Canoeing Through European Forests

We’ve been continuing work on expanding our themed Ticket to Ride sets to include Train Stations for Ticket to Ride Europe.

This week we added fir trees to our Camping set! Grab a paddle and embark on a canoe trip across Europe, planting trees in place of train stations to claim the use of opponents’ routes to complete your destination tickets.

Another Halloween Reject

We also worked on a train station for our Halloween set, but again did not like the way the design looked when printed.

We’ve got another idea though, and we’ll keep working on it until we get something that looks great!

Hot Mess

We were slowed down this week with another in our growing series of 3D printer problems.

After replacing a clogged nozzle (which happens every couple weeks), our next few prints were ruined by extraneous globs of plastic appearing amidst the expected game pieces. At first we didn’t know where it was coming from, but then realized the melted plastic was oozing out from the top of the heating block, instead of staying inside and feeding down through the nozzle.

Finding the Problem

Further investigation (which involved disassembling the entire extruder assembly) revealed that the heat break had loosened slightly from the heating block. The heat break is a metal tube that connects the hot end with the cooling radiator. It also holds the end of the Bowden tube that feeds the filament into the hot end.

Here you can see the disassembled hot end. The Bowden tube (blue, coming from the top) feeds down into the radiator (black with air fins, lying to the left in this pic). The heat break (seen in the next image) connects the radiator to the heating block (silver rectangle object). The nozzle screws into the bottom of the heating block, and that’s where the melted plastic is supposed to come out. But I had a mess of melted green plastic all over the heating block.

Oh, and to make this all more fun, bear in mind that I needed to do most of this work with the heating block heated to 220°C (428°F), because otherwise solidified plastic glued everything together.

The Big Delay

Once I had it all apart, it should have been relatively easy to put back together, ensuring it was all screwed tightly into place. But the threads on the heat break were covered in plastic and had to be cleaned.

Cleaning PLA plastic off of metal parts is not easy to do. Unlike other plastics, PLA is resistant to most solvents, unless you get into some very harsh chemicals that need a fume hood and disposable gloves costing $40/pair.

But I didn’t necessarily need to entirely dissolve the PLA, just soften it enough to clean the part. Enter ethyl acetate. This chemical does need to be used in a well ventilated area, but at least it doesn’t cause serious injury at the slightest whiff. It does require patience though. I had to soak the heat break in it for 24 hours!

My Gear

Here you can see the cleaning station I set up. The heat break is that little metal tube near the middle with threads on one end. The ethyl acetate is in the jar – keeping the lid closed saved me from the fumes and also prevented disastrous spills. Once it had soaked for a good long time, the PLA flaked off relatively easily – you can see the bits of it on and near the paper towel. I got the bulk of it off by scrubbing at it with the brass brush, and then picked the last bits out of the threads using a tiny screwdriver. The magnifying glass and head magnifier were very helpful in seeing it close enough to ensure it was really clean.

This picture shows some of the other tools I used, including a syringe of thermal paste to ensure good heat transfer between the heating block, the heat break, and the radiator. The long tin in the lower right holds my spare nozzles, as well as several acupuncture needles which work great for cleaning out a clogged nozzle. Probably the most important piece of equipment is the huge cup of tea (Earl Grey, hot), which helped me stay sane while tackling the project.


I’m glad to say the printer is working great again!

And boy, I sure appreciated having a second printer running while I dealt with the problem! It meant production didn’t need to stop entirely for two days while I resolved the issue.

Up Next

What’s on the agenda for the coming week? Another attempt at a Halloween train station, more work on the Jankó keyboard, and project X. What’s project X? Well, it’s not really a thing. I just made it up to make it sound more mysterious than “some other project we haven’t decided on yet”. It might be a new version of the Collapsible Dice Tower, or it might be some pieces for a new game. Find out next Monday!