Trail 70 Engineer

First prototype repair assembled and working. Spent $60 on broken Sony noise canceling headphones that cost $350 new. Fixed with 3D printed replacement parts! Then turned this fun DIY project into a small business.

Electrical 30 was a course offered at my community college to students with no prior experience with electricity or working with tools. I took it as part of my coursework to finish my machinist certificate. We did basic circuit analysis exercises using ohm's law to figure out resistance, current and voltage. We also built 3 awesome projects in this class from basic materials. I still have these 10+ years later and they still work. Plans for these projects can be downloaded below. 

3D Printed Chain Whip shown in use. 3D Printing has been a hot topic for the last few years. So much of a hot topic that it has found its way into the general consumer market. Many an aspiring maker has one sitting in their office or living room slowly extruding plastic into various shapes. The last part of the sentence, various shapes, is what concerns me a bit. It seems most of what gets printed are decorative trinkets that are generally useless. They sit on a shelf to be admired for a few months and then get discarded for the latest trinket... That's not what I've been printing. I've been designing and printing useful parts with a consumer FDM 3D printer focusing on mountain biking. So, here are five useful/functional prints I designed for my mountain bike.

A Haas VF-2 milling setup I ran in university.    When I finally get a garage again I am going to buy a small milling machine. It has been on my wishlist for a long time. But, before I purchase anything, I should figure out what my options are first. This is a list of various milling machines that interest me. My criteria are fairly basic. It must be rigid and robust. It will hopefully have a large cutting volume and as much horsepower as possible while running on 110V AC. I would like it to be CNC but digital readouts and X-axis power feed are more realistic. There will not be any toy CNC milling machines on this list. Must be able to rip through aluminum easily and cut steel even if only on a limited basis.

Last week I had a flat tire on my mountain bike. Patching the tube wasn't a problem, that was done in a few minutes. However, quickly airing up and re-seating my 29x3.0 tire was going to be a pain with only my small hand pump. To get around this pain I have an old high volume foot pump but it only fits on Schrader valves and my mountain bike uses Presta. Normally, I use a brass Presta to Schrader adapter but on that day I couldn't find it. (I still can't find it...) I ended up borrowing a plastic adapter for the job. This lack of an adapter made me think, "Why not 3D print a few of my own?"

Basic desk setup at my engineering day job. Here's something that has been on my mind for a while. The top 5 tools for engineers, tinkerers and people who just like to build stuff. Now, I don't mean expensive computer software or machinery. Mills, laser cutters and a copy of Solidworks are amazing tools but they are not on this list. This list is about basic tools that I think are often overlooked by up and coming tech people. Also, everything on my list is free, or can be purchased for under $100.

Left: Prototype pedal made with copolymer plastic with metal studs. Right: Proof of concept pedal made with PLA plastic. The proof of concept platform pedals I made a few weeks ago have been holding up great. ( https://trail70engineer.blogspot.de/2017/09/3d-printed-pedal-project-proof-of.html )They do have a few issues. The grip isn't great. My foot slips off even during normal riding. The second issue is the PLA plastic I used. PLA plastic is very brittle. This means the pedal could crack and fail during normal use. This actually happened with one of my proof of concept pedals. PLA also has inherent low temperature resistance. This means the pedal could nearly melt if left in a hot car. I made a prototype to address these issues.

Converted old SPD pedals to Platforms using 3D Printing. I wanted some platform pedals for an upcoming bike tour but only had SPD pedals. Spent a few days making some platform pedals using 3D Printer and a pair of SPD pedals for donor parts.

Printed 19T Singlespeed Cog Small project modeling single speed bicycle cogs to the ANSI standard. It was a fun project to get more familiar with Fusion 360.

I started looking into 3D printing for hobbyist and business purposes. A month later I bought an Ultimaker 3. Here's why:

Steerer Tube Storage. A simple way to maximize the storage on any bicycle. In February 2017 I had an idea for a bicycle product. I called it Steerer Tube Storage. It's exactly what the name suggests. A simple device that allows you to store small things in the steerer tube of a bicycle. (Watch the video below to find out more.) It was a simple idea but I wasn't sure it would be a financial success. This uncertainty lead me to using Kickstarter for this project.

