Tales of a modern life: 2015

2015-12-29

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.

bridging

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.)

[material]
name=NGen
temperature=220
bed_temperature=75
infill_speed = 40
print_speed = 40
fan_speed = 50
fan_speed_max = 50
flow=100
retraction_speed = 45.0
retraction_amount = 4.5
diameter=2.85

(Note: Inner walls are still too fast with these settings)

Experiment:

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.

Result:

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.

repairs

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

ngen.ini

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

[material]
name=NGen
temperature=230
bed_temperature=85
fan_speed=50
flow=100
diameter=2.85
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.

Cold pull of nGen doesn't work (yet). Clean the nozzle using a cold-pull with PLA!

Push until PLA exits the nozzle. nGen doesn't seem to stick to PLA/PHA.
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.

Clean glass doesn't stick. Use glue-stick as with PLA!

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.
At 220/75°C it doesn't stick to anything well. At 230/85°C this completely goes away.
The surface needs to be sticky. Not just rough as with PLA. So glue-stick must be fresh.

Warping! Avoid low tempeatures in the build volume. 85°C bed, no drafts from an air conditioning. A front door is not required.
Obviously keep the bed leveled and cleaned of excess glue-stick.
It may be requied to clean the nozzle very often. This is a good idea anyway.
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.

2015-12-27

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).

Update:
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.

Update:
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.

2015-12-23

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....
DAMN!!!
I think I found the problem. It was set to "time lapse interval 10min".
Just below the white balance setting.

2015-12-17

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.

WizoScript

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).

Examples

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.

BritishIdeas: Introduction to scripting
BritishIdeas: Python-Scripting in FreeCAD
BritishIdeas: Create an antire part library of bolts from one template.
BritishIdeas: Involute Gears in Alibre Design

much easier compared to a DXF based involute gear generator

BritishIdeas: Scripting easy to 3D print accurate holes ("Polyholes")

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)

BritishIdeas: using that utility to export multi-material/multi-color designs!

(Just assign an extruder-number to each color used in the assembly.)

BritishIdeas: Rendering with Blender

(I tried that with the included KeyShot recently and found it to be GREAT! It's a terribly trivial and fast workflow.)

2015-12-14

My new GPG / PGP key

-----BEGIN PGP SIGNED MESSAGE-----
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.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG/MacGPG2 v2
Comment: GPGTools - https://gpgtools.org
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=Un2Y
-----END PGP SIGNATURE-----

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

2015-12-08

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

graphics

NVIDIA Quadro M5000M 8 GB
supported?

sound

supported?

bluetooth

supported?

wifi

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

color sensor

supported?

pointing device(s)

support? for multiple fingers?

card reader

supported?

camera

supported?

Software

"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?

Status

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

Order a P70 from Lenovo at -10%
EosHD thread that gave me the idea and where I hope to find pointers
TonyMacX86 seems to keep lists of supported hardware
How to Install OS X Yosemite using Clover

clover

2015-11-27

nGen Filament, Olsom Block and Front Door ...upgrading the UM2ex

I'm upgrading my Ultimaker II extended.

nGen

Up to now I workes with the Colorfabb PHA/PLA mix. It's very accurate and thus I found it to be very reliable. (Their shipping options of DHL-Express and UPS are a mess. Both are pure Business2Business courier services and are not fit for delivering to home addresses AT ALL.)

Now I ordered 4 large spools of the new nGen filament to use with mechanical parts.
It's supposed to be even more reliable and that's my primary criteria.

UM forum thread about experiences (German)
nGen page lists it's 85°C glass transition temperat

Olson Block

I'm also upgrading my Ultimaker II extended with an Olson block, a set of nozzles and a steel nozzle.
I hope to be able to do thinner layers with larger nozzles (at the same, minimum flow rate) and finer horizontal detail with finer nozzles as well as give copper-fill a try with the steel nozzle.

ABS

I also ordered a front door for the printer to try ABS and Acetone smoothing for non-mechanical parts that require a perfect surface finish.

2015-11-16

Fun with robot arms

The Plan

I'm planning on building a large robot arm using stepper motors.
It shall execute G-Code with absolute, cartesian coordinates.
The job it so assist with some repetitive tasks in the workshop when casting small batches of parts that for quality, material or number can't be 3D printed individually.

As with all my blog postings, I'll keep updating this one.
It documents one, single project in all (public) details and all findings as I progress.

