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I have been actively printing with my Rostock Max V2 since August 2014 and ran into a problem this week that needs some help. I am getting a very rough finish on my prints with PLA that previously was fine. I tried using different slicers (Slic3r and CuraEngine) but the same exact problem occurs in both cases. For example when I print a calibration pyramid that previously smooth on all four sides is a little rough on two sides and very rough on the other two sides. I tried this with other designs and have seen the same issue. I check belt tension and cheapskates and they seem fine.

Does this sound familiar to anyone? Hoping for some advice to get back to printing

Thanks,
Eric

Got photos?

Good idea (see below). The image on the right was printed about a week ago with no problems and smooth on all four sides
The image on the left is what I am now experiencing. Interesting two sides are very rough as shown on the photo while the other two sides are just a little rougher than normal.

I am convinced that it is somehow related to one of the towers (or cheapskates, belt, motor, etc.) because of the fact that it isn't the same effect on all sides but I checked everything and it appears OK.

Hope that helps with the diagnosis....
Eric

My very first instinct would tell me to ask you whether or not your cheapskates are still tight?

check that by lightly torquing your cheapskates with your hand around the Z axis; if there is slop, tighten the eccentric spacers.

Beyond that, your print to the right looks gorgeous and if you haven't made any major changes to the printer, I've only noticed the cheapskates to work themselves loose after a while. I haven't had to retension my belts but one time.

In my experience the easiest way to check the tightness of the Cheap Skates is to grasp the wheel covers on the adjustable side and try to turn it while holding the Cheap Skate. If it will slip on the column it is a little lose. On the other hand you don't want to crush the wheel either. Loosen the eccentric and snug it up until the wheel just stops slipping when you try to rotate.

After the printer has set still for a while if you hear a skipping noise when the Cheap Skate moves quickly the eccentric is a bit too tight and the cover has a flat spot. Loosen slightly and continue the flat spot will relax out.

nitewatchman

So I've been playing with the cheapskate adjustments and it hasn't helped. If I hold the Cheapskate and start to turn the wheel cover on the adjustable side it will turn with some effort but they are certainly not loose at all. The Cheapskates are solid (no wiggle) on the track. I played around trying different adjustments over the weekend and still no luck. I was only able to make it worse not better.

Desperate for other suggestions.

Thanks,
Eric

It looks more like an extrusion issue to me, best guesses you have some sort of foreign body in the extruder partially blocking it. Temperature is too low or you have the extrusion width set too low, it could also be an issue with the extruder.
You can test the first two by manually feeding filament and seeing how it feels extruding into the air when at temperature.

When you under extrude, the filament snaps rather than stretching to make a continuous line and you get an effect similar to what you are seeing on the outside of that pyramid.

So I have tried a few things to test the possibility of an extruder issue. I examined the extruder and tried unloading and loading filament and didn't see any evidence of any blockage. It also seems to be running smoothly.

I did notice that when I bring the hot end up to temperature and run the extruder, the flow of PLA is not a clean thread that I have had in the past. It was doing a lot of curling back on itself around the hot end and when it did drop and extrude from the weight of the accumulated plastic it looked like two threads coming down rather than a single nice thread.

I'm thinking of taking the hot end (stock Rostock) down and taking it apart to see if there is anything obvious. I'm also thinking about building a second head which I was already considering before this all happened but seems like a good idea now. Thinking E3D.

Any other suggestions with the additional info or advice on a replacement hot end?

Thanks again to all of you making suggestions and trying to help me with this frustrating issue.

Eric

if there is a foreign body in the hotend, and it does happen sometime cheap filament contains particles big enough to partially block the nozzle.

You can usually clear the foreign body out without dissasembling, disconnect the bowden tube at the hotend, set the temp to just below where you would normally print, push a small amount of filament into the hotend by hand, drop the temperature bay 40 degrees or so then pull it out, you'll need to repeat several time using clean pieces of filament. Nylon seems to be particularly good for this. The idea is to trap the foreign body in the filament.

If that doesn't work you can always strip it down.

On hotend replacements, it depends what you want, for PLA I like the real JHeads (hotends.com), I have a love/hate relationship with the E3D hotends, I have a V4, 2 V5's and a Kraken, the V4 and one of the V5's won't print PLA reliably, the other V5 prints it really nicely, the Kraken I like and it currently on my printer, but it's too big an bulky. I've considered going to a V6, since it has many of the improvements of the Kraken without the bulk.

My current thoughts go like this, ideally you want to mount the hotend with a minimal amount exposed below the platform, this minimizes the twisting force on the arms when printing, dual extruders are more pain than they are worth, but designs like the Cyclops have the potential to change that. Unfortunately I think the cyclops is too large to mount the heat sink above the platform without the heater block potentially damaging the platform.

You can also get a spool of music wire just under your nozzle size. Cut a piece that is at least a couple of inches longer than the path through the hot end. Make sure the ends aren't squished, may need to sand.

Remove your tube, heat head, stuff wire in nozzle and push up through until it pokes out the top. Grab with pliers and pull out.

Aside from forcing junk out of the nozzle, the filament will ofter stick to the cold wire in globs and pull out any junk.

First, I want to thank everyone who responded to my posts. I'm back up and running. I am posting the follow-up in case any other noop comes along with the same issue.

It was a clogged head that was causing the problem. I suspect some foreign material got in there that started the problem,

Thanks again and appreciate all the help.

Eric

I've had my other printer running night and day for the past couple of weeks and since I started putting a bit of foam on the filament I haven't had any clogs. Had the platform go out of alignment, had the hot end connector work loose, but no clogs.

I've noticed that on some spools fresh out of the factory vacuum bag I get buildup on the foam. On others I don't. Don't know if the room is dusty where they bag them or what.