topic Re: Problem with Extrusions and 3D Printing in Fusion Design, Validate & Document Forum

Problem with Extrusions and 3D Printing

Anonymous — Mon, 23 Jul 2018 23:27:09 GMT

Hello,

I have been having an issue with Fusion 360 and 3D Printing my designs. I am certain that the issue I'm about to discuss is of my own making but I need some assistance in discovering what I'm doing or thinking that's causing my problem. If I have posted this in the wrong location, please forgive me and move it to wherever it is the most appropriate.

I don't know how to state my problem succinctly but it has to do with extrusions and the way they turn out on my 3D printer. I also don't know if it happens all the time with every extrusion or with just some extrusions, but when it does occur, the parts that get 3D printed are very weak along the boundaries of the extrusion. I have had this problem a number of times and I'm confused as to what is happening to cause the problem.

Example 1:

I will begin with a simple example to start off the post but this isn't the example I will be describing in more detail later on. I apologize that I don't have pictures of this one to show but hopefully the description will suffice, and perhaps more particularly when viewed in conjunction with the next example that I will provide several pictures.

I recently made a simple box shell in fusion 360. The top was open but that's mostly an irrelevant detail I think. On the back of the box, from the original sketch, I made four "standoffs" using extrusions from circles in order be able to have it mount to a plate that already has some bolts (bolt heads) in it that I wanted to clear. The "thickness" of the standoffs were 4 mm, so pretty thick. The thickness of the back plate was 2 mm, so also fairly thick. The box is for a model and is attached with screws to the aluminum plate. The plate was threaded for the screws.

Everything came off of the 3D printer seemingly in perfect shape. The box was well-formed, the thickness of the floor was right at 2mm, the holes for the screws were right at 5 mm and the standoff around the outside was right at 4mm. All as designed within a small variance. When I went to mount the box to the plate all of the holes lined up perfectly between the box and the plate. There was no twisting or bending involved in any way. But as I was tightening down the screws, they ripped the standoffs right off of the box as if they were nothing.

In examining the box where the standoffs had been, there was hardly any damage. It was as if they were hanging on by a thread to begin with and not integral to the structure of the box, which they should have been by 2 mm's worth of thickness along the structure of the box itself, and 4 mm's in diameter around the screw hole. And yet they tore off like they were simply paper.

Example 2:

Fusion 360 Part for examination: Deflector Plate

For my second example, this is a part I have been working on for a while and have gone through several iterations of it with each getting successively weaker in the areas between the extrusions. Which is pretty much the same problem I had with the box model in the previous example. The most recent version I printed out was so fragile it broke apart very shortly after I pulled it off of the 3D printer, just by handling it.

As you can see in the pictures below, rather than being solid models, they just fall apart at the extrusions.

In my sketches, all I'm doing is creating the various circles and whatnot and then highlighting what I need to extrude and entering the thickness. When I look at the part in Fusion 360 I don't see any problems with it. It is only when I download it and slice it up (and I've used several different slicers) and then print it out that I have problems.

I have other examples of other models that I've made that have this problem. When I examine the part it always comes back to problems around the extrusions. I do not have this problem with other parts that I download and print. Only the things that I design myself.

Can anybody help me understand what I'm doing wrong??

Thanks,

John

Here are some pictures which illustrate the problem:

Example of Finished PartAnother Example of Finished PartHow 3D Printer is Creating PartAn Iteration Showing Extrusion ProblemAnother View of Extrusion ProblemA Different IterationDifferent Iteration With Extrusion ProblemDifferent Iteration Another View of Extrusion ProblemExtrusions Seen in Simplify3DBottom Layers in Simplify3D

Re: Problem with Extrusions and 3D Printing

etfrench — Mon, 23 Jul 2018 23:50:46 GMT

It could be one or more of the following:

Hot end too hot or cold: Use one of the calibration objects from Thingiverse to set the temperature.
Under extruding: Increase the extrusion setting (depends on your slicer).
Part cooling fan is over cooling the part: Reduce the fan setting.

Re: Problem with Extrusions and 3D Printing

davebYYPCU — Tue, 24 Jul 2018 00:40:54 GMT

I can see two things you can check,

In Fusion, you have 2 bodies in the browser, combine joint to one, and try again.

Your slicer is printing a groove in the lower face, that would also be related to the separate bodies.

You will need to be satisfied that the top layers are printed onto something, solid or heavy infill?

I combined the bodies and no groove in my slicer....

Might help,

Re: Problem with Extrusions and 3D Printing

Anonymous — Tue, 24 Jul 2018 02:13:09 GMT

Nah, it's not the 3D printer. I print lots of things just fine. What I'm talking about only happens with things that I make with Fusion 360 and it only happens to the places where extrusions meet.

