Small Print Errors

Hello Everyone,
I purchased my MakerFarm Mendel Prusa and have been trying to get it working properly for a while now.

The beginning part of this print was a little shaky as leveling my print bed has been a difficulty for some time now. I am looking at a method to auto-level via non-mechanical means so it is reliable and will not suffer from break down. I will pursue that topic here:
[forums.reprap.org]

The only perplexing part of my print jobs are two fold,

1, the little bubbles all around my print job, anyone know what causes this?

2. When I finish a print job off that has either a dome or point the printer can not seem to finish the print off very smoothly.

I have included pictures of both of these problems.

Thanks guys!

[EDIT]
Forgot to mention that I am printing in ABS.
[/EDIT]

Edited 1 time(s). Last edit at 04/08/2014 04:12PM by mrburritoman.

---

MakerFarm Prusa Mendel
-PrintR Board
-Z Stabilizers
-Greg's Accessible Extruder
-Mk1 Heatbed under Glass using ABS Slurry
-J-Head Mk IV-B Hot End 0.35mm
-3MM ABS Filament being used.

About the weird top and bottom do you have a fan blowing on the print during these stages?

Iam also tuning my printer and got weird top segments if my fan whas blowing to fast at it while printing the top segments and seamed to cool the pla to fast?

And I recently learned to turn of the fan for the first layers to get it to stick and print properly there that also gave me weird prints.
I get better overhangs if I have the fan only blow slightly at the object while printing.

Iam currently experimenting with a wide brim at the bottom to get my print to stick to the bed.

There is my current problem but I got the same top and bottom as you before when I had to much cooling there.

Its extremely tricky to get good prints

I forgot to mention this but I am printing in ABS.

I have no cooling fan on my printer whatsoever. I read in some places that a fan helps these problems and have thought of adding one but have also read in other places that having a fan is not necessary for ABS.

---

MakerFarm Prusa Mendel
-PrintR Board
-Z Stabilizers
-Greg's Accessible Extruder
-Mk1 Heatbed under Glass using ABS Slurry
-J-Head Mk IV-B Hot End 0.35mm
-3MM ABS Filament being used.

The blobbing on the sides is probably due to retraction settings. Try increasing the length of retraction a bit more and/or retraction speed.

I have noticed this on my previous printer. What I believe the issue was, is there is a slight amount of double heating on filament just before it's about to be extruded it's gets pulled back in and then forced out at a higher temperature, it basically bubbles. My solution was the increase the heat on the hotend by 4 degrees Celsius, that sorta worked, but I added a higher retraction speed to this and it gave me better corners and better results.

When my printer was nicely heated up and running for around 5-10 minutes that's when it was giving me great prints. I get my printer now to loop at least 1 time around the print area just to get the flow and to make sure that the filament isn't cooling down the extruder to fast.

---

Larsen -
____________________
Creative Shift Workshop

It looks like several things that you have going on.... one your extruder is not close enough to the bed, you need to get it closer basically you should be able to do the paper test, bring your z axis to the home position you should be able to slide a piece of paper under the hotend, and feel a slight drag on the paper but still be able to move it. that should take care of the bottom portion of it, as for the top of your print not being finished you can try playing around with the extruder multiplier in your slicer. As for the surface blemishes you have going on looks like it is caused by improper storage or contamination of your filament. Your filament should be stored in a vacume bag, with a moisture absorber i.e desicant.

Edited 1 time(s). Last edit at 04/18/2014 05:21AM by Osios.