Help with stringing

[taggedzi]

Hola,

I've been trying to dial in the settings for a new filament, and ever so slowly getting there. I think Ive managed to get the temperature and flow down pretty good, but i'm having trouble with stringing. (Temperature and flow... yah..?)

Best so far.

I'm using Matter Controller 1.6 on Windows 10 with a RMax v3. Stock firmware 20170201

I'm using PLA Blue 1.75mm (Ziro Brand if it matters, found on amazon, highly rated... might still be awe full though I don't have enough experience to compare yet...) Stuff in BOLD are settings I've changed from Stock settings. after printing as many times as I have, I've tried a WIDE range of changes on most of these settings.

Measured (avg) diameter 1.7
Nozzle Temp: 208 (If I go lower than 207 the extruder clicks like crazy when printing the base layers.)
Bed Temp: 60
Retraction: 2.0mm
Retraction Speed: 30 mm/s
z-lift: .5mm
Minimum Travel Requiring Retraction: 2mm
Retract when Changing Islands: True
Min Extrusion requiring Retraction: .2
Wipe Before Retract: False
Extrusion Multiplier: .905
First Layer Extrusion Width: 180%
Outside Perimeters: 100%
Support Material: 100%
Min fan speed: 100%
Max fans peed 100%
Bridging fan speed: 100%
Disable fan for first: 2 layers
slow down if layer print time is below 40 seconds
minimum print speed 7mm/s
Layer height: .2mm
First Layer height: .3mm or .3%
Speed (all stock but here just in case)
Infill 40mm/s
Top solid fill: 40mm/s
Raft: 40mm/s
Speed for perimeters: 40mm/s
Outside Perimeter: 30mms or %
support material speed: 40mm/s
Bridges: 60mm/s
Travel speed: 200mm/s
First Layer speed: 15mm/s

The VERY best print I got (not shown here) was kinda crazy settings, but after reading the forums and looking around the retraction speed of 200mm/s was 10x the recommended especially for PLA... so I figured something else was off. And went back to the drawing board and came up with the settings above.
The settings that "worked" were the same as above but:
Retraction Length 3.0mm
Retraction speed 200mm/s

The process I went through to get here: First I calibrated the extruder. When I tell it to extrude 100mm I now get 100mm almost exactly every time. Next was finding the right temperature, I printed hollow towers (1 wall) and checked surface finish, and strength, until I found what had the best looking finish and seemed the hardest to break. Then I tried to find the flow rate, by printing solid cubes at 100% fill rate and going until they did not over/under extrude, and when finished had a nice smooth finish on the top.... Then I tried to calibrate retraction... and I've been stuck here for 2 days. Any help would be appreciated.

Thanks much,
Matthew (TaggedZi)

[JonIN3D]

I am getting some pretty crazy stringing on my prints as well. I came to almost the exact setting as you, but my extruder will click below 225 with the PLA I was using this morning.

I'm baffled. I have tried the three brands I have, varying the temperature as low as I can go, changing retraction, z hop, etc... and not having any success.

But the same pla prints perfect at the same temp settings on my Maker Select 3. No stringing.

[RichWP]

Here's what worked for me:

• 1. I stopped using matter control in favor of Cura - including this for completeness, not sure if it made a material difference or not.
  
  2. Calibrated my extruder: https://www.matterhackers.com/articles/ ... r-extruder (see the Bowden section of this post)
  
  3. In Cura, I enable retraction at 5 mm at 25mm/s. This is probably controversial - but it works for me without jamming, and I've done prints lasting 24 hours+. I have tried lower retraction distances, and it just didn't seem to work with my soup of settings.
  
  4. In Cura, there is an extension called 'TweakAtZ' that allows you to change printing parameters at different heights. I use it to print a tower at different temperatures every 5 mm (from 215 down to 185) to find what works best (strength, extrusion, sharpness)- for me it's 195 with eSun PLA. Note at 195, I still get the extruder click if I print too fast - I normally slow down to 30mm/s for walls, so If I get a 'click' it's on infill or support structures... But of course - the goal is for no click's at all. My point is that speed is also a factor here.
  
  5. In Cura, I also use the 'TweakAtZ' for extrusion 'Flow' as well - same drill: Print a tower, changing the flow rate every 5mm by a couple of percent. I found that the ideal for me printing PLA is 96%. This test is best if you've measured your filament diameter at 5 different points wide apart, and entered the average into the 'Diameter' setting in Cura (my latest roll was more like 1.72mm).

So - In a nutshell, I've found that stringing is mostly controlled by heat, extrusion and retraction. Print at the lowest possible heat, and tweak retraction till you works out for you. Note that even with these settings, I still get very minor/fine stringing in some cases.

Not sure if this helps or makes things worse (I'm hoping for the former)... I've done a fair amount of experimenting - and this seems to work for me - but I'm *FAR* from an expert on these things!!!!

[JonIN3D]

Here's what worked for me...

Not sure if it was the calibration of the extruder (Probably not, as it was 1mm under extruding)

Or if it was switching back to Cura after a week of matter control (Probably).

I literally typed the exact same settings into Cura that I had in Matter control and I have NO stringing. None. Same temps, same speeds, same freakin' everything (except a slightly more calibrated extruder).

Between leveling my entire bed and getting the first few layers down flat, I'm expecting to be able to print some pretty big/cool things with ease.

Thanks for the help.