Tag Archives: sfact

Slic3r, redux

I was thinking that I didn’t give Slic3r a fair shake last time. Doing 60mm/s and 0.2mm layers was probably a bit too much. I don’t think any skeining program could have held up to those requirements on my printer.

To be fairer, I thought I’d do another earbud holder, but this time at 30mm/s and 0.33mm layers, which are my current SFact settings, do a direct side-by-side. Here’s the results:

The earbud holder turned out fairly well (especially once cleaned up).The primary difference between the SFact and the Slic3r output is the flyaways – a function of the retraction settings. SFact’s retraction is clearly superior at this point in time. However, if your hot-end isn’t particularly oozy like mine is, then Slic3r may be a better option.

Watching the print, Slic3r definitely had some areas in which it was superior to SFact. SFact always starts each new layer at the same point. Slic3r instead just goes to the nearest point on the perimeter to where the fill finished. This helps reduce the ‘blobby corner’ effect that SFact produces with me. Its fill logic is a lot better as well, reducing unproductive travelling.

I’d really like to have a try at some of the other fill types that Slic3r has – it might produce better fill performance, and maybe end up with some better surface finishes than you get with SFact’s standard fill.

I’m thinking that the Slic3r might actually be a good choice for beginners. It’s definitely not as imposing or scary for people starting off, and produces quite good results.

Here’s all the earbud holders I’ve printed so far:

This is one thing that I’m really enjoying about doing this lot of earbud holders for Christmas presents – it’s giving me a good chance to refine my printer, and do a lot more side-by-sides, experimenting with just one variable at a time.

Removing Extra Shells

I’ve had the suspicion for a while that the ‘extra shells’ setting in SFact was causing a few of my prints to print out sub-optimally. Now, I’ve got some proof. Some 608 bearings arrived during the week, so I thought that I’d print out some Z-axis stabilisers. I’ve seen that the walls on my prints have a bit of ‘wobble’ in them. This wobble isn’t on the Y-axis, it’s only confined to the X. I’m thinking that the Z-axis is moving a bit, creating the X-axis wobble.

However, when my first print was done, it looked like this:

There was a clear gap between the inside wall and the outside wall of the bearing holder. This gap went all the way down. I think what’s happened is that SFact creates extra shells. However, once these shells are created, there isn’t enough space left for SFact to then do some infill.

To try and combat the problem, I went into SFact, and removed the extra shells on all layers except the base layer. I then tried out the same print again, and it came out perfect.

At the moment, I’m wondering why SFact even has the ‘extra shells’ feature at all. Just how necessary is it?

With another print of the earbud holders, I tried removing the extra shell on the base layer as well, but I ended up having trouble with my first layer. Once the infill started, the head would sometimes pick up the outside line, tearing it off the bed. Adding back in one extra shell fixed this problem.

Once two Z-axis stabilisers were finished, I fitted bearings in them. (They just pushed in with only a moderate amount of force. Perfect sizing.) I then mounted one on the X-motor side. (The one on the X-idler side will have to wait for some endstop fiddling). I then printed out another earbud holder for comparison. It came out beautifully. The combination of the Daily Branch of SFact, Marlin 1.0 Beta, and the Z-stabilisers is making my prints look absolutely fantastic.

This part needed absolutely no clean-up at all. This is the way it came out of the printer.

Before Z-stabiliser on left. After Z-stabiliser on right. Notice particularly the fill goes right to the edges much better.

Stabilisers on top holder.

In related news, the ooze problem seems to have disappeared. Have a look at the photo below. The vertical hole has printed perfectly, no strings at all. I’ve got my suspicions as to what’s fixed the problem, but I’ll leave that for another post.



Okay, I’m a bit sick of fighting ooze at the moment (see last post for more details), so I thought I’d get in and print some useful objects.

When browsing Thingiverse the other day, I saw this design for a holder for Apple earphones.

I thought that these might make ‘stocking stuffers’, and a good answer to the question ‘Well, what can you make with a 3D printer?’ that you often get asked.

Not willing to just print something out (heaven forbid), I used the opportunity to also give Slic3r a try. Slic3r is an alternative skeining program, different from Skeinforge and SFact. Unlike SFact, which basically works as a ‘plug-in’ to Pronterface, Slic3r is a stand-alone program. I’m not sure what advantages this gives, but it’s extremely fast to skein, which is probably due to running natively vs running interpreted Python code.

One of the supposed strength’s of Slic3r is in thin layers, so I thought I’d try something a little different.

I printed up two earbud holders. One, using Slic3r, would be at 0.2mm layers, but printed at 60mm/s. The other, using SFact, would use 0.4mm layers, and print at 30mm/s. So they should have the same printing time, but each have a different area of focus.

Here’s the results.

Slic3r’s output is on the right, SFact on the left.

I’m not totally impressed with Slic3r’s results. It’s clearly missing a lot of the fine tuning which has gone into SFact. I think that the 0.2mm layer was just a bit too thin, and the walls came out a bit unevenly.

I think that it’ll definitely be worth keeping an eye on Slic3r. It’s only very new, but doing pretty well so far.


Well, that was easy. Only a minute of searching the Reprap forums yielded the solution to this problem.

To auto-shutdown the hotend and heatbed after a print just go to the ‘chamber’ tab in SFact. Turn chamber on, then check the ‘turn off at shut down’ buttons.