Archive | November, 2016

Filament review: Printing with potatoes?

26 Apr

Filament review: Printing with potatoes?

One thing that fascinate people about 3D printing is the fact that the PLA plastic we often use as material is made from Corn. Now you can get a bioplastic made from potatoes as well! In this review of the bioplastic called Biome3D I'll highlight how it prints and how it differs from other materials. It has some quite useful properties!

The majority of PLA available comes from the company Natureworks. They sell the raw material to plastic manufacturers that add colorants and other chemicals to achieve their desired properties. The Corn based PLA most often used for 3D printing is the Ingeo 4043d grade but you can find other variants and producers.

The potato based bioplastic I'm testing here, is made in the UK by the company Biome Plastics and it's primarily sold through the website 3DomFilaments. I initially purchased some samples, but I picked up a couple more rolls since I wanted to test some more.

Not as brittle

The first thing I noticed is that it's nowhere as brittle as PLA. This is a major advantage. When you take a piece of the filament and bend it, it acts more like ABS. It bends and becomes more white in color. You won't break it until you bend 10-12 times. The material is strong and allows quite some bending before it breaks. It's not anywhere as tough as PET though, but much more suited than corn based PLA for applications that will be experiencing any degree of flexing. It is still stiff and solid and it barely shrinks at all. 

When printing, the layers bond really well and I can extrude it nicely all the way down to 175C - a very low temperature for my printer. It also has a nice, matte shine to it and theres basically no smell when heating the material. What I find the most fascinating about this material is how different it looks from other filaments when extruded!

Different consistency

When this material flows out of the nozzle, it behaves different than other 3D printing filaments I have. If you just push material out of the extruder, it will not hang as a nice, thin string. Instead, it will become a "lump" that gets a "skin", but keeps filling from the inside with hot material until the lump becomes so heavy that it falls off and create a new lump. Check the video below to see what I mean.

In other words, this material seem to "store" heat longer than other filaments. You can very much feel that if you try to squeeze one of the lumps of plastic that fall down.

The Biome 3D filament goes soft at 80-90 degrees, but you can print it at much lower temperatures than most other materials. As can be seen from all the horizontal stripes in the picture at the top here, cooling is essential. My printer is currently in the middle of a conversion to dual Flex3Drive (Writeup on this brilliant tech soon!) so I barely have any cooling. This shows clearly as lines along the prints. Lowering the temperature helps a lot and it prints well down to rather low temperatures.

Post processing!

This stuff can be sanded! Normal PLA will melt as soon as you start sanding or polishing it, but the Biome material seems to have a high enough Glass Transition temp that you can actually work it quite a bit before it deforms. That means that normal sanding is possible, but also tumbling with various mediums.

As can be seen above - my lack of cooling causes stripes in the print. I didn't sand the piece in the middle all the way down as the grooves were quite deep, but you can see how well it works. PLA will heat up and melt as soon as you sand it, but the Biome 3D filament holds up well as long as you don't repeatedly sand the same spot. I was even able to sand it using a Dremel as long as I kept moving to allow some cooling. It is impossible to polish the material to a shine like you can for ABS as it's matte by nature. I have not tested how well paint sticks, but I'll do a test and add that here later.

I can't find a proper datasheet, but the ability to sand the parts made me think that the Glass Transition temp was higher than the 70C typical for other PLA and lower than the 110C for ABS. I did some testing by submerging a printed part in 70C tap water. This revealed that it does indeed deform at this temperature and it also deformed at 60C. At 55C the object held up, so a Glass Transition temperature of 60C seems likely. That's actually lower than some PLA variants and makes it unsuited for parts that are exposed to heat. In other words - this won't replace ABS as a way to print spare parts for your dishwasher or similar tasks.

I also tried flame polishing the material. It does bring out a gloss but it's extremely hard to not apply too much heat. Since the heat builds up inside the material, I managed to get what looked like a perfect finish, but then after a few seconds it looked like above. The heat in the material kept melting it... I also tried to treat it with acetone, but it has no visual effect. It does however seem to dissolve the plastic to some degree.

All golden?

Now this seems all very cool, but there must be some negative things also? Of course there is, but they're not that bad. If you follow the manufacturers recommendation and use a heated bed at 60-70C, you'll see the prints sag at the bottom (Elephant's foot). I've actually seen this in all my prints to some degree, despite lowering the bed temperature to 40C. Like said before - a lot of cooling is required when printing with this plastic as heat is "stored" in the plastic. In other words - extra fans may be required.

