Custom Deskproto strategy

Project history

  1. current posting
  2. next step: add command line arguments and extensively test the strategy
  3. Next project: subdivide rotary axis operations to keep toolpath-distance constant while getting near the center of rotation


I have two problems with CNC machining either wax, plastic or soft wood:
  1. I lack experience with how much surface finishing detail I need. So I want a finishing strategy that graducally gets finer (distance of parallel toolpathes) until I stop. Without however milling the same path serveral times (like every second path when I do a tpd=tool-diameter/4 and then a tpd=tool-diameter/8 parallel strategy or every 15th path if I do a tpd=tool-diameter/3 and then a tpd=tool-diameter/5 operation.)
  2. I cannot machine the same part of the surface for too long a time. It will eithrer melt (wax and plastic) or catch fire (wood). It needs time to cool down. Duering that time however, I can maching other parts of the geometry that are far away.


Since the existing toolpathes did not offer such a strategy, I came up with a small Java program.
You would start with a Deskptoro CAM project containing one (e.g. "parallel along X") or two (e.g. "parallel along X", then "parallel along Y" or "along A")  FINISHING passes.
These would be marked by adding "REPLICATE" to their names.

The program will then make copies of these operations with the starting point offset by toolpath-distance / 2.
After these it will add copied operations with the starting point offset by toolpath-distance / 4 of the original and the copied operations.
Then it will do the same with toolpath-distance / 8.

The result is a finishing strategy that gradually increases surface quality and can be paused and aborted at any time.
At the same time it does not operate on the same part of the geometry until it has worked on all other parts.
Thus giving the part time to cool down where a simple parallel-strategy with a smaller toolpath-distance would mill over the same place dozens of times, thus heating up the surface and either melting plastic or wax or setting soft wood on fire.


Updated mounts for CNC homing switches

Project history

  1. Previous project: 4th axis homing sensor
  2. ATC upgrade
  3. current posting
  4. next step
  5. Next project: designing a chain link tool library

A while ago I posted some simple, 3D printable mounts for homing switches on my Chinese CNC6040.
After upgrading to a smaller USOVO ATC (automatic tool changer) spindle, the Z-Endstop no longer fit.
Formerly it would push against the upper spindle mount but this spindle only needs a lower mount.
So I added a 3D printed helper part to my design.

TODO: Photos of the assembled parts will follow next weekend



Returning to my CNC

I haven't worked on my CNC mill for a while.
This weekend I'm planning to:

  • Attach cables to the (already mounted) X+Y+Z+A homing switches (Update: DONE)
  • Test homing (Update: small issue to fix with Z first)
  • Test my experimented M6 tool change macro for my Usovo ATC spindle. (manual tests worked out) (Depends on homing)

Later I need to:
  • Add an M6 exception for the 3d touch probe to be stored in a different location (because it's too large for the pneumatic tool-magazine)
  • Find a way to get 10V, so the PWM-output of my PLCM B1 breakout board can control the Usovo spindle via 0-10V PWM because it doesn't have RS485 like my old China-spindle+VFD.

Raspberry Pi stage intercom system

Project history

  1. No Previous project
  2. No old posting on project
  3. current posting
  4. next step
  5. Next project: add LTC time code output using the unused RasPi on-board soundcard

Because analog stage intercom systems are way too expensive for what they do,
I started building a Raspberry Pi + Mumble based digital intercom that can work with existing Network infrastructure.
The software is based on the TalkiePi Walkie Talkie project.



Looking for EF to MFT electronic adaptors


I'm switching from Nikon-F to EF lenses.
Because I own a Panasonic GH5, I'm looking for an electronic adaptor that communicates focal length for the IBIS system (especially while zooming) and focus information.

I'm not looking for a speed booster. I already got myself a Metabones "S" model for that.


Because and smaller Micro 4/3 Blackmagic cameras have not been updated fro ages and the larger Blackmagic cameras are offered with PL, EF and B4 bajonett but not Nikon-F.


So far I have not found anything yet.
I'm documenting my findings in this blog posting for others with the same question.

electronics fail
  • I tried the "Commlite CM-EF-MFT " and it does not work at all on GH5 and GH4 (black image) and has no autofocus on the old GH2.
  • The "Andoer EF-MFT" does not transfer focus information.
  • "Kipon AF Adapter" - is reported as "Limited lens compatibility, reports of missing AF, battery drain, and some lenses aperture control is unstable or limited""
mechanical only
  • The "Fotodiox" is mechanical only.
  • The "K&F Concept Canon-EF (EOS)" is mechanical only.

too expensive
  • I trust that the "Metabones EF MFT adapter" (not speed booster) would work but it costs 300+€ 
  • The "Aputure Apt-DEC-EOS-MFT-PRO" even 550+€
  • There is also a 200€ "Viltrox EF-M1 Adapter
  • and a simialr priced Viltrox EF-M2 Adapter up for pre-order 


Alibre is back!!!


Back in 2010 I started 3D printing (later also CNC machining) and needed a CAD package.
I got myself a licence of Alibre Design Xpress. The small hobbyist version of Alibre Design.
Later this became the Alibrea Design Personal Edition (PE).

In 2013 it was renamed to Alibre-Geomagic Design V2013 because 3D Systeme aquired Alibre and I changed into a larger, more fully featured version of it.

