Ball joints, Fans, RPi, Hearts and fairy dust - #30DoC Days 19 to 22

Hello, and I hope you are having a good day? Here is an update of my RepRap adventures over the last few evenings -

For #30DoC - Day 19 I printed the Impossible Sphere for the weekly RepRap competition (see last post)-

Here is another one at 0.2mm layers - using the SCAD script richgain posted a few days ago -

I have not yet tried Greg's high resolution version, but it's on my list.

Day 20 was a Raspberry Super Pi Case - On thingiverse Here - It's a jazzed up version of the great case by HansH with added mounting ears and SD card support, light guides, etc.

Here it is in 'Special Edition' Gold and Glow in the Dark!

I also have my Printer running from my Raspberry Pi, with The Arduino, as it still does an ideal job due to the limited I/O on the RPi, I will do a separate post on setting up the RPi with Pronterface for RepRap printing. The Raspberry Pi is my excuse to finally learn more about Linux, so maybe you can give me some pointers along the way. There is also an active post in the RepRap forums on RPi, Pronterface and RepRap If you want to join in the development ideas with Raspberry Pi and RepRap.

Day 21 was an attempt to make a direct-able fan mount for MendelMax (and any other printer) - I have been using fans on and off for about the past year when printing in PLA, I'm really keen to understand how fans help with the build process, so in an attempt to learn more I wanted a mount I could direct airflow across, along, and even cyclone around my printed objects.

I used the ball joints from the great Fully printable PCB Vice by Sneakypoo as a starting point.

I love the Screw and threaded ball joint, it works perfectly.

The idea was to have it mount on the MendelMax 20mm Aluminium frame - but you attach it to any surface or bars with ty-wraps.

Above is the Vertical mounted fan.

As the ball joint can't quite do all angles, I have also done a Horizontal mount with M3 nut-trap (above), but not had time to test it yet, looks like it fits the 80mm fan just fine.

I have not yet had a chance to fit them to the MendelMax quite yet, but I'll keep you updated how well they work.

And for speed control I'm using a standard PC fan controller as they are just a few pounds, and give me individual control of four PC fans, it was easier to buy one than make up my own.
It also has one input power feed so you could still control it from the RAMPS Fan output but with the bonus of having individual power levels for all four fans.

The Universal 80mm Fan mount files are up on Thingiverse Here - 

For Day 22 we needed some urgent printed gifts for my daughters birthday party gift bags - after a bit of discussion and searching Thingiverse we decided on a secret box to store precious things or fairy-dust in, magic!

I first thought of the stratasys demo pot but that didn't quite hit mark -

Then we discovered the many twisted Boxed by Wizard23 and decided a Heart box would be great, check them out, they are all fantastic and they fitted together perfectly.

I needed to print 15 of them - here is a work in progress action shot -

Getting the size just right, they are very quick to print.

Printed in perfectly ideal colours from Faberdashery Buttercream and Cherry blossom pink - that reminds me, if you want a filament that sticks really well to your heated bed, I have yet to find a type or colour that sticks as well as Buttercream, from my experience with it, it's close to warp-proof.

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I have also just got my new extruder prototype assembled, and it works! with a simple first test - I just need to change the design a little as it's almost impossible to assemble at the moment. - More on that next week.
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Thanks for reading, more soon.

Cheers,

Rich.

Jammed Fr!gg!n Nozzle! - #30DoC Days 15...18

An update! - life and frustration with things failing on me temporarily got in the way of 3D printing :), but I did managed to design and print a few more things over the last few days while my main printer was down -

Firstly I had 4 jammed Nozzles in the last 4 days ! That's something that has not happened to me for about 9 months now, really annoying, but at least I worked out what was causing it! - I was not amused... see below for an insight and some questions...

This all started because I wanted to print a few things in Translucent plastic, and the only stuff I had was some old (about 1 year) Chinese PLA from Esun, I had given almost all of it away and stopped using it about 9 months ago when I switched over to use Faberdashery, Orbi-tech/GRRF and Ultimachine PLA's.

It seemed to print well and I made a few things, then I did a test print of a new extruder and it jammed up Solid, ground the hobbed bolt and stripped the filament.