Start Small

To start small, I got myself a laser cut hobby-servo driven robot arm and attached it to an Arduino Uno with my usual LCD+Keypad Shield.

The objective is to get my inverse kinematic calculations right and to see how much can be acomplished with this much simpler setup already.
I also wish to experiment with absolute posistion feedback by attaching and ADC channel of the Arduino to the potentiometers of the hobby servos (maybe using a multiplexer to get all of them).

Hobby Servo issues

So far I identified a number of issues with hobby servos, that I want to document here:

Power supply

Running the Arduino from USB you only have enough power for 1 servo.
Adding a 12V 1.5A power supply for the passive step-down DC-DC-converter of the Arduino Uno is enough for 2 service. Only the 12V supply works for 1 servo only.
The path to go seems to be a 5V supply powering the servos only, pulled to a common ground with the Arduino (so the PWM control signal has the right right voltage level).

If the display gets dark, the servo motion jerky, the software resets of ommits steps, then you are lacking power.

Jerky movement

The default servo.h that comes with the Arduino SDK allows for an integer of 0-90 (degrees).
This isn't a very fine control.
I found in this blog posting that:
It also assumes minimum and maximum PWM timings that are beyond the range of many servos.
You should set minimum and maximum milliseconds in the attach() call and use the servo.writeMicroseconds(int milliseconds) call with 1000-2000 ms. This allows for a much finer control and stays within the allowed range for your servos.

G-Code interpreters

I'm currently evaluating options for g-code interpretation.
What I want is the g-code to contain X,Y,Z coordinates, gripper opened/closed and interpret a number of micro switches as probe inputs or end-stops.

GRBL on an Arduino seems to be a common option but is limited to 3 axis, drives the Arduino at the absolute limit of it's capacity and only has a serial/usb-serial connection.
A Raspberry Pi CNC-Head is a GRBL-running, Arduino-compatible Atmel board as a shield for a Raspberry Pi. For 3 axis maximum this would be a simple solution.

I'd rather go with a Raspberry Pi that can be trontrolled via Ethernet and communicate with other machines to coordinate and integrate. E.g. tell another robot that it has placed an item or be informed that there is one of multiple possible things to be picked up and moved.

I found the L6470 dual-stepper controllers. Simply calling them stepper drivers is wrong because they do their own timing, support microstepping, take end-position, maximum speed, acceleration+decelleration as inputs, support a hard-stop input directly, have a number of safety checks in there,... and work via SPI. Even daisy chained, so multiple axis stay in sync.
(Simple "stepper drivers" just take DIR+STEP input pins.)
Of that that still needs the actual interpreter -part.
I'll have a look at rs274ngc . It seems to be the old base for the EMC g-code interpreter.

Next steps

Next I'll

convert my test-code to use writeMicroseconds()
map the servo-locations to angles
implement my inverse kinematic code.

Designing the Real Thing [TM]

TODO...

manipulator

My manipulator is a fairly standard gripper design that has been modified to perfectly grip one specific type of container.
Nothing special about it, except that I was too lazy to design proper gears and thus am simply using 3 9g servos opposing each other. Each gets the same signal and each moves one side of the gripper.
These things cost about 1.20eur, so I don't bother with the time to save one.

Y+Z axis (arm)

I'm definately going for an arm-type that always keeps the tool horizontal automatically.
That means less degrees of motion and thus more stiffness. (And less things to worry about.)

I'm also opting for maximum stiffness and am using bearings everywhere, so the arm stays accurate and lasts for a great many moving cycles without any wear and with little resistance.
For the attachment to the stepper motors, I'm thinking of using this:

involute spur gear generator (with proper undercuts)

X axis (base)

The arm is not to have a rotational base but slide along a table-edge.
Linear motion systems for >=3m length are hard to find, so I'm thingking about having it drive between 2 aluminium profiles using tracks.

Another option would be CNC milled rails in wood.

on thingiverse
involute gear part of the Guerrilla guide to CNC machining, mold making, and resin casting

2015-11-05

Tapatalk and ACCESS_COARSE_LOCATION

The last update for the Tapatalk forum reader software now needs the ACCESS_COARSE_LOCATION permission.
Obviously for reading web-forums there is absolutely no need for this information.

No Android except CyanogenMod with special privacy settings for this one app or Android 6 with as-of-yet unknown required settings would even ask the user.
Let alone allow the user to disable location access in the first place.
So almost all users out there will just have their coarse location inquired and handled without even knowing about it, without their consent and with no requirement to provide this information for the functioning of the app whatsoever.

