Issues with printing colorfabb xt

[Aki 0]

Hi all,

hello to everybody in this forum, it s great community ! I have been reading for a while and most times I found usefull hints !

But in this case I have no clue and could not find a solution for my issue, so I hope to get any support here :-)

After my first successfull prints with PLA, I tried out the colorfab XT wich is some kind of PET if I m not wrong.

On the box it says to print with 240-260 C

My first print with 240 C was awfull, I searched this formun and found some hints to reduce templ, so I tried with 220 C and 225 C and on the picture you can see the outcome.

The settings in Cura are:

print speed 50

retraction on, with standart values

combing on

travel speed 150

no plug in used

What I don t understand, is that there are some ares which look good and other look like material is missing ...

Would be glad for any hint, thanks in advance !

Aki

Edited August 12, 2016 by Guest

[owen 19]

Hi

You look like you have under extruding happening there so you need to find out why and fix that. I have been printing xt at 240c with fairly good results at 30 to 35mm/s that was before the new um2+ upgrade. Which printer do you have?

[gr5 2,167]

You definitely have underextrusion. You might need a new teflon but whatever problems you have should be helped by printing much slower. Try 1/8 the speed you were at and then if it looks good slowly increase the speed in the TUNE menu on the printer.

[Aki 0]

Many thanks for your input !

I have the UM2 with olson Block 0,4mm

I printed slower and set temperature to 230. The fil rate was very good, but then I had a lot of stringing.

I searched the forum, and I installed the "retract while combing" plugin

The shown print has the following parameters:

Material colorfabb xt red

Temp 230 C

Speed 30

"Retract while combing"-Values

starting z: 0

Ending Z: 100

min distance for reract: 2.0

retract speed: 30

rertact distance: 4,5

lift head during retract: 0,0

in the standard options of Cura, I set combing and the retract Z with 0.2 mm

What else options do I have to reduce stringing ?

I want to pront a robot (Inmoov) and I would like to avoid printing it with ABS, so I need a material which is strong and has a higher TG then PLA, that s why I started with PETG. Are there maybe other alternatives from your point of view ?

Many thanks in advance !

[gr5 2,167]

Why does the robot need a higher TG than PLA? PLA can go up to about 50C no problem. Will the robot be in temperatures that hot? Yikes!

Well to reduce stringing usually lowering temperature helps. If you have to make an hour print every time you change the slightest thing you will take days to figure this out. Why not change settings while it's printing? For stringing test I recommend 2 towers a few cm apart. Make sure it takes at least 3 seconds to print each section of tower - so maybe 2cm diameter towers with 24% infill and 2 shells.

Then you can play with speed and temperature and fan to figure out what stops stringing. Once you understand stringing you can try to get it to print overhangs better.

For high TG materials it's always best to enclose the printer. The warmer the air inside the printer the more fan you will need. With no enclosure you want as little fan as possible - the minimum to get the fan to rotate. If you raise the air closer to glass temp you need more and more fan.

Fan will help the overhangs greatly. So more fan implies better overhangs and better bridging. But more fan will hurt your layer adhesion (doesn't matter for PLA). So for example if you print a pencil shaped tower it will snap easily along layer lines if you have too much fan.

So for fan experimentation try printing a 45 degree overhang and adjust fan ever 2mm (and mark the part with a marker). Make sure the part takes at least 5 seconds per layer so you aren't confusing hot underlayers with fan issues.

Once you pick a good temperature that doesn't string too much (some stringing is fine) then pick your speed that doesn't underextrude - unfortunately to get all this to work you might end up with 10mm/sec. But hopefully you can get a reasonable speed like 30mm/sec to work with all these other parameters.

If you find the speed has to be crazy slow to not underextrude your printer is probably faulty. Most likely the teflon coupler is soft and pinches the filament but it could be 15 different things that causes underextrusion. I post about underextrusion more than anything else so solutions are all over this forum.

[owen 19]

Also you can raise your travel speed to reduce stringing.

[Aki 0]

Many thanks for the very detailed answer,

I will do the test prints as recomended,

and I will rethink the temperature requirements for Inmoov robot :-) I just wonder why most people are printing it with ABS ...

addinionaly I will search the forum for any hints for enclosuring the printer ! I found a product in a shop but I will try to build something on my own first :-)