03 apr

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LulzBot Unboxing

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Gemt under: Projekter

29 mar

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Arduino fylder 10år – Hal9k ønsker tillykke

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Arduino workshop på Platform4

Arduino workshop på Platform4 med Let-Elektronik

Hal9k, Let-Elektronik og Platform4 slog i dag plalterne sammen og fejrede Arduino’s 10års fødselsdag. Let-Elektronik bidrog med en workshop om brug af Arduino, Platform4 med kaffe, og Hal9k gav en række praktiske eksempler på hvordan Arduinoer kan bruges ud i den virkelige verden. Stort tillykke til Arduino – vi ser frem til de næste 10år.

Gemt under: Events, HAL9k

26 mar

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Hal9k vinder LulzBot give-away konkurrence

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Er der en investering Hal9k har lavet som for længst har tjent sig selv hjem i små og store projekter, så er der vores lille DIY 3D printer, en PrintrBot Jr. Desværre så har mean-time-before-failure været lidt lav og den har generelt været lidt lunefuld at arbejde med, omend Mads og Anders har fået tæmmet den rimelig godt efterhånden.  Vi er derfor ekstremt glade for at kunne annoncere at Hal9k har vundet en LulzBot TAZ 3D printer.

LulzBot TAZ 3 3D printer

LulzBot TAZ 3 3D printer

Se annonceringen af vindere her: https://www.lulzbot.com/blog/announcing-lulzbot-hackerspace-giveaway-2014-winners

Vi er selvfølgelig meget stolte, og glæder os utrolig meget til de meget forbedrede muligheder vi får med den nye LulzBot TAZ 3D printer. Der er allerede planlagt de første par projekter, som vi selvfølgelig nok skal skrive om når de er lidt længere…

Der skal lyde en stor tak til LulzBot, for at holde konkurrencen, men også for at støtte op om fri/åben software og hardware.

Gemt under: HAL9k, News, Udvalgte posts

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06 mar

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Lasercutter

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Jeg begyndte for snart lang tid siden at pusle med at lave en gammel Roland plotter om til en lasercutter. Her er en video der viser den skære i en gammel 3½ tomme diskette:

Mekanikken og elektronikken fra plotteren er genbrugt uændret, dog har jeg hævet X- og Y-aksen 3-4 cm så der er plads til større emner:

Laseren er en 800 mW IR-diodelaser fra kalecnc.com. En Arduino, kontrolleret fra en PC via USB, kommunikerer med plotteren via RS-232 og styrer også laseren vha. PWM.

Resultatet af at skære i disketten:

Gemt under: Projekter

17 jan

Kommentarer slået fra

Reparere billige Denver Wake-up lampe

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Jeg havde to billige wake-up lamper fra Harald Nyborg der begge fejlede med samme symptomer: lyset var permanent tændt så snart strømmen var sat til, i stedet for at kunne slukkes og dæmpes. Grunden til nr. 2 blev købt var at nr. 1 fejlede efter garantien udløb, og til 200,- kunne det jo knapt betale sig at kigge på det. Da nr. 2 fejlede med samme symptom blev jeg stædig og irriteret over kun at kunne lave “brug-og-smid-væk”.

Hvor svært kunne det være at reparere noget billigt Kina-skrammel? Ikke ret svært viste det sig. Skidtet blev åbnet, og viser ret tydeligt hvor meget kvalitet man får for ikke ret mange penge:
Billigt print
Efter lidt konsultation af nogle af de mere elektronik-kyndige fik vi lokaliseret fejlen til en Triac der nok var brændt af. Desværre havde producenten valgt at slibe teksten af, så det var umuligt at se hvilken chip det var (sådan noget svineri!) — det virkede dog heldigvis med en helt standard BT137. På den ene lampe var der også brændt en modstand af: den var helt forkullet, men heldigvis kunne vi se på den anden hvilken modstand det var.
Ny triac

Efter at have loddet ny triac og modstand på, virkede lamperne som nye :-)

Kan det betale sig at reparere billigt Kina-skrammel der er gået i stykker? Måske ikke økonomisk, til gengæld risikerer man at lære noget. Og så er det jo ret fedt at kunne fixe ting selv, i stedet for kun at kunne købe og smide væk!

Gemt under: Projekter

14 jun

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PrintrBot Jr getting closer to working state

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Yesterday our PrintrBot Jr made its first useful prints!

DSC_0078

It has taken quite some effort to get to this stage, mostly because I knew nothing about 3d-printers when we started the project, and the original builders were out of town (but have now returned).

