Updated Filament Spool Holder for SoM

Big thanks to Tom Klein for a great modification of SoM’s filament spool holder!

The original design used to have a printed ABS top roller and I just pushed the roller against the flanges and finger-tightened the nut.  The problem was people kept taking it apart, so I added rubber bands to pull the roller down, and a nylock nut to prevent tool-free disassembly.  Then the rubber bands kept disappearing, and Tom came up with the idea of making a heavy top roller so the rubber bands wouldn’t be needed.  He cut a new, steel top roller on the lathe and it works great!  The bolt is just loose enough to let the roller slide up and down in the slot in the frame.  The roller is heavy enough that it just falls into position on the spool flanges.

Tangle-free filament spool holder

ShopWare and Markforged

We had a visit from ShopWare during our open night on Tuesday, January 29th, 2019. They thought we might be interested in seeing a Markforged 3D printer capable of printing with nylon, Kevlar, and carbon fiber. And they were right, we were interested!

They showed a few videos that featured the capabilities of very strong 3D printed parts, and then answered questions, and had a number of samples to pass around and show off. They also brought a Mark Two for us to take a look at.

One of the weird things about how the Mark Two functioned was that it homed the x and y after every layer it printed. It also lowered the z just a bit while it homed the x and y, then raised the z back up to meet the extruder (which was dripping a small bit of filament) before then starting a new layer. (None of us could figure out why it was doing that, or what benefit it offered, though we had some guesses.)

These appear to be some sort of brake lever, maybe for a bicycle or motor cycle. They were very strong. There was no flex at all when trying to bend them by hand. Typically parts printed with PLA or ABS feel pretty “breakable” but these seemed like you’d need some tools to break them. (I really wanted to crush one in the hydraulic press when no one was looking!)

Printed threads are no problem, and again, appeared to be very strong, and the ball joint moved pretty good.

The metal part was not printed on the Mark Two, but another Markforged printer. The part gets processed after it’s printed, so it shrinks a bit, but the software deals with sizing up your model before printing so it comes out the correct size when done. We’re pretty sure this part was “finished” a bit after printing as well, perhaps on a lathe, which would explain why the rounded part is polished while the flat hexagonal part is not.

While the extreme cold weather kept some members away, we had a pretty good turnout to welcome ShopWare, and for those who were there, got to see some cool technology we home to someday have a the space.

We have a new Prusa i3 Mk3 3D printer!

This is the printer that we won in the Hack-a-Day contest about 2 months ago.  It arrived at my house last night, so I decided to open it up and inspect the contents.  That’s when I saw it…

Broken upper left Z axis guide rail bracket.

Broken upper left Z axis guide rail bracket!

I lifted it out of the box and discovered that the left Z axis motor mount was also broken:

Broken upper left guide rail clamp and left Z motor mount.

Broken upper left guide rail bracket and left Z motor mount.































A quick trip to the Prusa web site found STL files ready for printing…


New motor mount and upper left guide rail clamp printing on UMMD.

New motor mount and upper left guide rail clamp printing on UMMD.

Finally, printed parts installed…

Broken parts replaced.

Broken parts replaced.


Alas, it appears that the lead screw is bent- you can see it wobbling when it rotates.  I’ll be contacting Mr. Prusa for a replacement…

Hello Prusa i3 Mk3!

Wow! Wow! Wow! Mark our 3D Printing Champion is always busy, either building 3D printers, or designing and printing parts. He 3D printed a Prius Hatch Release Switch Cover and entered it into a Hackaday Contest and won an Original Prusa i3 MK3 3D printer for the space!

As we just got one of these where I work I can vouch for how nice this machine is. I built my first RepRap Prusa Mendel i2 about six years ago, and before that used a MakerBot Cupcake, so I’ve seen some evolution of desktop FFM printers. The first thing you’ll notice (or, don’t notice) about the MK3 is that it is quiet. Really quiet. Like, in our office we have to look at it to see if it’s running. It’s that quiet, thanks to the Trinamic stepper drivers. The PEI powder coated magnetic build surface is also nice, and… well, I could go on, but let’s all thank Mark for being awesome and winning this amazing new printer for the space!