Low friction filament spool holder made in 3 minutes

Here is a short post on yet another low-tech but functional tool (the last one was a dry box).

Give a maker a 3D printer and every problem is solved by 3D printing... A few years ago I started to re-realize that many problems are solved much better without 3D printing. At some time it was funny to see everything being 3D printable, including pipes, but how slow and inefficient it can be.

So here is a recent counter-example: I had to use a small, cheap but functional 3D printer recently (a sub $350 Me Creator Mini, a pretty good choice as an entry-level printer in my opinion). But it runs on 1.75mm filament and it lacked a compact, reliable low friction spool holder (the default is attached to the back of the printer, far from the side due to the electronics, and which is made of PVC pipe: the filament often jumps off the spool, which quickly fails).

Cooling 3D prints with an aquarium pump

3D printing cooled with an aquarium pump!
It works well and it cannot be quieter. The pump is bulky,
but the overall is a very compact hot end.
(the above was a preliminary experiment)

Interestingly, while this trick is not new, very few people seem to use it. For years I had an air pump on a shelf for this purpose. Only recently did I use it, and I really like it better than fan on the hot end.

The good thing is that aquarium pumps do build some pressure in order to pump air down into water. No regular radial or axial fan can do this, they only move air around. Do not get me wrong: regular fans works well, but the smaller the fan the noisier and the shorter its lifespan. And they are bulky anyhow and obstruct the view.

Actually, I printed almost years without fans attached to the hot end at all. Instead, I used a large, powerful and silent 120mm PC fan on the printer chassis. It blows a lot of air on the whole part, which is often even better, but it fails to cool down tiny towers or islands when the hot end never move aside (flowing air is very lazy and will not reach tortuous parts). Also, the big fan blows air only from one direction, which shows up on opposite sides.

So I still needed air again on the head....

Tribed: a fully automatic bed leveling and tool height adjustment, with FSR and 3 Z screws

This post is the continuation of my preliminary analysis regarding bed tramming and automatic tool height adjustment. So far I never made the step to redo my bed, even though it was on my wish list for years. Now it is a reality :)

Early testing of the complete setup : starting with a properly calibrated bed,

corrupting it manually, and letting the system auto-calibrate it again.
A faster / realistic movement is here, since speed was not a concern above.

So why now? A few months ago, someone came and talked to me about his wish to design a new, open source, user-friendly printer for the prosumer market. Please check this as your opinion counts!

All in all, it was an excellent reason to realize my idea of a fully automatic bed leveling. And since the new printer will also be opensource, here is the work, design and my analysis. How nice: not only I was given the possibility, but I was asked to do so!

As said, this improvement is part of a longer effort towards a user-friendly printer, for more reliability and less manual tweaking. My Ultimaker itself may eventually be ditched one day. Huh. No, I am joking. Well.. unless the new one is really is obviously better... Damn, that's exactly what it is all about :/

Contributing to projects hosted on github: a step by step howto, and an illustration with Marlin (3D printer firmware).

Git is powerful... and very painful the first time! / Github contribution howto / Tweaking Marlin for better 3D printer menus.

Git mess, only partially resumed by Oliver Steele.
Indeed, the upstream higher repository is not shown here,
as seen on this other bigger, clean and useful cheat sheet.

I eventually wrote a feature to fix something that annoyed me for years: allow multi-line commands in the LCD menus of Marlin, a very well known firmware for 3D printer.

I needed it for my Delta printer: these printer do require precise calibration, often with a sequence of gcode commands (check the end of this post for more and why I wanted these to be in my menus and not as initialization files on all my SD cards nor on a PC over a USB cable).

Now, Marlin is hosted on github, a community front end to many other open source projects. Actually, the linux kernel itself is developed with git so it works, for sure.

I often tried to use github, but I never went past a simple git clone of a repository. It was still better than to download a zip archive, because you can easily get the new stuff with a git pull. But here and partially out of curiosity, I wanted to try and contribute to a project at the source.

Now... what a huge and painful procedure just to give a hand! Seriously, it is mind boggling how much crap and megabytes need to be handled just to help and submit a few dozen f*king lines of code to an opensource project hosted on github. This is too bad since I am sure many programmers would be glad to give a hand to project they stumble upon (like me, often), but without this need to become administrators of complex and shared projects themselves!

This article is all about posting and contributing to a project hosted on github. You'll get the calibration g-code line I used at the end of the post if you really ask yourself.