Another thing that might be more of a problem is the inconsistencies I found with the spooled material. The diameter was quite consistent (+/- 0.2mm on my 2.85mm filament), but I had one case where it was way above normal (3.2mm). The material is spooled in a way so that it does not unspool perfectly. Towards the end of the roll it actually managed to pull my extruder back across half the build platform when the steppers turned off. This is probably easy to remedy and they've just started producing filament so they'll surely fix this. They should however also fix this:

Melted onto the filament was a lump of plastic from the production. This would have ruined the print on any printer. I happened to notice it, but you really don't want to see stuff like this. The material comes in the colors white, black, red, yellow, blue, green and pink so the selection isn't exactly stellar, but this is sufficient for many. Only opaque colors exist for now, so no translucent yet. When I purchased, I was first sent 1.75mm plastic despite ordering 3mm. As a compensation, they gave me half a roll of another color - so while the webshop isn't completely routined, they do offer good customer service.

In other words - I like the filament, but they need to ensure the quality is consistent. With that, I think this can be a good replacement for the fossil ABS filaments. I especially like that you can sand it and that it's more flexible than ABS/PLA!

BAMM settings for Biome3D filament

The BAM Makeblock printer has a Flex3Drive extruder with a Hexagon nozzle. I use the following settings with this material:

  • Temperature: 175-190C
  • Speed: 50-100mm/sec
  • Retraction: 2.5mm
  • Extruder tension: normal
  • Heated bed: 40C
  • Fan: full (& then some)

 

Filament review: PlastInk Rubber

05 Jan

Filament review: PlastInk Rubber

This flexible plastic filament from the Italian company PlastInk has been on my desk for a while and it's quite interesting! It's flexible, has massive friction and behaves like Nylon in many ways.

They actually don't call it plastic, but rather rubber. I wouldn't say it behaves like Rubber in any way, but it has some properties that make the comparison valid. The plastic prints with a nice shine and I've not experienced any dimensional deviations (2.85mm).

How Flexible is it?

The Flex is nowhere near as flexible as NinjaFlex. NinjaFlex will typically go back to it's original shape, but while this plastic stretches, it will loose it's shape if pulled really hard. It can stretch to 2-3 times it's own length before breaking, but actually breaking it is really difficult as it's super strong! It is so strong it's hard to cut the 3mm thread with just scissors and in this regard, it is quite comparable to Nylon. It's actually so solid that proper pliers are required!

It bends nicely, so it's not rigid like PLA & ABS, but is also extremely solid. I'd say it behaves something in between PETG and Ninjaflex, but more towards the PETG side. It's very different than PETG though. It has such an extreme friction that you have to spool it so it feeds nicely into the printer. If you don't, the plastic will get stuck in all possible parts of the printer. It simply must be on a spool as it doesn't slide - even on a hard surface. This frictional property is quite unique and makes it a good choice for printing grips and tool handles. This is also how it compares the most to rubber.

How does it print?

When spooled, this filament is very print-friendly. It can be almost as strong as Nylon, but it's more flexible. It can go fairly low in temp and does not warp very much. It is however rather hard to make large prints stick on glass with glue, so you'll have to use the heated bed & print with a brim so that the heat sucks it down.

I've printed this rim with several plastics. It's a good test-object as it has both solid and flexible parts. In PETG it's hard. In Nylon it can flex a bit but is quite hard. In Ninjaflex it is uselessly soft. With Plastink - it's something in between the NinjaFlex and Nylon. Thicker parts are stiff, but thinner parts are rather flexible. I still think Nylon is right for the rim's, but I like how the Plastink plastic feels! Very little stringing overall. It's also interesting to note that this filament does not require you to print slowly like NinjaFlex does. Despite it's frictional properties, it's stiff enough to print with bowden systems as long as the tube is Teflon / PTFE.

Surface finishing

One important thing I found out is that you can actually torch this plastic with a burner to get a smoother surface. You'll need to be careful doing this as it's very easy to apply the flame for too long, but if done carefully you can get some quite smooth results. Applying acetone to it seems to do very little. I put a sample in a small bottle of acetone, and there's no sign of it dissolving in any way. I can't seem to find a datasheet for the material, but it would have been really interesting to see what this is based on given it's resistance to acetone.

Skatefins printed with Plastink's white Rubber - seemed like a great idea for solidity, but the frictional properties really work against it being suitable.

Versions available

I initially got a couple small samples from the vendor, but found it so interesting that I wanted to test some more. I found an extra roll in the Arduino.cc webshop and picked it up with some other original Arduino gear I needed.

The filament from Plastink comes in just 7 basic colors (Black, Blue, Red, Green, White, Yellow & Clear), but the exact same colors exist for Flex, PLA & ABS. This is very interesting when thinking about multi-material objects as you can make parts that look like a solid, single colored part, but has elements that can flex. I especially find the Crystal (transparent) rubber fascinating even though I have not tried it yet.