Aparently it requests the location every time the app starts, a fragment becomes visible and when the app ends without any visible feature using the information.

Here is the answer from Tapatalk support:

Thanks for contacting us. Location data is not required, and you have the option to not provide location data.

You can also change your location permission by going to Settings>Scroll to bottom to the apps and select Tapatalk>Location. You can change the setting to Never. (Remark: This only exists in CyanogenMod)

All information collected is non-Personally Identifiable Information.

2015-09-24

The perfect messenger

There are so many messengers around but none of them seems to meet the criteria I have for a reasonably secure messenger.
Since this gets discussed over and over again, here are:

My Requirements for a messenger service

security

If there are one or many central operators/brokers/hubs, they can not read ANY messages past, present or future
encryption is always end to end.
I can change between my different devices and continue a chat (key exchange between my devices)
end to end encrypted group chats (this basically means changing keys and distributing them to all participants whenever someone joins or parts)

privacy

I can have multiple full identities (not just usernames as aliases that share a profile image+text+contacts-list)
I can receive and send messages as all my identities at the same time (no logout+login)
Nobody can find out IF I am using this type of messenger at all by knowing my phone number
Neither my phone number nor any other information about my real world identity are stored with the operator (exception for temporary storage of IPv6/IPv4 addresses)
optional: If there are one or many central operators/brokers/hubs, they can not know the identities that communicate with each other
optional: I can set up my own server/hub/broker

usability

texts, images and locations can be shared
one to one and group chat
there is a chat history that I can access from all my devices (my be stored encrypted with my own key on a server or local on the client)
optional: videos can be shared
optional: voice and/or video -chat
optional: voice and/or video group-chat

2015-09-19

Nexus 7 repairs

The USB port on my generation 1 Nexus 7 tablet (with GSM SIM card) was getting wonky and more often then not it refused to charge.
Luckily the replacement part is cheap.

...while at it I got myself a very nice set of phone-opening tools with scratch-free plastic hooks, spatulas, suction cups, wedges, cleaning tools, scalpels, metric <2mm a="" and="" full="" nbsp="" of="" p="" screwdrivers="" set="" tiny="" torxes="">...I just can't resist a good set of tools.

2015-09-11

Ciclop 3D scanner

old and busted: FabScan

I have a FabScan Cube (build from the kit sold at Wattenrott) for quite some time now. However I'm massively disappointed by the software. The last software (100.9) that supports MacOS is neolithic and can no longer be used since MacOS 10.9 "Mavericks".
There is a processing script to use the scanner but calibrating it is a game of guessing and source code manipulation. If I got a scan out of it at all (very touchy about environmental light), it was all ball shaped and incomplete.
A new software (that requires a Raspberry Pi) was promised to be released half a year ago...it never happened.

new: Ciclop

http://diwo.bq.com/en/presentacion-ciclop-horus/

So being fed up with the FabScan, I got myself a completely new Ciclop scanner as a factory made kit. The parts are 3D printed very well and everything more or less fits.
You can 3D print the parts yourself and just get an electronics kit and a number of nuts, bolts and (metric) threaded rods.

The scanner is not stable against torsion forces. So it must rest on a perfectly flat surface.
The stepper movement is not very gentle. So any flexible object will move around during scanning.
It does require 2 USB ports and 1 power socket (to power the stepper motor).

Horus

Horus is the software that is supposed to operate with the Ciclop.
It looks very easy to use but seems to still have some practival issues in doing the automatic calibration. Notable one but where it will constantly tell you that the stepper direction is wrong.

I haven't gotten it to scan using 2 (or more) lasers yet as this results in 2 scans that don't match up at all. With a single laser it has a very limited scan volume and your object should contain all parts of the axis of rotation inside itself but it does work.
I haven't gotten around to check if the physical dimensions as replicated precisely yet and that there are no distortions.

2015-07-14

Debugging Android Wear support for K-9 Mail

I started a branch to develop proper Android Wear support for the popular K-9 mail client.
The last few weeks I was grinding on a strange error.
It would create PendingIntents for the different actions for each individual message.
Because on Wear the messages are shown as a stack and you can act on each of them.

What I found was that it would issue the right action...on the wrong message.
Always the firt message of the notificaiton.

I think I found it.
PendingIntents are not created. They are requested.
If the same PendingIntent already exists, it is returned.
The "same" means same Action, same Data, ... But not same Extras.
The message ID was transmitted as an Extra.

