What's new
What's new

machining 3d printed plastics

NewtonPens

Plastic
Joined
Jan 6, 2016
Which of the plastics from shapeways machine the best? I want to print a tube with inclusions, then pour resin in there, and machine it so the inclusions show up as little ribbons in the finished part.

Thanks
 
Machining 3d printed plastics is a pain in the ass, it's either hollow, soft, and brittle...or a combo there of. Sla parts are easier to hold but are brittle as all hell and is prone to chipping and outright splitting. Nice thing is super glue works well with it :).
 
Hmmm ... I wouldn't be ready to give up just yet. The variety of different kinds of 3d filament continues to expand, and options go far beyond PLA (which I assume is what is in view above - it's the one that glues well with super glue). For one, you could try any number of "filled" PLA filaments - filled with wood, or with metal or even carbon fiber. Then there's PETG, ABS, nylon, acetal (if you have a 3d printer that can handle it), ... and many of these in "filled" variations ... and the list goes on.
 
I may be picturing what you are doing wrong, but why not print it without a tube, slide a tube over it, then when your resin sets up, pull the tube off and not have to machine it? As mentioned above, most common substrates don't print well due to material composition and the inherent layers and infill voids. Usually, (not always) if you have to machine on something 3d printed from plastics, you are taking a longer road than you need to take.
 
machining PLA isn't too bad at slow speeds with sharp cutters, we did this to make a temporary thread dial for a couple of the lathes at the shop. (American Pacemaker parts are hard to find) printed them in multiple parts, super glued them together, machined the necessary parts to spec. works great. on a side note, 3D printing parts do distort to an extent if they are very large, at least on our printer so machining is usually necessary for accurate parts.
 
machining PLA isn't too bad at slow speeds with sharp cutters, we did this to make a temporary thread dial for a couple of the lathes at the shop. (American Pacemaker parts are hard to find) printed them in multiple parts, super glued them together, machined the necessary parts to spec. works great. on a side note, 3D printing parts do distort to an extent if they are very large, at least on our printer so machining is usually necessary for accurate parts.

To add, some plastics shrink differently than others. They can shift and change dimensions upon cooling.
 
How much of the 3D printed material are you looking to remove? Would it be possible to make all of the printed material "scaffolding" for lack of a better term, so it could be removed by means of melting rather than machining?

It also will depend on what kind of "resin" you want to use as a filler. More specific information will lead to better advice!
 
The resin used as filler is something pen makers often use to turn - alumilite.
Here's a quick screen grab of the tube with flat things in it. This would create a layered look that you don't often get in pen blanks.

flats screen grab.jpg

Once the resin is poured and cured, I would just machine it like normal leaving the plastic lines through the resin. It would be drilled and ID threaded, turned and OD threaded with 36 tpi threads.

Thanks
 
Ok, just connect the layer pieces in the middle where it won't be seen, or where you'll drill out, and like said above put it in a tube and fill with resin. Turn a bit off the outside to clean up and polish.

Make sure you print with 100% infill or you'll have voids.
 








 
Back
Top