AutoPass Patterns: Star and Spiral

Instructions

To cut these patterns, we use the ramp phase of the AutoPass extension in a somewhat creative way. AutoPass plunges the cutter deeper into the workpiece with each pass in a linear motion. The length of this ramp phase varies depending on the depth of cut and the selected plunge speed. Since we can calculate this length relatively well, you get great opportunities to create three-dimensional patterns with Origin. The following is a bit complex. In case of questions, need some help, have suggestions, ideas or just want to show your results, stop by here: http://community.shapertools.com/t/autopass-patterns-star-and-spiral SOME BASICS: (1) Since AutoPass does not work with open paths (lines), the patterns consist of several shapes, of which we always cut only a particular segment (= our cutting path). The remaining segments of the shapes are only a means to an end to be able to use AutoPass (= irrelevant path segments). (2) We simulate an online cut by setting the negative half cutter diameter as the offset. This has the advantage that you can also cut the pattern backwards to get a completely different look. So for my V-cutter with a maximum diameter of 3 mm, I choose "-1.5 mm". (3) In order to have good control over the start and end when cutting, the shapes are designed in a way that they always have a hard angle at the start and end points. This makes it easy to prevent Origin from cutting into the segments of the shape that we want to leave out. Be sure to avoid using Auto-Lock during cutting! (4) If you want to adjust the size of the start/spiral, you can scale the SVGs proportionally. After that you have to recalculate the plunge speed. The same applies if you want to change the cutting depth. See below how this works. (5) You can use a trick to test whether you have set the correct parameters to get the perfect ramp length. Since the usual AirCut is not suitable for this purpose, let's use the manual Z-Touch. Start the manual Z-Touch function and move down the bit juuuust a little and set this value to zero. Now you can test without turning on the spindle resp. without cutting into your material. The behavior of AutoPass is the same as real cutting. During (air) cutting our patterns, Origin should always display a light blue line. This is an indicator of the ongoing ramping phase. When the line turns dark blue, the ramp phase is over and the maximum cutting depth has been reached. If the line turns dark blue near or better directly at your the end point, you have set the perfect plunge speed. HOW TO CUT: (1) Prepare your workspace and Origin: mount the cutter, z-touch, set spindle speed, scan the workspace, grid, load and place the SVG. (2) Do the settings: Activate AutoPass. Open the AutoPass settings and deactivate the "Pass Depth" toggle as well as the "Roughing Passes" toggle. Set the cut depth to 3 mm, your offset to minus (!) half cutter diameter and the plunge speed to 304 mm/min for the star. If you're cutting the spiral, set plunge speed to 221 mm/min. (3) Bring Origin near the starting point of the first segment to be cut. Make sure that you bring Origin a little above the starting point and on the opposite side of the segments that should not be cut. Please see my visualized explanations to make this more clear – sort of as a cheat sheet: https://community.shapertools.com/t/autopass-patterns-star-and-spiral/11047/4 (4) Start cutting and don't active Auto-Lock! Cut slowly along your segment until you reach the end point. Stop cutting. Repeat this process for each stroke of the star resp. the spiral. Here you can see videos on how the segments are cut: https://community.shapertools.com/t/autopass-patterns-star-and-spiral/11047/2 (5) If you want to cut the patterns the other way – from the center to the outside – just switch from an outside cut to an inside cut. You will get a completely different look – try it out! CHANGE THE CUTTING DEPTH: To change the cutting depth, you must recalculate the plunge speed. The length of cutting path remains the same and is still 12.5 mm for the star and 17.08 mm for the spiral. You can calculate the plunge speed precisely with Beau's calculator (see link at the bottom of this page) or use my quick and easy to remember formula. If you use my formula, you get a good approximation but may need to do some fine tuning: Plunge speed in mm/min = ( cutting depth in mm * 1300 ) / length of cutting path in mm With integer scaling, this is very simple, since doubling the depth of cut results in doubling the plunge speed, and vice versa: For a cutting depth of 2 mm set the plunge speed to 202 mm/min for the star and 147 mm/min for the spiral. For a cutting depth of 4 mm, set the plunge speed to 404 mm/min for the star and 294 mm/min for the spiral. SCALING THE PATTERNS: The SVGs of the two patterns can be scaled proportionally directly on tool. After scaling, the plunge speed must be recalculated (see above). For this calculation you need the length of the segment to be cut. You can either measure the length with a graphics program or simply calculate it: In the case of the star this is quite simple, because the height of the SVG is exactly twice as long as the segment to be cut. So if you want to cut the star 40 mm in height, the length of cutting path is 20 mm. In the case of the spiral, it's not much more complicated either. Simply multiply half the height of the SVG by 1.22. For example, at 40 mm, the length of cutting path is 24.4 mm. FURTHER READING: – General discussion about RampArt: http://community.shapertools.com/t/autopass-ramp-art – Beau's pretty cool calculator: http://community.shapertools.com/t/engraving-and-autopass-ramping-and-calculators – Discussion regarding this project: http://community.shapertools.com/t/autopass-patterns-star-and-spiral MORE PATTERNS: – 5-point star: https://hub.shapertools.com/creators/623dae1dfb4d27f71b9ebdb0/shares/65dfa95a3c4f43b001f32a70 – Double Helix, endless pattern: https://hub.shapertools.com/creators/623dae1dfb4d27f71b9ebdb0/shares/63bfea2907f13e3dc4972b69 – Moulding Style: https://hub.shapertools.com/creators/623dae1dfb4d27f71b9ebdb0/shares/63dbca43e086cc02ed83c3ef