In my last post I had an image of one of the guides and the slider in the background. The slider is an aluminum extrusion and the guide is 0.75″ thick Oil Filled Nylon. Nylon is resistant to stain and other chemicals we are using as well as having a low friction coefficient.
Here is a close up of the 3D Assembly taken straight from my computer screen.
Here is a photograph taken with my phone of the actual part that has been machined and installed. There is something satisfying about designing something and then making it exactly (within tolerance) to the size and shape you wanted.
A friend of mine needed a bushing assembly for his street bike to be reduced in width by about 0.230″. Having a 1930’s South Bend Lathe in my shop, I naturally said “come on over”.
My respect for machinists just went up a few notches (it was already high). I’m also glad I got a 4 jaw chuck for the lathe instead of a 3 jaw.
4-jaw chucks allow you to hold irregular work and precisely center it. The process for doing so can be tedious, but it’s a good feeling when your indicator reads in at less than 0.001″ variance from side to side.
This little project was fun for a few reasons. The assembly comes apart into several pieces. The little ring has multiple inner diameters used for different things, so it needed to be machined carefully on both sides. Holding small and irregular parts is a challenge. But seeing it all come together was great.
Have recently acquiried a nice stepper motor from Jameco Electronics. It is a small motor, less than 2″x2″x2″, but still has substantial torque. I will get into more Arduino + Circuits + Electro-Mechanical detail soon, but for the moment, I wished to share a couple of screen-shots of the 3D model and the actual parts that I am modeling and assembling.
In this model, I’m (quite happily) making heavy use cross-part references in the assembly. I caught onto that concept by reading the Top Down Design Overview at the SolidWorks website.
Some time ago, Eli asked me to build a toy shotgun. We wanted something that would give a real “bang”, but be simple and safe.
Provided that a large mass of metal was collided into another at sufficient speed, the user would experience both a “bang” and a “kick” (although inverse).
We milled, drilled, and fit a bolt into a square aluminum tube. A spring connected the front of the bolt to the front of the tube. When the bolt was retracted and released, it would collide into the square tube with the desired effect.