Questions and Topics from Club Members

Good Afternoon,

At the University of North Florida 3D Printing is in its infancy. I am the founder of its first 3D Printing Club and in the past three months tremendous leaps have been made but soooo much more needs doing. I am printing as we speak and have been printing now for a week non-stop and I would like to ask some questions in one post which could provide both myself and other new comers a valuable source of information in one location.

What is the difference between the size in both hot ends and extruders? I.E. .35 mm j-head vs .50 mm and 1.75 mm filiment vs 3.0 mm.

A lot of the prints I have been trying that have gaps and bridges have a lot of DRAG. You know- when the plastic strings accross the print as the etruder head jumps. I have done a lot of different prints adjusting the verticle clearence between the hot end and the bed as well as changed the flow rate and speed. I printed 3 of the thingiverse stl of winterfell and they were all about the same- this is with a .50 mm J jead with plactic assembly housing and PFTE tubing.
So- Would I have cleaner prints with less drag using .35 mm? Or a 1.75 mm hot end? I am going to buy a full-metal hot end any day now and would like to know how this effects "clean" prints- less blobbing, higher small detail capability ect.- also where is the most reputable place to purchase an all metal extruder?

Also- supports. In Slicr cnfig 9.9 when I try to print, say, a lion from the chicago muesuem I have to use supports. Only when I turn on supports in Slicr printer settings on the print is basically immersed in supports so you cant even see the lion let alone cut out all the solid support walls and get the ridges left over- it looks super crappy. How can I manipulate support settings or change the way in which the printer does them? Like small cylinders instead of thin rectangular walls the length of the print which is what is currently hapening. Also, how do you clean the supports left over on the surface of the print? Acetone bath and stiff bristle brush or something?

Other than that I seem to be able to get decent prints but if I was to want really nice looking prints for say- printing the 600 mm eiffel tower- what would I put my settings in SLICR to besides .1 mm. and could someone please provide a link to an explanation of the print settings, filiment settings, and printer settings SLICR uses so I know when and what to use why. As of now I have not changed anything ecept layer height because I do not know why I should change anything else let alone what it would do.
Perimeters, solid layers, fill density, fill pattern differences, pattern spacing, extrusion multiplier, retraction, ect.

I think this will help myself and a lot of other club members here in Jacksonville. We really need to get this down over the summer so we can provide the most epic and awesome club possible come fall semester!

Thanks Rep Rap!
-UNF3D

---

[www.facebook.com]

hi,

Quote

You know- when the plastic strings accross the print

have a look at the extruder setting in slicer you need to alter the retraction setting . .8 worked well for me with a jhead printing at 180c.

I will change that setting and redo a winterfell print to compare the results. Thank you for the reply!
-UNF3D

---

[www.facebook.com]

Quote
UNF3D
What is the difference between the size in both hot ends and extruders? I.E. .35 mm j-head vs .50 mm and 1.75 mm filiment vs 3.0 mm.

.15mm and 1.25mm respectively. You're at a university? That's like 2nd grade math.

Generally speaking: Nozzle diameter is directly related to extrusion speed/volume. As nozzle diameter goes up, extrusion speed can go up. But nozzle diameter is inversly related to horizontal resolution, detail, and finish. As nozzle diameter goes up, extrusion speed goes down but resolution, detail, and finish go down. It's a very broad generalized statement and I'm sure someone will be along to argue that they can print better at .5 then .35, or faster at .35 than .5. And it depends on what material you're printing, what exactly you're printing, desired quality, etc blah blah blah. But the general idea is that the .5 can cover a larger area, but doesn't have as fine of detail capability as what .35 does. Think like if you're coloring in a picture with broad markers or fine tipped markers. You'd get done faster with the larger, but you have less control than with the finer.

Filament diameter is personal preferenece mixed with printer capabilities. Smaller diameter filaments can make direct drive easier or allow for more compact extruders. At one time 3mm was cheaper than 1.75 but anymore they are usually close in price if not the same so I'm not sure how much that's a factor. Given the same gearing and drive mechansim diameter, smaller diameter requires faster turning of the motor to match the same output extrude volume. But smaller diameter also can give you more control over the flow and having a smaller volume melting zone in the hot end. Any more for most printers I think it's just a personal choice.

Quote
cdru
As nozzle diameter goes up, extrusion speed goes down but resolution, detail, and finish go down.

Check it- As nozzle D rises so does speed, quality lowering; vice versa.

Quote
cdru
Filament diameter is personal preferenece mixed with printer capabilities. Smaller diameter filaments can make direct drive easier or allow for more compact extruders. At one time 3mm was cheaper than 1.75 but anymore they are usually close in price if not the same so I'm not sure how much that's a factor. Given the same gearing and drive mechansim diameter, smaller diameter requires faster turning of the motor to match the same output extrude volume. But smaller diameter also can give you more control over the flow and having a smaller volume melting zone in the hot end. Any more for most printers I think it's just a personal choice.

More turning for the same distance=more control over flow. Filament diameter is pretty much the same as nozzle diameter, smaller is more control, larger is faster. But filament diameter is much less something to look out for in detail, namely with wade's gears/etc. I like 1.75mm filament because I like accuracy over speed. I mean, with how little the extruder motor has to work for filament distances using 3mm for speed is pointless since 1.75mm can easily keep up with the other mechanics of the printer.

Edited 1 time(s). Last edit at 04/23/2014 05:07PM by MrDoctorDIV.