Testing nGen filament

    I'm currently on the 32C3 congress, testing Colorfabb nGen filament (Amphora AM3000) on my Ultimaker II extended using an Olsson block with a 0.4mm brass nozzle.

 work in progress....


I solved some issues with:
  • first layer adhesion to the glass bed
  • unexplainable underextrusion
  • warping
So now I'm printing the hell out of it to see about it's reliability.
See the bottom of this posting for an Ultimaker .ini file for this material and the preliminary conclusions I draw from the tests described here.

  test cases

nozzle cleaning 

A Cold Pull/Atomic cleaning doesn't seem to work anymore.
Below 100 degrees it's impossible to remove by hand and
above its not pulling out anything but stretching like bubblegum.
I need to find a temperature that works for a cold pull to have repeatable test-conditions...

 at 240°C

There seems to be a recurring underextrusion issue.

All test-parts are brittle. A part that would be strong in PLA/PHA I I can now crush with 2 fingers in nGen. (1cm thick, 20% infill, 3 solid layers)

After I temporarily fixed the underextrusion by changing to another new nozzle (as a cold pull doesn't work), I noticed very heavy warping.

These are the settings:
  • 240°C Nozzle
  • 85°C well leveled glass Bed with glue stick
  • 4.5mm retraction at 45mm/s
  • fans at 50%
  • 0.1mm layer height (Cura "normal" profile)
  • 0.8mm walls (Cura "normal" profile)
  • 0.6mm tops/bottoms (Cura "normal" profile)
  • 60mm/s (Cura "normal" profile)
  • 5s minimum layer time (Cura "normal" profile)
I printed with and without a front door present on the UM2extended.

at 220°C 


I'm currently doing a comparison print in 220°C/75°C with the speed reduced from 60mm/s to 40mm/s as suggested on the "recommed settings" page below.

The part simply doesn't stick to the glass surface at all with or without using a glue stick.

at 220°C with a very hot bed

    Still at 40mm/s. Let's try the lower printing temperature with a very hot bed, to make it stick...
    It doesn't stick as well as 240°C+85°C but better then 220°C+75°C. It seems to actually get a first layer down. ...some of the times.
    It still doesn't still every time. Even with a fresh layer of glue-stick.
And I was not able to get a working print.  Cleaning the nozzle with a very soft accupuncture-needle and test-extruding into thin air dosn't show any signs of clogging. Cura is also set to the correct nozzle diamter. Drastic meassures like +30% overextrusion didn't work due to the first-layer adhesion issues.
I have the impression that the issues are getting worse since I can't clean the nozzle via a cold pull.

nozzle cleaning using PLA 

32C3 is over and the printer is now placed in a private home.
Based on some feedack on Google+, I just cleaned the nozzle using some PLA/PHA (my usual melt at 220°C, then pull at 70°C). As the melting points are so similar, this worked well. I also cleaned the bed from excess glue-stick using a wet paper towel.
I'm attempting another nGen print at 230°C + 85°C now in this new environment.
Fan still at 50%, no front door. 
First layer sticks well, no signs of any problems yet.....still printing. 

The part did come loose from the cleaned glass. It is however strong and shows no signs of underextrusion.
I'm trying again using 220°C/75°C after some fresh glue-stick. (no intermediate nozzle-cleaning)

Some signs of underextrusion. Aborted to do another cold-pull cleaning using PLA. I did not push until only black PLA exited the nozzle.

Printing again (230°C/85°C fresh glue stick applied after heating up)...
...Severe underextrusion.
Cold-Pulling PLA again. This time pushing until there is no more white nGen.
I'm thinking of exchanging the expensive Teflon-inset in the Ultimaker II hotend.

