Search

Drop cutters Tuesday

Now the drop cutter function is enabled to handle horizontal edges as well as vertices of the surface. It’s the trivial case, because you take the closest point in the edge to the cutter centre and send that to the drop cutter on vertex routine. Most of the day was spent getting rid of the […]

Drop cutters Monday

I’ve got quite a few distractions this week, so it’s not realistic that I will be able to completely rewrite the cutter location code by Friday to be fast, but I’ll have a go. I started working on it last night and have the initial interface of it sorted out. The main innovation is that, […]

First drop point results

Beginning with the easiest, I’ve done cutter location against a set of points picked from a model. I’ve learnt my lesson and done it for the uncommon tapered cutters from the start, rather than going for the easier cylindrical type of cutter, and then having to fit this feature into the code later. I’m also […]

Basic Cutter Location Studies

Neel D asked in an email about how to do cutter location for a 3-axis tool. He’d read: http://dimacs.rutgers.edu/Workshops/CompAided/slides/lee2.pdf The interesting thing about all the academic publications of cutter location (using offset surfaces) is that it bears no relation whatsoever to how it is done in the real world. I’ve had conversations with the academics […]

Implicit areas in the tool surface applied to five-axis theory

Following my work attempting to create five axis toolpaths using tracking methods, I’ve fallen back to the more conventional techniques used to create 3-axis toolpaths of defining areas theoretically and then computing their boundaries. For three-axis strategies almost everything is computed on an XY weave an efficient aligned subdividing structure. When things are aligned in […]

Line intersecting a finite cylinder

This is part one of a two part posting that deals with one component of the 5-axis drop cutter function. (It’s also the programming problem given to me when I applied for a job at Parasolid in about 1995.) There’s a big problem with the finite cylinder because you need to deal with 3 separate […]

Five new scallop ideas before breakfast

Here is an example random part which the great folks over in Copenhagen have been throwing at my scallop routine. The problems thrown up by these computer generated random parts are easy to ignore — there is always something better to work on — because no one is actually getting let down by them. But […]

The slot drill that fell through a triangle

No one thought there could be a bug in something as fundamental as the drop cutter onto triangles function, which has been in use at the heart of most every machining algorithm since I had started writing these functions 20 years ago. But the farm found one.

The non-axial projection subjection

You don’t begin a project that will take the rest of the year and more without evading it as long as you can. Finally I’ve begun to break ground on this. Background: Almost all industrial algorithms for generating toolpaths for 3-axis machining are based on the Drop Cutter function, where the tool is lowered along […]