CNC parts (finally making useful stuff)

Here are some pictures of a case that I machined from SINTRA (PVC sheet). It is for my Raspberry Pi. I designed the part in Sketchup, then used an export plugin to send it as an STL file to CamBam, where I created the toolpaths.

I am really pleased with how the SINTRA machined, though it meant standing over the work table with a vacuum during the entire cut. A vacuum attachment would alleviate this...

CNC WINTER UPDATE

Time for an update on things in the workshop. It's been months since i checked in but lots of stuff is always happening.
I've made good progress on the CNC machine. Originally, it had 5/16 allthread rods for the linerar motion, but I recently swapped out the X and Y axes to 3/8"-12 ACME screw, from ENCO. Their black oil-finish acme screws are  on perpetual sale, so I ordered some for $3.99 in 36" lengths. The X-axis is 36" long and the Y- is about 28" This left me some scrap, but I decided to leave the Z-axis as allthread. Instead I used the leftover to make a tap so that I could cut thread into UHMW plastic to make the leadscrew nuts. This worked out pretty well, I need to take some pictures of that process.
After watching things run, I decided that the Z-axis carriage was not stable enough, brass bushings that were just press-fit in place could fall out, etc. I have been working on a new design for the Z-axis carriage that I will attach soon.

And for more showoff, a part that I made. This is going to be a toolholder for a Rotozip to replace the Dremel:

First Aluminum pour

IMG_0290 a video by pfblackwood on Flickr.

I built a quick and dirty furnace for melting aluminum. This is the first pour. No mold, just poured it out on sand. Made a lost foam mold later on, didn't video it.

Lathe Progress

I have an update on the lathe.
This is the housing for the head stock:















This is the assembly - an 8" bolt for the shaft, v-belt pulley, lawnmower bearings and shaft collars to hold it together. The large nut at the right end will be modified to be a drive center.

This is the assembled headstock. the base is tapped for 3/8" bolts to holt it firmly to the lathe bed. 

More updates coming soon.

coming down the pipeline

So, I was thrift shopping and ran across an old lathe. I didn't buy it (shocker) but thought the premise was good. I have been sitting on a salvaged treadmill motor and controller for some time, and thought that I could replicate the style of the lathe in a larger format (also using as much scrap/salvage as possible).
Here is the inspiration:

Here is the current construction (lathe bed completed. headstock, tailstock, toolrest in process:

For the motor, I have the aforementioned treadmill motor. This is a 130VDC 3HP motor. The controller is an MC2100, fairly standard for recent treadmills. It came from an abandoned treadmill, found dumped near my neighborhood. The motor and controller were perfectly intact, but the controller was more or less useless without the treadmill's dashboard. So I poked around on the internet and found a way to interface an arduino microcontroller to provide the necessary pulses to make the treadmill motor run.

It has a pretty high top speed, close to 4000 rpm's. I will gear it down when attaching it to the lathe, maybe 4:1. Also, I hope to replace the full-size arduino with a smaller clone, and maybe add more features like a tachometer.

CNC update April 2013

It's been a while since I posted about the CNC machine. In the past year I have changed jobs and have been staying pretty busy. I found some time here and there to work on the CNC but made some great headway in February. My main problem was the Z axis. The original design was flimsy, so I beefed up the structure a little more. Also, I spent a lot of time making the individual parts, working on accuracy and alignment. In tests this axis moves so smoothly that it makes me realize how sloppy the X axis is. Some other projects are on the front burner now, but I am close to being up and running.

I am a cool dad.

My 10 year old has been reading through the Lord of the Rings Trilogy. She just finished it last week, in fact. While she was reading, she showed me the maps in the back of the book. There were 4 separate pages, like a larger map of Middle Earth had been chopped up. So, I scanned each page and used the photoshops to blend them back together into one.  Here is the result:

Big thanks to Grandma and Grandpa for sending her The Hobbit for her 10th birthday.