(230°C/85°C/130% feed rate/fresh glue stick applied after heating up)
Despite 130% material flow and a perfectly clean nozzle, still underextrusion.

the PTFE liner

I took apart my hotend and replaced the PTFE liner. This part needs to be replaced regularly with any kind of filament. Aparently mine was at the end of it's life. (My failed attempts to cold-pull nGen with nGen surely didn't help.) Surely this has caused at least some  of the issues.

Sadly Ultimaker sells this part for 15eur + 20% VAT + 20eur shipping=38eur. Currently the ship sends you to end endless loop of selecting a reseller where you can only select Ultimaker itself to be sent to select a reseller....
This was my last spare one.

You can get them in China but they are probably not glassfiber-reinforced as Ultimaker claims their ones to be. Beware that at least one dealer there seems to oversize them (3.2 instead of 3.0mm on the inside and +0.1mm on the outside.)

Printed again (230°C/85°C/back to 100% feed rate)
Not perfect but not far from it either.

Cura infill speed

Objects with thicker infill have underextrusion in the infill. I forgot the fact, that Cura by default prints infill MUCH faster (80mm/s). Way outside the speed these settings are recommed for.
Since I can't change that mid-print, the photo shows layers where I manually adjusted the flow rate to 110% to compensate and not loose this part.


I accidentally did some extrusion into mid-air and the nGen handled that surprisingly well.

wear and tear

...now doing more testing to compare it's reliability to PLA/PHA.
I started to have underextrusion issues again. These are 2 out of 5 attempts. The others had walls you could shine light through or break with 2 fingers. Could it be that the PTFE liner didn't last for more then 5 prints? Everything else seems to be accounted for (cold pulled, bed cleaned and glue stick re-applied, no moving air in the closed room, bed leveled, correct nozzle diameter, no dust).
I'm currently trying to reduce speed by -20% to see if less pressure helps as I don't have yet another 40eur PTFE liner and receiving UPS shipments in this private home address doesn't work (I have to work during office hours because these are...office hours).

I checked the PTFE liner and, while it didn't show much wear, it did have a grove on the inside.
Luckily I still had 2 of the expensive hotend-kits. Both are no longer of any use after the Olsson Block upgrade. So I took yet another PTFE liner from there.  ..this is getting real expensive.

I'm testing some lower temperature, slower settings from the recommed ones.
At 75°C hopefully the glue stick won't evaporate as quickly and at 220°C the PTFE liner may hold up better.(I'm printing a spring replacement, so the PTFE-liner is not pulled up during a cold-pull.)
infill_speed = 40
print_speed = 40
fan_speed = 50
fan_speed_max = 50
retraction_speed = 45.0
retraction_amount = 4.5

(Note: Inner walls are still too fast with these settings)
  • be more careful in cold-pulling (the PTFE liners are getting real expensive here)
  • use wood glue with water insted of glue sticks. It is sticky and stays sticky when the water evaporates.
  • use colder temperatures and lower speeds.
  • With the lower temperaturs it sticks to the print bed even worse.
  • wood glue doesn't work.

Cleaned, new PTFE liner, spring replaced.... this 18 hours later. (This object must be strong to perform it's function. It has 35% infill and 1.2mm walls for that purpose.)
I fear my reliability-test of Colorfabb nGen filament has failed completely.


Due to feedback as to the size of the spring-replacement, I found out that my Olsson block was not perfectly installed.
This may  or may not have any inpact. The machine has been taken apart, the spring is installed again, the Olsson block is 3mm deeper, so is the nozzle, the heater cartridge is sanded down and inserted deeper, heat sensor is still sticking out by 2mm as before, everything is cleaned again and currently printing a small 10h job at 230°C/85°C and 60mm/s. It starts of perfectly but real results as to the reliability won't come until it has completed 5-10 real world prints.