Re: Problem with Extrusions and 3D Printing

Anonymous — Tue, 24 Jul 2018 02:15:07 GMT

I will give that a try. Just for my own info, when I extrude two things side-by-side, how do I prevent them from becoming multiple bodies-- or is combining them all just a step I need to take before sending them to the 3D printer?

@davebYYPCU wrote:
I can see two things you can check,

In Fusion, you have 2 bodies in the browser, combine joint to one, and try again.
Your slicer is printing a groove in the lower face, that would also be related to the separate bodies.

You will need to be satisfied that the top layers are printed onto something, solid or heavy infill?
I combined the bodies and no groove in my slicer....

Might help,

Re: Problem with Extrusions and 3D Printing

Anonymous — Tue, 24 Jul 2018 02:23:58 GMT

I tried your suggestion and while I'm waiting for my printer to heat up, I can already see the difference in the slicer. I took this screenshot from Simplify3D and you can see the difference. The base part is a solid and the standoff ring is a solid which grows out of the base. I suspect it will print better.

So thanks for that part.

But how do I do that from the get go, or do I have to go through that step of combining with everything I extrude?

Solid Part

Re: Problem with Extrusions and 3D Printing

davebYYPCU — Tue, 24 Jul 2018 02:34:58 GMT

Each part to print as one body until you get to multicolours.

In your model, I changed the second extrude from New Body to Join, but Combine Join will also work.

With that groove in the base plate, it was always going to break - but it should have filled the groove.

I also think there is a setting in S3D for that program to merge the bodies.

Re: Problem with Extrusions and 3D Printing

chrisplyler — Tue, 24 Jul 2018 02:38:31 GMT

When you've already got one Body, and you're Extruding another, use the Join option. They will become one Body.

Re: Problem with Extrusions and 3D Printing

Anonymous — Tue, 24 Jul 2018 02:46:33 GMT

It's not a multi-colored print, it's just the way that Simplify3D colors the various pen move types. The printer is only printing in one color of filament and as one continuous print.

Also, there isn't supposed to be a groove in the part. That's the problem I was pointing out. The section that appears to be a groove is just extruded a different distance than the other portions to make a ring that juts out.

Re: Problem with Extrusions and 3D Printing

Anonymous — Tue, 24 Jul 2018 02:48:41 GMT

Hmm.. I wonder if that's my problem. I'm still pretty new to Fusion 360. Been getting better but there's lots of stuff I still haven't figured out yet. I can't say that I've always done a 'join' extrude. I will pay more attention to that as I move forward and see if that's the issue.

Thanks for the tip!

Re: Problem with Extrusions and 3D Printing

etfrench — Tue, 24 Jul 2018 05:06:57 GMT

Joining components isn't necessary to create the stl for printing. As long as each part is a subcomponent of the same component, you can create an stl. This includes the top level component in the Browser. Turning the visibility of a subcomponent off will keep it out of the stl.

Re: Problem with Extrusions and 3D Printing

chrisplyler — Tue, 24 Jul 2018 14:08:45 GMT

@Anonymous wrote:
Hmm.. I wonder if that's my problem. I'm still pretty new to Fusion 360. Been getting better but there's lots of stuff I still haven't figured out yet. I can't say that I've always done a 'join' extrude. I will pay more attention to that as I move forward and see if that's the issue.

Thanks for the tip!

I am only guessing because I don't have any 3D print experience, but I suspect that the Slicer or whatever software you use looks at two different bodies, even if they are intersecting, and decides a separation exists between them. I'm guessing that if it is all Combined/Joined into a single body, maybe that won't happen.

Re: Problem with Extrusions and 3D Printing

mavigogun — Tue, 24 Jul 2018 14:47:02 GMT

@etfrench wrote:
Joining components isn't necessary to create the stl for printing. As long as each part is a subcomponent of the same component, you can create an stl. This includes the top level component in the Browser. Turning the visibility of a subcomponent off will keep it out of the stl.

In this case, it is. If you want the parts of an internally captured joint- say, a socket or hinge -to function after printing, then, for sure, do not join them in Fusion- but if you want the standoff and base of a flange or bracket to be one, they better be Join(ed) in Fusion before exporting the STL. While closely-related-but-not-joinged forms are typically mutually ensnared coming from the printer, if the extruder temperature isn't set too high (or, worse, still, very high with a high movement speed, resulting in unintended fusion), the points of contact should shear free.

Re: Problem with Extrusions and 3D Printing

Anonymous — Tue, 24 Jul 2018 16:45:00 GMT

I see that I need to spend more time looking through the part before I send it over as an .stl to make sure that things are combined / represented the way I need them to be for printing. You (all) have certainly clued me in to a big thing that I need to learn about and be aware of.

