Toothbrush Fatigue Testing Machine

Our First 3D Printer - It's Coming!

I am excited to share we purchased our first 3D printer.  Soon it will be in our hands and we won't know what to do with ourselves.

https://shop.ultimaker.com/product/8/ultimaker-2

We settled on the Utlimaker 2. We were looking for something that can produce production ready parts but also to be used as a design tool, during the engineering design process, for part validation.  We also have a limited budget for investing in this technology.

Checking Out the Ultimaker 2 Series of 3D Printers at CES

"We believe in open source, we believe in sharing.  We don't believe in patents, it's outdated.  It doesn't work anymore, the world has changed"

After searching the market we settled on the Utlimaker 2 being the best fit for us.  We need to use this for Product Development, so we need to it work out of the box.  That was the biggest selling point for us.

Ultimake 2 Review by WTFBBQ Gaming (43min)

It is also great that this product is Open Source:

• Design Files and BOM
• Firmware 

Stay tuned for more updates on our experience with 3D printing.

Arduino 24 Volt DC Motor Controller

What are the benefits of a diy Arduino DC motor controller?

• The project can be made open source.
• The ability to use different size motor controllers, depending on the load requirement.
• The ability to incorporate sensing (current, speed, direction, temperatures, etc) and other controls, with the easily programmable Arduino.
• Gaining knowledge and experience with such systems at a relatively simple level.

Major components:

• Arduino Uno
• Arduino shield for making connections
• 24VDC to 5VDC power supply
• LCD 20x4
• 3 position switch
• 10K potentiometer
• System enclosure
• Terminal blocks

Our Objective

To control a 24VDC motor speed with a display, giving us the ability to run our Bridgeport milling machine from our solar powered electric system.

How did we come about to design our controller?

Ultimately, we designed our controller based on major components we had laying around.

Victor 883 Controller

The motor controller we used is a Victor 883, which is now discontinued.

It is controlled with a PWM signal that is sent from the Arduino.  The Victor directly controls the amount of power transmitted to the motor, which is taken from the batteries.  When the PWN signal value is 0, the motor controller sends full power in one direction, let us call it forward.  When the number is 90, the power is turned off and the motor is in a neutral state.  When the signal is 180, the controller sends full power in the other direction, called reverse.  In this way, the motor can be controlled to go at maximum speed, or slow, in either direction and anything in between.

Arduino Uno

Since the Victor 883 has no human interface built in, the Arduino Uno and some other components have to come into the mix.  While the Arduino itself generates and sends the signal to the Victor, we have to be able to control this signal.  

To do this, we employ two simple components.  One is a switch that has three positions.  With it, we can send the signal in the forward direction, reverse direction, or off.

The second component is a 10k potentiometer.  Turning the knob all the way one way, makes the resistance go to 0.  In the other direction it goes to 10,000 Ohms.  The Arduino sends a 5 Volts through it and measures the voltage across it.  When the potentiometer is turned fully in one direction, and provides no resistance, the voltage remains at 5 V.  When it is turned completely in the other direction, it provides a very large resistance, and the voltage drops essentially to 0V.  Any values in between provides an intermediary voltage.  

The Arduino has a special function to translates the voltage reading to a simple number.  When voltage is 0, the number is 0.  When the voltage is the maximum 5 V, the number is 1023.

When the “potentiometer number” is 0, we code the Arduino to send a “PWM number” to the Victor of 90.  This is the neutral state, which will not move the motor.  When the “potentiometer number” is 1023, and the switch is in reverse, we send a “PWM number” of 0, which is full reverse.  When the “potentiometer number” is 1023, and the switch is in forward, we send a “PWM number” of 180, which is full forward.  Anything in between is scaled accordingly.

LCD

The 20x4 LCD displays the numbers previously talked about via some Arduino code, converted to a speed (RPM) for human readability purposes.  It also shows which direction the motor is made to spin.

Power Supply

The 15W power supply transforms 24VDC from the batteries to 5VDC for the Arduino and LCD.

System Enclosure

It is a watertight PVC box, which houses all the components and can be mounted to the Bridgeport.

Arduino Code

The code is available Bitbucket.

Schematic

Below you can see a rough sketch of the components and their connections.

Solar Powered Bridgeport

It's been 9 months since the last update.  Much has happened in the mean time, most conspicuously being the name change.

What BrainDrain was, is now a legal entity named Novali Group.  Yay!

Our almost 3 year project of running a machine shop from solar power has reached a significant milestone.  We are now able to run our Bridgeport milling machine from our solar power system, updated since the last post.

It is approximately 800 Watts worth of solar panels, attached to a 24 volt battery bank with an approximate capacity of 560 Amp-hours, which can sustain the 1 HP motor on the milling machine for about 10 hours continuously at full charge.

To run the motor, we put together an Arduino based speed controller with an LCD, seen at the bottom of the picture.  Above it is the Mitutoyo digital read out.

The Mitutoyo DRO is made to run off of 110VAC but we wanted to run it off of our battery bank. The AC-DC power supply (110VAC - 5VDC) inside was removed and power was ran, via the black flexible conduit, from the controller box below it.  The controller box has a DC-DC power supply (24VDC - 5VDC) housed inside.

The box itself is a drip proof enclosure and all of the conduit is water tight and oil resistant.  A compromise was made with this USB connector in order to be able to program the Arduino.  There are connectors rated for harsh environments, which may make their way into the next revision. 

For now the controller has basic features and still has room for improvement.  It's time to figure out what to mill.  

Here is a video of the controller in action. Enjoy.

Update

We have not left for good.  There has been some considerable work done on the garage PV system this past year, some of which can be seen via pictures on our gallery.

Unless somebody sends us a request for a post on a particular subject or question, we shall refrain from contributing here at the moment. We are busy planning and preparing to move on.

Completely reworked system wiring.

Solar panels re-mounted on top of garage with strut channel.  This is not ideal, as the roof tiles cannot be replaced without removing the entire mounting system.  In this case, the roof tiles are no more than 1 year old, so they will remain in good condition for many years to come.