Monthly Archives: December 2011

Praxis

This weekend, I’ve just been having fun printing out things.

First up, I printed out a few of these snowflakes. This piece gave me a lot of grief during the week, trying to figure out the right settings to print it. It’s a real testing piece. Lots of sharp corners will test the limits of your printbed for adhesion on the first layer, and it’s an absolute nightmare for retraction. If your retraction isn’t perfect, it turns ugly, extremely quickly.

At one time during the week, I had my retraction spot-on. However, I hit the perimeter-speed bug in SFact, which prints out the perimeter of the first layer at 60mm/s. That was way too quick for this complex piece, so I had to upgrade SFact, which then means all the retraction settings were obsolete, and I had to start back from scratch. I got them sorted out on Saturday morning, and I’ve been having fun just printing ever since.

I’ll be printing out four of these snowflakes. My daughters are going to decorate them, and them give them to their grandmothers. Should be a nice Christmas present from them. Here’s a video of the snowflake in print. Have a look at all the retractions / relocations during this one layer!

Next up I printed up a screwable jewellery box. I thought that this would be an excellent piece to demonstrate just how well the printer is working now.

The box turned out beautifully, and screws together perfectly.

Just for comparison, here’s how far I’ve come in two months:

Next up, I printed out a pair of pliers. Just because!

I also lost a couple of prints during the week. For some reason the extruder was skipping steps. I tightened everything up on the extruder, re-mounted the motor and motor gear, but still had issues. Turned out one of the extruder motor wires was loose. It was being pulled too tight by the x-carriage and losing connection. So I rotated the motor to give the cables more slack, and re-connected the wires. All good!

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.