This was no problem up to now, because most people you would only ever have one notification.
But even in the existing code this bug would have hit (and hit hard inc ase of the "delete" action) if you have multiple accounts configured and choose an action on the second notification, you would get it with the parameters of the same action on the first notification.

I'm considering the Android Wear branch of K-9 to be BETA-quality now
and am using it myself daily to find bugs.

2015-07-04

printing working threads on an Ultimaker II extended

Even at 20 micron and less layer height, most theads have too many threads-per-millimeter/threads-per-inch to be reasonably 3D printed.
I'm regularly using a thread cutter on 3D printed parts to do this instead.

Now I have some solenoid valves with a very strange NPT1/2 thread.
This is a very rare imperial sized, trapezoidal (getting smaller, not staying at one diameter)
thread with only 1,814mm per thread instead of 1mm.
(BTW NPT1/2 isn't even near 1/2" in size. )
So it looks like a perfect test to 3D print the thread without cutting.

Due to the extreme heat recently, I had some issues with my Ultimaker II extended at first.

But int he end it worked out.
Here is the same thread printed in normal quality, high quality(at 200% speed) and ulti quality (40 micron).
The (at first) strange result it, that the thread printed at normal quality was far more clean then the other ones.
...that is until you think about a thread as one giant overhang. A thicker layer-height seems to work better for overhangs as it's not as compressed by the next layer. This is no problem in solid areas bu when there is air below the layer...you can guess.

Fits perfectly!

2015-05-02

implementing K9 mail wear support - stacked notification issue

I'm currently implementing K9 issue 619 "add Andoid Wear Support".
You can find the code in branch issue-619_AndroidWearSupport.
Basic support to delete(if no confirmation on the phone is configured), archive and spam all messages of a given notification is done and working well.

My currently issue is that I added stacked notification exactly as documented.
The problematic code starts in MessagingController:4941 .

My summary notifcation is only shown on the phone, not the watch. OK.
BUT: my stacked notifications (With setGroup(...) but no setGroupSummary(true) are ALSO shown on the phone. These are supposed to be only visible on the watch.
Every documentation, example and StackOverflow posting shows me that I'm doing everything right and that there should be no way for this to ever happen.

I guess I need an additional pair of eyes to look through at this code.

2015-04-28

Added Android Wear support for K9

I just added some very first Android Wear support for the K9 mailer.
The default actions where unsatisfactory as "reply" doesn't work on a watch unless you implement the voice recognition feature. "delete" shouldn't be offered if "confirm delete" is active and thus the user needs to confirm an action on the phone that he/she initiated on the watch.

For the time being I added "delete" (if confirm is off), "archive" and "spam".
Extensive checks are done to make sure these actions are possible. Since afterwards the user can not be informed about them failing as Toasts will apear on the phone, not the watch.

The plan is to

have the user select what 3 actions to show on watch+phone for single messages and groups of new messages
stack the notifications about multiple new messages
add the ability to reply using voice input

2015-04-26

Ultimaker II Glue Stick issues

Help!

As glue-stick I have used the triangular Teasy EasyStick so far and they worked great.
However now the winter is gone and I had to move the printer to another city.
It's not as cool and the room is much smaller.
The ambient temperatures are rising above 23°C at 50° humidity indoors with a 75°C or 60°C heated bed and nearly no air flow in the tiny room and the glue stick completely evaporates within 10-30 seconds.

Filament either doesn't stick (if applied too early) or objects curl up and detach from the glass (if applied right before the print starts).

What European household brand of glue stick works in high temperatures? (Sorry, no Elmer's Invisible Glue on the right side of the pond.)
I don't have wood glue in the house but I'll try to get some and mix it with water to try.
I don't like to apply hair spray directly and the brand I tried doesn't work when applied to a piece of paper and then rubbed onto the glass.

2015-03-29

Ultimaker II servicing

My replacement glass fiber reinforced PTFE liners for the Ultimaker II hotend arrived.
While replacing parts I looked up just how long this Ultimaker II has been printing so far:
machine has been on for 2954 hours
printing for 1855 hours using 1166 meters of 2.85mm filament.

The PTFE is pretty banged up for sure.

In the forum people talk about 300-500 hours before seeing serious degradation.

I replaced the PTFE,
doing a cold-pull cleaning in the process,
Added a piece of aluminium foil,
cleaned the extruder gears
cleaned the bed

...now let's start with the next 2000 hours of printing.