I was also sent samples of the PLA & ABS. I only tested the PLA and it behaved nicely, just like other high quality PLA I have. They've also just launched a series of metallic colored PLA that looks interesting. Despite a loack of information regarding the origins of the plastic, I just got an email that suggested that the plastic is produced by Aquilacorde.com - a manufacturer of guitar strings. That could explain the nylon-like properties & strength.

BAMM settings for Plastink Rubber

The BAM Makeblock printer has a BulldogXL extruder with a Hexagon nozzle. I use the following settings with this material:

  • Temperature: 220C
  • Speed: 50-70mm/sec (can certainly go faster)
  • Retraction: 2.5mm @ 20mm/sec
  • Extruder tension: screws 2mm out
  • Heated bed: 50C
  • Fan: full

 

Filament review: ColorFabb PLA-PHA variables

23 Dec

Filament review: ColorFabb PLA-PHA variables

This is the filament I have the most experience with, on both good and bad. I purchased my first rolls 1.5 years ago. I had worked really hard for a long time and thought that I would reward myself with some prime quality filament so I stocked up on 10 rolls of all the colors I wanted!

Up until buying from ColorFabb, I had only used filament from high quality vendors like Faberdashery, Diamond Age and Ultimachine. Given all the positive comments I'd seen from others I expected the same (or maybe even better?) from this Dutch vendor. I was wrong. Months of clogged extruders ensued.

The cost of troubleshooting

I purchased spare parts for several hundred Euros from Ultimaker, just so I could exclude that as being the problem. I practically rebuilt the entire extrusion system without being able to solve the clogs. I even went as far to buy a proper Fluke HWAC multimeter so that I could measure temperatures properly. I also incorrectly blamed Ultimaker & Cura for some of the issues hmmm

Tons of tests...

I eventually came down to the conclusion that the clogs came from inconsistent diameters (sometimes above 3mm, far from 2.85mm) and very varying quality of the plastic. For most plugs I'd find some black thing at the nozzle tip while cleaning it out. I should point out that cleaning out an ultimaker isn't very simple as you'll often have to disassemble half the print head. Not a fun task to do several times a day, especially since I also printed 800+ meters of Faberdashery plastic on the same printer without a single filament error...

Replacement rolls

I wrote several polite emails with the support crew at ColorFabb and I have to say their support is really stellar. Nothing to complain about there. They told me that both the formulation & diameter had been off on several of the early rolls, and offered to replace all my rolls with new filament at no cost. That's pretty good service?

Problem was - when I got the rolls, some of them were better but by no means all. Argh... I've paid almost 450 EUR for those rolls, I have to make them work! After a lot of testing & rebuilds of extrusion system on my Ultimaker, I came to the conclusion that the only way I could print with them was going far above the recommended 210C. Even then it would clog now and then if I tried to go too fast. Others at my hackerspace had similar experiences, but a friend using 1.75mm Colorfabb filament never has issues? My Ultimaker Original is equipped with a 100% original extrusion system and the only speciality is the added dual extruder & heated bed. None of these should have any effect on the printing.

New printer, new problems

I solved most my ColorFabb problems by printing really hot and cooling the Ultimaker hotend down with an extra fan as I printed. If I tried to go anywhere near their official recommendation, the printer would clog right away. This worked so well that when I built my new printer, I was completely flabbergasted when I got similar problems here. The new printer had an E3D hotend that I had heard tons of positive feedback on. As soon as I added ColorFabb's PLA/PHA, the printer choked unless I printed at 20-30C above the recommendation.

After a month of trying to solve the problem without using extra heat, I gave up. I then realised that my roll of Ultra Marine Blue didn't have a consistent color? The color varied quite a bit along the roll. I contacted ColorFabb and yet again they replaced the roll. Excellent service, and this time half the roll have printed nicely. Strange?

Tangles! I never had that with any other vendor of plastic on spools hmmm

The PLA / PHA combo has major differences from other vendors. One is the addition of PHA, another bioplastic. It is apparently this that gives this PLA it's shine and makes it less brittle than other PLA. I'm by no means an expert on bioplastics, but there is something that makes this PLA/PHA mix more prone to stick to the inside walls of the extruder. Most often, you'll pull this buildup out with the filament after a blockage, but some will remain and must be removed with the "Atomic pull" method.

