In FDM (Fused Deposition Modeling) 3D Printing, “support” refers to structures onto which model material is printed. Every part requires, at the very least, a surface onto which the first layers are laid. Beyond that, support structures provide a platform for any material which would otherwise be extruded into mid-air. In other words, supports exist to carry vertical loads.
When parts require additional Lateral Stability, GrabCAD Print and Insight users have a couple of “one-click” options: Use the Surround Support Style, or rely upon contact with normal support structures. Unfortunately, Surround Support can double or triple the build time (and support material use), and the shape and position of other support structures isn’t always convenient. Stabilize Walls provide an easy way to improve lateral stability with very few downsides. Read on to learn how to add them using Insight.
In addition to the vertical loads applied to FDM printed parts (gravity and extrusion pressure), parts are also subject to the lateral force of chamber fans blowing across the build chamber and the extrusion head dragging thick melted material around. These forces threaten to impair surface finish or knock parts over altogether. Tall parts, thin parts, and otherwise flimsy parts are especially susceptible. Like other support structures, Stabilize Walls are built layer-by-layer alongside the part and any other supports. But unlike other support structures, they don’t provide any vertical support for overhangs, and don’t add any support material.
Stabilize Walls can be added any time after an STL has been sliced; before or after Support Curves are added. I recommend processing an STL as normal (adjusting Toolpath and Support parameters as necessary, adding Custom Groups, etc.), saving the Job, then adding Stabilize Walls. This encourages experimenting with different options, with little risk.
Navigate to a layer at or near the top of your part. The curve(s) on this layer will be used to define the topmost points of contact with the Stabilize Wall. Start the Stabilize Wall command from Support>Stabilize Wall. The view orientation will automatically switch to a Top View, which is best for this command.
The next step is to define the points of contact that the Stabilize Wall will make with the part. This is a 4-click process.
Start by selecting a curve on the current layer (either click directly on it, or drag across it); the curve highlights and a yellow arrowed cross-hair will appear (note: the arrow is irrelevant; ignore it).
The cross-hair defines the first point of contact with the Stabilize Wall, which would typically be placed near the edge of a thin wall of the part. You can re-position this cross-hair as desired. When satisfied, click the ‘+’ to lock it in.
Next, place a cross-hair some distance away from the first, to define the last point of contact with the Stabilize Wall. This would typically be near the opposite end of a thin part wall. Again, you can re-position this cross-hair as desired. When satisfied, click the green ✔.
Clicking the green ✔ will create the Stabilize Wall.
On the current layer, you’ll see a light red curve as below.
A finger contacts the part where your first cross-hair was placed, and every 6 in (as defined by the “Contact Interval” parameter) up to the position of the second crosshair. If you zoom in, you’ll notice:
- The fingers actually extend 0.006 in into the part (“Penetration”).
- The fingers penetrate the part every 10 layers (“Layer Interval”) all the way down to layer 0 (“Lower Layer Limit”).
- On non-contacting layers, the fingers stop 0.030 in short (“Non-contact Gap”).
- The length of those fingers is 2 in (“Separation”).
- The back side of the Stabilize Wall loosely follows the contour of the Part (it’s flat in this case, but “Flat Back” will force it to be straight regardless of the shape of the part).
- This is an open curve, as indicated by the arrow at its endpoint (open curves that aren’t yellow define the center-line of a single toolpath).
- When shaded, you can see that the “Toolpath Width” is 0.040 in.
View all layers to see how the Stabilize Wall will work out for this part.
Notice that the light red fingers continue straight down from the selected layer, all the way to the build tray, automatically extending to contact the red part curves as the shape changes. This is usually desirable, but can sometimes cause minor problems. In this case, the part geometry changes enough that it is missed by the Stabilize Wall in some areas, so the fingers there automatically extend to make contact with the wall behind it. It’s important to note that Supports are never added to hold up Stabilize Walls.
So if this were printed as-is, those first few extra-long fingers would be unsupported, and would likely droop down and make contact with the part where indicated. This probably won’t cause the build to fail, but will mar the surface unnecessarily. In this case, I would try a different position for the wall.
Clicking the red X deletes the last-added Stabilize Wall.
Sometimes it takes a few tries to get the Stabilize Wall in the right spot, and to get the settings just right. Remember that you can add as many Stabilize Walls as you want, so it’s OK to be conservative.
If you need to delete more walls than just the last one, use the Edit>Delete command, and set the selection filter to allow picking only open curves.
Remember also that these Stabilize Walls are just single-toolpath open curves, and they can be edited like any other curve.
It’s also OK if Stabilize Walls cross each other (after all, that’s what happens normally in the Sparse-Double Dense infill).
In this case, I added a total of 5 Stabilize Walls; 3 separate Stabilize Walls at 27 in.
Another at 15.5 in to stabilize the slanted wall.
Finally, about halfway up (layer 700), I added another wall just to hold everything together. This one intentionally intersects all the other walls, to lock everything in place. To make sure this wall doesn’t touch the part, I set the “Lower Layer Limit” to 700, but the wall always contacts the part on the selected layer, so I just deleted the curve on that layer. It’s not at all necessary to use this method to join Stabilize Walls (or to join them at all), but it’s nice to know how.
Because there are so many points of contact throughout this part, I increased the “Layer Interval” of my walls to 20 to halve the number of pockmarks.
In this case the Stabilize Walls do add about 11 hours to the build time, compared with the extra 40 hours Surround Supports would add (and this number of Stabilize Walls is a bit overkill for this part).
When the part finishes printing, Supports can be removed as usual (e.g., dissolved), and the Stabilize Walls zip/peel off easily – a heat gun or light sanding makes short work of the contact pockmarks.
In addition to providing lateral stability to flimsy parts, Stabilize Walls with Flat Backs can be used for shipping dunnage that perfectly cradles the part. Or they can also be used as wind-shields, to prevent hot air chamber from the blowers from warping thin parts (for this effect, it’s not even necessary that the wall contact the part at all; adjust the Lower Layer Limit per the intersecting wall above.)
Whether or not Stabilize Walls are used, I would also advise adjusting toolpath parameters to minimize small rasters in thin parts. Adjusting the number and width of Contours and enabling Variable Width Remnant Fill will reduce the lateral force/vibrations on the part, improve the strength of thin walls, and often reduce total build time.
Stabilize Walls are versatile and easy to add in Insight. I hope you’ll give this feature a try on your next part! Learn about this and other advanced topics in our Advanced Insight Training class.
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