How to get stringless print

[bbinnard]

I did several tests with different parameters (Retraction Distance and Extruder Temperature) to see if I could print a stringless copy of this test part:

All of the results looked pretty much the same:

But if I slice the same part with the same parameters in Craftware the result is far better:

So I am confused about what settings to use with S3D to get stringless prints.

[KeyboardWarrior]

Is retraction speed the same in both programs? Also, what printer are you using? 10 mm of retraction is quite a bit, unless you're using a bowden printer.

[bbinnard]

Yes, I am using a Bowden printer - it's a delta style machine called the Atom2 (http://www.atom3dp.com/).

I just checked Retract Speed; it was set at 50 mm/sec in Craftware and 2000 mm/min = 33.33 mm/sec in S3D. Granted these are not the same, but still pretty close. Could that amount of difference in retract speed cause the stringing?

Based in what I've been able to find online so far it seems that the 2 biggest factors affecting stringing are retract length and extruder temperature. As far as the latter goes, I've read that both hotter and colder can help with stringing. I think I'll try hotter next because it seems like my PLA starts to melt at about 180, and I don't think going lower than the 185 I already tried would be good.

[JoeJ]

That's not really all that close. That's a big difference in retract speeds. I would start by matching your retraction speed, retraction distance, and print temperature, as those all have a large affect on stringing.

[DarthRevan]

This print looks like it would also benefit from the option to print islands sequentially. This will allow equal amounts of cooling as the tips of those spires keep getting smaller and smaller.

[bbinnard]

Thanks for the tips. I'll try those and see what happens.

I don't understand what "sequential" means so I'll read up on that too.

[DarthRevan]

Thanks for the tips. I'll try those and see what happens.

I don't understand what "sequential" means so I'll read up on that too.

excerpt from Tip of the Day 4- Layer tab, a technical analysis:
Print Islands Sequentially without optimization: Lets say you are printing the part below. If you went from pillar to pillar in the most efficient order, you may get to the next layer so quickly there may be issues with heat-build up and the previous layer not being solidified. Therefore, you can turn off optimization, and then it will print the pillars in a random-order therefore helping you prevent from heat-build up.

[bbinnard]

Because of the way my print head is designed I can only use sequential printing if I were to space out the pyramids really far apart. And even then I'd have to find a way to ensure they were printed in the proper order. So that option is not going to help me.

I did try duplicating exactly all the settings I used in Craftware and there was no change in the results from S3D. Changing Retract Speed to 50 mm/sec (3000 mm/min) produced the same types and amounts of stringing as with what I guess is the default setting of 2000 mm/min.

I think I should learn a bit more about GCode and then compare the GCode files from Craftware and S3D. Perhaps there is some subtle difference there that will point me in the right direction.

[mcage]

Using Craftware since a week as I couldn't get rid of stringing and blobs with my makerbot replicator clone (Wanhao 4S) using S3D.
What a difference it makes!
Using the same retraction amount, temperature and printing speeds the difference in print quality is massive.

Also I found that the printer seems to print a lot smoother with Craftware compared to S3D, meaning it jerks a lot less and runs quiter because of smoother movement it seems.

The only thing Craftware is currently missing is dual extruder support, but with some customer header and footer gcode it's not a big deal when you don't use them at the same time.

The unique selling point for S3D regarding manual support placement is also covered with Craftware.. So... unless someone can proove me wrong and can get my settings for S3D setup so that the quality is in par with Craftware it's goodby S3D for me for now...

[bbinnard]

I used Craftware first, before S3D, but opted to get S3D when several bugs in Craftware prevented me from printing. The latest version of Craftware fixed most of these bugs, but not all. Here is one that caused me to use S3d instead:

http://www.craftunique.com/forums/view-thread/1166