Month: March 2012

Uncategorized

Drawbot Experimental Branch with Look Ahead Ring Buffer

2012-03-31 Dan

I’ve created a new experimental branch so as not to ruin the latest working version. It has two big changes.

Feed Rates
The old feed rates were units/s.  I’ve adjusted the feed rate setting and display to be in units/minute – call G21 and it will display mm/min, call G20 and it will display in/min. This makes more sense because most machines are rated in in/min. I didn’t think 2cm/s was fast until I converted it and realized I was running almost 50in/min. Not bad for a hobbyist!

Look-ahead Optimization
Let’s say the machine has to draw 5 lines in a row, all in the same direction. In the past the software insisted that the machine come a complete stop between each line segment because the software had no idea what was coming next.
In the latest version the software stores the next several lines in a ring buffer and plans ahead: if the lines are all in the same direction it doesn’t slow down. If they are on a slight angle it slows a little. Anything 90 degrees or more is an automatic full stop.

A generous user on http://reddit.com/r/singleline/ created a new “Hello World” vector that I’ve been using to test and the results are fantastic! Using the old method it took 11 minutes to draw. In the new method it takes only two!

At this point I feel the software is “good enough” and I’m going to focus on pen up/down.

Uncategorized

How to Drive the Drawbot Manually

2012-03-26 Dan

Draw > Start Driving

Click+drag in the Preview window

The black line is your speed and direction.  The red circle is your top speed.  The green circle is the dead zone.  If the black line is inside the dead zone, the robot won’t move.  If the black line is on the edge of the dead zone then it will move very slowly.  In the picture above, it is moving at about half speed down and to the right.

Tutorials

How to convert SVG drawings for Makelangelo

2012-03-26 Dan

So you want to prepare SVG drawings so they can be drawn on a Makelangelo.  Nice! Scaleable Vector Graphics (SVG) are an great way of storing images as lines because they can be made bigger or smaller without losing detail. Since the Makelangelo “thinks” in lines, they are a natural fit together.

Inkscape: create your art

Inkscape is a free vector drawing program that loads a ton of file formats, including Adobe Illustrator.  You can use it to turn a photo into line art or sketch something totally new. I used this picture of Darth Vader for this example. (Please support them to show your thanks.)

Darth Vector
Darth Vector

Inkscape: Ungroup

Select everything and choose Object > Ungroup. In some vector images you might have groups of groups of groups, so keep going until the Inkscape status bar says “N objects selected of type Path in root.” Fortunately this Darth Vader image is pretty simple and only needs one Ungroup command.

Inkscape: File > Save As > Desktop Cutting Plotter (AutoCAD DXF R14) (*.dxf)

This is another format well respected in the machining communities.  It is used by everything from Automatic quilting machines to CNC lasers to robot arms. Makelangelo software added support for DXF files in ~2014

Makelangelo: Convert > Open File

You should now see your picture on the screen. The picture will automatically fill the paper as much as it can.

Here you may discover a catch: SVG files can be made from many overlapping shapes, with junk hidden under the top-most layers. When you ungroup and save as DXF, the DXF file will have all the lines. The Makelangelo has no idea what lines are supposed to be on top, so you might need to clean up the vector file in Inkscape before you send it to the Makelangelo.

Makelangelo v7.2.9
Makelangelo v7.2.9

Makelangelo: Start

And that’s it! Much easier than pre-2014 when DXF files needed a lot of massaging.

So where do I get a Makelangelo?

Final thought

I’d really appreciate your feedback about this tutorial.  Please comment below with your questions and I’ll do everything I can to help.