PS:
I just found out you can get them (for a premium price) at Reichelt or
remakes (no mention of glass fiber) at another German Store and in China too.
Without Fedex.

2015-03-23

LPG Preismelder Android app updated

Project history

Previous project: none
last step: Improvements to LPG/CNG Price Reporter
current posting
next step: LPG Preismelder Android app updated again
Next project: Android App for Blackmagic Pocket Cinema Camera 4K

After a long time, I have finally found the time to update my old fuelstation finder for GPL/CNG fuled cars to a current Maps API and current design language.
The buggy OpenStreetMap code had to go. For the time being there is only the Google Map now.
The overlays are completely redone,
the layout of cause uses proper fragements,
the geolocation API usage and settings handling is updated as well.

Links:

App on Google Play

2015-03-18

Google Code to Github Migration tool failing

Due to Google Code shutting down,
I scheduled the OpenStreetMap Vespucci Map editor project for Android to be migrated tonight (all commits done).
However the migration tool offered seems to consistently fail. :/
And I'm not alone.
Github has identified files >100Mb to be the most prominent cause but since my and other people's entire repository is considerably smaller, that isn't the case here.

2015-03-16

Kevin Lee

I just found this excellent blog by Kevin "0x7D" Lee.

Must reach these later:

3D Printed Precision Paste Dispenser
https://0x7d.com/2014/08/41-gearbox-for-nema-17-stepper-motors/ (with "Guide to Designing Gears for 3D Printing in Autodesk Inventor")

He seems to be using the same printer I am (Ultimaker II) in the same way (very high precision parts at maximum reliability).
Not just "buy a printer and print trinkets I found from Youmagine or Thingiverse"

Ultimaker II issues

I'm using my Ultimaker II a lot and I'm taking good care of a clean nozzle.

Now I'm starting to get underextrusion issues.

I cleaned the bed of any glue stick residue
leveled the bed
cleaned the nozzle using cold pull until I could see through
Extruder tension was at minimum, I tightened it until the indicator was in the center

The issue is still there. Just with a bit more skipping then before
It started last week with an object that requries lots of retraction and happened after hours of printing.
Usually my objects need no or nearly no retraction. So I didn't think much about it.
How it happens in a perfectly cleaned and recalibrated printer within the first layer.

Next steps
I fear my PTFE liner may be completely used up.
I did order 2 new ones but since they get delivered with FedEx, they may not reach me.
(No delivery after work hours and no possibility for me to pick them up.)

I'll loosen the extruder tension again and redo the cleaning.
Maybe I just over-tightened the extruder.

Results
The underextrusion returned within minutes in the first layer.
I lowered the extruder tension and set my first layer to run at 50% speed until my replacement parts arrive.
This helped a lot.

2015-03-12

Ultimaker Pro and Contra

3D printer (Ultimaker II) working on another 26h build...
That's a small one by my standards. While I'm away for the weekend it will do another 3 day job and I have even run extremely detailed 40 and 100h jobs without any hickup.
...at 20 Micron, that's 0.02mm compared to 0.1 or 0.2 or 0.25mm in other printers.
...out of the box with good quality filament.

Reliability

I just love the reliability. Never seen anything like it with RepMan 3.0/3.2, ThingOMatic (on the contrary), Makibox. For exactly that teason I'll never, ever again buy a Makerbox Industries product.
(Apart from "Takerbot")
I hope Makerbot will get a lot of competition, now that Ultimaker has extended from Europe to North America.

Maintenance

You should regularly

check extruder tension. The indicator on the side should not be in the upmost position. Insert an allen key/hex key in the top and turn left (out) to make it tighter, right (in) to make it loose
check bed leveling
clean your nozzle with a cold pull (manually push filament through, then cool to 70-90°C and pull it out). Don't pull or push too hard as the PTFE liner is only held down by a spring and downward filament movement. It's als called the "atomic method" but it was known long before there was a U2 forum.
clean the bed of residue glue stick with a wet paper towel, reapply a very thin layer of new glue

Maximum spool size

Given that reliability, it's printing A LOT. 750g spools are extremely inconvenient.
These 2.2Kg spools from Colorfabb from are great.
I'd have loved 5Kg or 20Kg spools (both sizes I used before, stored next to older printers using garden hose holders)
but 2.2Kg is the maximum the Ultimaker II can hold.
Everything else would be wider and lower then the body of the printer itself.

