Archive | January, 2019

Heated Build Chamber for Ultimaker

25 Oct13

Heated Build Chamber for Ultimaker

No - I'm not giving my Ultimaker away as a fancy wrapped gift in the image above. I'm just working around the most stupid patent ever granted in regards to 3D printing. Printing with ABS has one core problem - it shrinks when cooled down by almost one percent. This will cause all printed objects to have clearly visible cracks along the edges where the tension is the highest. It is very easy to solve the problem, but not without breaking a patent that should never have been granted.

Working around the Heated Build Chamber patent

It's incredibly easy to make a heated build chamber on the cheap. In my case, I used cheap oven bags from my local convenince store as suggested by Andrey on the Ultimaker forums. You just unwrap the backs, cover open surfaces and tape it in place. It takes some time to cover it all up, but it creates a fully working Heated Build Chamber. The oven bags are flexible enough to not break and they have no problem withstanding the heat.

Heated Build Chamber solves ABS cracking in 3D printing

I have now printed several ABS models using this method and I get no cracks in the surface at all. I also measured the inside temperature and without overdoing the tape along the oven bags, I can easily maintain 60C inside the printer - enough to prevent cracks. It is also important to let the object cool slowly after printing, so I just let the machine stand there until it's cooled to about 30C. Works like a charm and given that we have had ABS plastic since the 1950's - it should be fairly common knowledge that ABS needs to be cooled uniformly and slowly to prevent cracking and warping.

The patent and the problem with it

In June 2000, the company Stratasys was granted a patent that covers pretty much any way you can think of to cover your 3D printer to maintain a constant temperature as the object is built up. This idea did clearly not originate from Stratsys. It was common knowledge in the polymer business. However - Stratasys applied for a patent on this in regards to their already patented FDM printing process and they got it. The biggest problem with this patent is that it prevents you from doing what is obvious. It should not be possible to patent something obvious, but Stratasys managed to do so anyway.

So, patent US 6722872 effectively prevents ANY other firm from creating a printer with an enclosure around the printer that prevents ABS plastic from cracking up. They can of course contact Stratasys to license this or any of the 900+ patents that Stratasys holds. I do not know what terms a small scale 3D printer manufacturer would get, but I doubt it will be interesting to them. Just looking at the list of patents that Stratasys holds makes you cringe. These ideas won't be available to the general public until the patent expires in 20 years.

Why is that a problem then? My best illustration for how patents PREVENT innovation is looking at the RepRap family tree. The original FDM patent was filed by S. Scott Crump in 1989. Before the patent expired, there were only the Stratasys models as well as a few licensees. Just look at what happens in terms of diversity as soon as the patent expires! There's now more than 500 different 3D printers based on FDM out there. Now there's REAL innovation happening where crazy ideas are being tried out that Stratasys never persued like delta-printers and even more excotic ideas. That's not the biggest though. The price has come down from several hundred thousand dollars to below $300 for a machine that produces comparable quality. That alone should tell you quite a bit about how Stratasys has been milking the original patent.

Despite the patent having expired, we still cannot use the term FDM (Fused Deposition Manufacturing) since this is a trademark of Stratasys. Due to this, the RepRap project has come up with the definition FFF (Fused Filament Fabrication). Other patents are also attached to the FDM patent, preventing the full potential of 3D printing to be realized.

Can I break the patent?

Yes, but you cannot make a business out of it. In Europe, anyone is free to break patents like this as long as it is for personal use. In other words - you can break the patent, but you cannot sell a kit that allows you or others to break it. This previous weekend I was told that this is not the case in the US, but I have not been able to find good info on it. Please post links in the comments if you know more about US patent litigation and enforcement against individuals.



Promoting 3DP

11 Sep13

Promoting 3DP

It's great fun when your hobby gets exposure. Walter and I are doing our best to tell the world just how cool 3D printing is. For Oslo Mini Maker Faire, the national broadcaster did a full 15 minute feature on Walter (my son). He'll soon be in an article in Magasinet/Dagbladet as well and today it was my turn.

During the last 3DP meetup at Bitraf, we got visits from a couple press outlets. Liam, Ketil, Elias and myself was interviewed and it took quite a chunk of the first day. The first to surface of these were a 2 page article in the magazine "Hjemme PC". Tonight, the TV show called FBI (ForBrukerInspektørene) had a nice segment on 3D printing as well. The main segment was from the Meetup, but as a fun side-note - the printer mentioned initially (that had some problems printing a good iPhone cover) was fixed a few days later by Ketil.

If you want to check out 3DP and are nearby Oslo mid October, feel free to drop by the 5th 3D Printer Meetup!

( Image credit/facsimile: NRK1/FBI )


3D printing trick: ABS sludge

08 Jul13

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 Mar13

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 ( 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 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 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.