 preliminary conclusions


 (this is the content of an ngen.ini file that you can import into an Ultimaker II)
infill_speed = 0

preliminary findings

It doesn't seem to me to be as reliable as PLA. Certainly not more reliable. Sadly that's the whole point of this material in the first place.
  1. Cold pull of nGen doesn't work (yet). Clean the nozzle using a cold-pull with PLA!
    1. Push until PLA exits the nozzle. nGen doesn't seem to stick to PLA/PHA. 
    2. Beware of your PTFE liner. Don't go below 70°C to not damage it and/or replace your spring with a printed tube that doesn't give in when pulling. 
  2. Clean glass doesn't stick. Use glue-stick as with PLA!
    1. beware. Glue stick doesn't like high tempearatures. It evaporated quickly and isn't sticky anymore. So apply it after the hot end has heated up and moved upards but before the print starts. 
    2. At 220/75°C it doesn't stick to anything well. At 230/85°C this completely goes away. 
    3. The surface needs to be sticky. Not just rough as with PLA. So glue-stick must be fresh.
  3. Warping! Avoid low tempeatures in the build volume. 85°C bed, no drafts from an air conditioning. A front door is not required.
  4. Obviously keep the bed leveled and cleaned of excess glue-stick.
  5. It may be requied to clean the nozzle very often. This is a good idea anyway.
  6. Chek your Cura settings for infill-speed. By default in "normal" profile it's 80mm/s while these are recommed settings  for just 60mm/s. I got underextrusion in the infill but not in the 30mm/s(outher)+60mm/s(inner) surface layers.



32C3....I broke my 3D printer

I am on the 32 Chaos Communication Congress (CCCFr space in the hackcenter).
The plan was to upgrade my Ultimaker II extended to an Olsson Block and then try some new filaments with the replacable nozzles.
Including to print some important parts that I need in my workshop in the first week of january.

What the installation instructions on the Ultimaker site fail to mention...
you are likely to rip apart your themperature sensor and a new one from Ultimaker costs 55eur including shipping with no choice to NOT use a B2B courier (a very common 1eur part installed into a 3mm tube) including FedEx-shipping (that doesn't work for delivery to private homes. Only business offices open continously Mo-Fr 8-16:00).

That's exactly what happened to me.

"luckily" it's Sunday, the first day of 32C3. So I ordered my replacement to be shipped directly to my hotel and told Ultimaker in an email that it MUST arrive in time or I won't be able to receive it at all.

....somehow I don't think it will actually arrive before I leave Hamburg. Tomorrow I'll call Ultimaker in the Netherlands to see what they think about their chances of this happening. Fedex is a courier service after all. So let's see if they ARE faster then a regular parcel (2 days).

Ultimaker can't ship due to the holidays. Igo3D doesn't list the part but says on the phone that they have it in stock and can ship it right away.

Where igo3D and Ultimaker both failed, another Ultimaker-Forum user stepped in. I was able to pick up a sensor from him, just 2 train stations away from the congress.


BMPCC did not record...solved

(See below for the reason. I found it while typing up all the details for this blog posting.
 The camera is actually working fine!)

I just had a problem with my Blackmagic Pocket Cinema Camera.
I thought I had recorded dozens of snippets of a 2 hour event.
Instead I ended up with 926KB or 640KB or 1 DNG-file (with no wav-file) per clip!
1 Frame!

What I did

Batteries in the BMPCC don't last long. So I had to switch the camera off whenever it was not in use and switch it back on just before recording (and hope whatever I wanted to record was still there when the camera was ready).
The audio recording with the Zoom H6 (that I used as a counter-weight at the back of my shoulder rig) simple ran all the time. I just canged the levels via the remote control on my left handle.

The symptoms

After half of the event was through, I noticed that the red "rec" indicator was glowing but the counter didn't move at all.
Since I can not watch my footage on the BMPCC, I had to go on and hope for the best.

The circumstances

I recorded on 2 different SD-cards. Both "Sandisk Extreme Pro 64GB" that I used before and that always performed flawlessly.
One formated by the camera as HFS+, the other formated by the camera das exFAT.