I've learned that most industry players use PLA from NatureWorks. ColorFabb buys their PLA from FKuR Kunststoff in Germany. I dunno what to say other than that it has some other (and less desirable) properties than the NatureWorks PLA. ColorFabb did however tell me that they only use NatureWorks PLA in their transparent PLA filaments and sure enough - it performs a lot better.

Colorfabb's response

ColorFabb says that the printer settings may vary (even among the same model) and that their recommendations can't work for everyone. I must say that I find frustrating to hear that from a vendor when all my 3 printers (PrintbotJr, Ultimaker Original, BAMM) as well as friends printers need to go to the same high temperatures to extrude it well. What makes this even more frustrating is that companies like MadeSolid publish guidelines for lots of printers and these worked for me right away?

I am now printing successfully with PETG from MadeSolid, PLA from Faberdashery, some really old ABS from Makerbot (back when they made 3mm filament), ABS from Protoparadigm, Proto-pasta's carbon fibre infused PLA, 2 year old PLA from Diamond Age, NinjaFlex, PLA/ABS/flexible rubber from PlastInk, PLA from Ultimaker and even Taulman 618/645 Nylon. Not a single blockage with any of these, but as soon as I insert the PLA/PHA mix from Colorfabb, my extruder will clog up. How fast this happens will vary, but I can't trust it for longer prints.

I just had to throw away two entire rolls of white PLA/PHA since the quality was so inconsistent that the layer height varied so much it was clearly visible (see below). Printing the same object with the same settings using Silver colored Ultimaker PLA gives me excellent looking results:

They're so different that you'd think it was printed on two different printers? This really is a shame as my two black rolls of PLA/PHA (made the same month!) will produce great looking results, even at fairly low temperatures???

I have completely given up on ColorFabb and it's a shame as they make so many cool things such as WoodFill, CopperFill & BronceFill. I just can't afford to spend more time on it as I've easily spent more than 100 hours cleaning out nozzles, solving clogs and failed prints. That's bad for business and not what I'd call "production quality". It's simply too inconsistent. I have a "trick" of working with it that "sort of" works and that's doing 5-6 atomic pull's with Taulman 645 Nylon before anything more than tiny prints. I'm also printing at speeds far higher than I like (due to the mass of the 30x30cm heated bed). This causes bandings in the prints, but then at least I can use the filament rather than just throw it away. It'll still get me plenty of jammed nozzles though.

Since MadeSolid now sells 15 different colors, so I'll get my PETG from them instead. As for PLA - rumours say that Faberdashery will soon begin shipping their 28 different plastics on spools. I guess I might buy my xmas filament from them instead.

BAMM settings for ColorFabb PLA/PHA

The BAM Makeblock printer has a BulldogXL extruder with a Hexagon nozzle. I use the following settings with PLA/PHA from ColorFabb:

  • Temperature: 220-240C
  • Speed: 70mm/sec (faster = less jams / clogs)
  • Retraction: 1.5mm @ 20mm/sec (less retraction = less deposits)
  • Extruder tension: screws 0.0mm out (solid pressure)
  • Heated bed: 50C
  • Fan: full (to compensate for excessive temp required to prevent plugs)

 

Filament review: NinjaFlex rocks!

06 Oct

Filament review: NinjaFlex rocks!

I've been meaning to test the flexible NinjaFlex materials, but having an Ultimaker made that impossible. Flexible filaments and bowden tubes don't play well as the friction of the plastic makes it curl and stop. With the new BAM printer, I have a direct extruder mounted just above the hotend. This is the ideal setup for flexible filaments and with the newly fitted Bulldog XL extruder it's a snap to change materials.

It's incredibly strong!

I can't quite get over how solid objects printed with NinjaFlex are. They're soft in that they can be curled together, but will regain their shape easily. If you print a single wall of NinjaFlex (0.4mm thick) it will take a lot of force to tear it apart. My first print was exactly that - a single wall stretchlet.

My first reaction was how soft it felt? Then I tried to tear it apart and I failed? I gave it to my teenager son, but he also couldn't tear it apart. I then put my foot on it and pulled with full force by two hands... It expanded to 5-8 times the original length and then snapped just like a rubber band. Only when it snapped (main image) could you see any sign of layer separation. Amazing stuff!

Uses for flexible materials

The elasticity offers some very desirable properties. For instance, a 2-perimeter bracelet can also be used as a hair band in a crisis. It is perfect for making noise dampening rubber feet for your Makeblock printer, BMX grips, phone bumpers and RC tyres. Fenner Drives that makes the NinjaFlex filament, recently came out with more colors including silver & gold! I'm really looking forward to play more with this filament. I picked mine up from E3D along with other parts, but you can find it many places.

