You get what you pay for…

And I was aware of this when I bought the the Chinese Machine! but In my professional life I learned this and I was prepared

When I was installing and running the first tests with the wooden car the machine one of the Stepper Motor flexible couplings broke. I contacted  the vendor an made the claim, and I am still waiting for the replacement part but I order 4 spare parts from other vendors of better quality expecting that this will happen again and it did!

I lost two pieces of good wood and a lot of time. Now I replaced all the couplers in the three  Stepper motors and I order 3 more they cost $8.00

 

The Broken coupler and the new one:

New coupler installed on the three motors:

Building the “Toucan” wooden clock Part 1

I will be posting the advances and the leanings while working in this project. I am working as much and as fast as I can in this project because very soon I will start a new contract (life is not always hobbies )and I will be traveling a so the available time to play in my garage will be dramatically reduced …

First step was to finish all the finish the drawings in CAD, second step is to post-process each part to generate the G code for the CNC. this means also to select the tooling and the material.

Wood (good wood) is not easy to find. For the wheels and internal components   I will use Birch ply-wood for the wheels and pinions and also for the clock arrows but for the frame, the base and  dial I wanted good wood. and good and nice  wood is expensive and not easy to find .

The most difficult part from the machining point of view is the dial ring because I changed the design and instead of cutting a disc of wood and then glue the numbers in wanted to carve the wood to form the numbers. I also modified my original design and now the numbers will be Roman style and

In the internal ring  face there will be inserts of brass rods marking the hours so I decided to start from the dial ring.

The main problem was to find a good wood for the dial, The best wood I could find for this was in Michaels and is a cross cut of bass wood that is about 11” diameter (Basswood Country Round® – Large) , perfect for the size of the dial ring. This is a very good wood for carving that is exactly what I planed.

The thickness needed for the design is 3/8”plus 1/8th for the numbers so this is  is 1/2”. the wood was a little bit less than 3/4” (.605”) so I had to mill it down to 1/2”.

After this cut the center part and make a rough milling of the numbers and the front face:

Next step was to make a finish milling of the face. This  creates a  surface with almost no irregularities and this will reduce to a minimum the work with sand paper for stain and finishing:

Finally the finish mill of the numbers the internal ring face and cut the dial from the main wood:

Total machining time was about 5 hours as I used very low feed rates and small step advances to avoid stressing the wood and obtain a good finish.

 

And this is the final results! now the dial ring is ready for a nice wood finishing.

Next Challenge: A wooden clock

I have been working the last 2 days in creating a 3D model of a beautiful  pendulum clock designed by Clayton Boyer. I received the dxf files from him and worked very hard to make them usable for 3D solid extrusion. The final result is amazing and I really hope to finish this fantastic clock very soon. I already ordered the brass tubes and the 1/8” rod. and I have in my garage all the material needed for the electrical part (The clock uses a home winded coil) and a 9V DC power supply.

Tomorrow is shopping day for wood although I will probably will mill the wheels in plastic…

Here are the Images from the 3D cad software:

I have not stopped working with the wooden car and the Arduino. I am testing several things to make a very nice project…

Technical Aspects Part #1

The Machine:

As promised here I start with technical information. If you goggle “CNC 3040” you will see that this is really a popular machine and there is a lot of information, especially in YouTube but it is hard to find a full operating manual of the machine and also the best settings for the controller software. Here I will try to summarize the most important aspects:

Where to buy it:

I purchased mine online via Ali Express but you can find it with similar price in Amazon or eBay. The title for the one I bought is: “3040Z CNC ROUTER DRILLING/MILLING MACHINE WITH 1.5KW VFD WATER-COOLING + 800W SPINDLE MOTOR ENGRAVER PROFESSIONAL”. I prefer not to share the links as they normally disappear when the machine is sold or obsolete. The vendor I selected offers free shipping from USA with no custom payments and price was the same of other alternatives. Below I copied the specs from the Ali Express vendor page.

3040z tri-axial engraving machine specifications:

Effective working travel	410(X)mm*290(Y)mm*75(Z)mm
Shape dimension	665*525*465mm
Max.thickness of the materials	90mm(the distance between Z axis and the bottom of the working station)
Max. work piece dimension	390mm*290mm
Work table dimension	560mm*360mm
Frame materials	6061 aluminum alloy/ 6063 Industrial aluminum
Driving units	X axis 1605 ball screws
Y axis	NEW 1605 ball screws
Z axis	NEW 1605 ball screws
Sliding units	X axis Dia.20mm chrome plate shafts
Y axis	Dia.20mm chrome plate shafts
Z axis	Dia.13mm chrome plate shafts
Stepping motor type	57 two-phase 2.5A ,super-low noise ,NEW
VFD Power	1.5KW VFD,NEW
Principal axis collet	ER11 / 3.175 collet  or 6mm
Spindle speed	24000rpm/min (PWM steeples speed regulation)
Empty line speed	0-4000mm/min
Resetting accuracy	0.05mm
Engraving accuracy	better than 0.04mm (has been tested)
Spindle precision	radial run out 0.03mm
Control unit	tri-axial one-piece drive + ring variable power + PWM speed
Carving Instructions	G-code/.nc /.ncc/ .tab/ .txt
Communication interface	through parallel connection with computer
Software environment*	Windows 2000 / xp
Carving speed	0-2500mm/min (different materials differ)
Machine weight	46KG

*Please see below for additional software information

I copied the picture below from the Amazon.com page as it has a full description of the components. The machine from Amazon.com is more expensive than the one I bough.