Printrbot Jr Heated bed upgrade

12 Mar13

Printrbot Jr Heated bed upgrade

I was so happy when my Printrbot Jr heated bed kit arrived, but it works far from optimal. I didn't expect to be able to print any bigger with this upgrade, only to enable ABS printing and maybe sticking the first layer down a little easier. Instead, I actually got less space to print on despite the huge 6x6 heated bed PCB.

The problem is where the heated bed is positioned. Here's a video highlighting the problems with this $65 kit.

It's not set to be centred on the 6x6, but rather towards the far Y-edge of the platform. The result of these misplaced holes is that I'm actually loosing 1,5 centimetres print area along the Y-axis since the print head may hit the bolts holding the PCB heater.

Another couple things that make me suspect the kit have been made in a hurry, is the metric machine screws that should hold the PCB in place. These are too short to reach through both the PCB and the plywood. The instructions are also unclear about the need for an extra PSU. It says that you should not use the "laptop power supply" that came with the printer. Mine didn't come with a "laptop" PSU but rather a huge 300W ATX supply. I assume this is good enough to drive both the printer and the bed.


I also bought a nicely cut 6x6 sheet of Kapton tape. I love the quality of it (feels thick and solid) but I can't get over the fact that you can buy a 100 feet roll of 6" kapton on Ebay for less than the price of a single sheet from Printrbot. Given that you have to manually cut off those nicely rounded corners to make the sheet fit between the bolts that hold the PCB, it's even less of a value. If there was holes cut for these, I could see the value but I think I'll just pick up some 6" kapton and place it next to the 20" kapton I use for the Ultimaker.

The above probably makes you think that I'm not too happy with my purchase, but that's not the case. For it's price, the Printrbot is a really good kit and I dig hacking my printer to make it better. The fan-holder I added helps immensely on the quality of PLA prints. My next upgrades will be some belt tighteners and a better suited industrial PSU that I can fit beneath the printer.

I really feel that all the Printrbot's I've seen have some unpolished edges that could be smoothed quickly. If Printrbot / Brook want's to stay in the 3DP business for a long time, he should look to companies like Ultimaker, RepRap Pro and Makergear. They don't churn out lots of new products, but rather listen to the customers about what must be fixed for the existing kits to be really good. Printrbot is on the right track by adding necessities like fan holders, belt tighteners and this HBP kit.

I think it is now time to polish the three kits (LC, Jr & Plus) to perfection. There's no better advertising then happy customers that has a printer that "just works".




3D Printer meetup #3

09 Mar13

3D Printer meetup #3

Last weekend, I organized the third 3DP meetup in Oslo together with @kefir from Quite a good turnout of people and 14 different printers there. My two favorites were the Adapto printer that is using pretty much only parts that are avilable in normal hardware stores. How's that for RepRap? The other favorite were the two Rostock printers being built by two AHO-students. Very cool to see these in "real-life" and I could even help a tiny bit so that was fun as well.

The next meetup should be some time in May and I'm REALLY looking forward to see Johan's DuoHex machine! It has one of the smartest RepRap designs I've ever seen, using Hexagonal rods to drive a dual extruder design. Below is a short video showing the different machines at the event and here's some nice pictures that Kjetil took.


Meetup Pocket Sign

08 Mar13

Meetup Pocket Sign

My brother is thinking about going back into the signage business and as he would start up his own company, he'll need to build himself a network. My favorite way to connect with people and communities these days is - a website that help you host meetings with ease. So - I set out on a mission to help people remember my brother and what his company delivers.

I've long wanted to do something with the neat little 1.8" LCD screen I picked up from Adafruit some months back and looking through their site I found that they also have this neat Lipo charger as well as slim, matching batteries. What if I made a small LCD-sign that he could drop in his pocket? I ordered the components and started modeling.

About a week later, the parts arrived and I modified Adafruit's example file a bit to load images one by one from the SD card beneath the screen. That gave me a simple, but effective slideshow. All my brother needs to do is to to change the contents is to make some BMP images and dump them onto the SD card. Easy!

After a few iterations I came up with this case. The part containing the battery is not the slimmest, but it's also meant to go inside your shirt pocket. I could have made it slimmer, but then I would have to sacrifice battery time. With it's 1300mhA battery pack, it lasts 2 hours on one charge and charging it takes a little less than an hour. I could have saved a little space by skipping the proto-board that lies in between the electronics and the battery, but it made mounting things and getting the USB-port right for charging. I might remove that if I do a next iteration.

The part that is visible on the outside of the pocket is much slimmer and it looks like the red and white logo. It took quite a bit of fiddling to get the case right. I learned that by slanting the print 28 degrees while printing, a lot less cleanup was required.

The supports came off really easy and printing the parts like this actually made them much stronger and easier to glue together in the end. I usually use PLA plastic for all my 3D printing, but for this I used ABS since it can be grinded and polished (PLA can't). Towards the end of the project I didn't quite get the time required, but it was a fairly polished thing I gave away. It took me 4-5 evenings to make this project and I think it was worth it. I could of course have bought a CD or something from a shop, but this was a personal gift that (as far as I know) nobody has. Much more fun!

