Project by Jeremy Fryer-Biggs
One of the truly unique capabilities of the microfactory is the ability to print and mill the same part. We are going to devote several posts to the special capability but first up - printing a custom bracket and then precision milling in screw holes. Have you ever noticed that when you print parts the screw holes never go where you want them? This project will demonstrate how to use a microfactory to make this a thing of the past!
you will need a 1/8th endmill for milling the plastic bracket.
first we designed the part we want to make in CAD
then we remove the holes so that they WON'T be printed in and export to .stl
We use Slic3r to create a g-code tool path of the general shape
then we allow the machine to get up to temperature. we recommend using a mebotics spoil-board for this operation because they are designed to be optimal surfaces for printing AND milling operations. ALSO for the best results we recommend mixing a small quantity of acetone with scrap abs in a glass and spreading the slurry directly over where you intend to print. This will minimize warping and improve adhesion (which is particularly crucial during the milling step).
print the part!
(watch a video of the part printing)
Next we export a .dxf version of our part file from our CAD program and use CamBam to make a tool path. You can write a combined file and put a "tool change" into the program but for simplicity's sake we prefer making two separate programs to run
when the printing has stopped, raise the gantry and put in the 1/8th endmill. Perform a touch off to the table to re-zero the tool then run the milling program
(see video of the milling program running)
and voila a printed bracket with precision screw holes!!
Rachel Tine - for doing the cool photography
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