Monthly Archives: April 2009

Work Gloves

Posted on 2009-04-07 by pappp

How did I ever get anything done without them?
workgloves_sm.jpg
At the recommendation of a friend I got some machinist-style work gloves (these) for working on my CNC Mill project (which is coming along rather nicely); I don’t know how I ever accomplished anything without them. They allow you to use your hands with incredible abandon — accidentally clipped your finger with a file? no problem. Tapped yourself with a spinning dremel bit? no problem. Grabbed a razor-sharp freshly cut metal edge? no problem. They also allow you to maintain grip irregardless of what may be on your hands, both from the cutting oils and slippery bits perspective and from the tiny sharp metal fragments perspective. There are even nice little pads on the tips of the fingers to make the important areas grippier.
Then there’s my favorite feature; the knuckle guards. This style of glove is typified by rubber splines over the backs of the knuckles, which absorb and spread out any impacts, so when your hand slips while tightening something, there is no cursing and bleeding. The splines do however make one feel compelled to punch at things, just because you know you can.

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Diploma

Posted on 2009-04-05 by pappp

diploma_sm.jpg

My diploma finally showed up in the mail about a week ago, and I feel compelled to put a picture of it online to brag, especially for the contingency that I need to link it to prove my credentials in matters electronic (yes, even college degrees can be reduced to “I’m going to use it to be a jerk on the Internet”). I was curious how they were going to fit 3 degrees; apparently UK isn’t especially well prepared to handle people earning more than two simultaneous degrees, and there is even some sort of opposition to people trying the EE/CompE/CS trifecta, but the engineering staff are seeing to it that we get our diplomas. I’m pleased that the major with which I most associate is the big one, but I’m a little disappointed they didn’t fit the math minor on, my transcript says I did get it.

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SmartPixels

Posted on 2009-04-03 by pappp

ColorSample.jpg
One of those things I’ve been playing with intermittently just came to fruition: SmartPixels. Cheerful little LED+Microcontroller widgets which light up in interesting ways. All the code is written in a modular way so it is easy for me (or anyone else) to add sensors to the two remaining pins, or modify the behavior in other ways. Full source is available at the page above.

The biggest holdup in completing this little project was not actually the result of a difficult problem, but me forgetting, AGAIN, that when writing code for AVRs, any variable accessed inside an interrupt service routine MUST be marked volatile , or it will be treated as invariant by the compiler.

If I can figure out a convienent way to post video I will, even the simple color fade behavior I currently have loaded is mesmerizing.

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CNC Beginnings

Posted on 2009-04-01 by pappp

The beginnings of my CNC project, in the form of parts for the XY table, and associated tool pile:
XYParts_sm.jpg
The motion capability will be 9” in the X dimension and 6” in the Y direction, the Z axis is on hold until after the semester is over, there just isn’t time to design it in now.
Drives:
Each axis will be driven by a 130 oz-in NEMA23 Stepper (Lin Engineering 5618S-58-01)
The lead screw to run the axis is a 3/8” coarse threaded rod, cut to length
The travel nuts are 1.125” coupling nuts (long, to help with backlash without spending money)
One remaining problem is couplers for attaching the lead screw to the drive shaft, there are lots of options, but they all seem to cost at least $10/axis. I suspect unless something better appears I’ll end up with lovejoy couplings.

From aluminum square tubing (1” OD, .062” walls):
8”x8” (outside) square frame for Y axis
6”x12” (outside) rectangle for X axis
The framing will be assembled with bolts, tabs cut from 90deg angle stock, and a bit of epoxy to make it easier.

The next big fuss is figuring out the driver circuits. The motors are rated for 2A at any practical voltage, and only show about 2.6Ohms/coil of resistance, so its going to require proper current-controlled drivers, which may be expensive.

The thing I’m liking most about this project is that I’m learning a huge amount of practical, hands-on knowledge about metalworking and mechanical devices in a hurry, in a low-investment environment so I can experiment and really get a feel for things. I’m not sure if I’ll ever do much more metalwork, but its a good skill to have.

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