BAM printer settings

The BAM Makeblock printer has a BulldogXL extruder with a Hexagon nozzle. I use the following settings with Ninjaflex:

  • Temperature: 220C
  • Speed: <= 30mm/sec
  • Retraction: 2.5mm @ 20mm/sec
  • Extruder tension: screws 2mm out (almost none as friction is extremely high)
  • Heated bed: 40C
  • Fan: none

If you go faster than 30mm/sec, the plastic will curl up inside the BulldogXL extruder.

Filament Review: PET+ from MadeSolid

28 Sep

Filament Review: PET+ from MadeSolid

Some time ago I posted some tests done with Colorfabb's XT plastic. I'm guessing that the people from MadeSolid read that and wanted me to test their PET+ filament? I love testing new plastics so of course I said yes to getting some samples!

Just like Colorfabb XT, the PET+ material from MadeSolid is made from PET plastic so I expected the two to be kind of similar. PET is the plastic used in drinking bottles and food containers, so just from that you know it's solid. It's much more solid than PLA as it's not brittle at all. It's stronger than ABS and extrudes at temperatures somewhere between PLA & ABS.

More colors

I had actually looked at the MadeSolid materials just the week before as they could offer both transparent, translucent and opaque PET+ filament with a decent range of colors as well. Just last week, Colorfabb also introduced some opaque colors, but at the same time they upped the required temperature from 220-240C to 240-260C making them harder to use for many.

As opposed to Colorfabb, the MadeSolid guys offer extensive printer profiles for their filaments http://madesolid.com/printers It is quite interesting to see as this highlights how differently the various printers are tuned. A Leapfrog printer should be set to 225C, but a Makerbot should be at all the way up to 255C!

Testing

I really like how the final prints look. They come out glossy and the material is very easy to work with. There is a tiny amount of warp, but a brim is sufficient to hold things down on the build surface.

T-Rex at 0.2mm & UltimakerRobot at 0.005mm. One can clearly see that I need to tune the printer a bit more as I have some "wobbly" somewhere, but the prints look really good despite that.

I received about 5 meters of the clear & 10 meters of the white PET+. With this I printed quite a few tests, but I ran out of sample plastic before I got the settings properly dialled in for my printer. That is - I thought that I had it right, but when exposed to pressure it turned out the layers had not bonded fully?

I did some bonding tests and it seems that on my current Hexagon hotend, I need to go to 235-245C to get proper layer adhesion. Oh well...

The transparent PET+ actually seems a little easier to work with than the XT as I'm not getting these tiny blobs along walls that I do with XT. All the walls of the Raaco resistor-box came out looking perfect and the final print is so solid that I need pliers to damage it. When reflecting a light-source it also appears to be more shiny/reflective than the XT, though the transmissive properties are very similar.

Bridging & supports

Bridging was interesting. I had a model that has a decent bridge. It's 29mm so I didn't expect that to work, but initially it looked to be going well. Then the plastic started smearing onto the nozzle and things became really ugly. I set the print to pause, cleaned it up and kept running at a higher speed. That turned out to be a bummer. After a lot of cleaning, I realised that going slower was the best. Next time I'll use Slic3r instead of Cura so I can tweak the speed for bridges.

The print came out fine in the end and I was really impressed by how easy it was to remove the supports? That was of course related to the poor layer adhesion that I discovered later, but after testing some more it seems to be just as easy to remove PET-based support as it is to remove ABS.

I am really liking this plastic, so I just purchased some rolls with the translucent colors (red + blue) as well as opaque white. I wish that MadeSolid had more colors available (like translucent & opaque yellow, orange, purple & more), but I guess that'll come with time.

Next up for this weekend is testing flexible filaments. I have two rolls of NinjaFlex as well as "transparent rubber" from the Italian company PlastInk. Should be fun!

BAM printer settings

The BAM Makeblock printer has a BulldogXL extruder with a Hexagon nozzle. I use the following settings with PET+:

  • Temperature: 225-235C
  • Speed: 50mm/sec
  • Retraction: 2.5mm @ 20mm/sec
  • Extruder tension: screws 0.5mm out (quite solid pressure)
  • Heated bed: 40C
  • Fan: none

Just days after I sent my order, MadeSolid published a lot of new colors. Now they have 15 different colors to choose from. Pretty good!

Filament review: Colorfabb XT

27 Apr

Filament review: Colorfabb XT

I've had a few really hectic months with a crazy amount of client projects. Hopefully that'll manifest itself on my bank account, but this weekend was my first few days of calm in two months. Time to play with the 3D printer again and experiment with one of my favorite filaments - ColorFabb's XT!