As a positive item resulting from the conversation here, I did 3D print the combined / joined part last night and it printed perfectly without any issues. Everything was nice and solid-- one piece and with no grooves or joints.

Thank you everybody for all the help and assistance!!!

John

Re: Problem with Extrusions and 3D Printing

Anonymous — Tue, 24 Jul 2018 16:51:15 GMT

Is there any FAQ or discussion that you know of for people using Fusion 360 and 3D printing? I would like to learn more about the issues, tips and tricks of going between the two processes. One thing in particular that I've been working on is calibrating / tuning my 3D printer for the best accuracy and fidelity that I can achieve based on the specification contained in the Fusion 360 part design. Additionally, I have noticed that there are two (at least) "distortion" / "precision" factors based on whether the item is an external (outside) or internal (inside) feature. Such that outside measurements are "off" in one manner while inside measurements are "off" in another. I have been printing out a lot of test items to tweak the printer in the various ways to achieve the best dimensional fidelity that I can. My goal, hopefully, is to compensate at the printer, or at least the slicer, level and keep the Fusion 360 CAD files pristine.

Re: Problem with Extrusions and 3D Printing

etfrench — Tue, 24 Jul 2018 17:28:04 GMT

@mavigogun wrote:

@etfrench wrote:

Joining components isn't necessary to create the stl for printing. As long as each part is a subcomponent of the same component, you can create an stl. This includes the top level component in the Browser. Turning the visibility of a subcomponent off will keep it out of the stl.

In this case, it is. If you want the parts of an internally captured joint- say, a socket or hinge -to function after printing, then, for sure, do not join them in Fusion- but if you want the standoff and base of a flange or bracket to be one, they better be Join(ed) in Fusion before exporting the STL. While closely-related-but-not-joinged forms are typically mutually ensnared coming from the printer, if the extruder temperature isn't set too high (or, worse, still, very high with a high movement speed, resulting in unintended fusion), the points of contact should shear free.

It probably depends on the slicer. Slic3r doesn't need the parts to be joined first.

p.s. Actually Slic3r failed to create the correct shape

Re: Problem with Extrusions and 3D Printing

davebYYPCU — Tue, 24 Jul 2018 21:22:16 GMT

You are spot on, keep the Fusion model/s pristine.

Calibrate and test the Printer settings, to conform.

usually the dimension accuracy is to do with the Printer, and not so much the Slicer, but finish and appearance is more in the Slicer than the Printer, (all things being normal).

Youtube searches for your Slicer, and then your printer, will overwhelm you, then there are specific forums as well, but we did ok for a start.

Re: Problem with Extrusions and 3D Printing

Anonymous — Wed, 25 Jul 2018 04:56:17 GMT

I have a Creality CR-10s and I like it overall. It does a pretty good job and is fairly accurate. But it has a tiny bit of Z-skew (not enough to really bother me, but I know it's there), and I think the other issue that I have is getting the E-steps set just right. It does a pretty good job with outside features, it's the inside features that are just a little off. And I think that's a factor of the E-steps thing, squeezing out just a little too much as it goes through the arcs in the circle. The "ooze" tends to be toward the inside which in turn tends to occlude the holes / inside features just a little.

Re: Problem with Extrusions and 3D Printing

mavigogun — Thu, 26 Jul 2018 13:15:04 GMT

@Anonymous wrote:
Additionally, I have noticed that there are two (at least) "distortion" / "precision" factors based on whether the item is an external (outside) or internal (inside) feature. Such that outside measurements are "off" in one manner while inside measurements are "off" in another.

I'm disinclined to suspect any relation to Fusion or Slic3r- temperature/extrusion material I reckon the likely culprits. Temperature (and, of course, distance) impacts how wide the extrusion is smeared on the platen or underlying print layer. Moreover, some extrusion materials are dimensionally reactive to temperature- say, due to a temperature gradient between a heated platen and print extents, or defacto or intentional annealing. Some materials feature MUCH more post extrusion dimensional stability, such as a carbon hybrid vs PLA.

If we're not talking about geometric imperfections not uniform in all axes, relating to the printer's design (motors, belts, etc), but rather predictable byproducts of the nature of the process, it seems to me Fusion might be of great help scaling the models to compensate.

Re: Problem with Extrusions and 3D Printing

Anonymous — Thu, 26 Jul 2018 20:59:43 GMT

I do agree that you can use Fusion 360 to compensate, and I certainly do do that when I need to, particularly in the interests of expediency a lot of times. But my goal is to tweak and tune the process, up and down the line (and most particularly at the hot end) to get things to work the best they can and hopefully keep my designs pristine. When I have to "adjust it in Fusion", I make a copy of my original and then tweak that.