Blobs or Zits - Simplify3d

[willnewton]

Agreed on the 6.00mm but tried it as a "what the hell, because Cura has it" moment.

This is your problem.

You are using Cura defaults. Cura is designed for the Ultimaker, which is a Bowden drive printer. You can change them, but the default settings are not universal by any means.

The M2 is a direct drive. The print settings aren't going to be the same.

The 6.0mm retraction is your first clue that the settings are not going to be optimal. 4-6mm is the retraction used for Bowden drives.

[MattF]

Here's a new example.

The left model is printed via Cura at .1mm layer height. The right two are printed via simplify3D at .1mm layer height with the VEDual PLA Left Single Extruder profile found here on the forums.

What am I doing wrong?

[Jules]

Did you adjust the layer width to account for using a 0.1mm layer height on those profiles? (Those are set up for 0.2 mm layer height.) Or do you still have them set at 0.4 mm?

[MattF]

Still set at .4. I did not know I need to change that. I did some reading just now and not sure if I'm correct or not but I should be increasing this value when I lower the layer height? .5mm sound correct? (I'm doing everything I can to learn here!)

Thanks much for the help.

[Jules]

Yeah, you need to change the layer Height back to 0.2 mm, you're over-extruding by a mile.

There is a ratio that we maintain when we print. It has to do with the size of the nozzle that you are using (I'm guessing you're using the standard .35 mm nozzle that came with the machine) and the height and width of the filament thread that is being extruded.

While you technically can print at layer heights outside of this "golden range", the results look just like what you wound up with, because the nozzle doesn't have control over placement. It can squirt out the sides where you don't expect it to, and there's no way to control it.

The rules are:
1. You have to keep the width of the extruded thread larger than the ID of the nozzle you are using, and less than the OD of the flat face on that nozzle.

For a .35 mm nozzle, that range is from 0.36 mm to 0.5 mm. So the width of the thread should fall in that range. I tend to stick with 0.4 mm.

2. The short version of the second rule is that the Height of the layer should be half of the Width of the layer. So if your Width is 0.4 mm, you set the layer Height to 0.2 mm.

You shouldn't really use a 0.1 mm layer height with a 0.35 mm nozzle, because according to rule 2, that would give you a layer Width of 0.2 mm. And the 0.2 mm Width is less than the 0.36 mm minimum for a 0.35 mm nozzle from Rule 1.

The minimum Layer height that you can control with a 0.35 mm nozzle is 0.18 mm.

(If you want to do a controlled 0.1 mm layer height, you can get a 0.25 mm nozzle, because the results will be much better.)

But for now, you can either switch the layer Height back to 0.2 mm and give your print a try, or you can switch from Manual to Automatic for the Extrusion Width setting. (I've never tried it, but S3D might have some way of compensating for the extrusion rate to compensate for it.)

Did you ever read the Beginner's Guide? It answers a lot of these questions and will help you to set up some excellent prints.

viewtopic.php?f=3&t=3542

[MattF]

Did you ever read the Beginner's Guide? It answers a lot of these questions and will help you to set up some excellent prints.

viewtopic.php?f=3&t=3542

I have twice but apparently missed the part about the nozzle

Here's the latest. I switched back to .2mm as a test. Once again Cura prints on the right and Simplify3D on the right. I did not reprint the Cura prints just showing them again from before... The Simplify3D prints use your fff settings. Thanks so much again, for your help!

[Jules]

Yikes! That's a mess!

1.How small is that castle you're trying to print? Based on the .2 mm layer height it's a lot smaller than I thought it was. You've got a serious heat soak effect going on.
2. What kind of filament are you printing?
3. (If you want to print things that small, you REALLY need to invest in a .25 mm nozzle and go back to using the 0.12 mm layer height.)


Change the numbers on the Cooling Tab to match this

I'm in the middle of a project right now, but if one of the guys wants to explain heat soak before tonight that would be great...if not, I'll get back to you later tonight. Or you can do a search for "Heat Soak".

And if you want to upload your factory file, someone will probably be able to take a look at it and see what's going on with the file.

[MattF]

The castle is small - the size of a nickel.

I guess the good news is that the printer is fully capable of doing it as seen by the print via Cura. I think if I can get Simplify dialed in it will be as good or better.

I will read in more detail about heat soak. I'm printing Inland pla at 200c. Bed is at 60c. Same temps for both programs.

[Jules]

Printing extremely small is very possible, but it requires a different set of parameters than the ones that have been set up in those Dual Profiles that you are trying to use.

The bad news is.....I've never tried to do it, so I can't give you an easy set of "plug-this-in-and-go" numbers. But you do need to use those profiles for the duals, (the scripts are optimized for duals), so you're just going to have to adjust rather a lot of the settings in them and build a set that works for the smaller nozzle.

Couple of things will help you:

1. If you're going to be printing a lot of very small items and you have a dual, you might want to set one of the nozzles up as a 0.25 mm nozzle and use the regular sized 0.35 mm nozzle on the other one.
2. As you develop the profiles for the smaller nozzle, you're going to want to save them separately with 0.25mm in the name of the profile, so you know to use those for the smaller nozzle.
3. The heat soak effect happens when the item is so small that the layer underneath doesn't have time to cool enough to support the next layer. You can adjust those settings that I gave you this morning to slow down the printing time, giving the layers a little bit more time to cool. It will help.

The other thing that will help is to print multiples of very small items at the same time - with the items spread as far apart on the bed as is practical. The travel time going from one item to the next by the machine gives the layer you just laid down time to cool.

4. Print at the very lowest end of the range for PLA for the filament you are using. 200° isn't bad - if you can knock that down to 185° or 190° it will be even better. PLA needs to cool off quickly and the lower the temp you print it at, the faster that happens.

5. Hit it with an external fan if you have one. That will cool it off quickly as well.

6. Like I said, I've never tried to print that small but others have....if someone comes along and tells you to do something completely different, you'll be better off listening to them.

7. It might work better to go back to using the Default Dual Extrusion Profile just as it is, with a few changes outlined below. I've never done it, but other people do it regularly, so it might work out just fine:

If it works, great! If it still needs some adjustment, try the changes to the cooling tab or try reducing the extrusion temp a few degrees.

Good luck, and let me know how it works out....I might need to print something microscopic one of these days!

[MattF]

1. If you're going to be printing a lot of very small items and you have a dual, you might want to set one of the nozzles up as a 0.25 mm nozzle and use the regular sized 0.35 mm nozzle on the other one.

I was going to ask about this! I love the idea of changing one of my nozzles to a .25mm. It will see more use than two of the same nozzles (and I can always change back fairly easily).

Any recommendations on what .25mm nozzle to buy?

Also - I've made some tweaks and reduced my blots and zits to almost nothing. I'll update this thread later with my settings and a picture. However, I printed the tiny structure again and had issues. I'll also post more on that later too.