Stl Files For Cnc Router | Machining An Stl In Fusion 360 – Project #114 [cnc]

Winston Moy

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Machining An Stl In Fusion 360 - Project #114 [cnc]

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[MUSIC] Hello guy’s, Winston here today. I want to talk about STL files. Stereo lithography standard tessellation language, Whatever it stands for STL files are about as ubiquitous on the Internet as PDF documents. The ability to carve these files opens up endless possibilities by making accessible, enormous model repositories found on sites like Thingiverse way Back in the day. I used mesh Cam to carve my STL files. But it’s also possible to use fusion 360 to do this. And that’s what I want to talk about today. I was approached by a bloke near Sydney, who needed a one-off prototype. He wanted forming dyes to press some thin sheet metal into end caps for the ribs in his van’s roof. Traditional machine shops wanted several hundred dollars to make these. So I was asked if I could undercut those prices by using cheaper materials and lower end CNC technology, he would provide models in STL format Since this would give me a perfect excuse to learn to set up. STL files in fusion. I agree for those of you who want explicit step-by-step instructions for running an STL through Cam Lars Christensen. As always has you covered? I’ll be going through an abbreviated version of that tutorial today. I started by using the import mesh option in fusion to pull in an STL file using various positioning tools. I got my model upright, scaled for metric and aligned with my origin now. This model is fine if I just want to drop a 3d toolpath on it and let fusion Whittle away at it automatically, but if you want to have more control over the machining process, you’re gonna have to convert it to a boundary representation or B rep to do this. You need to first enter direct modeling mode by disabling capture of the design history, this tells. Fusion, you’re excusing it from tracking changes and that you take full responsibility for how a mesh is modified. You’ll no longer be in a parametric environment, and that’s fine, because I really don’t want to make any changes to this mesh. I just want to be able to select the edges and faces to define machining boundaries. Now this STL file I received has about 12000 Facets ten thousand is the threshold that fusion typically considers reasonable. It just means that some operations here may be a little slower, but since I have a pretty solid desktop in a good measure of patience, I disregarded the warnings and pressed on work. I actually did one better. I also imported the other half of the forming diet, which brought my poly count up to 25,000 I then entered the cam workspace to define my stock. Since these models were 20 millimeters tall, I had to glue up some birch ply to provide a sufficiently thick volume of stock. The dimensions of my plywood stock ended up being five and a quarter inches by 12 inches by fifteen sixteenths of an inch. I added the appropriate margin around my model in fusion 360 so that the virtual stock matched my plywood next. I applied a facing operation to bring my thickness down to 20 millimeters. Then I added an adaptive clear, leaving about 10 Tau X true everything to separate the contoured regions from the flat surfaces. I sketched up some crude containment boundaries in the patch workspace Because I was using a B rep instead of the raw mesh. I could have directly picked the vertices in the model for this fusion tries, its best to figure out the optimal closed contour to match your intent, but it doesn’t always work with this many. Polly’s it would have been a bit tedious inside my improvised boundary for the contoured regions. I would apply a parallel finishing toolpath outside it. I’ll use a pocket tool path to bring my pieces down to final thickness for 3d milling. A lot of people think ball and mils are necessary, but unless the floors of your contours have tight radii, a flat end mil will actually do a pretty good job to complete the cut out of my pieces. I would use a contour operation to true up my walls since I was using a compression end mil here, I wanted to make sure the top edge of my plywood was cut by the down cutting portion of my end Mil. This end Mil was from Harvey tools and looking on the website. The down cutting portion of the flutes Don’t come into play until you reach a depth of cut of about 1/4 inch. So that’s what I set my contouring step down to in a future video. I’ll be doing a more in-depth comparison of surface finishes and fibrous materials using different cutter geometries. The last thing to do was to add a contouring operation with an eighth inch end mill to Bawra clearance holes for m5 Hardware. This is where you really see the benefits of converting to be rep without that step. You can’t select a profile from the mesh to create a 2d tool path. After posting my g-code. I went to my garage to cut. These dies out using a moderate amount of double-sided tape. I secured my plywood to the table. Then I loaded up. My program zeroed my z-axi’s against the waste board zeroed x and y a quarter inch from the bottom corner and watch the magic. My operations combined took about an hour. I could have gone a little more aggressive with my settings during the roughing phase, but a safe cool path is a good tool path in my opinion, much less stressful. [MUSIC] The surface finish of my walls and edges was fantastic with the compression and mill. I went over them with some 400 grit. Sandpaper just to make these nicer to handle. I also one of the contours with a little sandpaper to smooth out some of the machining marks, but they were subtle enough that it wasn’t really a high priority. There was a small void at the exact depth that I cut to, and I just stabilized it with some wood glue. That’s just a risk you always run with plywood and that’s pretty much. All there is to machining in. STL file import a mesh convert it to be rep applied. Toolpaths like you would for any other model and machine hope. You guys found that useful. If for some reason, you guys feel like you want. The concepts in this video reinforced. I’m actually going to be doing a live stream over on my second channel. Winston makes more with my friend George. He’s going to Harry Potter world in a couple weeks and wants a DIY wand. So I’m teaching him How to do a cam setup for a wand from Thingiverse. Expect that to happen next week in the evening. I’ll have the exact date and time in the description When we figure that out, I can’t promise it’ll be good, but feel free to come. Hang out, ask questions and laugh at George’s CNC ignorance. He recently got a maslow and has no idea what he’s doing. Thank you all very much for watching, and I’ll be back with another. CNC related project video in a week or two [Music].