The first two failures, little did I know what was causing it - see below - 

I tested a few things and came to the conclusion my hot end had failed in some way so, I disassembled it and investigated.
An hour later I had cleaned everything and checked all the hot-end parts, and it all looked fine so I re-assembled it.

I switched over to some Black Makerbot PLA and finished my test print, It all worked fine.

Then the new Reprap challenge appeared (Impossible Spheres puzzle - proposed by Richgain) and I thought   I would try the translucent (Esun) Chinese filament again - I printed with Yellow, switched to red and back to yellow and then my nozzle Jammed again.

'Bad' Esun PLA - see details below.

With the nozzle hot and some manual pressure on the drive gear I inserted a 0.45mm drill bit into the nozzle, it immediately allowed PLA to extrude out, I twizzled the drill bit and removed it, the nozzle jammed again straight away. I removed the extruder and disassembled it cleaned out the hot-end and continued on printing.

I had another jam and another clean out, then it jammed again so I switched over to some White PLA and attempted to push out the block, it did not work, and after using the drill bit again and having the same results, flow when the drill was inserted and no flow after removal I concluded that something was inside the nozzle and I was pushing it up with my drill bit, it was flowing back down and blocking when the drill bit was removed.

It was only when I cleaned out the nozzle again with the help of the white PLA I noticed a dark spec in the blocked filament.

I thought it was part of my hobbed bolt's teeth to start with, but after looking at it closly I was starting to think it was a ball bearing...

I checked it under a microscope and - I was right! 

This ball bearing was removed from my hot-end after using some PLA manufactured by Esun PLA.

Since this had happened 4 times and wasted quite a lot of my weekend with cleaning out my hot-end I checked over the last 100m of this filament and I found another 3 ball bearings embedded inside the filament!

The question is how and why are there ball bearings in this filament?

I had ignored bubbled in the filament before this as it's a common fault of low-grade / low-cost filament, I just had not expected to have contaminants also embedded inside. Signs of the bubbles along the filament usually indicated a ball bearing close by.

I had four blocks this time and I found 3 more bearings in the remaining filament, god knows how many more  there could have been in the Black stuff I had struggled with in the past?

So if you have any filament with bubbles you can see, check if it also has any contamination in it.

If you were looking to block a 3D printer hot-end in the most effective way, using a ball bearing bigger than the nozzle size is the best way I can think of, so is this an accident or intentional?


I stopped using the Black Esun PLA last summer after it caused so many blockages and fine stringing with my 0.4mm nozzle, I now wonder if they were also ball bearings or other contaminates, 

Image from Last summer (2011) - the black Esun PLA also shattered on me last summer, I still don't know why.

The moral of the story, you get what you pay for, buy materials from a source where you know who makes it, and watch out what you put in your 3D printer. 3D printing is already hard enough without nozzle blockages to deal with.


I will take my revenge on the last 100m of this Esun PLA, it's going to make a nice piece of PLA scrap Art, not that this nasty PLA deserves any more of my attention... I won't be putting any of this in my 3D printers ever again.

Has anyone else had any experiences like this? am I very unlucky?

Translucent plastic can look really amazing, just watch out where you get it from and what's in it!.

I am still after some high quality translucent PLA, if anyone can suggest a good source.

The only other thing that comes out of this experience, is that if we could find a way to control a bearing in a nozzle you could almost completely stop any ooze in a dual extruder set-up, we were recently discussing how to overcome dual extruder dribble over on the forums, if someone can think of a valve, I can now vouch that a ball bearing makes a perfect blockage and a 0.45mm drill bit acting as the 'pin' releases it.

And now my printer is back up and running I managed a nice print for the RepRap Competition with my Faberdashery PLA -

Slic3r 0.8.3 - 0.3mm layer height, 60mm/sec print speed, 0.5mm nozzle (or so I hope after all the blocking and clearing incidents!).

I feel better now, having vented all that.

I have some Raspberry Pi, a new extruder prototype and some other interesting things waiting to print out, I'll catch up on my missed #30DoC days now.

Thanks for reading.

Cheers,

Rich.