ColorFabb XT has been one of my favorite materials for a long time. In terms of properties, this PETG is sort of a crossover between PLA and ABS. As opposed to PLA, it is strong and quite flexible and it's much easier to work with than ABS since it barely shrinks at all. I've had varying results with it over time so I thought I'd experiment a bit with what are the best settings.

I first ran a series of tests to see how it's affected by speed (A), flow rate (B) and temperature (C).

I started with a base of 50mm/sec / 235C and the output looks good at both 50 and 100% of that speed. As soon as you go above, you'll see the pillar becoming less transparent. This is due to small bubbles of air and indicates that it's not feeding enough plastic through the extruder. This could be compensated somewhat by increasing temperature, but it seems that 60mm/sec is about as fast as I can go. When it comes to flow, the output looks good even at 90%, but at 80% it suffers (as expected). Nothing really interesting there, and also not when it comes to temperature. The 220-240C that is printed on the box the filament arrives in, looks quite correct.

Transparency

One of the things I really like about XT is it's transparency. You can't really make it fully transparent, but you can get some very nice effects by calculating your model to have walls that are a multiple of your nozzle size. In the image below, you can see how thickness affects transparency.

The wall thickness is written below the different wall segments. Opacity is quite good when holding the object close to the XT, but as soon as the distance is increased opacity suffers. The upper piece is a shorter model with the same thickness, but it's standing upright. What is interesting is how much the slicer affects transparency. I'm using Cura 14.01 for slicing and it constantly calculates the feed rate for infills incorrectly. To get enough material when filling 100%, I have to increase the Flow Rate to 160%? This must surley be a bug in Cura, but you can work around it by setting the Shell Thickness (= # of outlines) to a very high amount.

Another observation is that you will get the best transparency when you have long, straight lines. Curves & corners will automatically give you less transparency.

A couple tricks and a breakthrough

A hot tip if you get blobs or threads on the walls of your model, is to turn off Combing. This will force retraction on all moves and if your settings are otherwise correct, you'll completely remove the blobs. Another tip is that if the first few layers look good but the object then looses transparency, you can often save things by just slowing down a little as in the image below.

The biggest breakthrough I had in getting the XT to become clear, was after suggesting that Cura did not deliver enough infill. Daid (the maker of Cura) was quick to dismiss this possibility and I spent the whole evening doing more tests. After some cross-comparing with transparent PLA, I realized that Daid was completely right - no errors in Cura:

The first two of these are PLA and the last one is XT - otherwise using similar settings. Why was the XT so much less transparent? There were no difference? I then understood what the problem was.  To get XT fully transparent - you cannot use the fan!

In the image below the first one (A) was printed with the fan turned off until starting on the walls of the box. The second (B) is the best I could do with the fan turned on. The third is the reason I had the fan on - unless the fan is on, you'll get small blobs along the wall (C).

This is easy to solve however - Cura has a brilliant plugin-system that can turn the Fan on after either X layers or X millimeters of printing. Now, these boxes come out nicely every time!

So my magic settings for getting ColorFabb XT as transparent as possible - 35 mm/s, 235C, 105% flow & no fan for the transparent area. If you have a heated bed - crank that up as well as it'll help the layers blend by keeping the XT as hot as possible, so it blends better the next time the nozzle passes. Then you can crank up speed to 50 mm/s and turn on some careful fan cooling.

The reason I played around with this was to make a cutlery basket for my kitchen. Below you can see how it turned out and you can download and print the model here.

3D printing trick: ABS sludge

08 Jul

3D printing trick: ABS sludge

One of the most common problems when 3D printing objects, is to make the print stick to the build platform. As the plastic cools, it shrinks a little bit and this makes the corners of large objects pop loose. There's many tricks to solve this, but none as simple as using ABS sludge.

UPDATE: I no longer use ABS sludge. Glue stick on a glass plate is way better and easier. It's the same as using PVA glue dissolved in water, but less messy. Glue sticks come in different strengths and you will easily wash them off the glass with a damp cloth.

Making ABS sludge

One of the most common misconceptions is that using a heated build platform prevents this curling. For PLA it's pretty much true since PLA hardly shrinks when cooled. For ABS, it is very much a problem even if you have a heated bed and it's very easy to remedy. All you need is a dab of ABS sludge in the corners where the print would come loose from the Kapton or Pet tape. The end result is that the print sticks really well and it is thus much harder to remove it from the platform after printing it.

So how do you do you make this magic goo? To make the sludge, you need three things:

  • Glass container (a nail polish bottle is convenient)
  • Acetone
  • ABS in a color that is fairly similar to what you want to print.