DSC_0059

We have made quite some modifications to the printer, mostly inspired by this blog post. Specifically we have (as documented on our wiki):

  • Upgraded belts to GT2, in our case with a 20-tooth pulley, all ordered from 3dnielsen.dk (although the GT2 belt seems quite expensive). This has definitely improved our accuracy, now the X- and Y-axis are at a nice even 80 steps/mm, as calculated by the very awesome RepRap Calculator.
  • Replaced some of the LM8UU ball bearings on the Y-axis because they were very unstable. This was probably the most important modification, although I don’t know if there is a difference in quality between the old and the new bearings. We still use the old bearings on the X-axis, they seem okay.
  • Added cork mufflers to the motors. I doubt this is essential or even provides much benefit on the Printrbot Jr because the motors touch the chassis at multiple points, but they are cheap and can be retro-fitted with little effort.
  • Made sure the circular ball bearings were properly tightened such that the middle part, that is not supposed to turn (as I learned), does not turn. Additionally, add wafers to get the bearings height aligned with the belts.
  • Replaced the Z-axis threaded rod with a metric one: This is an almost too easy upgrade to not do, as an M8 rod fits the Printrbot Jr without any problems. The benefit (as can be calculated by the very awesome RepRap Calculator) is that the Z-axis will need an even number of steps to move from one layer to the next. As an example, consider a layer height of 0.3 mm with the old 5/16″ rod: this will result in an error of +1.1217541105598867mm over 10cm, where with an M8 rod there is no such error.
  • We have not yet added a brass nut to the Z-axis because we have been unable to find one locally. An additional benefit of going for an M8 rod is that it requires no further modifications (unlike an M6, which needs a printed bit), but the M8 can still be incrementally improved, e.g. http://www.thingiverse.com/thing:64738.

At this point our main problem is with adhesion of the first layer. We have experimented with a glass plate because we want to add a heated bed. We learned a couple of lessons from that, namely:

  • Kapton tape on top of glass is not very adhesive, if it is not heated.
  • We experimented with hair-spray. Hair-spray on painter’s tape is not a good idea, it makes the tape bubble and dissolves it a bit.
  • Printing on glass with hair-spray is almost doable, but not quite convenient.
  • Adding the glass plate on top of the original wood plate adds quite a bit of height, and the plate adjustment screws cannot be tightened too much because two of them will then hit screws on the chassis, resulting in the X-axis crashing. A good solution could be a longer Z-axis stop screw.

At this point we are back to printing on painter’s tape directly on top of the original wood plate. It seems sufficiently flat for the small prints we have done until now. A heated bed is definitely a thing to do, we plan to mill a PCB on our Bungard machine, following something like http://www.thingiverse.com/thing:91403 (however note that I read double-sided PCB is recommended, because heating only one side will result in the PCB warping).

With regards to calibrating the axis for the correct number of steps the instructions at http://reprap.org/wiki/Calibration has the following quote:

The following information concerning steps/mm adjustments is outdated. It has since been agreed that steps/mm should be set to the exact calculated values since printing with non-ideal steps/mm results in an accurate test piece, but makes the dimensions on every other part even more inaccurate.

… which sort of appeals to me because it is less labor, and the correct solution can be calculated. Thus, we are now using calculated values from the very awesome RepRap Calculator: X-axis: 80 steps/mm, Y-axis: 80 steps/mm, Z-axis: 2560 steps/mm. The extruder is currently at 600 steps/mm, but this is per calibration; the PrintrBot documentation mentions a default of 569 steps/mm.

With all this effort we are now able to print various small items improving the printer:

  • Z-axis bolt holder: http://www.thingiverse.com/thing:78023. The derivation was too tight for our build, the original fits snugly.
  • 4 bed levellers: http://www.thingiverse.com/thing:90336. Nice little addition, and additionally it validated that our calibration was not totally off: one nut could be inserted by hand, the three others only needed a little “Jysk kærlighed” aka. a very small smack with a hammer.
  • New gears for the extruder: http://www.thingiverse.com/thing:26243. Our large gear already has a small crack from the original assembly, and some of the teeth on the large gear have started grinding leading to slips in movement, so we will need new ones at some point. We have printed the small gear, and will go for the large one soon.
  • An 8-bit heart, to try to explain to wifes and girlfriends what we do: http://www.thingiverse.com/thing:21795 :-)

 

03 jun

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Billeder fra Åbent Hus

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Her lidt billeder fra Åbent Hus arrangementet. Tak til alle der deltog og medlemmerne som gav en hånd med. Det var en kæmpe success og helt sikkert noget vi vil gentage næste år!!!

Gemt under: HAL9k, Udvalgte posts

27 maj

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Torsdagsbilleder

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Her lidt billeder fra sidste torsdag!

Gemt under: HAL9k