HACK A WEEK

I had a project this week that required a level piece of ground prior to erecting a metal storage shed. I decided to use a water level to help with the site leveling. A water level is an old and very useful tool. It dates back to Roman times when they were used to engineer the slope in aqueducts. You can build one yourself in little time with just a few hardware store items. The one I use in this video cost about $10 to make.

Keep on hackin…

Lots of viewers suggested that I install the engine by laying it on it’s side then lowering the frame onto it, bolting it in place then tip it back upright. This seemed cumbersome to me and I just had to come up with a better solution.

This idea popped into my head one day at work. It’s simple, just the way I like it. Lisa helped out in this one too. 🙂

Keep on hackin!

It’s not uncommon for video viewers to make suggestions to projects and since this entire project was based on viewer demand I’ve once again listened to some input. YouTube viewer Pete Prodoehl suggested that I use the DRV8835 Dual Motor Driver Carrier from Pololu instead of the motor driver shield that was using. I ordered one from Pololu and two days later it arrived in the mail. In this week’s video I removed the old motor driver and installed the new one which takes up less that half of the space the other one did. This makes more room on the perfboard so I decided to mount the battery in the available space.

Another suggestion from YouTube viewer cfavreau was to use a 5 mm LED as a low friction tail for this little tail dragger robot. I’ve since installed one.

Thanks guys!

Here’s a parts list for that parts I’ve used so far. They can be purchased from Pololu.
Prices are as of 5-2015

Item #   Item Description                                                                                Price US$

2356   14×4.5mm Wheel Pair for Sub-Micro Plastic Planetary Gearmotor     1.95
726      Maxbotix LV-MaxSonar-EZ1 Sonar Range Finder MB1010             24.95
1939    USB Cable A to Micro-B, 5 ft                                                               2.49
965      0.100″ (2.54 mm) Breakaway Male Header: 1×40-Pin, Straight          0.99
2358    136:1 Sub-Micro Plastic Planetary Gearmotor 6Dx19L mm              11.95
3101    A-Star 32U4 Micro                                                                              12.75
2135    DRV8835 Dual Motor Driver Carrier                                                    4.49

The 3 Volt coin cell batteries and the dual bettery holder are from SparkFun Electronics

PRT-00338   Coin Cell Battery – 20mm (CR2032)                                          1.95
PRT-12618   Coin Cell Battery Holder – 2xCR2032 (Enclosed)                     1.95

The perfboard is from Radio Shack.

Here’s the wiring diagram:

This week’s video. Keep on hackin!

At the request of several viewers I’m launching a Mini-bot project this week. The goal of this project is to provide a basic guide on how to go about building a small robot from scratch. There are many sources for parts for a robot and for this one I chose Pololu. They offer parts as well as robot kits at reasonable prices.

For this project I chose the smallest components I could find. The micro gear motors are an amazing piece of hardware. It’s incredible that there is a planetary gear transmission inside the 5mm diameter housing! The micro controller I chose is about the size of a postage stamp and the motor driver board isn’t much bigger. This allows for a final assembly that will fit on a small perfboard.

In part 2 I’ll post a wiring diagram and a parts list.

Keep on hackin!

This week I’m doing some final cleaning and polishing of a few aluminum parts. I made some sodium hydroxide to help get the job done. This solution also works well as a de-greaser that can be washed away with water. Sodium hydroxide is also known as Lye. It’s in all soaps in very dilute quantities. It’s also the primary ingredient in most off the shelf de-greasers like Purple Power.

USE CAUTION WITH SODIUM HYDROXIDE! WEAR EYE PROTECTION AND RUBBER GLOVES! IN CONCENTRATED FORM IT WILL SLOWLY DISSOLVE FLESH! ewwwwwwwwwww

Sodium Hydroxide will eat aluminum! The byproduct is hydrogen gas. Use a dilute solution (2 – 3 tablespoons per gallon of water) in a well ventilated area.

It’s a caustic base chemical and can really irritate bare skin. If you get a concentrated amount on your skin rinse thoroughly with water. Follow the mixing directions and precautions in the video. I made mine from Draino drain cleaner in crystal form. Don’t try this at home. 🙂

Keep on hackin!