Upgrade YOOCNC6040 from LPT to USB

Since my new touchscreen PC for MACH3 is way too new and uses TTL levels on it's LPT ports,
I just got myself a USB control board.
Originally I wanted to wait until the RS485 version of the famous Gecko G540 (with >3 axis) I couldn't wait and use my very, very old laptop any longer.

With the new board I can control all my 4 axis and got a ton of space inputs and relay-outputs to spare.
It's supposed to give 200KHz output. No idea if that means 200'000 step+dir for all 4 steppers or just 200'000 time per second switching the level of one step+dir pair. (so 100KSteps/4 steppers=25000 steps/second when all 4 axis are moving at the same time)
Also no idea if and how much it buffers.
It seems to come with an integrated g-code and jog -buffer.
The well known (and much more expensive) smoothstepper card only gets speed+direction from the PC and does all the pulsing autonomously. Thus also independent of any timing-issues from the PC.

The second thing I got me was a USB handweel.
Except it doesn't have an actual weel but it was only 20eur.
I can always use the potentiometer that came with the USB board for that task.
Aparently that handweel is still on it's way to europe.


CCC-Freiburg "Hack 'n Play"

Had a very nice evening at CCCfr during today's "Hack'nPlay".
A mixture of talks and lightning talks and a free software lan-party.
Including a ton of retro games. Handheld, console and early PC based.

We're so lucky to have share in the infrastructure of the ArTik with our small Club in Freiburg.

I was called to help my record the talks while hackers from Karlsruhe would take care of a live stream and a media trainee took photos. (Being there, of cause I took my fair share of photos too.)
I hope to have my photos up on Tuesday. The videos will take a few days as I have to get the official audio recording first and sync my clips to it.

Met some nice folks from Chaos Computer Club in Zurich, Switzerland.

2013-01-22 CCCfr HackNPlay


ThingOMatic broken, making a better one

When installing a tensioning mechanism for my heated, titanium conveyor belt,
the acrylic side on my Thing-o-Matic broke.

Now my bed it too long and hits the Z-rods during the normal homing sequence. (left, then back, then center).
I wrote a custom homing homing sequence that avoids this. So I can still print small parts that don't require the back lack 2x4cm of the print bed.

As I need a replacement anyway, I'm now working on a new ABP design that combines:
 into one design that can be printed using only 2/3 of the already tiny build surface of a Thing-o-Matic.

Installing Conveyor Belt Tensioner on ThingOMatic 3d printer

Am about to install the heated conveyor belt -tensioner to my . The belt itself is already replaced with 0.025mm titanium with a Kapton surface.

The missing tensioning mechanism is some heavy oversight in the original Mekerbot Industries design as is the original plastic belt that expands+warps due to temperature ('heated' conveyot belt *hint*) and wear, is slightly too short after purchase because it hasn't expanded yet and the completely missing bed-leveling mechanism.

Designing a shortened lever-arm for this one as the lower bolt is a bit higher due to my removable ABP mod.This allows me to quickly replace the belt with e.g. my PCB routing platform to mill electronics.
Have to start from scratch as there are no original design files for the tensioner are posted. Only an STL export and only as a complete bed of 4 parts.


3d printed camera slider

 A while ago I designed a 3d printable camera slider using cheap LM8UU bearings.
(Why use 608ZZ ball bearings if you can get real linear bearings for cents.)

Now I finally found the time to make one.
I also updated the design to include a clamp on the sled. So this can be upgraded to a motorized slider later!
On the photo I haven't inserted all the bolts yet that hold this together.

I wanted to use steel rods but they turned out to have vastly inconsistent diameters.
So I had to use aluminum rods and am currently inserting a second, smaller rod into them to keep them from deflecting in the center.

PLA: heated bed(/belt) too hot

    I just learned that some of the warping I'm experiencing with PLA may be due to my heated bed being too hot.
    Usually warping in ABS is caused  by very hot ABS from the nozzle of the 3d printer cooling down fast and shrinking. Thus the higher the temperature difference betwee nozzle and bed, the more warping. That's what you learn everywhere.

    So I usually crank the heated bed up as hot as I can to keep the temperature difference between top and bottom of the object low and thus hope to reduce warping.
    So my bed is usually at 120°C and with problematic prints at 130-135°C.

    It seems that PLA melts and expands at these temperatures and thus creates warping of it's own.
    I should run the bed at 55-65°C and run a fan as strong as possible.

    (During CCCongress I ran a big fan and the warping became much stronger instead of lower.
     But then again I had raised the bed temperature to 130°C because the fan would cool the bed.)

    Didn't try 55°C yet, will do so in the next print and update this posting with the result.


    New Multimeter

    I've beet putting off getting a good multimeter for some time now.
    My original requirements where:
    • auto range
    • hold+peak
    • USB/serial to log meassurements against time
    • meassure inductance (for stepper motors) directly
    I couldn't find anything that had inductance AND USB.
    So now I got myself a Uni-T UT61.
    • auto range
    • hold, peak, range, delta
    • USB
    • no inductance


    Help us develop an alternative design hosting website

    Anyone up to develop an alternative hosting site for 3d printable/laser cuttable/CNC machinable designs?
    Outside the control of a single, commercial company?
    At least help in brainstorming the ideas and coming up with options (e.g. where to host the files and images)?

    We're still filling up the wiki, starting to brainstorm and plan and have a quick skaffolding to experiment with:


    Engineering link collection

    I'm not a mechanical engineer, so let's collect links to quickly look up best practices, part nomenclature (e.g. bearing name codes) and similar information
    Obviously this blog posting will be updated every so often

    Best practices


     Nuts and Bolts



     Shafts and couplings 

     Planar linkage





    monetizing open designs for 3d printed parts

    Current state

    There's a lot of talk about unrealistic DRM schemas for 3d printed designs.
    Mostly centered about limiting the ability to print replacement parts by putting DRM on the design files. ...and forgetting that the original design files are never published but instead reverse engeneered using screwdriver and caliper.

    There's also a lot of talk about selling the right to print a published design (a bad and unrealistic idea) and about the selling of physical manifestations of designs instead.

    We've had small CNC machines in above-average hobby-workshops for years now.
    Particularly in the model-building works these are common and parts made in these hobby-workshops are regularly sold.
    Personally I don't think that the world will suddenly collapse just because a new kind of CNC device that is less dirty and produces plastic instead of wood and metal arrives.
    Parts still need bolts, bearings, electronics, labeling, painting, ... . There is no reason to believe that any design consisting of only one plastic part with no regards for material and tollerances (in the case of selling a DRM-controlled right to print a design) is of particular relevance or importance.

    The experiment

    So I'd like to try something.
    I published quite a few designs under CC-BY-NC(-SA).
    Due to the -NC part I'm the only one allowed to monetize them. Sell them, advertise with them, sell physical copies.
    So I'm posting some parts that I find useful to a general public on eBay.
    1. The designs are still CC and published, so everyone is free to print them for themself.
    2. Everyone is also still free to ask someone else to print them and they can even charge a fee for the service of printing.
    3. I only sell physical objects after they are printed and tested and found to be of good quality.
    4. I include required non-printed parts and may even go so far as to do some simple packaging and instructions. 

     Expected results


    I don't expect many items to be sold at all.
    I expect the need to brush up my skills of presenting the parts in a more professional way in order to actually sell some.
    Prices will probably stay very reasonable (1-5eur, maybe more).
    I expect a more practical discussion about licenses, where we want the world to be headed and where it will be headed regarding open designs and personal 3D printers.