Yongnuo YN560-II + SF18 as mains powered studio flashes

Just modified a (Canon compatible) Yongnuo SF18 battery pack to accept mains power.
Now I can use the cheap YN560-II flashes on mains power.
With my older YN460-II I had to disassemble the flashes and modify them.
With these it's enough to modify the external battery pack.
Pro: I can pull the cable and use them on battery power without powering them off. (e. G. When the cable is in the way or I'm tripping over the cable)


First day of GulaschProgrammierNacht #GPN was great.
I took a few minor projects with me that I didn't have the time to finish in recent month.
A small, slow going hacker meet is exactly what I need to finish them.
Currently I'm on the train back home to take a shower and collect some missing that tools.
My 3d printer had been resurrected.
I hacked an IPreAmp into the 20 eur phantom power injector with additional headphone output.
Planning to attach the larger stepper onto my 4th axis of the CNC and finish some Arduino work later.


Investigating 5 axis CNC milling


Since I have a 4 axis CNC machine and already converted the electronics to USB and am working on a 4/5/6 axis CAM program, let's investigate what would be involved to upgrade to 5 axis machining!

Current setup

I have a YOOCNC CNC6040 from carving-cnc.com with the 4th axis option.
The 4th axis is very weak and nearly unusable.

I have lisended MACH3 as  control software and am very happy with it.



Antonio Eduardo Martins Palmeira pointed me at the PLCM-E3P CNC Controller (For use with Mach3).
Let's see...

5V DC via XP9 or
5V from USB or
48V via Ethernet (PoE)

Maximum frequency of STEP signals 100 kHz (my current board does 200KHz pulses)
15 buffered CMOS(5V) inputs
36 buffered CMOS(5V, 10mA) outputs
6 axis
extra status LED connectors (connect, estop, power, traffic)
max 2500ms buffer on card in addition to max 5000ms buffer in MACH3
logging can be enabled for debugging
The controller does the actual step generation using it's own clock and the acceleration profile provided by MACH3.
It also does probing and limit switches by it's own (no software=no delay)

Stepper driver



Free 4+5 axis CAM software

I got an idea and am currently implementing it.
It's a very simple 4 (and 5) axis CAM software to generate G-Code from STL models.

The problem

Well,  I have an affordable 4 axis CNC milling machine. The 4th axis "A" is commonly a rotational axis along Y or X.
But aparently all free software you can get only does 3 axis milling.
The only affordable software I that claims to support 4 axis milling was DeskProto. A fine piece of software and using it with the 4th axis works very well but it only does 3 Axis milling using X,A,Z and keeping Y stationary.
All "real" 4 axis software costs an arm and a leg. Any 5 axis software I could find is completely and utterly out of every hobbyists budget.

The idea

Now what I'm implementing won't work for every type of geometry.
I'm trying to but there will always be cases that don't fit my algorithm.
The idea is as follows:
  1. Run along the A axis from 0 to 360 and along the Y axis, determine the location of the surface (classic pseudo-4-axis milling up to now)
  2. Then determine the surface normal at that collision point.
  3. Now calculate the inverse kinematic required to turn the part until the surface normal of that collision point points straight up.
  4. Determine if this new orientation creates collisions of the tool with other parts of the part or the machine, is outside the movement ranges of the axis or otherwise impossible.
  5. If it is impossible or if there is a cave beneth the surface, find the start and end of the region that has this property, put a plane through these 2 points that is normal to the A axis and do classic 3 axis milling in these planes.

Why this strategy?

The idea of following the surface normal is that this works like cutting along a contour. You get a surface without any visible steps.

The problems

Dents in the surface that can only be reached from certain directions are one problem. The fallback strategy of 3 axis milling takes care of many such cases but cannot work for all cases.

Optimizing the collision detection for finding the surface is much more difficult then in 3 axis milling since you cannot partition your model in advance to only test the triangles that actually can be below the cutter.

I haven't yet thought of any proper algorithms to deal with the fact that the tool has a shape.
Currently it assumes a ball cutter of diameter 0 that can cut with the side just as well as with the tip.

The details of the collision detection of tool and collet with the part are still not clear.

As you see, I need a lot of help with thinking about the proper algorithms, implementing them correctly and a ton of testing.

Update: 4 axis milling with this surface-normal strategy works in the emulator! Debugging mostly done.


"R. P. M." 3D printer with serious CNC mill

Tim Rastall on Google+ showed me an interesting project today. This is a beta of a combined 3D printer and desktop CNC mill. Future upgrades for a 4 th axis, laser 3D scanner,… are planned.

R.P.M. Rapid Prototyping Mill ( 3D Printer / CNC Mill )


There have been many attempts to mount small Dremel, Proxxon and other hand tools to 3D printers for small milling jobs. Usually these suffer from the low mechanical stability of 3D printers compared to heavy CNC mills, the high runout of the mounted hand tools and the low mechanical
strength of the axis and axis stepper motors.


This one is different. It uses a water cooled, heavy spindle with a dedicated VFD. Just like a conventional “desktop” CNC mill. The frame looks very sturdy and employs ball screws. It looks more like portal style desktop CNC reshaped into a cube. The Z axis is done RepRap “Darwin” or BitsFromBytes “RepMan” style. On these 3D printers it is overconstrained and introduces the well known “Z wobble” because 4 cheap, threaded rods are employed that are never really parallel or straight. This design uses 4 precision ball screws. So it may work out and allow for the (for a CNC mill) very large Z travel and support the very heavy tool.

Analysis and outlook

I am finding a combination of 3D printing (clean, no storage of blanks), CNC milling (very high precision, diverse materials and tools) and resin casting (diverse material properties, easy small-scale production) to be one of the most interesting fields of research In hobby machines.
As for myself this could be an ideal tool if it would employ metric parts (for easy repair) and the performance in 3D printing and in medium duty CNC milling was known. My own CNC6040 is very limited in it’s Z travel and very long and wide. This one could be small enough to be transported to Hacker meets and –conferences with a car. (Much too heavy to carry a long in a train. 70lbs=30Kg)