Saturday, June 30, 2007
Printing the night away
Heretofore, Slice and Dice has been a once-through routine that simply takes a STL file of an object that you want to print and slices it at a given thickness and creates a STL print file that can be used in the Tommelise Control Panel. While it gives a graphical display of what is going on while it is processing I typically haven't got the patience to sit down while it grinds through 30-40 slices.
Since I haven't been trying to do anything too complicated printing out a layer or two to check to see if anything is amiss has been no big deal. With more complicated object, however, you are talking about 15-20 minutes/layer. That's slow. What I needed is a simple graphical method of displaying a print layer-by-layer. I'm not trying for anything as grad as what Adrian is doing in Java, just a 2D display of a slice or several slices so that I can see how the infill is fitting together.
Here are two overlain slices of zone two of a polymer pump that I designed in Art of Illusion. This cheap little bit of code is letting me spot problems in a layer without having to spend half an hour watching Tommelise print. Once I can see where they are it is a relatively simple matter to edit them out of the XML transfer file.
Can you see the problems in this view?
Just as a matter of interest, though: why cross hatch in that direction though? Why not horizontally and vertically?
Eric: I did two layers this time. I'll be showing the range as soon as I get a moment to work on the GUI.
Diagonal cross-hatch lets you use both the x and y axis motors which meant that you get an aggregate speed of 2^0.5 times what you would get with only one axis.
Right now I get 1.7 mm/sec on one axis. When I use both I get 2.4 mm/sec. :-D
If and when I decide to shift over to 3/8-16 studding from the 3/87-24 that I'm using now my diagonal speed will push up to 3.6 mm/sec.
Mind, since I'm using HDPE with a 50% infill which I can get by with because of its strength I'm getting effectively twice that speed.
If your one-axis speed is a limit (although I agree with Vladimir in that I'm not sure how it could be) why not turn the whole part diagonal-wise as you print it, and make the whole thing, crosshatching and all, 45deg from the axis?
Kyle: If you rotate the object 45 degrees you are able to extrude the perimeter faster but you've translated the infil into pure x and pure y movement. That slows down the print dramatically.
Kyle's point was that you can rotate detail 45 degrees _and_ make cross hatch parallel to the sides.
(And even extruding 45 degrees-turned detail according to your interpretation wouldn't slow down extrusion if you make traces sparser as per my first point.)
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