Eight New Features

January 19th, 2016 by Nick Williams

We are planning a new release near the beginning of February. The last release addressed a number of usability issues and a few bugs specifically the serial communications. The next release will have eight new features and a handful of bug fixes. what follows are the details of these eight new features.

1) Path Optimization

2) Vector Highlighting

3) DXF File Support

4) Firmware downloads to the controller from ObjectWorks Software

5) Relative / Absolute option on both vector and image files

6) Reciprocating vector cutting, will allow to cut thick material by moving the laser down for each pass.

7) Pixel streaming for image rastering (Turbo Mode).

8) Y Scaling for image rastering, allows you to have a greater pixel resolution in Y as compared to the pixel resolution of X.

Path Optimization:
Currently the software randomly moves from one line segment to the next for vector paths defined by SVG files. Currently we are using the order defined by the original SVG file. This is horribly inefficient because of the extra time consumed in doing none cutting moves from one line segment to the next. We have implemented an optimization sorting routine for determining the next line. The feature will significantly reduce the time for doing vector cutting.

Vector Highlighting:
When doing vector cutting from svg files we select the strokes as colors from the left hand side. It may be difficult to determine the actual line segments that are effected by selecting a given color. The problem arises from multiple causes, over-lapping lines and similar colors are two of the most common. To make this easier for users we will now highlight the lines on the art work based on the currently selected item in the grid based on the color. This should improve ease of use.

DXF File support:
DXF files are now supported for doing vector work just as SVG files are supported. We have tested with QCad and Auto Cad both work well we have also tested with OpenScad and these file are not able to be imported. I expect that by release we will have it working 95 % of the time but it may take another release of so to flush out that last 5 percent so be patient with this feature.

Firmware Down Loads:
With the next version you will be able to update your controllers firmware directly through our the Objectworks Software. Additionally we will be able to post firmware updates for download over the internet.

Currently vector files are rendered in an absolute mode. This means that vector files are moved on the virtual deck inside of the software and this is were we do the cutting. On the other end of the spectrum image files are rendered in a relative mode meaning that the current position of the laser becomes the lower left hand corner or upper left hand corner depending on your machine orientation. There Are merits for both strategies depending on your work flow so we are going to allow the user to define each job to be relative or absolute for either images or vector files. This will include the ability to move images.

Reciprocating Vector Cutting:
This feature has been requested from the community and I think it is a great idea. Basically the problem we are attempting to solve is the ability to cut thicker material. The idea is to focus the laser on the top of the material do a pass then lower the laser some step down distance and repeat the operation. This is continued until the material is cut. This is a slow process but greatly increases the material thickness that we are able to cut. There are limits to how well this will work. If we try and focus the laser too far into the cut energy is transferred into the walls of the cut reducing the cutting power. There have been a few of you who have done this by hand modifying the GCode, the software will now support this ability.

The last two features are designed to address a specific problem related to the performance of grbl in relation to image rastering. The modification that have been done to the firmware allow us to plan laser power changes in relation to the machines movement in the X axis. The smaller the pixel spacing the faster we need to move to compensate for over burn issues. So theoretically we can reduce pixel spacing and increase the feedrate to get better contrast. Of course we run up against a limit were we are sending GCode block faster then we can process them I have found that limit to be about 0.35 mm @ 1100 mm/min. This is floating limit for example you can easily increase the pixel spacing to 0.5 mm and go 1300 mm/min and inversely if we drop the pixel spacing to 0.2 mm then 1100 mm/min would be to fast. The effect of pushing this limit is that the instrument stops mid line when there are no more GCode blocks to process. After these stops the instrument must ramp back up to the feedrate this results in a blotchy images. The next two features are designed to increase image contrast and to work around this limit.

Y Scaling:
So we have a fixed limit that we can space pixels in X as we do a single raster line based on the feedrate. Currently each line that we traverse down is spaced symmetrically according to the pixel spacing. With the next release of the software you will be able to scale the Y spacing based on dividing the pixel spacing by (1,2,3,4) this will allow us to increase contrast without exceeding the limits that grbl can handle, This also allows you to remove the line effect.

Pixel Streaming:
This is a major advancement and has required a custom GCode block. With this feature the whole raster line is sent as on GCode block the controller is put into a special mode where pixels are streamed. The software to generate these new blocks is done but the firmware still has some issues. In early testing I have been able to achieve feedrates of 7000 mm/min at 0.01 mm pixel spacing if you do the math this is about 2500 dpi:-) There are a number of issues I am still working on in the firmware but the software to generate these streaming blocks is done. My plan is to release the this feature in the next software release(Note: will not be complete without the firmware update) then in mid to late February will release the firmware update.

Thanks for all your support

Blog Coming soon

September 25th, 2014 by Nick Williams