Printer Suddenly Printing Whiskers and Ridged Walls

I have a Wanhao D4S that has been printing well...until just recently when whiskers have started to appear even from solid walls.



In addition the walls are much more ridged than what the printer used to accomplish.

I use Simplify3D as my slicer and am using the same profiles from what I had been using. I don't think anything else has changed...?

Thanks in advance for any advice of what to check!
Will

Check over the printer, belts, rods, motors, ect.. make sure everything is tight and aligned. I recently had the same thing, where prints just went to hell for no reason, turned out one of my x rods had become loose.

That was my first idea as well and I did check for something loose and did not find anything that was...though I had not checked the two bolts that hold in the extruder assembly...which I had out some weeks ago to do some leveling for two color prints...and while it was not very loose...it was not super tight. The other thing I noticed when I went to tighten these bolts was that the nozzle was quite the mess with melted on filament. It is hard to see in operation as I use a fancy directed cooling thingy but I also cleaned it.

The problem is that I don't have a small print that shows the whiskers problem. On a smaller test print it looks like the layer ridges are better but it is hard to say for sure.

The other thing I was wondering was if a stepper driver going bad could show the same kind of issue? It seems to get worse with a longer print...maybe as the driver heats up?

Thanks,
Will

Edited 1 time(s). Last edit at 04/20/2015 02:07PM by Wisar.

I have a CTC printer and it is pretty much the same. Your problem in in the extruder/hotend.

Have you replaced the PTFE liner in the hotend barrel? And cleaned the nozzle lately? Are both nozzles at same distance to the built plate? Have you cleaned the extruder gear recently?

If I have been printing non stop for 4 or 5 days (specially with ABS) I have to clean the gears as the get pretty clogged with plastic, and once a month or two I have to replace the inner liner.

You can swap the drivers and check for issues, but most likely is in the hotend.

Yeh, I think the state of the nozzle may have been an issue. It was hidden by my directed cooling duct and it was a mess. It is clean now! I checked the extruder gear and it did not look bad but I tried to give it a clean anyway. That and tightening the extruder assembly and I hope my issue will be resolved. I am redoing the problem print now so will know in the next several hours!

Can you point me to anything that talks about how to replace the PTFE liner?

Thanks,
Will

Two hours into five hour print and the whiskers are back. If anything worse after cleaning the nozzle, tightening the bolts holding on the extruders, and cleaning the extruder. The first sign of a problem happened around layer 47 (.2mm layers). I am still wondering about stepper drivers heating up and will try changing them out as I do have some spares. The other variable that seems in play is height? I am not sure what to look for if it is being triggered by a height be achieved.

Thanks for help to date, any further ideas appreciated.
Will

To check your liner on an standard extruder You will have to unscrew the 2 bolts that holds the fan, heatsink and stepper motor to access the set screw in the aluminum block. Once loosened you can pull down your barrel, unscrew it from heater block and remove the liner inside. Its usually a 4mm outer 2mm inner diameter and you will know if bad if the end looks brown to black and shrinked at the end.

The whiskers won't happened in the first layers, it will happen usually in the upper layers since the filament will have space to curl there.

Extrude some material in the air and see if goes down straight or tend to curl up, that will indicate if your issue is with extrusion.

Edited 1 time(s). Last edit at 04/21/2015 05:53PM by ggherbaz.

Ridging and whiskers have improved..at least to a large extent. It seems that something was loose, namely my build platform. I did replace the hotend and PTFE tubing but only on one side and the other side is operating the same as the side where the replacement was done.



In any case the PTFE does not look to bad, to me anyways!

What is interesting, and that only just occurred to me, is what can be seen in the following image.



The grey print is before I tightened up the build platform and the blue after. Blue is significantly better though there were some whiskers that I had brushed away. What only just occurred to me is that the issue always happens in the same place...is this a slicing issue? I am using Simplify3D and don't actually have any other Slicer configured to work with the printer though I guess I could get something working.

I use Simplify3d too and have never seen issues like that with my prints, but one thing it might be causing that is if you are using wipe or extruder ooze rate.

ggherbaz:

Question for you or anyone that has a Makerbot Clone: What speed are you printing at (and on what clone and slicer)?

Thanks,
Will

CTC Replicator 1 dual, Maximum speed used 50mm/sec but usually print at 40mm/sec for my own parts and 20-30 max for customer parts. Simplify3d as slicer.

Well then. I think we may have found an issue. My problem prints have been at 60. Am now trying one at 50. Does explain why smaller pieces, ones slowed down by layer print times, look so nice! Doop.

Will

I think this can be classified as solved. Ultimately it boiled down to a couple of factors. Both pretty simple and high on the list of try this first! First, I do believe that my build platform was a little loose. Fixing that got rid of some of the larger abnormalities that I was seeing in test prints. The rest of my problem went away when I slowed things down. Printing the case at 60mm/sec = problems with whiskers, printing at 50mm/sec = almost no whiskers. I suspect that dropping further would further improve things but the parts that I am printing can live with the quality at 50mm/sec. I guess I should have slowed things up sooner...! Especially since that was the advice rendered by technical support from Wanhao :-o Thanks to all that chipped in with advice.
Will