Finally a follow-up regarding the upgrading currently happening to Plan B. I was sick for a week, so stuff happened slowly.
Plan B is now capable of printing at 150mm/s. This is due to the new controller, the Arduino DUE, and a few modifications to the firmware. Not only the increased speed of the controller is used. Also the massive amount of RAM memory is being utilized. Because the buffer is now 1000 lines big, an entire sweep can safely be stored in the RAM. Now, I do not have to read the SD card during printing. The SD card is read after each sweep is done. This means no interruptions, and this is very noticeable. Before, you could hear clicks in the X-axis movement when it was printing at speed, now, not any more.
First, the video how it was (start at 32 seconds), then, how it is now.
Also, I got around to upgrading the spreader. It is now rotating. I already had the design ready since the original Plan B, but I never got a way to fix the tube to the axis. I now have a system with a 3D printed holder (pictures later) with grub screws to adjust it. It takes some time to adjust, but it can be made on a 3D printer. It doesn’t have a drive, it has a wire that runs across the way. There are 2 guide pulleys that guide the wire once around the spreader. I haven’t printed with it yet, but it seem promising.
Time for more upgrading