Fusion Remix of Topsie’s CNC Router

thingiverse

Topsie’s CNC Router Fusion Remix This remix is based on Topsie’s 3D Printed CNC Router (https://www.thingiverse.com/thing:3813481). I want to thank Topsie for creating this design, which I have chosen to build and assemble in Fusion 360 as a way to get familiar with the design. Since I am not yet ready to start building it, I thought it would be a great opportunity to learn more about the design by bringing it into Fusion. The idea behind this remix is to create a version that can be used with aluminum parts for increased strength and rigidity. By having the design in Fusion, generating milling g-code will be much easier. This implementation is shared as a Fusion export file (.f3z) and via Fusion’s design sharing service (https://a360.co/2msX988). I recommend using the sharing service link if possible. As I brought the parts into Fusion, I was efficient with my time by not bringing in both the left and right front feet. One is just a mirror of the other, so I brought in only the right one and mirrored it in Fusion for the left. Same for the Top Y Axis parts. Also, I figured that all the drag chain links having a hole in them wouldn’t hurt anything, so I brought in only the screwable one. This remix is definitely a work-in-progress, but I have converted and assembled the basic mechanism. The spindle mount moves in 3 axes under Fusion’s mechanical simulation. BTW, the NEMA 17 steppers are from Barspin (https://www.thingiverse.com/thing:83340). I tried to articulate the drag chain, which works sort of in isolation but brings my laptop to its knees when added to the rest of the machine. Instead, I brought in short lengths of drag chain and only the curved end assemblies move with the gantry and z-carriage. Note that none of the fasteners (bolts, nuts, screws) have been included. The parts are held together by what Fusion calls joints. These joints allow movement depending on the kind of joint and the joint limits. Since I’m never going to machine individual screws and since the fasteners would more than double the number of parts (further slowing simulation), it is better to leave them out. I am implicitly signing up to keep this Fusion version in sync with Topsie’s original. We’ll see how well I do with that. Right now it is in sync with Topsie’s v1.3. UPDATE 20191110: Added v1.4 components. Old cable chain supports are still in there, but hidden. New components are in red. I only added one shim as an example. To use the shims, print four and place one under each foot. For some reason the cable chains have shifted position - I fixed the Y-axis but X-axis cable chain is still misplaced. I feel the need to make a comment about the new Leadscrew End Supports. In the old design alignment between the stepper bracket and the T8-Nut supports was not as critical since misalignment would just shift the far end of the leadscrew. Now since both ends of the leadscrew are fixed, misalignment will cause the T8-Nut to bind or possibly deflect the rail. This is why in some designs they warn to not capture the end of the leadscrew and in others they warn to leave the T8-Nut mounting loose. In this design with the leadscrew ends captured you should probably loosen the screws holding the nut to the nut support block. The nut needs to be able to move normal to the axis of the leadscrew but not have play along the axis of the leadscrew.