Embedding Components within Parts
How to embed components into 3D printed parts.
Last updated
How to embed components into 3D printed parts.
Last updated
Embedding a part using a MarkForged II is a simple process, albeit with several landmines. This portion of the guide will lay out some ideas of how to get the job done, however many of these solutions can be quite contextual.
All methods of embedding a part generally adhere to several similar ideas. The first and most flexible of these ideas is to embed the part into the top of a partially completed build. This will be the method focused on and explored in this guide.
This method was found to be the easiest of the methods if the construction allows for it. Simply do an extruded cut into the top of your print, outlining the part that would wish to embed. This is effectively for things like a nut whose threaded hole is parallel to the Z direction or a screw that sticks out of the top of the part in that same direction. The largest limitation to this method is the print head's inability to avoid something sticking out of the top. If that is desired the inserting of the embedded part must occur after print completion.
The above example would allow a screw to join with the hex nut embedded in the part. If you desired the screw to have no head on the top end, an option would be to order a screw that is simply a threaded neck with no head.
The easiest method of creating a gap for your part in SolidWorks is to outline one end of it and do an extrude cut through your part.
If you want a gap enclosed on all sides for something like the head of a screw or a standalone nut, you can select Offset for the From option and set it to how deep your part will be embedded into the part and a Blind Cut set to the thickness of what you intend to embed.
The size of your gap is not perfectly definable if you desire a tight fit. The amount of additional clearance can be anywhere from a tenth of a millimeter to a half. If trying a new size, try to do a test print first to ensure clearance and not waste material.
When selecting a layer to pause at in Eiger choose the last layer in the 2D view that does not show a covering over the interior gap or the neck gap if there is one. This will allow the embedded piece to rest in the part without protruding above the next print layer when you resume it.
This method is often needed due to the embedding of the part requiring complexity beyond the first method. A good example of this would be for when you need to embed a part on its side.
For this method you must create the profile of your screw head the same as you would with Method 1, but this time do sketch of the cut on the side of your part you wish to cut into. Do to the nature of the printer needing to be completely clear, this may introduce additional complexity. Thus this method can be broken down by what you are attempting to embed horizontally.
Embedding something horizontally that also must stick out requires a side gap for the screw's neck to exit the part that matches or exceeds the height of the interior gap for the head. It is possible to embed a hex headed screw using square cuts into the shape as shown below.
Refining this method using better shapes can lead to a better fit. The top of the interior gap must remain square and cannot be used to match the angle of the hex head due to the printers inability to avoid obstacles. Ignoring that, we can create an angled bottom to fit while leaving the top unchanged. An example of this can be found below.
A possible concern that may arise in this method is the need for supports above the gap for the neck as there will be an unfilled portion above the screw's neck as well as the sides of the interior gap. Generally this is not an issue until the scale is increased significantly.
Due to the concerns and difficulty surrounding embedding a more complex part such as a hex screw, a good recommendation is to use square headed screws and nuts instead. This will simplify the process and eliminate some of the unavoidable gaps in the tops of interior gaps.
Embedding an object with a square profile is far easier that a hexagonal as above. The only difference is your cuts will be based on simpler square sketches than attempting to mold only the bottom. It is worth noting that this method still requires an exit hole that matches the height of your interior gap so you can maintain a "slot" for the screw's neck to slide into an rest in the bottom of.
Choosing to embed a nut instead of a screw can simplify the process further. Doing this will mean you no longer need to consider having an opening for a screw neck to enter into the top of and by extension have a gap that matches the height of the interior gap.
When embedding a nut instead of a screw you can choose to have a circular hole since, yet again, there is no screw neck that needs to enter the part from the top. This is applicable to many smaller size of screws. Once you try to create a circular gap to fit anything larger than an M4 spec the print sag may impede the fitment, however a light drilling out could solve this if you desire both a larger size and a circular hole.
