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.

• Design files on Thingiverse
• My free 4+5 axis CAM software

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.

• Design files on Thingiverse
• My free 4+5 axis CAM software

Email to Makerbot Industries support

After this hilarious answers from Makerbot Industries to a discussion thread on Google+, I sent the following email to Makerbot Industries....let's see what the answer will be (and open our strategic popcorn reserves).
The support-Ticket number is #121248.


Aparently whoever manages your Google+ page is under the impression I would get actual help with any of the following questions:
(I doubt it.)

Device: Thing-o-Matic

Is there any kind of support infrastructure to send in my bot in Europe to get the brownout fuses fixed,
so the devices doesn't erase it's settings every time is stays connected via USB while powered off?
(And a way to ship it without the extruder breaking off in transit.)

Is there any "service kit" or similar to fix the following design failures in your after-sales suport:
* inadequate mechanical extruder support
 (third mounting hole unused, stepper motor hangs in mid-air. Only supported by 2x M5 bolts through 5mm balsa wood with a 100mm lever for the heavy stepper to break that wood any time the bot is transported and thus shaken or even placed in a not-upright position)
* Glued together lower parts of the "dinos" not connected strong enough for long-time usage.
* any way to dismount the extruder for transport despite the next issue named here?
* missing plugs on the cables to mount any of the alternative tool heads you sold without disassembling the entire machine just to swap between extruder, plastruder MKII or unicorn.
* missing plug on the interface kit -cable.
* missing mechanism to tighten the belt (or mount a fresh belt since they come 1-3mm too short to mount by hand and expand to be 1-3mm too long/wavy when in use.)
* non thermoplastic replacement belts that don't expand and stay flat when heated often for long times
* metal support tube to support the PTFE being supposed to stay cool yet being directly screwed into the hot-end, thus warming up the filament, causing it to expand and thus jam.
(Using a dozen heat-spreaders and 2 fans to keep the effect of this design failure to a minimum at the moment. Not exactly pretty. RepMan 3.0 had a PEEK tube years before you started designing the ToM.)
* The delrin plunger in your 6th generation extruder filament drive mechanism. (high friction, no spring, no lever. Thus shakes loose every 5 minutes and doesn't react in any way to minute changes in filament diameter. Everyone else hat this one sorted out while you where still playing with DC motors.)
* Any official way to organise the cables in the lower "cable hell" compartment?

as expected:

Hi Marcus,

Thanks for contacting MakerBot Support!

Unfortunately, no, we do not have any official repair shops in Europe, or even in the USA, which can work on a Thing-O-Matic. We haven't sold this product in over a year, nor have any of our distributors to my knowledge, and there is at this point simply a lack of resources. For the same reasons, there is no available service kit.

I took a look at your order, and it seems like we've got a record of some support parts being purchased back in June of 2011, but no record of your Thing-O-Matic being purchased through us. If it is the case that you purchased it through us, please provide your original order number so that I can look it up. If it is the case that you purchased it through a distributor, I'd recommend contacting that distributor to see if they have any repair parts available.

If you have any other questions, feel free to let me know and I'll be happy to help!

Best,

Alex
MakerBot Support

Just as I expected.
I didn' ask for any kind of repair. There's nothing broken. What's broken is the design itself.

PS:
I ordered via a UK distributer since that meant european consumer protection laws apply. 

new Zoom H4n camera rig handle

I'm currently designing a new camera rig.
Based on the idea of the RotoRig it shall be shoulder rig and travel-jib in one unit.
 However mine shall be CNC made and feature my camera-remote handle and a new version of my Zoom H4n remote control handle.

So I designed the new handle and prototyped it on a 3D printer during GullaschProgrammierNacht.
Next step: verify that it fits and CNC machine it in wood.#

I already designed the other parts for the rig but they are too big to prototype on the crappy ThingOMatic 3d printer. So I'm planning to prototype them in cheap wood and later do them in aluminum.

Update: Added photos.

• Design files on Thingiverse
• My original handle
• RotoRig 1 2 3
• My CNC

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)

GulaschProgrammierNacht

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

Motivation

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!

• my 4/5 axis CAM on Google Code
• Remember: If you have to ask for prices, you probably can't afford it.

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.

• next generation of my machine
• MACH3
• my current USB board 

 Mechanics

• here (you can get it slightly cheaper too) 
• and another one
• cnczone thread 

Electronics

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

• CNCZone thread 
• British shop (£130.00 tax excl > 150eur)
• Russian homepage (sold there for 500 rubel = 12.32eur)
• user manual (english)
• software
• listed on the official MACH3 plugin page

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

TODO

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.

• Executable beta version

• Sourcecode 
• 4th+5th axis I'm thinking about 
• Aparently SmoothStepper can control 6 axis it's not well documented, has no optical isolators and no galvanic isolation of it's 5V like my current, cheap 4 axis board has.
• USB control board (can't use it. Doesn't work with MACH3)

"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 )

Context

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.

Description

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)

• R.P.M. Rapid Prototyping Mill ( 3D Printer / CNC Mill )
• Kickstarter 
• Announcement
• Preproduction model on YouTube