Four in the morning. Just had a few tweaks to finish my upgrade...

Eventually "implemented" my upgrade! I certainly did not think it would take me so long, but once you start to sort the mess that's below a 3D printer you just can spend days on it! There is a brief list after the break.

I am sure a lot of 3D printer owners share the "two minutes into two hours" syndrome.

Features and improvements for a would-be homemade Ultimaker 3D printer

How would I re-design the original Ultimaker?

Quite some changes on the back of
my Ultimaker Original (aka v.1)!

The Ultimaker 1 (aka Original) is a well-built printer. It is probably one of the oldest and still best designs as proved by its incredible longevity.

I bought mine two years ago and, still, I feel quite confident that it would compare favorably in many aspects against a 30K€ FDM printer that a client bought last month. Is Stratasys really serious with this beast? May be there are better properties (eg. less warp due to fully enclosed?) But it also features a smaller build volume, a ridiculously limited and exceedingly expensive printing set of material. They also solved warping ABS by printing on... ABS beds (just try to remove it now when you forgot the in-between support!). You bet they bought Makerbot: overpriced "serious business" printers ought to be past, crappy obsolete printers. Too bad they are polluting MKI with greedy business practices though, and not the opposite.

OK, back to our subject. The "UM1" is one of the few printers you can take around you and which will keep printing very reliably without the need for re-calibration. It is also the only one I still blindly recommend... once the user knows that it is not that trivial to 3D print something. The new UM version is probably better in this regard, but it loses some "hackability" that I am fond of...

Still, the Ultimaker printers are big and they sometimes do not suit all my needs. If I was to re-design a clone, there are a few cosmetic but also structural modifications I would make, especially to the original design. Actually, many of my designs are all about improving the printer. Time to summarize what I did and what I would like to do!

Auto shutoff at end of print

Kill your 3D printer when it gets lazy !

Given the heat a 3D printer can generate, even when idle, I would better kill it than let it powered unattended, both for the planet, and to reduce the slightest risk of fire. ;)

I stick here to the simplest and most straightforward modification, partly because it is already supported by the Marlin printer firmware.

By the way, the total cost is less than $10, and you will just need a few solder points!

Poll: what are the features you added to your stock Ultimaker ?

What are your Ultimaker features?

Here is an on-going poll motivated by this post on the Ultimaker google forum. So please keep your comments for the forum!

I finally developed my own blogger poll system after failures with the official and restrictive blogger polls.

Lock the filament feeder in place

When I pushed the filament manually, I had to prevent the feeder from popping out of its attachment slots.

I designed this thing to make my life easier. Interestingly, it is also one quite popular object on thingiverse, so there must be a lot of people annoyed with this attachment (and because of failure with the hobbed bolt).

Actually I almost never had to push the filament manually anymore, but this is due to my new and own filament feeder design.

Heat sink on the stepper motors

Clean passive cooling on a stepper motor

Cool down your steppers : active or passing ?

For some time I was developing a new filament feeder, made out of PLA plastic, and finally, after a long print, I stumbled upon a feared issue : the motor gets hotter with work, and since it was over-extruding it got hot to the point it started to melt the pla around its screw mounts...

Belt tensionier : the best so far

Tighten the printer belts

Update: before you cut you belts, you probably better try my banana XY blocks! They replace the ugly wooden block that try to both hold the head rod and to tighten belt (and they fail at both in my opinion).

Back to the old post: I tried many ways to better tension my long X/Y belts (the short belts are another fixed issue). All other (PLA) printed belt tensioners I tried just failed miserably after a while because they could not stand the stress in the long term. Or they were bulky and hit the sliding blocks.
So the best I found definitely were dumb zip tie tensioners !

Varnish your printer plywood before it is too late!

Paint or varnish your 3D printer plywood first ! 

Since I could not think of a good color to use, I applied transparent varnish on the raw lasercut plywood.

I diluted a bit the first application to get it deeper into the wood. After waiting a bit I applied a thicker layer, and started assembly before it was fully dry (as I could not wait).

In fact, it made the parts stick a bit on each other, which proved to be good for the overall robustness !

Considering other's Ultimakers, I think my varnish protects all the wood parts against dirt and oil, so I warmly recommend this. Even hot melted plastic probably can stick enough on unprotected plywood to damage the surface when you remove it later.

And moreover, it must be much harder to do afterwards, so do not rush to assemble yours... make it happy first!