Print Consistency Across Different Material Problem

[JoshiTravels]

Hi all,

I cant quite think how to describe the problem im facing, so searching for answers is proving difficult!

I have a FlashForge CreatorPro that I am extremely happy with. I have also recently upgraded one of the extruders to the MicroSwiss All Metal Mk10 hotend in order to experiment with more interesting filaments than standard ABS/PLA.

I have a particular project I am working on of a small part - footprint the size of your thumbnail. In ABS and especially PLA this prints PERFECTLY.

However, when I change to Taulman Nylon Bridge or ForumFutura’s CarbonFil at their recommended settings the print quality just goes to crap - what was once a sharp cornered, perfect miniature model of what was on my computer screen is turned into either a stringy mess, a blobby mess, or a combination of the two with really poor layer adhesion - so bad I can literally pull it apart myself.

I have tried increment the temperatures by 5 degrees in the full recommended range and either side of it and no changes seem to have been made.

I am using ReplicatorG and do really want to upgrade to something a little better - considering taking the plunge with Simplify3d.

My RepG settings are:

Fill - 50-100% (at this size, seems kinda irrelvant)

No. of shells - 0 (small part)

Layer height - 0.28 (standard)

Feedrate (mm/s) - 41 (for ABS/PLA this is perfect)

Travel Feedrate - 56 (for ABS/PLA this is perfect)

Print Temp - 210 (pla), 220 (abs), Bridge (+/-250)

Bed Temp - 70 (pla), 110 (abs), Bridge (45)

So yeah - thats my question, can anyone help me identify the reason why a file that I know prints perfectly in both ABS and PLA, looks like a Picasso when I so much as glance at another type of filament.

Thanks in advance!

Josh

[Rhonal89]

Does it make popping sound when printing. If it does it must have moisture in it. That makes the print look ugly. Look online on how to remove moisture.

[PalmersPursuit]

My default S3D nylon settings are Ex 230 and bed is 80.

Bed covered in blue tape, then extra elmers glue applied to the tape. Keep the bed under 80 as the glue on blue tape wont handle much more than that.

Nylon likes to shrink so anything over 25% infill is going to have trouble.

The trick with nylon is to print at the lowest temp possible, increase the temp until you get good layer adhesion. I noticed when the temp is just perfect. The nylon will steam when sitting idle. Once the machine starts to extrude the steam will stop.

I generally find the best printing temp by preheating the machine. As the machine is warming manually feed filament into the extruder. This will allow you to find a good flow rate at the lowest possible temp. Temp settings will change based on the size of the part, If the parts are small, add a few extra parts, This will give the layers a chance to cool down before the next layer is applied.

Nylon bridge is formulated to capture the moisture at the outer layer and stop there. So steam is un-avoidable when filament is sitting idle in a heated machine. It also prints at a lower temp than PLA or ABS.

My recommendation is to the give up on Nylon and switch to PETG. It prints like PLA, Flexible as Nylon, and as strong as ABS. The only reason to use nylon in an FDM machine is for wear resistance.

I’m told carbon fiber will wear out a nozzle in one roll. (Ive only printed about 3 hours worth) . Is your carbon fiber ABS or PLA based. Use settings that meet the base material. I also found it was heavier than ABS, thus the extra expense for carbon fiber did not pan out.

[jarodtoups]

I have printed with both Taulman 645 and 910 with good results however the key for me has been to keep layer height around 150 microns (.15mm) and slow the speed 25-30mm/sec. The 910 is FAR superior in its printability and exhibits less shrinking when compared to previous generations of Taulman Nylons.

[Scramjet_3D]

Get your fan running. According to taulman you dont turn on your fan for their nylon when the part is larger than some 1.5cm3 i think it was. I had the same problem before but once i turned on the fan for those really small prints, such as a marvin, my prints came out well. Also if you’re getting too much crackling and bubbling, put the nylon in the oven at around 80 or 90C and let it bake for an hour or so to get rid of the moisture.

[wrbehel]

I’m new to 3d printing but if your shell is set to 0 what gives it the outside profile? From watching my printer it lays the shells and then connects the inside to them. The last shell always goes slow, which I assume gives it the clear definition on the outside.

[KuL3D]

Yeah, you definitely want at least one shell; I almost always go with 2 shells. The shell gives it a nice layer on the outside that’s going to look a million times better than the infill pattern, especially if you’re not printing solid.

[pherbs_backyard]

I use the Nylon 618 and it is pretty stringy when melted. You have to set the retract to about 10 times the extruder diameter - 4 mm for a 0.4mm extruder. I think the retract setting for ABS and PLA is 0.5mm for comparison. That should help a lot with your rats nest.

To answer the question about shells: The number of shells in your setting is in addition to the minimum of 1. So a setting a 0 gives 1 shell. A setting of 1 gives 2 shells, 2 gives 3 and so on. Multiply the total number of shells (2 if it is set to 1) by the layer height to approximate your wall thickness.

Hope this helps