Random extrusion gaps

I'm struggling to find a fix for a weird problem that has popped up. In the attached pictures, you can see that small gaps where it looks like it is under extruding. I have check my extrusion rate. I have done a bunch of cold pulls with nylon filament, I have adjusted temperature and tension on the filament. This filament is fairly fresh and has not spent too much time in exposed air. I am also having the same problem with ABS filament as well. Nothing seems to be making any difference in how my parts look. Any suggestions would be greatly appreciated. I also attached a picture of my set up. It is a direct drive with an e3d v6( I also replaced the PTFE to see it that was the problem)

Don't know if this helps, but I had similar gaps when I used a particular filament brand, whereas my normal filament leaves no gaps. Perhaps you got a poor batch, at least if you have an alternative brand (ebay has actually worked pretty well for me) you could try and see if it makes a difference.

What temperature, speed and layer height are you printing?

It seems to me that you are printing with a bit too low of a temperature. Try printing it hotter and possibly a lower height.

ABS tends to shrink when it is cooled too fast and that will cause the layers to detach. I've had the same problem with ABS, and it seems to me that you have the same issues. An enclosed chamber is mostly advised to print ABS, but a lot of people do it without and with success.

Quote
dbrewski
I'm struggling to find a fix for a weird problem that has popped up. In the attached pictures, you can see that small gaps where it looks like it is under extruding. I have check my extrusion rate. I have done a bunch of cold pulls with nylon filament, I have adjusted temperature and tension on the filament. This filament is fairly fresh and has not spent too much time in exposed air. I am also having the same problem with ABS filament as well. Nothing seems to be making any difference in how my parts look. Any suggestions would be greatly appreciated. I also attached a picture of my set up. It is a direct drive with an e3d v6( I also replaced the PTFE to see it that was the problem)

I'm printing around 40mm/sec. My layer height is .25mm with a .4mm nozzle. The picture storm trooper is printed in PLA around 230 C° (seems high for PLA but it is the temperature they recommend). I've gone up to 240 with no visible difference. The filament is from makergeeks and is probably 1 or 2 months old and was stored in a large ziplock back with desiccant. I have also tested ABS from them all the way up to 265° with the same problems. I was getting great prints, but recently this problem has popped up with no big changes on my part.

this will not solve your problem: i asume you have M5 treads on your z-axis? the it is not wise to print with a layerheight of 0,25. see reprap calculator

It can't be z-axis related, because the bottom layer shows the same gaps already. To me it looks like uneven extruding, from a loose setscrew in the drivegear or the gear has collected dirt.

Interesting thing is the roughly same length of the gaps, this might lead you to the cause.

Good luck
-Sherlock

Are you printing external perimeters first? Flip it and print the inside first and do the outside last.

Can your extruder gear be crudded up with shavings from your filament? Can it be worn? Is the tension right? Is your bearing rolling smoothly?

The atomic pull method of cleaning out your nozzle often works but sometimes it does not. Have you tried to clean your nozzle with acetone or Methyl Ethyl Ketone (MEK) available in the paint section of Home Depot or Lowes? If that does not work try burning it out in a self cleaning oven. To do this put your nozzle in a stainless steel container. Use something dedicated for this purpose. I use a small stainless steel ashtray I bought off of eBay for $1.50. Do not use your wife's stainless steel pot. It will discolor and she may pull out the Bobbit knife while you are sleeping. Place the container with the nozzle in it on the bottom of the oven (racks removed). Start the oven in clean mode. In a few hours the nozzle and your oven are clean.

Do not use a blow torch!!!! This method could melt the tip of the nozzle and disfigure or close the orifice.

You can also just change the nozzle. Nozzles are cheap. I always have a few extras on hand.

I took apart my extruder and the gear teeth had some spots that were in pretty bad shape. I have an old wades geared set up sitting around I might need to dust off and see if it works for me. Thank you everyone for the input. I'll post some before and after pictures just incase anyone is curious.