The Near Future

I can't wait for the Ultimaker II Extended, that I already preordered!
The increased hight combined with the reliability of an U2 is exactly what I need for my parts.

Spare parts and shipping

The only downside is that is demanding steep prices for the wear parts (PTFE liner, nozzle, hot end pack), dubling the price with their enourmous shipping fees and seems to use express curiers.

(Of cause if this is a minor issue and if it's the only thing I can complain about, that says a lot about the quality and reliability. I'm using this printer nearly constantly day and night.)

Express meaning it takes twice as long and may not reach you at all if you just so happen to work during the day. Curiers don't have post offices everywhere where you can pick up your packages after hours.
They often don't have storage locations in the same city reachable without a car and they don't deliver or offer pickup on weekends.
So for me they are evil as I work Monday to Friday in different cities.
Express curier services are for and ONLY for deliveries to businesses that have offices open 9-5.
NOT for delivering to private citizen who work in these offices 9-5 and are thus not at home.
They are NOT replacements for postal services. They where never intended to be.
With the new Ulti-Quality setting the first layer needs a lot of attention and benefits from reduced speed and increased filament flow.
After that it's great. I don't mind that that it takes ages as it reduces the time I spend in sanding and other post processing after the machine has finished it's job.

2015-02-26

Free OpenFx plugins for Resolve

Since Resolve (and the free Resolve Lite) doesn't support one OpenFX method,
the Openfx-Misc set of free plugins needed an update.
After a discussion in the Blackmagic forum, this has now happened.
I was able to compile them without any issues and they do show up in my Resolve 11 Lite on MacOS.

On a side node: openfx_yadif (for deinterlacing) is still crashing in export after 5-20 frames. It does work in the color tab. Even with playback running.

2015-02-10

Searching for a monitor

I'm thinking about a wide color gamut display for Color Grading in Blackmagic design - Davincy Resolve.
It will also be used in Final Cut Pro X.
...and VLC. ;)

Options

The HP Dreamcolor Z27x (720eur 2048 x 1556)
sems to be more affordable compoared to
the EIZO ColorEdge CG247-BK (1500eur 1.920 x 1.200)
or EIZO ColorEdge CG277-BK (2000eur 2.560 x 1.440).
You save 100-200eur for the calibration device but both need the Ultrastudio Mini Monitor as an added cost factor.

NOT the smaller Z24x (400-550eur 1920x1200) because
* that doesn't calibrate without a PC like the Z27x does and the software only exists for Windows.
(http://www.liftgammagain.com/forum/index.php?threads/new-hp-dreamcolor-monitors-4k-capable.2694/page-6)
* it doesn't have the same kind of panel or the same precision as the Z27x
http://www.liftgammagain.com/forum/index.php?threads/new-hp-dreamcolor-monitors-4k-capable.2694/page-8

100% sRGB Coverage
100% Adobe RGB Coverage
100% BT. 709 Color Coverage
99% of DCI-P3 Coverage

Setup

I'm planning to use the
Blackmagic Ultrastudio Mini Monitor
to output 10bit 4:2:2 YUV
since the newer Z27x supports the DreamColor Engine with YUV and not only RGB now and the Mini Monitor is limited to YUV only.

Calibration

One problem I have is that the cheapest, supported calibration device (HP DreamColor Calibration Solution(B1F63AA)) for the Z27x seems to be half the price of the entire monitor (200eur). :/

A Spider4Pro or Spider4Elite that cold also calibrate my other displays and laptops would not work with the internal LUT of this display. :/
On the other hand the B1F63AA is much more accurate then the Spider will ever be.

Evaluation

Z27x
720eur + 100eur + 150eur = 720eur

less quality control
no sun shade
4K downscaling, 1:1 4 corners + center + dynamic panning
2 DisplayPort 1 HDMI
100% sRGB Coverage
100% Adobe RGB Coverage
100% BT. 709 Color Coverage
99% of DCI-P3 Coverage

CG247-BK
1500eur + 100eur = 1600eur.

100% sRGB
99% AdobeRGB
100% Rec709
95,4%DCI

CG277-BK
2000eur + 100eur = 2100eur.

4K downscaling and 1:1 4 corners
100% sRGB
99% AdobeRGB
100% Rec709
DCI: 93%

2015-01-18

About screws and screwheads

I just found this interesting posting about different types of screw-head and -drivers in Google+.
"When a Phillips is not a Phillips!" by arcticpenguin