In 2015 I got V17=V2015. That was the last update anyone got. 3D Systems had added support for their 3D printers and 3D scanners including a very cool Mesh-to-Solid conversion that works very well with very large meshes.

Then there was silence. 
Nothing happened for 2 years. Not even bug fixes.

The good news!

Some ex-Alibre employees have created a company called Alibre LLC and are reached an agreement with 3D Systems to get sale, support and development of Geomagic back into their hands.

...let's stay tuned.



Filament sensor broke off

Looks like there was a knot in the filament and the pulling forces broke off the arm with two of the three "ultimate filament sensor" s on my modified Ultimaker II extended.
It houses the load cell to meassure filament pulling force and the encoder to meassure filament odimetry.
Both where not enabled at that time and thus didn't pause the print as soon as forces exceeded the allowed range.


ATC: parts for my CNC arrived

Project history

  1. After evaluating my choices in  back in February
  2. I decided on what ATC system to get for my CNC mill in March. (posting contains MACH3 software references)
  3. Now the Usovo parts for my CNC finally arrived.
  4. next: mounting spindle and cables, improved mount for Z axis homig
  5. Defining M06 tool change macro (WIP)
  6. Next project: designing a chain link tool library

Too late to install them during the easter holidays but they arrived.

PROBLEM!!! - update: Solution in progress
The water-pump Usovo has shipped in the WZW105 kit,
does not fit the spindle and tubes they included. It has fittings for much larger tubes.
I may find out what thread they use and find fitting to fix this however it may mean that the water pump is not strong enough to push water (and more importantly: small air bubbles) through the smaller tubes.

Update: It'2 now 2 weeks with no answer from Usovo regarding both issues.

Update: I got an answer. The water pump fitting where an honnest mistake and apparently I got 5 SK15 tool holders for the ring system, not for this system and a single, DIFFERENTLY LOOKING SK15 holders also for the ring system. I'm making an adapter to use the top-system, pneumatic tool magazine with tool holders designed for the ring system.


I already have the Usovo Manual in German and English.
I also found this document with meassurements (page 9) for the tool magazines

tool #1 X=0 Y=565 Z=0
tool #1 X=0 Y=530 Z=0
tool #1 X=0 Y=495 Z=0
tool #1 X=0 Y=460 Z=0
tool #1 X=0 Y=425 Z=0
tool #1 X=0 Y=390 Z=0
tool sensor X=18 Y=585 Z=0


Since there are so few detail photos of them
(especially of the backside and inside of the control box)
I made some photos for everyone who considers the same upgrade.

Photos - Unboxing


Photos - main box


Photos - Power supply 

Photos - water pump


Because the pump has no mounting holes, I designed a simple mount for it:

Photos - spindle and mount


Hand strap for my GH4 and GH5 cages

Project history

  1. designing+prototype cages for GH5, GH4, GH4+battery grip and GH4+YAGH.
  2. add hand strap
  3. next step: machine cages from Aluminium
  4. Next project: unknown

Hand strap

Last month I started designing my own cages for GH5, GH4, GH4+battery grip and GH4+YAGH.
I am considering these cages to be finished and a carbon fiber prototype of the GH5 cage is currently in the first of 2 field trials.

However one thing bothered me all the time.
I did not find a good way to add a leather wrist strap.
This is a feature I enjoyed on my previous (chinese) cages.

Now it hit me.
All this time I wanted to add holes for the strap at the top and bottom. However at the bottom the mounting screws where not allowing for enough space.
However the GHx bodies do have attachment points for a strap already.
So I just designed a small modification to the bottom of the cages and will test it next week.


The modified GH4 cage design has been printed and it works very welll.
I'll do the same modification to the GH5 cage design...


More jaws for the 4th axis chuck on the CNC

Design intent

This is my 4th axis.
A "K11, 100mm, 3 jaw chuck".
I already made a custom steady-rest for it but still, the existing jaws are not very good at gripping soft, cylindrical blanks to mill.
So I want to have either cylindrical chuck-jaws or base jaws that I can bolt any kind of custom jaw-geometry onto.

Existing hardware

Thanks to Jeremy Parton on Google+, who pointed me to this website ,
I know that:
  • K11 is grouped into K11 (1 jaw), K11A (3 centering jaws) and K11C (3 independend jaws)
  • meaning we have K11A here
  • K11A are ISO3442 standard clutches.
 K11 100mm is defined as
  • D1=72mm
  • D2=84mm (diameter between mounting-bolt center-points)
  • D3=22mm  (shaft diameter)
  • H=74.5mm (thickness of chuck with jaws)
  • H1=55mm (thickness of chuck)
  • H2=n/a
  • h=3.5mm
  • Z-d=3-M8 (bolts mounting the chuck to the face plate)
(Without a copy of the DIN/ISO3442 standard, I found this catalog of chucks and jaws containing a reference drawing. It shows where these measurements apply.)

Options considered

I'm currently investigating these 95mm jaws for turning machines.
The  chuck they come with is not compatible because it uses a thread to attach to the shaft.
This doesn't work when changing direction. So I need to use them with the existing chuck.

This chinese seller seems to sell K11-100mm chucks and the chucks I want. So he should be able to answer if they fit together.

What I actually did
In the end I now meassured the existing jaws and created a parametric CAD design.
The single design has 3 configurations for labeled Jaw #1, #2 and #3 .
After getting a single Jaw #2 to fit properly....

...I'm now printing Jaw #1 and #3