Thursday, March 20, 2008
More Nose-Wiping Action And A Boo-Boo
I've upgraded to the latest code (SVN #1428 at time of writing), and rediscovered why we're turning the extruder on and off a lot. In this video we see the extruder nozzle go to my hand-made Meccano nose-wiper, nicely clean itself, then shoot off on the Y axis at X=0. After turning on its extruder feed, the nozzle builds up a nice thread of goopy plastic en route to where it really should be printing, and wipes it off on the workpiece. Charming.
Finally, after printing out a Y motor bracket looped with festive decorations, the RepRap software drove the Z axis back to zero, pushing the workpiece through the cooling fan and kindly lowered it again to show off the damage. Did someone say holiday? Oh, good.
Vik :v)
Finally, after printing out a Y motor bracket looped with festive decorations, the RepRap software drove the Z axis back to zero, pushing the workpiece through the cooling fan and kindly lowered it again to show off the damage. Did someone say holiday? Oh, good.
Vik :v)
Labels: bad, nose, nozzle wipe, reprap
Monday, March 17, 2008
Nozzle Cleaning Part Deux
RepRap doctor blade in operation from Adrian Bowyer on Vimeo.
The doctor blade I blogged below is a sharp V notch which you run the extrude head over once to clean it. This works really well, but the extruded junk builds up in the V. So this little lever, nudged by the extrude head before it cleans itself, cleans out the last bit of extrude junk. As you can see, this one is made from bits of scrap plastic. We'll ad an RP version to the RepRap design soon.
Labels: nozzle wipe
Saturday, March 15, 2008
Doctor blade
After looking at the cool stuff nophead is doing, and stealing an idea from Ed, I have improved the nozzle wiping on my RepRap considerably.
The picture shows a doctor blade cut with scissors from brass shim. It has a V notch that the extruder uses to discard excess extrudate.
I have upgraded the Java code in the repository to use this type of wiper, which works better than the previous toothbrush-wiper blogged a few days ago.
Tricks: make the V angle very acute, and curl the profile down slightly so it comes up to meet the nozzle as the nozzle moves over it. Also take care to align the nozzle with the very centre of the notch when it does the wipe.
We still nead a way to clean the cleaner, I think. As you can see, lengths of extrudate build up in the notch and are going to cause trouble eventually.
Labels: cleaning, doctor blade, nozzle wipe
