Guilloche!

[Hessel Oosten]

And another SUPERIOR guilloch?  video:

https://www.youtube.com/watch?v=b-6B776Hw3I

See eventually from ~ 8 minutes.

Hessel

[Mooselake]

Thanks, haven't seen that one yet.  I'll watch it later today, have some appointments and maybe bring a new dog home from the animal shelter to keep the moosedog company

70 1.5"/38mm brass blanks arrived today, 50 that were lost in shipping for almost two weeks and 20 that I ordered yesterday to replace some of them (funny how that makes the missing ones appear).  Need to make a fixture and see what engraved brass looks like

Kirk

[ArtF]

>>couldn't figure out how to get back to upright and flat

  Double click on Vexx's screen will return to flat plane x,y.

Results are looking great...

Art

[Mooselake]

Hessel, thanks for the video, we watched it yesterday evening.  Now I'm motivated to try straight line guilloche too.  This presenter was less down on CNC than my other sources

I've been trying to avoid doing any actual programming (something about retired and wanting to do new stuff), but am becoming interested in the Processing environment, mostly because it looks like it handles most of the visualization details along with simplifying vector output.  I was mostly a real time and OS programmer, missed all that gui stuff.  The challenge with simulating a straight line machine is the pattern bars; sawtooth and sine should be straightforward but DIY pattern bars would be trickier especially trying to avoid lots of short vectors.  Phasing doesn't look to hard, figuring out how to represent horizontal movement, particularly trying to do some of it automatically looks about middle difficulty.  Of course, that's from a non-graphical programmer and could be totally wrong.

I'm starting to dream about how to add geometric chuck patterns to Art's style of envelope.  Not sure if that qualifies as nightmares or not.  The math looks pretty straightforward, which means I have no clue about what it would take 

Kirk

[Mooselake]

This may not look like much, but the svg file was generated with a 30 line program written in processing that creates a triangle straight line machine pattern bar and then steps it across the workpiece.  The scaling is way off, one might say non-existent, no way to change parameters except recompiling, no phasing, masking, spacing changes, pattern bar changes, etc.    Lots more to go but actually achieved a CNCable file!  First code I've written in quite a while, first attempt at processing too.  Not the easiest way, but it allows for other styles, or even customized, patterns.  Who knows, might evolve into a straight line guilloche machine simulator. 

25mm sq, 90 degree diamond drag on anodized aluminum, 800 mm/minute.  Still haven't got the lighting thing, very sparkly in real life.

For grins here's the program, probably needs some comments :

Code: Select all

// create a PShape representing a triangle patternbar
//  with pitch spaced teeth, eventually this will be generalized 
//  to create additional types

import processing.svg.*;

PShape patternbar;
float pitch=20, pattern_spacing=10;
String output_file = "testZigZag.svg";

void setup() {
  size(400, 400);
  background( 0); // #b5a642);
  stroke(255);
  noLoop();
  beginRecord(SVG, output_file);
  patternbar = createShape();
  patternbar.beginShape();
  patternbar.noFill();
  patternbar.stroke(255);
  patternbar.strokeWeight(1);

&nbsp; for (float y=0; y<width; y++) {
&nbsp; &nbsp; patternbar.vertex(abs((y % pitch) - pitch/2), y);
&nbsp; }
&nbsp; patternbar.endShape();
}

void draw() {
&nbsp; for (float&nbsp; i=0; i < width; i += pattern_spacing) {
&nbsp; &nbsp; shape(patternbar,i,0);
&nbsp; }
&nbsp; &nbsp; 
&nbsp; endRecord();
}

Kirk

[Hessel Oosten]

evolve into a straight line guilloche machine simulator

Now I'm motivated to try straight line guilloche too

Who knows ? May be... Art is reading this thread ?.

It really looks great -and- promising !

Hessel

[ArtF]

It does look good. Seems its more a function of technique than program
from the most part.

Art

[Mooselake]

A straight line machine traces a machined pattern bar, which can be pretty much any shape but from what I've been able to tell, based on perusing online sales,  are mostly triangular waves, sine waves, and some special designs.  To be traditional they need to be traceable by a "rubber" that rubs along them, so no undercutting or aggressive angles.  Of course a CNC program isn't bound to that, but might as well try to stay close.  Right now I'm working with 100mm pattern bars but eventually that should be extended to 150 or 200mm, just change a couple variables...

It's progressing. Added sine waves, some sliders for pitch (mm per repeat), spacing, and amplitude (amplitude currently only for sine waves, triangle is fixed at 45 and depends on pitch) and a button to write the SVG file, wasted a couple days trying to put the controls in a separate window and gave up over variable scope issues, seems I couldn't pass a boolean back to the main window out of a button and just added some whitespace on the right of the window for them.  Processing's an overlay/preprocessor for java, and while I spent several years writing java EJBs in the early aughts my library's up north and memory's a little fuzzy on esoteric details.

To Do includes being able to switch patterns without recompiling, not hard but leads into another issue which is specifying pattern designs, spacing, and phase (aka up/down pattern bar displacement) on each line.  Besides the canned pattern bars need to add a capability to read a properly formatted SVG file as a pattern bar (it's only a couple lines of code), designed elsewhere.  Need to add workpiece scaling rather than a fixed 100mm square, zooming (need to see exact line placement in some designs and 3.8 pixels per mm (96 ppi) is too tiny for my eyes).  Also need to figure out how to do masking, as in remove all of the design that's outside a selected shape, will probably limit that to rectangles and ellipses including circles.  Still a long way from basket weaves which need variable spacing and phasing.  Other than that one zigzag pattern the CNC machine has remained idle.

Art, are booleans implemented in Vexx?  Specifically I'm trying to do intersections, remove everything outside a closed shape, and couldn't figure out how to make that work.  My patterns are multiple single lines, not a closed shapes,  but the outside shape would be closed.  All I really want to do right now is be able to use 38mm brass disks without aircutting the parts outside.  That would be tough with the spring loaded diamond drag.

My doc wants a biopsy of my knee, the surgeon says he'll have to open it up again rather than a needle or endoscopic (he didn't think much of my suggestion of a small hole saw...) and take pieces from various places, and is scheduled for 10/2.  Of course it's a rare (in prosthetic joints) and difficult to cure infection so essentially no guidance in the literature of how to get rid of it (they only found one sort of applicable case in the database), the biopsy is to see if the treatment has worked.  If it has, new knee joint about a month after the biopsy, if not then ??  Might be away from the router and programming desk for a while after that depending on how the knee bends and chair sitting goes.  Moose might have 4 knees, but the redundancy just didn't work out on this one.

Kirk

[Hessel Oosten]

Here today some "straight-line engine turning...", with the mill.. .

The "basket weave"".

Small diamond engraver, aluminum (polished previously), diam. 30, depth ~ 0.05 mm, feed 75mm/min.

Nice explanation of the pattern-making by watchmaker Roger Smith:

https://www.youtube.com/watch?v=LBiiDpexmA8

Hessel

[Mooselake]

Nice!

You're ahead of me!  I'm still working on a simulator and spent the afternoon trying to debug a basket weave pattern generator,  darn thing is having some display issues.  Had other distractions lately or maybe I'd have gotten further.  How did you create that pattern?

I've been using both Peter (?) Shapiro and Roger Smith's videos as inspiration and design advice, thanks in part to your links.  There doesn't seem to be a lot of online info on straight line machines, and I'm guessing at some of the terminology and looking at eBay and other sales offerings to get an idea of what was available as pattern bar designs

Kirk