Fill the bottle three quarters full of Acetone and then cut small pieces of ABS plastic that you add to the bottle. Shake well, leave it for an hour and then shake again. Repeat until the ABS is fully dissolved. That's all you need to do. I've experimented with various densities and it does not need to be a "thick" sludge to provide the required stickiness.

Now you can start printing and while it prints, you paint the corners of the object. If you don't have a stationary build platform like the Ultimaker has, just print a model with a "skirt", stop the print just as it starts to print the model and then use the skirt as a guide for where to put the sludge. I often let the first perimeter print and then apply sludge to the corners, before the fill is printed. This gives a super-strong foundation. You'll need to experiment, but be careful to not use too much sludge as it'll be next to impossible to remove the printed object. I try to use as little sludge as possible, but some prints require that you use quite a bit, so you'll need to experiment.

I haven't seen this published online, but maybe it's because it is so easy to do once you know it? It's by far the best trick I've learned since I started with 3D printing two years ago. It is also the same trick used by some of the larger 3D printer manufacturers. They call it something fancy (like Magic Glue), but it's usually just transparent ABS dissolved in acetone. The only drawback that I can think of is that colored sludge that is deposited outside of the model's area will remain there. Over time, your build platform will look somewhat messy unless you change the kapton tape.

Other solutions to make prints stick

I have not tried this myself as I find it messy, but many RepRap'ers say that Hairspray will have a similar effect on a heated bed. I'm a little unsure about what happens if you use too much and the bed temperature reaches 100 degrees+ but the flammable bits will probably fume out long before those temperatures. It is however certain that your entire printer will become somewhat sticky over time unless you take the build platform off every time you spray it.

Another trick is to do the first 1-2 layers on a much higher temp (100-110) and then reduce the temp for subsequent layers (70-80 degrees) to prevent the model from "sagging" from the heat. If your prints come loose, many will tell you to use Acetone to clean off the build platform. This works for blue-tape, but if you have a bed that is coated with Kapton- or Pet-tape, don't do that. Plain old soap and water will dissolve any oil-like substances (like finger prints) much better than Acetone.

That said - with ABS sludge, you can even stick down parts that come loose mid-print or support/parts that break, so it's still the best solution I know of.

Filament review: Conductive ABS from Repraper

26 Mar

Filament review: Conductive ABS from Repraper

I'm working on a really great 3DP project but I will have to wait a little while before I can tell all the details. However - in this project I'm making some really cool touch-sensors with 3D printing and I thought that I'd share my experiences with the "Conductive ABS" that is sold by Reprap-Walmart (Repraper.com) and numerous others sites.

1. It's all the same

It may seem as if there are multiple vendors for conductive plastic, but in reality it's just a single, chinese company. I bought mine from Repraper.com and I suspect that most of those selling Conductive ABS are getting theirs from the same source. They all have the same spool, so it's easy to spot just this. This means that if you see Conductive ABS in a RepRap webshop, they most probably got this and all their other filament from china/reprapper.

2. It needs very tight temperature control

This plastic is difficult to print with. The main reason is that to be electrically "conductive", it contains a lot of carbon. This narrows the useful temperature area. On my printer (Ultimaker) I had to use 230-240 degrees. I suspect it will be similar for any other Reprap or other 3D printer. Anything less than this and the print delaminates (click the image above to see this on the cylinder to the right). Anything more and you also got a plug. Since I got my Ultimaker (a year++ ago) I never had a plugged extruder. While printing with this material I had 8 plugs and it's a real hassle to fix.

3. It's soft

This makes filament grinding a major issue. Took me forever to figure out exactly how much pressure to use when feeding the filament into the Bowden. Because of this, it's also next to impossible to print with retraction, so keep that in mind when modeling.

4. It's probably not too well mixed

I can't really prove this, but it seems that since most of my prints failed due to contaminations in the filament. I must have done maybe 20 attempts at printing the same model (12 cm tall & tube-like). Only one of these succeeded. This makes me suspect that some bits of this filament isn't too well mixed so that when a bit of almost pure Carbon come along, there's no way you'll manage to push that through (see #3...)

5. There's a better solution...

While it's conductive, you can't really print circuits with this material since the resistance is much too high. If you just print the same model with normal PLA or ABS and then use Conductive ink to paint it, you'll get the very same effect. No need to over-do things, is it?¨

So to sum this up - try to avoid this material unless you enjoy dismanting your printer. It is certainly conductive and small prints can probably print without a problem. Just don't think that this is as easy as other materials. It's annoyingly hard. If you know of alternate providers of 3mm conductive plastic, I'm really keen to try them out so please post a comment below.

