Daily Print Sagas

[TommyDee]

I thought I start a topic with our daily print successes and failures.

Share yours here.

[TommyDee]

Yesterday I tried to print the Yoda using ABS at 70um. Turns out the supports generated by MeshMixer were not strong enough to support the ears.
However, the actual bottom facing surface generated a real nice contour with minimal supports.
I stopped the print when a piece went flying across the room.
The supports broke away very nicely.
The ABS was Neon Orange and where the supports broke away, it left a white stress mark.

I did learn a new trick. Where you do have discoloring from stress, I found a nice flameless torch that solves these quickly.
It is called a Micro-Torch by Mag-Torch model MT-765 C (and several others). I found this one at ACE H/W.
It uses a ceramic catalyzer that glows read-hot from butane but no flame.

[TommyDee]

And also yesterday, I had a cartridge go from fabulous to fail between two prints.
This is a PLA color Coral that has been a very nice extruder after I originally replaced the feeder mechanism.
This spool had 40% remaining.

I don't know how, but somehow a bunch of black sticky goo made it to the nozzle.
This tar was coated on the outside of the plastic tube that goes into the metal extruder tip.
No matter what I did, this was permanent! Where did it come from?

I tore the whole mechanism apart only to be thwarted at every turn to make it work.
I wholesale replaced the entire feeder with a known good Neon Green setup and all works like a charm.

So, what introduced the black tar?

[TommyDee]

Ever notice how ABS curls from the heat after being deposited?
Ever notice that after a while, it prints to the outside of the previous pass?
Incomplete cooling shows up in many different artifacts in your prints.

During the summer, I noticed a lot of little issues due to insufficient cooling.
And I came up with this little gadget:



The snorkel is just pushed into the pancake style fan. The wooden strip is 1/4" x 1-1/4".

There is a little rotating height adjuster. This has to clear the tray at the tip level.

During the hot days, this really did the trick.

However, as it is cooling down a bit and the house is more consistent temperature-wise, I find a lot more good prints with no fan.
I can remove the snorkel and have a broader airflow for ABS. I can even move the fan back away form the machine.

I did have an ABS print failure due to the thermal error when, I assume, it couldn't keep up the nozzle temperature.

I wonder how well these things would do in a fridge at say, 60F.

[bolsoncerrado]

What a cool idea indeed Thanks for sharing! Will post on the wiki! Or you can do it on your own as well

Mind sharing the files @TommyDee?

[TommyDee]

Of course, but you'll need the same fan. Still available on eBay.
I'll have to do the write-up to make this make sense.

Also need to figure out the storage limits here.

[TommyDee]

My poor printer got lonely... but it was being punished.

I had the black goo problem with a cartridge that had; a) replaced extruder assembly from feeder because the original one probably came from the proto-shop. Wholesale replaced! and b) whatever the black tar was that they used to hold the needle on the tube (probably an attempt to quit shooting tips across the room during assembly...) ends up working it's way to the tip, where is never clears. That was the green sample I sectioned in the other thread. I wholesale replaced -again- the entire nozzle string.

So yesterday I printer this... and it behaved very nicely... again.

70um ~1.5" high feeble settings

[TommyDee]

4 STL files in the a zip.

The wooden strip is 1/4" x 1-1/4" trim from Home Depot

the fan is Matsushita Electric FAL6F12LH

It puts out some air and can easily operate at 15V for more.

You can probably find 5V and 120 versions of this fan if you try.

eBay seems to have a lot of them. I got NOS for under $10.

[TommyDee]

This weekend I made some engineered pieces to use in a design review.

I learned a few things;

1. The initial pattern has a lot of small enclosed supports. These tend to clog the nozzle from the constant pumping action. It never really gets a chance to clear out the soft pre-melt that is being pulled back. Eventually, this gets too thick or hard to continue into the extruder. This is when the dreaded click begins.
* A solution that helps is to make a single wall surround... anything that doesn't fill but extrudes enough plastic from the previous layer to work on a new fresh section of the filament.

2. Build your own supports. The part has to be split in two. The part on the build plate has 12 each 1/2 holes. Inside each hole I place a small "block" that extended past the hole on both sides. I left about .01" clearance between the semicircle of the hole and the blocks. At the end of the print, they broke out easily.

3. The printer glue is a very nice glue for joining pieces. Just put it in a small syringe. Just make sure your hands are dry when handling the parts.

[bolsoncerrado]

Re 2. how do you build your own supports? and feed them into the printer i mean.


For 1. i miss the "brim" option from other softwares, yes. I hope someone will come to a 1 step solution for converting simplify3d files to .cube3 files