Allow faster bitmap moves

[pbrier]

Bitmap marking moves may be faster than the normal engraving moves,
as usually only one axis is involved, and this axis is faster than the other axis.

Now the speed is calculated relative to the axis speed (xspeed) instead of speed.
The axis speed configuration parameter (x.speed) can be set higher in the config file than the general speed parameter (motion.speed).

[pbrier]

Download firmware here: http://redmine.laoslaser.org/binaries/master.fbcd2b0-dirty.bin

[pbrier]

make sure you add x.speed and x.accel in your config file, and set them to sane values.

x.accel: typical 1000 to 10000 mm/sec2, (lower if it skips steps)
x.speed: typical 100 to 1000 mm/sec (lower if it skips steps, or quality is bad)

[peteruithoven]

Great work! I'll test it soon.
Is this version build with the new compilation method and new libraries? In other words, should I also briefly debug the whole system?

[pbrier]

No currently the GCC4MBED route is still used.
There are some issues when using the latest mbed libraries.
Please use the GCC4MBED route, with the referenced MBED library revision when compiling.

[peteruithoven]

It looks like I was able to independently increase the speed for engraving. But it looks like our small lasercutter just won't get very fast so it's hard to know for sure. When the bigger lasercutter is free I'll try it on that one. No big issues though.

[peteruithoven]

Seems to work nicely!
I engraved the following image in 1min and 9 sec.
200 dpi
5x5 cm
with:

x.speed 1000 
x.accel 10000 

The movement is a bit weird, some horizontal movements go quicker than others...

Fablab Amersfoort is grateful

[peteruithoven]

In the end I used:

x.speed 1500
x.accel 12000

But again, there is something strange happening during acceleration or deceleration. Using the closed source contoller it moves a bit more consistent.

[pbrier]

Describe "strange"
Does it jerk during moves, or just waits between some moves?

[peteruithoven]

It moves irregular, not consistently. Some horizontal movements go slower than others.

It happened much sooner on the smaller lasercutter, maybe I'm just on the limits of what the motors can handle.

On the smaller lasercutter there sometimes was a slight deceleration 1/3 of one movement to the left.

[peteruithoven]

Watch out with the settings. I set the speed and acceleration so high the whole lasercutter was reset because it was probably asking to much power. I noticed this while engraving wider images. So a good test is to engrave an image of 20 cm wide.