Finished Steerer Tube Storage ready for install. In the middle of my semi-retirement I found myself having a lot of time and no garage or tools to work on stuff. So this is the first project of mine where all the manufacturing was outsourced. That means this project includes creating real engineering drawings, sending them out for quotation and having a prototype manufactured. I have done this a few times while working as an engineer but things are always a different on a smaller scale and when its your own money on the line.

Sample problem introduction to Nodal Method. Basic Circuit Analysis class. (Eng6) A mandatory class for all engineering students. Im fairly proud of my overall notes and grade for this class. Everything is scanned into one big 179page pdf for you to download. University:  San Joaquin Delta College Year Taken:  Spring 2009 Course Number: Eng6 Professor: Robert Crawford Prerequisites: Calc Based Physics for Electricity and Magnetism Downloadable Content: All homework, notes, quizzes and tests

Top half of the notecard I made for a test. Basic Electronics, EE321, was an interesting class that I don't remember much from. My main focus has always been on mechanics and not electricity. University:  Cal Poly SLO Year Taken:  2010 Spring Quarter Course Number:  EE321 Professor:  Gary Perks Prerequisites:  Electric Circuit Theory, Basic Downloadable Content: Class Notes, Midterms, Quizzes and some Homework. Bottom half of the same notecard I made for a test.

Random screen shot taken from my notes. Looks like this is for verifying a fundamental sets for a given function. Differential Calculus, Math 4, is one of the toughest and most interesting classes I have taken. Luckily it was taught by an amazing teacher. His organization and way of describing the problem simply is the only reason I passed with a high grade. These traits are also shown in my notes. University:  San Joaquin Delta College Year Taken:  Before 2009. Course Number:  Math 4 Professor: Chris Barker Prerequisites:  Calculas 1 & 2 (Derivatives and Integrals) Downloadable Content: Class Notes & Sample Problems, Hand Written

Sample problem from my class notes. Mechanics of Materials, CE204, is an entry level engineering class taken by all engineering students. Its covers... "stresses, strains, and deformations associated with axial, torsional, and flexural loading of bars, shafts, and beams." University: Cal Poly SLO Year Taken: 2010, Winter Quarter Course Number: CE204 Prerequisites: Statics Downloadable Content: Example Problems Class Notes, More Examples

Finished Prototype of my motorcycle stabilizer. The best thing about having this blog is sharing ALL the things I've worked on. This includes past projects from my university days. Specifically my senior project at Cal Poly SLO for my Bachelors Degree in Manufacturing Engineering. It was a project to help motorcycle riders with disabilities support their bikes when not moving. There are other products that do this but typically didn't look good or they adversely affected the motorcycle riding experience. I was charged with designing and manufacturing a product that worked, didn't change the way a bike rode and was hopefully less expensive. A very difficult assignment.

Rabbit Laser QX-80-9060 setup in my garage. In January of 2015 I bought a CO2 laser engraver. The idea was to operate a small business out of my garage and to make some cool stuff. I named the small business Mutant Lasers. I didn't have a big budget or a big space to put it but also wanted a powerful machine with some automated and industrial features. I owned the machine for 1 year before my semi-retirement started. In that year it made enough money to pay for itself and make a little profit.

I've replaced forks, bottom brackets and even done a little wheel truing. So when I decided to build a mountainbike from frame up I felt fairly confident about building the wheels too. In the end this wheel build went well for my first build. I did have one problem, I miscalculated the spoke length. The spokes ended up being about 3-4mm too short and will have to be built a second time. Even factoring in this mistake, building the wheels myself saved money, gained me valuable knowledge and added a few good tools to my garage.  Front wheel laced and ready for truing.

This is a Live post. I will continue to update it as I make or find more tools. Throughout my career as a student and then an engineer, I hated doing repetitive tasks. Especially tedious calculations. Doing this not only waists time but is also a good way to make small mistakes. Here are some tools I created to do many of these basic calculations. Some are Microsoft executable files but most are in excel spreadsheets.