On 7/17/20 6:03 PM, Gene Heskett wrote:
> ...added 5.00 to the extruder feed, and gave it another go.  After 
> 4 restarts it laid down the first two layers of a raft, with no missing 
> lines and only one little bump, all while running at 20 lb paper 
> clearance, so the lines it was laying down were about 50% coverage, but 
> no missing gaps because it ran out of PLA.

Rather than adjusting the extrusion rate to get a good first layer at
the nozzle height you used to level the bed, I'd first calibrate the
nozzle to extrude the correct amount of material.  Andy described how to
do this earlier in this painful saga, where you mark the filament 120mm
back, have it extrude 100mm of filament, measure how much filament it
actually extruded, and then adjust the extrusion multiplier until it's
extruding 100mm.  Once the extrusion rate is properly set, leave it
alone.  Fix the first layer adhesion by tweaking the nozzle height using
the bed leveling nuts, or by adjusting the first layer height and/or
first layer extrusion multiplier in Cura.

Your 3D printing experience has been needlessly difficult.  Maybe the
default settings were grossly incorrect when you received your 3D
printer but that's very rare these days.  Most people don't mess with
the basic settings.  Most of us get a new machine, level the bed and
start printing.  There is generally a little bit of a learning curve
getting good first layer adhesion on your first 3D printer, but none of
the ongoing problems you've experienced.  That sounds like hobby 3D
printing ten years ago when the burden was on the hobby builder.  These
days, 3D printers are built in factories and are almost consumer
appliances with no need to adjust basic settings.  It's as if you bought
a new car and it idled rough so you are building your own engine
computer to fix it.

I'm cheap, but I've learned that there is value at every level and it's
usually the case that saving that last 10% is a negative value
proposition.  I buy low cost items but usually not the lowest priced
item, particularly on something as complex as a 3D printer.  I don't
want to spend $220 on a 3D printer that was built in small numbers by
people with little experience with 3D printers, who may not have
configured it properly, used the very lowest quality components with no
warranty or customer support, when I have a much better experience by
spending $30 more.  If I need to spend $150 and three weeks of my time
fixing problems, saving $30 was a bad deal.

I just finished 3D printing 4kg of ABS parts for a small production run
for a friend.  I did have two clogged nozzles but those are now an easy
three minute one dollar repair.  I put another 3D printer into service
in my small 3D print farm and the set screws backed out in an X axis
idler pulley so I had to fix that.  I'll Loctite and properly torque the
set screws on all of my 3D printers to avoid that failure in the
future.  Otherwise, that 430 hours of printing those 132 parts was
pretty much a matter of picking a part off the glass plate (they self
release when cool in 15 minutes), adding a tiny amount of glue juice,
distributing it on the glass plate with a nylon bristle brush and
selecting Print Another Copy.  Once your 3D printer is adjusted
properly, hardware and software, it should be reliable.

I'm getting better with FreeCAD and I always preview the job using
Simplify3D after slicing it.  Cura allows previewing too, so you can
ensure that it's printing what you want, the way you want it to print.

I hope your 3D printing becomes a lot easier and a lot more fun soon,
Gene.  It shouldn't be this difficult.  I wish you could start fresh
with a known good configuration.

The only time I use a raft is when I'm printing a large number of very
small parts with little contact area on the build platform, where any
part that failed would ruin the entire print job.  Glue on glass makes a
reliable first layer adhesion with ABS, PLA or TPU.






_______________________________________________
Emc-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/emc-users

Reply via email to