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I no longer like 3D printing

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  • #16
    I just set up my grandson's 3D printer in my office and ran a part to mount a small blower. 6 hours to print. I would have spent 10 minutes programming 10 minutes cutting it on the CNC! However the goal was learning how to use it for making parts that would be difficult or impossible on the CNC, or very expensive due to machining away a lot of expensive material. Every tool has its place.

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    • #17
      FTW: Forget The World. in the same vein as FTA: Forget The Army. but not in this instance.

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      • #18
        Originally posted by ad5mb View Post
        ftw: Forget the world. In the same vein as fta: Forget the army. But not in this instance.
        ftn.. Jr
        My old yahoo group. Bridgeport Mill Group

        https://groups.yahoo.com/neo/groups/...port_mill/info

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        • #19
          Try photogrammetry and 3D printing and you'll come to appreciate 3D printing again.

          Photogrammetry is the process of scanning an object by getting a number of photos of the object from all angles. For small objects put them on a turntable and take 75 or so pictures while it's rotated 360 degrees. For large objects walk around them as you shoot photos. Run the photos through Meshroom (free, open source, only runs on computers with nVidia graphic cards though) or one of the reduced capability free softwares. You'll come up with a 3D printable or machinable model. For an object with any amount of complexity you won't be able to machine it, only 3D print.

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          • #20
            I thought that photogrammetry had the same restrictions as machining due to the way that scanning is a line of sight process. You can't necessarily see into an undercut part from multiple angles, if at all. Another example is the difficulty of scanning featureless surfaces optically. It seems to be hard to capture concave surfaces accurately.

            Working with my friend on his 3d printing, one key learning was that 3d modeled parts tend to be more ornate than is necessary for the function. Curves and bevels are added because it looks good, not to save materials or structural integrity. Removing the frills makes machining it much easier.

            Having said that, I really wish I had a 3d printer and scanner, just for the fun of it.

            Dan
            At the end of the project, there is a profound difference between spare parts and left over parts.

            Location: SF East Bay.

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            • #21
              RB211 has a probe now, he can do 3d scanning with it into a point cloud and then make the parts from that. Give him time, he will go down that road too in time.

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              • #22
                Originally posted by Sparky_NY View Post
                RB211 has a probe now, he can do 3d scanning with it into a point cloud and then make the parts from that. Give him time, he will go down that road too in time.
                Especially if my job didn't interrupt me every 2 weeks.

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                • #23
                  Oh, heck... this whole thread was just so you could show off your fancy probe wasn't it.
                  *** I always wanted a welding stinger that looked like the north end of a south bound chicken. Often my welds look like somebody pointed the wrong end of a chicken at the joint and squeezed until something came out. Might as well look the part.

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                  • #24
                    Originally posted by danlb View Post
                    I thought that photogrammetry had the same restrictions as machining due to the way that scanning is a line of sight process. You can't necessarily see into an undercut part from multiple angles, if at all. Another example is the difficulty of scanning featureless surfaces optically. It seems to be hard to capture concave surfaces accurately.

                    Working with my friend on his 3d printing, one key learning was that 3d modeled parts tend to be more ornate than is necessary for the function. Curves and bevels are added because it looks good, not to save materials or structural integrity. Removing the frills makes machining it much easier.

                    Having said that, I really wish I had a 3d printer and scanner, just for the fun of it.

                    Dan
                    Yes, it is a line of sight. I scanned a 3" high action figure, looking down to the head at a 45 degree angle, another series of shots straight on, and the last series looking up from below. 5 degree increments on each series. I have an indexing turntable with a shutter trigger. 216 pictures. It takes a fair amount of time to process those in Meshroom, maybe 4 to 5 hours.

                    I think I read the software requires any detail to be shown in at least 3 pics.

                    I also have a probe on my big mill. Relatively slow. Worse on the line of sight issue, no way to get under overhangs. 3D prints aren't the best using PLA like I do, still more detail than ever possible with the probe. The probe excels on gently curved flat-ish areas where a photo can't pick up the surface well . Photogrammetry doesn't work on shiny objects either.
                    Last edited by DR; 10-13-2020, 07:23 PM.

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                    • #25
                      My probe is a 3 point type that apparently suffers from kinematic errors. I'd also need to spend another $300 for the advanced probing routines to use it for that need. One nice feature however is that if I had it, I could probe two points on my vise for each axis and correct for any alignment issues, kind of like auto bed level on a 3D printer but in X,Y and Z.

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                      • #26
                        This is just because you haven't gone down the rabbit hole of printer tuning! Just like with cars, there are ways to greatly speed up your prints. Also like cars, this can sometimes be pretty expensive too! 🤣

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                        • #27
                          Originally posted by MikeWI View Post
                          This is just because you haven't gone down the rabbit hole of printer tuning! Just like with cars, there are ways to greatly speed up your prints. Also like cars, this can sometimes be pretty expensive too! 🤣
                          People just don't respect 3D prints like they do machined parts. Far fewer can produce machined parts and they sell for more money. And metal is a lot cooler than plastic
                          When some one sees a 3D printed part, their first thought is that they could of made it themself with a $150 printer. Just like being a photographer in this day and age, everyone thinks their pictures are, "good enough"

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                          • #28
                            3D metal printing looks interesting. Still too expensive to do at home.

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                            • #29
                              Originally posted by pinstripe View Post
                              3D metal printing looks interesting. Still too expensive to do at home.
                              They also have an issue with long cycle times. Plenty of people having their 3d models metal printed at Shapeways, for small detail parts on model locomotives. Cost a lot and the finished product is very difficult to machine or tap.

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                              • #30
                                3D printers can print parts (within reasonable limits or with support structure) with overhangs and undercuts that would be difficult to machine on a mill. Even a 4 or 5 axis mill. They can also print some details that would be expensive to machine due to the need for smaller and smaller mills to remove materials that would never have been there to begin with in a 3D print.

                                I have had my son 3D print mold masters to make silicone molds for resin casting that would be beyond my practical limits on the CNC mills.

                                In my opinion 3D printing is a complimentary process. It is not necessarily a directly competing process.

                                That being said, you could machine your tool organizers in minutes out of HDPE, some woods, or some other fast cutting material. Even on your Taig with its roughly 6x12 envelope you could setup to cut several at one time.
                                *** I always wanted a welding stinger that looked like the north end of a south bound chicken. Often my welds look like somebody pointed the wrong end of a chicken at the joint and squeezed until something came out. Might as well look the part.

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