Tuesday, April 15, 2014

Mowbot 3.1 new toolbox

Unfortunately I ran into too many things with the mowbot and cracked the old tool box that protects the electronics. Fortunately I had a new toolbox laying around to replace it. Here are some pictures of the new hotness.

I've also added a foil insulation layer on the top to prevent sun damage, added a bumper to help me resist the urge to run into (and destroy) things, and cleaned up the controls.

Monday, March 31, 2014

Building the OSE Power Cube

If you're not already aware of the Global Village Construction Set from Open Source Ecology, please check them out. I have wanted to build parts of the GVCS and contribute to OSE for some time now and finally decided to go for it. It is my hope to build a Power Cube in 2014 and a Liberator brick press in 2015.

I plan to build a GVCS Power Cube v6, with my own improvements, and then try to sell it. If I can't sell the Power Cube then I'll use it for my next adventure, the Liberator CEB (Compressed Earth Block) brick press. Someday I'd like to build a castle with CEBs.

At the moment I have two parts orders out and a quote request from my favorite metals provider. My plan is to build my first PowerCube "by the book" using the exact parts from the OSE BOM. The build will take a long time as I will only order parts and assemble them when I can afford the time and money to do so. The focus on this project will be completeness (as in pretty), not cost or time savings (as in recycled parts).  


If I build it (the powercube), would you buy it?


Preliminary welding is complete on the outer frame. I'm working on cutting the 6"x12" tube for the fuel and hydraulic tanks. 

I will try to take more than one picture next time. 


Grant and Aaron got the tanks cut from the massive 6"x12" tube. Great work guys and thanks a bunch!

On the parts front, I have 55 of the 70 line items on the BOM. One more order should do the trick. 


Grant and I worked on attaching a few of the fittings on the fuel and hydraulic tanks.

Grant also spent many hours grinding and welding on the frame and tanks and they are looking great!

Saturday, December 14, 2013

Turning a free copier into ... recycling ?

Some time ago I picked up a free copier from craigslist (Sharp AR-M355N) with hopes of turning it into a 3d printer or some type of robotic project. Foolishly I was also hoping to sell some of the parts that would not be interesting to me (AR-FX12, AR-DU4, AR-MU2). Now it seems as though most of that will go to recycling. Here are some mixed tear down and eBay listing photos from the salvage operation.

picture of duplex unit for ebay listing

It turns out that interest in buying my salvage parts on eBay was very low, well zero to be precise. Oh well, the copier was free anyway. My hopes of turning this into a 3D printer were also dashed by the lack of any high precision linear shafts or bearings or screws. There were a lot of drawer slides, though, so I might still try to make a RepStrap, JunkStrap, or DeltaBot. Here are some shots of the good stuff that I kept for making robots. There are DC steppers, motors, solenoids, wire, and photointerruptors. I even found a complete linear slide with a stepper already attached to position the slide. 

I'm still trying to figure out what to do with all of these motors, gears, and solenoids. My latest idea is a robotic orchestra or sorts. In the meantime the rest of the copier is off to recycling where it can one day become useful again.

Tuesday, August 6, 2013

SSL With Microsoft SQL Server 2008-2012

MS-SQL SERVER 2005/2008/2008-R2/2012 Administrative chronicle.: SSL With Microsoft SQL Server 2008 Cluster Box.:   Overview of Using SSL with Microsoft SQL Server.

Thanks to this guide I was able to get SQL Server Configuration Manager to show my self generated SSL certificates under Protocols for MSSQLSERVER->Properties->Certificate.

system cpu usage and Linux kernel profiling

One of my systems was showing high system CPU utilization. While trying to diagnose this high system cpu usage, I discovered the profiler built into the kernel.

To enable Linux kernel profiling, you must set the profile parameter on the command line [1].

Boot the kernel with command line option profile=2 (or some other number instead of 2). This will cause a file /proc/profile to be created. The number given after profile= is the number of positions EIP is shifted right when profiling. So a large number gives a coarse profile. The counters are reset by writing to /proc/profile. The utility readprofile will output statistics for you. It does not sort - you have to invoke sort explicitly.

Here is my sorting command and some of the output, in case you were interested. 
# /shared/readprofile | sort -nr | head -20
2420865 total                                      1.2731
1511144 default_idle                             16979.1461
449875 shrink_active_list                       503.7794
 59360 schedule                                  22.6825
 44295 shrink_inactive_list                      24.4184
 38420 list_del                                 417.6087
 31976 generic__raw_read_trylock                1880.9412
 27377 release_pages                             92.8034
 24292 __list_add                               296.2439
 18459 list_add                                 1845.9000

This allows me to look up each of these functions in the kernel source and make guesses as to why the system is spending so much time performing those tasks. 


Friday, July 26, 2013

Mowbot dies, long live edgebot

Due to unfortunate mechanical failures on my mowbot robot I was able to piece together a prototype for my long running edgebot project. Here is a video. Yes, wheelies are awesome. 

Edgebot Prototype from Daniel Epperson on Vimeo.

UPDATE: It cuts!

edgebot trimmer first run from Daniel Epperson on Vimeo.
The mowbot suffers mechanical failures from time to time that require interesting fixes. This time around the mowing deck has broken around the motor mount.

Additionally, the plate holding the carburetor to the engine has split into two pieces. This is preventing the engine from getting the proper air/fuel mixture and causing it to run erratically. I haven't been able to find a replacement mounting plate for this carb yet. I am also considering looking for a clamp-on style carb instead of this tricky plate shenanigan.

Hopefully I'll have these sorted out by the time the yard needs mowing again, as the mowbot is my only mower. 

Wednesday, July 3, 2013

Laptop charger modification

This DC ammeter was taking up space on a shelf, just looking cool. Hooking it up to my laptop charger showed a decent amount of movement so I decided to combine the two devices. Read on for more details about how I shoved my laptop charger into this old school ammeter. 

Removing the screws on the face was all it took to get the ammeter open. The way the terminals are wired to the meter are quite interesting. For this project I will be using the 10  amp terminal which uses most of the wiring you see here.

The charger looked like it was going to fit but I didn't actually measure it.

This is the completed project in action. The battery in the laptop was charging and the screen was active, pulling just over 5A DC.