Long Board Mishap

I was bouncing on the board a bit..... I thought the 3/4" plywood would have been a bit stronger, but I guess I have a reason to finish the polycarbonate deck now.

Long Board Improvements

I decided it was time to add a few new features to the long board. I Threw on some EL wire for under glow. It isn't very bright, but it can be seen at night. I also had access to a CNC vinyl cutter. I stuck my test piece to the bottom of the board. The yellow looks kind of weird, but it's still better than the bland plywood.

Tape always seems to make a good kludge.

Long Board Upgrade Parts

As it turns out, the polycarbonate side plates were not as strong as I had hoped. I hadn't realized this until now, but polycarbonate develops micro cracks that spread under small amounts of stress. Every machined surface has micro cracks, so a number of the parts showed signs of cracks developing around the bolt holds. In order to prevent me eating the ground again I decided to suck it up and machine the plates from aluminum as I had originally planned to do.

 As you can see I attempted to use my material as efficiently as possible, so I crammed the parts into the smallest piece of 1/4" aluminum plate I could. The 1/8" mill bit took as long as I expected it to take. It was around 2 hours a part... Painfully slow as usual in aluminum...

Long Board Finished... not really...

I couldn't wait to get the board into a usable state, So I hacked together a wooden board from 3/4" plywood. I threw on some old skateboard trucks at first in order to see if the shape was what I wanted. I finished the remaining parts for the trucks. All of the pieces came together nicely and looked really clean.

Sadly I couldn't decide how to make the rubber bushings cleanly... As with all of my kludges I turned to my favorite tool in the shop: the 3 TON ARBOR PRESS!!!!!!!!
I had a 1/4" thick sheet of rubber, but I needed to cut somewhat clean circles out of it. I figured scissors couldn't do the job, so I looked around for somewhat sharp tubing. I couldn't find any so I turned to the next best thing... socket sets. The socket heads were round on the bottom so they can't cut you. Normally I wouldn't expect them to cut through a sheet of rubber, but 3 tons is enough force to cut nearly anything. The socket sets cut the rubber like it was butter.
The rubber was too soft.......
I succumbed to speed wobble and became a road pizza..... (there's no need for a picture of my leg... I'm pretty sure I'll have a large scar to remember the test of this long board.) I added more rubber to make the trucks tighter, but they're still alot looser than I hoped they would be. I guess I'll just have to learn how to ride better.

Long Board Progress

After a week of spare time I popped out a few parts. I avoided using the CNC as much as possible because it removes material so slowly. None of the parts were particularly difficult to machine. All of the setups could be done in a vice and they had fairly sloppy tolerances... although I did aim to get them as tight as possible for the fun of it.

 I also started to polish the parts. This is the first time i had a polishing wheel, so I got a bit carried away and started to polish everything. I still need to improve my technique. Machined surfaces polished easily, but the machining marks still remained. Surfaces left unmachined look alot better, but they aren't perfect mirrors.

 I got lazy and decided to make the side plates from polycarbonate. I can cut it at more than 10 times the rate of aluminum and I don't have to baby the machine as much. It should be strong enough and it looks aesthetically pleasing, so it's a win - win situation!

The spherical bearings worked perfectly and aligned up as I hoped they would. The bearing seats were a bit tighter than I hoped they would be. It's not a problem as long as I don't need to replace them. The trucks have really started to take shape, but the whole board is still a long way from being completed.

Long Board - New Project

After a year of walking to class I decided I needed a long board to get to class. In my usual style I figured I should make one instead of buying one. I started by doing some research on the designs and standards for long boards and skate boards. I saw a number of different truck designs that seemed common. It seems that the rubber bushing style of truck is the most popular. In this design the truck is forced to straighten itself out by squished pieces of rubber. These pieces give the boarder more resistance as they attempt to steer the board. My personal favorite design used metal springs instead of the rubber bushings. I like to design things to last. I figured the springs would never deteriorate with time. Unfortunately I couldn't figure out how to make the trucks small and use the springs. Eventually I decided to go with the standard design for long board trucks. The one thing that really bugged me about this truck design was there wasn't a defined mechanism that caused the truck to turn. The pins in the trucks relied on a loose fit in order to actually turn. I started to look for an improvement when I stumbled upon spherical bearings on Mcmaster. These bearings gave freedom in all directions, which was the exact motion I needed. I designed the trucks around these bearings.  The spherical bearings give the trucks fully defined motion.

After deciding on the components I immediately started up SolidWorks and started poking around with different designs. Eventually I settled with this design for the trucks.

This render of the entire board has an older design for the trucks. I spent a few days changing around the design to make it easier for me to machine. The best looking board in my opinion was one made from 1/2" polycarbonate. I figure this board will really stand out when around the regular long boards.

I split the truck into many different pieces to avoid material removal. The biggest limiting factor when I'm machining is removing material. Splitting up pieces meant a large portion of the parts were extruded aluminum with holes drilled in them. Parts like that are really easy to produce with a manual machine. The design also meant that I only needed CNC work for the bearing seats and the side plates for the trucks. I attempted to locate the parts by geometry instead of the bolt holes themselves. The most critical surfaces required parallel edges, which are very easy to produce in one setup on either the manual or CNC mill. The only new thing for me on these trucks was the use of spherical bearings. I hope they perform as well as I imagined them performing.

Powered Desk Chair

This project had a lot of potential, but I kind of let it fail. Maybe I'll finish it one day, but it probably won't be any time in the near future.

I had an Ikea desk chair that didn't roll very well, so I figured I'd modify it into a powered desk chair. It would have "swerve modules" to give it the ability to strafe and turn just like a normal unpowered desk chair. The design was fairly simple stuff that I had basically done in robotics at my high school. The intended final chair would have looked like this, but the electronics required to make it run properly were a bit out of my budget range.

The continuous 40A motor controllers put the electronics out of my budget considering the ones I had used in the past cost around 90 dollars a piece. I made the three swerve modules before I decided to ditch the project.

 As with most of my projects I had to use the arbor press. It took apart that Ikea chair with ease.

Even though I bagged the project I learned a lot from its construction. In order to make the sprockets I wrote a program in python to generate the g-code for my CNC to cut any size sprocket. I also learned what tolerances are needed to make a chain drive without a chain tensioner and I also learned what tolerances work with bevel gears. Did I mention that I also have 3 very cool looking paper weights?