2013-09-27

The perfect multitool

I think I found the perfect multitool for me.

What I found I need are:
  • LED lamp
  • pliers
  • phillips #1 screwdriver
  • flat screwdriver
  • knife
  • sometimes a bottle opener (although Germans open bottles with just about everything...except bottle openers.)
  • wire strippers would be handy but not needed.
I like full sized multitools but they tend to stick out in an office environment, so I can't wear them all day (wich is kind of a point of having such a tool on your belt).
Instead I carry 3 tools:

The first thing I carry on my belt is a foldable and very tiny xacto-knife. Extremely tiny, extremely sharp and with a number of replacement blades inside. I think I'll keep that.
It's similar to this one except in color and name and that it comes with a tiny belt holster:





I had to ditch a small chinese tool at the airport, having forgotten to put it into the checked in luggage
(Not because of the knife...but because it had a screwdriver. Aparently airlines are afraid Germany Engineers can do just about anything given a screwdriver and duct tape.).
In San Francisco I got myself a Portland Coast  C2899.


I also carry a small 1xAAA flashlight but can't find a belt holster tiny enough for it.
The Coast was supposed to replace it because it already HAD a flashlight.
...only that it was way too weak, required a size of batteries you don't easily get in continental Europe and constantly empty because the button was accidentally pushed by just about anything in your pocket.
...and it didn't come with a belt holster.

Now I found something else.
A chinese dealer named Yuki Guan sells a RUISS RS1016A.
It doesn't show but he answered that it's also avaliable in black and it comes with a very sturdy belt holster.
It has the same, nice grip that the Portland Coast one has but the LED lamp is bigger and cannot be activated accidentally anymore.

custom XL45 pulley for 8mm D-shaped shaft



My CNC milling machine has a weak 4th axis.
I want to attach a larger stepper motor with seriously mor torque.
However that motor has a D-shaped 8mm shaft while an XL45T10 pulley always has a 6mm shaft.
I ordered a conventional one, hoping to drill it up but it was stuck in transit (damn Hermes. An envelope would have worked better.).
So I had to design a custom pulley that could me machined without a rotary axis (less of a top guard) and fits snugly onto an 8mm shaft.

In fact, I'm 3d printing a first one and plan to do the final one with a full sized top guard on the, thus fixed, 4th axis.


    2013-09-25

    Blown stepper driver

    After doing some test cuts yesterday I'm doing the first real milling on my TravelCNC today.
    I want to find out if it doesn't loose any steps now.

    First problem:
    after switching it on there was smoke any my Y-stepper driver went belly up.
    The FMD2740A stepper driver is rated  for 12-50V DC input.
    Internally they use an LM2576S-5.0 to generate 5V.
    Maximum input voltage 45V.
    ...They do not use the LM2576*HV*S-5.0 with a maximum input voltage of 60V.
    And I'm using a 48V power supply.
    ....go figure.


    Update: The chinese dealer very forthcoming and is even offering to pay for the repair (shipping to china and back to get a replacement with the same chip is expensive, time consuming and not a permanent solution).

    I now connected the Y stepper to the A channel, set MACH3 to interpret the A channel as  a linear axis and search&replaced the axis in the g-code.
    It's not cutting.....
    The operation will take 2x 1h . That should be enough to detect any lost steps. Particularly in Z.
    Touching the hand weels on the steppers there is no jittering. So it looks good.


    Update: Test was a SUCCESS. No lost steps whatsoever anymore!!! Very smooth operation for multiple hours and interrupted with shutting down the machine for a night before resuming.

    Update: My replacement FMD2740A died too. (during 30C3) Post mortem showed a bad solder joing on capacitor 1.

    Update:  2 other stepper drivers blown. Dealer "Thomas Wu" confesses they are only good up to 45V. Not 50V

    2013-09-24

    TravelCNC doing it's first cuts

    My TravelCNC reached it's most important milestone!

    The mobile CNC workshop in a custom made flightcase now has completely new electronics and made it's first cuts using it.
    It's now a usable, mobile 4 axis CNC milling machine.
    ...soon it will also be 3D printing and vector cutting.

    TODO:
    • add Basotect sound proofing
    • connect the USB control board to the spindle controller (speed in software)
    • add table legs to the top panel to use it as a collapsable work table
    • test 3D printing (ThingOMatic already disassembled, should work)
    • Replace 10A power socket with 16A version
    • add IP64 power sockets (you always need power socket in a workshop)
    • add mounting for vector knife (like drag-knife but cutting real 90° angles)




    2013-09-11

    The last honours for my Thing-o-Matic

    Looking at this blog, it must feel like I'm not doing nothing at the moment.
    This is far from the truth. Since I tried to keep things focused and have just one blog-post per project with all the infos one would need to replicate my work.

    Problem is: Where does one project and the next begin.

    Yesterday I prepared the new electronics for my TravelCNC.
    Today I gave my untrusty ThingOMatic the last honours and dismantled it.
    I'll keep the main boards, the extruder controller and the extruder stepper driver.
    However the mechanics will be that of my TravelCNC.
    Mach3 will control the CNC's motion and also give STEP+DIR pulses to the extruder stepper driver.
    The external display and keypad will help me set just the temperature while Mach3 executes the g-code. (With the extruder=E axis renamed to A.)

    One thing I noticed was that the GND cable of the extruder heater had molten it's mounting port.
    Since the extruder never had any issues with heating up or keeping hot, this doesn't seem to have had any impace. The cable never moved after all.


    Excuse the pool photos as  I didn't bring any of my cameras to this location.