The software:

In order to run the machine it is necessary to have a software to translate the milling commands to electrical signals so the motors can move to the correct position and speed. The universal command language for CNC machines is the G code (http://en.wikipedia.org/wiki/G-code)

For this machine I use a very popular, powerful and inexpensive software: Mach3. In theory the machine comes with the software and the license. Mine came without it and the vendor send me a link to download it. I found that the version and the license in that link is outdated so I decided to buy the license for $175.00 directly from the software developer. And I did the right thing!

Mach 3 was originally developed to use as I/O port the parallel printer port in the PC, after the introduction of USB and Ethernet this port disappeared from all the laptop computers and is basically discontinued and difficult to find the expansion board for desktop computers. Also the old software doesn't run in Windows 7 or above.

The new versions of MACH3 can use what they call “Plugins” to be able to use special developed “Motion Controller Interfaces” that are basically USB or Ethernet converters to parallel printer port. Be aware that low cost USB to parallel port converters will not work and they are not fast enough to process and buffer the high speed pulse commands to the stepper or servomotors of the machine.   The Plugin page of the Mach3 site lists all the plugins available and you can download there the drivers for these devices. I Selected the  UC100 USB Motion Controller and bought it from eBay (CNC USB CONTROLLER for Mach3 Smooth Stepper Motion Control , UC100) for $150.00

Important Data to know before starting:

Whatever controls software you will use (I use Mach3) there is important data you need to know in order to properly setup the machine:

Here I am sharing PrtScn of the setup pages of Mach3 for my machine, but you need to check with the vendor the exact data of your machine. It seems that the CNC 3040 is built by different companies and the ball screws and stepper motors can change from vendor or manufacturer.

I setup my machine in metric units but this is only for Motor/Screw ratio. The G code and the postprocessor takes care of the working units via the instructions G20 and G21

I think this is enough for now, I will continue with more technical information in future posts.

First full project: A wooden car!

 

I am the kind of person who likes to read manuals and learn all the aspects of the technological gadgets. I found that the best way to learn all the aspects is to start with a complex project that forces me to apply if not all, most of the capabilities of the new gadget.

I like to program microprocessors and PLCs and now we have the Arduino, which has become one of the most popular devices for robotic toy design and the teaching of electronic controls in technical schools and universities.

The new project is a motorized wooden car that will be controlled by an Arduino. I have not decided what type of control or what operations will perform the car but I designed it to have enough place inside to hold the Arduino, batteries and any additional electronics needed.

With this project I learned a lot! I broke a milling tool; I had to throw a lot of wood and parts damaged due to wrong feed rates, spindle speeds or tool selection. I also learned a lot regarding the milling strategy to select while post processing the job. 

I also learned about how unsafe this machine is and all the precautions I need to follow to avoid accidents in the future. I also learned that even it is a nice machine; it is Chinese and uses a lot of low quality parts. The machine had a major failure that took several hours to fix plus a lot of mails back and forth with the vendor.

The design using Inventor:

Post processing using BobCad V26:

Milling with my CNC 3040 and Mach3 CNC software

Final Product:

There is a lot to share and I hope I will be able to find the time to write and post here. I will do my best…

My new toy

After all these years working with CAD software, designing machines and parts I finally decided to start using this knowledge as a hobby.

At the beginning I was planning to design and build my own machine but the Chicness made my life easier and now it is possible to buy a 3 axis router, engraver for a very low price. Ebay did the rest…

For $1,250.00 with free shipping I received last week my new Chinese 3 axis CNC3040

The installation process took 1 full day as I had to build an extension of the workbench and install everything properly fixed. I hate provisional installations! because they have the tendency to become  “permanently  provisional”

The machine came without the software and manuals. I contacted the vendor vie Ebay and they sent a link with the software, I also goggled  and was able to find the manual. The vendor sent the manual via post mail from China and I am still waiting for it

I had to buy some additional electronics and also pay a new license  for the latest version of the MACH3 software. The one sent by the vendor is not updated and cannot be used with laptops. I will leave the technical details for the next post.

Here is a video of the first run using a sample G code that came with the MACH3 software. I used the engraving V shape bit that came with the machine and uses a piece of wood that was part of the shipping case.

I will share the initial experiences, technical findings and issues in the next post