Here's a shot of junior showing off the final sign and if you want to make your own - grab the files on Thingiverse and components from Adafruit.


Using Printrbot Jr with Kisslicer

06 Dec12

Using Printrbot Jr with Kisslicer

While my Printrbot Jr keeps impressing, the software side is a little less overwhelming. I use Kisslicer with my Ultimaker and setting it up for the Printrbot was quite easy. Kisslicer is a very good slicer that thinks differently than many of the other alternatives such as Skeinforge and Slic3r. I tend to toggle between mutiple slicers, but lately I've more or less settled on Kisslicer. It simply makes better toolpaths and it's easier to work with. It's also easy to set up for use with multiple 3D printers and it's a free download that isn't crippled in any way. Paying the $42 gives you a few "Pro" features, but most user won't need this. I basically just bought a license because I wanted to support the future development.

Here's the current Kisslicer settings I'm using with my brand new Printrbot Jr. It's not possible to save settings for simple distribution, but by just typing in the values here, you'll get a good starting point. The settings work perfectly for prints, but I think I'll need to up the E-vaule from the current 569 to a little more as too little plastic is used.



Printrbot Jr - built by Jr!

05 Dec12

Printrbot Jr - built by Jr!

My son loves hacking and I've thought about getting a second 3D printer. I figured, this could be a fun activity for the two of us. The idea is to have this one in the office, while my Ultimaker stays at home. I've followed all the Kickstarters that involve 3D printers and thus far, only one has really delivered - the Printrbot. The kit I decided to get was the Printrbot Jr.

The PrintrBot Jr is the cheapest kit out there and I was really curious to see what kind of printer you could get for just $399. They also sell it Pre-Built for $449, but we wanted to put it together ourself. The instructions and videos supplied are reasonably good, but at many places you just had to guess and see if things were right. There were also some screws missing, but I found replacements. The stupid thing was that the supplied screws were mostly american sizes so it's hard to find the correct replacement screws unless you're in the US. I got it to work and I'm happy with that, but I wish they had counted correctly in the first place. Also missing is all the tools required, so make sure you have the following:

  • Umbraco's (2mm and 4mm)
  • A little wood-glue
  • Blue painters tape for the bed
  • Unless they update the kit, you'll also need the seven 1/8" 40mm bolts (that were missing in my kit). I used 3mm as replacements, but it's not ideal.
  • There is also no filament in the package, so order a Rainbow pack from Faberdashery or something to get you started.

To get the most out of your printer, you should also get:

  • 40mm fan (you'll find this in any decent computer store)
  • Micro SD card. A small one (2-4Gb) will do

What I missed the most was good pictures of how the extruder fits onto the rest of the assembly, so I took some pictures that I have posted on my Flickr account of how this is supposed to look. Here's how you mount the hot-end and here's how the motor assembly should be. Assembly speed wasn't amazing (compared to the Ultimaker), but hey - my son did almost 70% of it himself and he's only 11! Not shabby at all. And with a little better instructions, I'm sure he could have done it all himself.

We're still to get a print out of it, as the software side is a bit rough. We got everything working with Printrun/Pronterface but we didn't get anything sliced to print. That's the part where companies like BfB and Makerbot has a big advantage. They have a complete end to end solution, whereas the Open Source printers also use an Open Source toolchain. I'll post images of the first prints when we have time to set up Slicer. If you're setting up a Printrbot Jr, be sure to check out the rest of the pictures of Flickr so you can see how to mount the extruder to the printer.

Update: Now printing!

After following the official Getting Started Guide, we're now getting decent prints! I just tried printing this Thing and it highlighted another thing that is missing with this printer - a proper PLA cooling fan. It'll be incredibly hard to get anything good looking without it, so I guess that's where I'll start…



3D Printer weekend

04 Dec12

3D Printer weekend

Last weekend I organized the second meetup for 3D printer enthusiasts in Norway. I host these meetups together with Kjetil that runs and we're trying to make it a place where both entusiasts can meet and curious can come and ask questions. As the first time, the event was hosted at my local hackerspace (and daily office) called Bitraf.

Bitraf is the biggest hackerspace in Oslo (in terms of area) and it consists of a big room for hackerspace activities, a sofa & film area with projector, a workshop with soldering, cnc and 3dp equipment. The perfect place to host tech meetups!

Kjetil with his new MakerGear M2 - smiling all weekend!

Kjetil with his new MakerGear M2 - smiling all weekend!

The first meetup saw more than 35 attendees in one evening and it got quite hectic. This time around, we wanted people to have more time to hang out so we set it up as a combined meetup- and build-event. Throughout both events we've had Ultimakers, Makerbots, Makergear, BfB and several Reprap Mendel, Prusa & Huxleys on display. If you have a printer, feel free to come along for either help or showcase!