One big step closer to good dual extruding!

So the up’s and down’s of 3D printing roll onwards, and experiments to find a good dual extrusion set up continue to be not yet at a conclusion, but some interesting and promising happenings have occurred along this journey…

Last post I had just installed the Micro-Swiss Nozzles, but I had found that, if anything, I was getting worse prints! So I went back on the Google forums to ask the collectives opinion on this new install.  A solution that got the print quality back up to scratch came from a most helpful usefully guy by the name of Jacco (thank’s Jacco!) who had this to say –

‘The stock nozzles on Wanhao printers are 0.4mm, going to a 0.6mm will reduce the details . Further, you will need to set your slicer to the new nozzle diameter (to accurately calculate tool paths, so that the lines do not overlap).

Some guide to help with layer height: You never want to print at lower than 1/4 nozzle diameter (for 0.6 it is 0.15mm), and higher than 3/4 of the nozzle diameter (for 0.6 it is 0.45mm), with the normal at 1/2 nozzle diameter (high quality, low quality and normal quality respectively).’

So, in the MakerBot software, via selecting my printing setting profile (Edit in text editor) in Notepad++ (side note: If you don’t have Notepad++ search for it and download it! Way better than the normal notepad, and free) I scrolled down and changed the setups for both print head –  “nozzleDiameter” from 0.40 to 0.60. I found that this fixed the problem and the prints are now good. I also found that it was printing just fine straight onto the blue tape with no need for my usual double sided tape.

Nice clean prints. No raft or adhesive required!

So the question is: Are the Micro-Swiss 0.6mm Nozzles an improvement from the regular nozzles? Well, it’s hard to say with certainty just yet, a least until I really get  working regularly with them, but I will say that loading and unloading filament does work better, with no jamming as before, and the prints are good quality. It is a shame that now the minimum I resolution I can print on is 0.15mm, up from 0.01mm, but to be honest I rarely print smaller than 0.2mm for my prototyping. So this may not be a big issue for me personally.  I guess you pay your money and take your choice. As my printing continues I shall let you all know my further opinion on the matter.

So back to dual extruding…

It’s been interesting. On the right print head I printed the PLA, and on the left the HIPS as support structure. I also tried adjusting the nozzle retract rate to 2mm and made sure the travel speed was set high at 150. What I found was there was no oozing at all with the HIPS, yet the PLA, although there was an improvement, was still oozing and creating the stringy mess.  Now, reading around the web I have found that the retract rate is not the be and end all of preventing oozing, as gravity will always pull the molten PLA downwards, bit it is a factor.  Keeping the travel speed up is more important.

Subsequent to this my right print head overheated due to the thermocouple being damaged (again!) so this must have affected the PLA. It is interesting that the HIPS did not ooze.  So, maybe the new nozzles and settings are good and the problems may have just been due to mechanical errors? After I fix this I shall try again. I have hopes that I may be on to something here.

On a final note, I had to change the left D4 Motor Cable – 110cm cable for the motor, as  there is some ware and tear on the wire, so creating a banging noise during prints and creating  irregular lines . This involves unclipping it from the top of the motor on the top and doing the same on the motherboard. Very simple to do –

It’s easy to unplug the D4 Motor Cable from the motor.
2016-04-15 15.09.31
Motherboard location for the D4 Motor Cable (Top – B-STEPPER)

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So watch this space as dual extruding experiments continue!