[KevCan]

Thanks everyone for you thoughts and input - I think I've replied to everyone who has responded below. I'm coming to the conclusion that this is a print process rather than my design. I'll try rebuilding the design in version 0.17, run it through 3d builder and Netgen and maybe that will make a difference, but most likely I'm guessing the printer settings need adjusting. I have a few ideas to try in FreeCad, and some suggestions to make to the printer company so that's progress.

Thanks again everyone for your time, much appreciated, and exceeded my expecations!!

Printed only the upper section of the Clasp/post… It printed fine.

Thanks oldmachine for taking the trouble to test print- much appreciated! I'll forward your comments on to the printer co. I think this might be the best bet.

If you create the mesh in mesh design workbench, using netgen -> very fine the resulting mesh looks okay except for some fold on surface errors

I'm going to check out netgen, thanks for the suggestion.

Many 3D print services accept Step files as well. That avoids on your side the additional step of meshing.

Thanks Chris - I'm going to check out step files, that's a new one for me and sounds useful.

If you would rebuild this model in 0.17/0.18 you would rather model it completely in PartDesign than to switch to and fro between Part and PartDesign. Might be a good exercise.

Yes - I'll give that a go. thanks for the best practice tips too.

Basically what I'm saying is that this isn't a problem with the model. Your model is fine.

Thanks for taking the time to look into this, I think you are probably right!

[rosparovac]

Where are you from? I will print it and send it.
Because from my point as a maker there is no problem with model.

Výstřižek.PNG (715.48 KiB) Viewed 947 times

[dbecad]

This middle thingy is higher than the rest so one layer doesn't take much time. There should be some time gap between layers.

Ding ding, this is the money comment (as long as the model has no errors and the slicer is properly configured). You will need a very effective ventilation or the clamp sides won't have time to cool down. Resulting in curl-up and failure. Going slower does not work because it inject more heat in the model. Pausing between layers might be possible but could create oozing issues. So ventilation to bring the temperature down or creating a side (lost, a cube for example) structure might be the only way.

Cheers
-dbe