PS: I should also mention that the color-changing filament from Reprapper.com only changes color BEFORE you put it though the printer. I got the purple-to-pink filament and after printing, it's impossible to make it purple again. Would have been fun - if it worked.

3D printing with Color!

08 Sep

3D printing with Color!

After having a 3D printer for some months I've realized that it's so much cooler to use plastic with the "right" color, rather than just printing in black and white. If you are printing with ABS plastic, the selection is somewhat limited and your best choice is shopping Makerbot (27 colors) or Diamond Age (22 colors). However - if you're printing with PLA plastic - you're in luck! There's a massive selection of great suppliers and you can also have translucent colors with varying finish. I've gone totally overboard in buying different PLA filament samples. At the moment, I have no less than 47 different colors!

I've found it really hard to find the right color for my projects. Many of these colors have fancy sounding names that make it harder. Another thing is that some suppliers take filament pictures in a dark room with a crappy camera, while others use high quality cameras and experiment with the lighting to bring out the colors. What I've really wanted is a single picture showing colors from multiple vendors in different lighting settings so that I can see how much reflection there is in Bling Bling Gold and how translucent the Amber Red really is. To help others wondering about the same, I figured that I'll make a simple guide by sorting the colors that I have and photographing them all in the same lighting conditions.

Below you can find pictures of all my filament samples photographed outdoors in sunlight. You can then compare that with the list below that shows the name of the colors and their supplier. As you can see from the list, my favorite suppliers are Faberdashery (offering 35 colors) and Diamond Age (offering 23 colors). Faberdashery is the shop that I would recommend to beginners as they ship by the meter! The minimum order is 5 meters, but being able to order by the meter makes me prefer from Faberdashery over Diamond Age. I can't really order a roll of 100 meters just to test a color to see if it works for a project, so it would be great if all PLA vendors realized this and offered "Sample Pack's" with 5-10 meters of each color that they stock (hint, hint...) If they did, I would probably buy more from them.

Click any of the images to go to Flickr for the high-resolution version (5000 pixels+). 

Note how the translucent colors change from white to the darker background

Notice how the translucency does not show really well here?

List of colors (use the number on the white base as reference):

  1. Robot Silver(Faberdashery)
  2. Silver (Ultimaker)
  3. Earl Grey (Faberdashery)
  4. Crystal Clear (Faberdashery)
  5. Translucent Natural (Filamentprint)
  6. Glowbug Yellow (Faberdashery)
  7. Glow-in-the-dark (Diamond Age Solutions)
  8. Flexible White (Ultimaker)
  9. White (Ultimaker)
  10. Pearly White (Faberdashery)
  11. Cherry Blossom Pink (Faberdashery)
  12. Punk Star Pink (Faberdashery)
  13. Solid Purple (Filamentprint)
  14. Princely Purple (Faberdashery)
  15. Lilac Pearl (Diamond Age Solutions)
  16. Lapis Blue (Faberdashery)
  17. Blue Translucent (Ultimaker)
  18. Sapphire (Diamond Age Solutions)
  19. Galaxy Blue (Faberdashery)
  20. Translucent Blue (Filamentprint)
  21. Electric Blue (Faberdashery)
  22. Solid Blue (Filamentprint) *
  23. Glacial Blue (Faberdashery)
  24. Blue Translucent (Ultimachine)
  25. Translucent Green (Filamentprint)
  26. Jade Green (Faberdashery)
  27. Emerald (Diamond Age Solutions)
  28. Greenery Green (Faberdashery)
  29. Village Green (Faberdashery)
  30. Green (Ultimaker) ***
  31. Cyber Yellow (Faberdashery)
  32. Mellow Yellow (Faberdashery)
  33. Yellow (Ultimaker)
  34. Solid Yellow (Filamentprint)
  35. Translucent Yellow (Filamentprint)
  36. Buttercream (Faberdashery)
  37. Orange (Ultimachine)
  38. Squeezed Orange (Faberdashery)
  39. Amber (Diamond Age Solutions)
  40. Transclucent Red (Filamentprint)
  41. Fire Truck Red (Faberdashery)
  42. Red (Ultimaker)
  43. Ruby (Diamond Age Solutions)
  44. Woodland Brown (Faberdashery)
  45. Solid Black (Filamentprint)
  46. Bronze / Gold (Ultimaker)
  47. Bling Bling Gold (Faberdashery)

* = is indeed translucent and not solid?

If you have any idea on how to make this more useful to others (or other feedback), plese leave a message below. If you're a PLA vendor that want to send me some samples to include in a future follow-up post, email me at jenschr [at) gmail <dot> com. And yeah - next time I'll use a raft when printing the holders wink