I used 2 lenses. a Panasonic 12-25mm f2.8 Power-OIS and a Panasonic 7-14mm.

I used 3 or 4 batteries.

I recorded just after the camera was switched on, after it had been running a minute and after it had recorded and was idle for a minute.

I recorded as ProRes422HQ, ProRes422 and as  RAW in 1920x1080p25.
ISO 1600 and 800, 180° shutter, 7000K white balance....
I think I found the problem. It was set to "time lapse interval 10min".
Just below the white balance setting.


Scripting Geomagic Design Studio / Alibre Design

I've been using Alibre Design Express, then Alibre Design Personal Edition, ... now Geomagic Design Studio for years now. Lately for my robot arm project, I had the need for involute gears and stunbled across this one.


Aparently someone wrote an application that uses the (very limited) API to write a Python script interpreter that can create and modify designs in the CAD program. It apears to exist for quite some time now and was formerly known as ADScript. A blog named Britishideas posted about it back in 2013 with a series of cool examples. WizoScript (as it is now called) already contains functions to make gears. Although it seems to not do the undercuts properly (as aparently many involute gear generators do).


Beware that the examples all expect the planes to have english names. In a German Geomagic Design you need to change "XY-Plane" to "XY-Ebene" for the examples to work.

There is more!

  • BritishIdeas: Assembly Export utility that orients each part properly for 3D printing! 
(Just create a plane from any face and name it "Bottom" in each part)
(Just assign an extruder-number to each color used in the assembly.)
(I tried that with the included KeyShot recently and found it to be GREAT! It's a terribly trivial and fast workflow.)



My new GPG / PGP key

Hash: SHA1,SHA512

My old GPG/PGP key  was getting really...old. The crypto that was state of the art back then, is no longer considered secure and it was time to roll over to a new key.

This is my new GPG key:  61845B5C

Fingerprint:E57F 2A9C 5C20 2FAB 6784  F7DE 0EE9 A625 6184 5B5C

It is valid until 2015-12-13.

I will probably extend the validity then.

It is replacing my OLD GPG key: 7F58-4F9E-4DD9-D1C4

I set up my old key to expire in 2 weeks.
Version: GnuPG/MacGPG2 v2
Comment: GPGTools - https://gpgtools.org


 The signature is on the copy&pasted ASCII text above without the HTML.


Lenovo P70 or P50 Hackingtosh

The Plan

My current 2011 Macbook is great and enough except for the old graphics card.
I want a Macbook with
  • >2TB of disk space (=mechanical drives),
  • lots of upgradable memory (>=32GB)
  • Thunderbolt 2 or 3 for my existing Thunderbold 2 hardware
  • A CUDA 1.2 capable graphics card with lots of memory
These are hard requirements

It is supposed to run
  • DaVincy Resolve  
  • Final Cut Pro X
  • VMWare for my Geomagic Studio CAD
  • Dual Boot into Windows  >=8.1 for the Kinect V2
  • Android Studio
 Thus I set my mind on the Lenovo P70 (2 TB3 ports, 2 HDD+1SDD) or P50 (1 TBB3 port, 1 HDD+1SDD).

This blog posting is being updated as the project progresses.


P70 hardware notes


NVIDIA Quadro M5000M 8 GB






Intel Dual Band Wireless-AC/B/G/N 8260, Bluetooth-Version 4.0 vPro

color sensor


pointing device(s)

support? for multiple fingers?

card reader






  • "Also I recommend Unibeast to do the install, then Multibeast to do the drivers post-install bit... Clover was too advanced, I didn't get it as well." 
  • "Clover, however, provides a more native experience, a modern UI, faster boot times, iMessage/iCloud/Facetime support, on-the-fly kext patching for things like SATA, Graphics, Power Management, etc. General consensus is that if you have a newer configuration with a UEFI motherboard, you should choose Clover method."
  • Wat are kext files?



Just collecting information yet since I never build a hackingtosh yet.