#GENERATE SPIRAL OPENSCAD HOW TO#
#GENERATE SPIRAL OPENSCAD CODE#

I’m decades older than I’d like to admit - and I’ve been coding since about 1976. Using other techniques, the filament clip could be tricky to describe, but with this trick, it’s only a few lines of code. For each adjacent pair of points in the set, all you have to do is drop a cylinder at each point (diameter = line width, length = extrusion length), and then wrap a hull() around both. If the shape you’re trying to create can be represented as an extrusion of a line drawn through a set of points, then it’s pretty easy to whip up. While I was writing the code, it occurred to me that it’s a nice, compact illustration of a couple of I decided to model a little clip that keeps the loose end of a spool of filament from wandering off.

Un-comment each of the following in turn to create test objectsĪ Handy little filament clip and a trio of openSCAD tips.SocketExtraDepth=.8 // I do this to leave room for glue. These values are a decent starting point for 0.4mm line width.

Clearances to compensate for nonidealities (Cut/paste the rest into an openSCAD file)Įpsilon=0.001 // to remove geometric ambiguities I’ve found that by tweaking these two values, I can come very very close to an exactly square interior corner. It then reverses this deviation as it begins printing in the new direction. What follows is a few snippets of code, that you’re welcome to cut/paste into your own creations.Īs the nozzle approaches within a certain distance ( CornerEaseA ) of a corner, it veers to the outside by a smaller distence (CornerEaseB), and past the corner (also CornerEaseB). The technique isn’t restricted to openSCAD, of course in fact I first used it in TinkerCAD, in a piece I had printed at the local library before I got my own printer. The solution is to model a little alcove at each corner of the socket, to provide space for this bunching-up to happen without rounding off the corner you’re trying to create. If your control board has enough storage and computational grunt to enable linear advance in the firmware, you can tune this behaviour, but there will always be some residual imperfection to deal with, and in any case, many of us are running stock boards or have other reasons not to fuss with the firmware. As the mechanism slows to a stop in one direction and them accelerates in another, filament continues to be extruded, so it “bunches up” at the corner. Even in a CoreXY machine, but much more so in the more common “moving-bed” style printers, objects of considerable mass have to be decelerated and accelerated again to get the extruded bead of filament to go around a corner. The second issue has to do with imperfect extrusion. You have to leave a little extra space in the X and Y dimensions of the socket to allow for this non-ideality in both it and the matching post. This is because the cross-section of a line of extruded filament isn’t exactly rectangular, but bulges at the sides. If you print a very narrow vertical slot, you will find that it is slightly narrower in real life than in your model.

#GENERATE SPIRAL OPENSCAD CODE#

This little article contains code snippets that let you deal with these issues, at least for cases where the cross-section of your socket and post lie in the XY plane. If you’re designing things that plug together, you have to account for a couple of issues. Here’s the same bit of code, but using epsilon to avoid the geometric ambiguity.

#GENERATE SPIRAL OPENSCAD HOW TO#

(Just how to include it can involve some thought if your model is complex). The solution is to define a special variable - I always call it “epsilon” that is small enough that when you use it it does not damage your model, and use it to force the objects to overlap or to be separate. The same thing will happen at point intersections as well, and when adjacent holes just touch. The problem is that the cube and cylinder intersect along a line - that they touch but do not overlap. UI-WARNING: Object may not be a valid 2-manifold and may need repair!

If you cut/paste this snippet into openSCAD and try to render it, you’ll get this message: Translate() cylinder (h=10, d=10, center=true) Once you start using openSCAD, it won’t take long before you create a model that won’t render.

Generate spiral openscad