Friday, January 09, 2009
First Print – Version 3.0.0 Laser cut machine!
The version 2 machine I have been testing ground to a halt a couple of weeks ago. Cause of the failure was worn out brushes on one of the two motors used to drive the extruder. Not too drastic a failure considering that I have used the same two motors on my extruder for months.
The failure took out the FET controlling the motor so the whole print head has had to come off the machine for repair.
I have been working with Bits from Bytes to develop Version 3 of the Laser cut design so this failure seemed a good time to make the switch over to the new machine. Ian at BfB has done a tremendous job with the update, particular credit should go to his new design extruder and improved drive systems. I will leave it to Ian to fill in the details over the next few weeks. Bear with him though, his priority at the moment is to get production going.
In addition to the mechanical changes, I have worked with Ian to produce a set of electronics based on the PIC32/SD card solution. Ian has taken the PIC designs and produced two new boards for the machine, one for the main controller incorporating the stepper drivers and SD card, the other, is a small board for controlling the extruder with serial coms connecting the two.
Initial results are promising, very close, if not as good as the prints from CNC Mill solutions. The stiffness of V3 is far better and you can see this in the print, V2 was good but the extruder head was able to move a little causing a slight ripple in the printed filament(see the magnified image in my blog “PLAy time”) Contrast this with the latest result from V3, we now have a very clean print at double the speed!
The Print is in ABSTemperature 240DegC (measured at the nozzle)
0.5 Dia Nozzle
Printed direct onto MDF with no raft (Not easy but possible!)
I think this cup would not need a raft because the surface contact area is already large and flat?
Any chance you'll be posting your code? I'd be curious to see how it all fits together.
I am not sure what is happening with the code, I tried to get parts of the PIC solution integrated into the core project but development along these lines were rejected as not open source enough and that going back to a PIC solution was never going to happen. Both Zack and Forrest went to great lengths to detail the longstanding politics for going down their chosen route. I don't have any issues with those reasons but equally I was not ready to give up the work I have done then fall in and learn what would be a new platform for me. I am therefore resolved to play on the fringes much like Nophead( and no doubt others) and maybe continue to feed in a few details of my experience as appropriate.
Another complication is a large chunk of the source(FAT32 system for the SD card) is supplied by Microchip and I had to agree to their terms before I downloaded and used it.The Microchip terms are along the lines of not porting the source to any other manufacturers chip. I would not be able to distribute any Microchip source so it would be for others to download this code and agree to the Microchip terms.
The project is based on the PIC32 and as such is of little use to 8bit processors. Even if you could port the code, it is way to big to fit on one of the Arduino/Sanguino solutions. The project was developed without reference to anyone else's code so I have no idea how much there is in common with the core software/firmware. The project has never been directly connected to a PC and only runs from SD card so again, how you would run it with ReplicatorG or Java script I have no idea.
The main control used is a Joystick, plus the file system and remote nature of the machine requires it to have a complete interface to set and run the machine. As far as the extruder goes, I have used another PIC32, I admit this is overkill for the relatively simple tasks that the extruder has to do but what I do know is that it has resources for anything that I could possibly want to do. Both the main control and the extruder are now running OLED graphic displays, I don't think the Arduino or Sanguino have the pins spare for this activity.
Just to finish off, the complete solution forms part of the new V3 Laser cut design from BfB and this is to be distributed through Unimatic so I would need to see if there are any commercial issues with code release. I am not saying it will never be released, only that its not quite so simple and for those running Arduino/Sanguino electronics it would be of very limited, if any use at all.
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