Fabrication Skills

It's been hectic at work lately so I haven't had the time to do much prototyping. I did however start working on my fabrication skills and technique this weekend. Unless otherwise dictated by specification I will be making all "body parts" out of fiberglass. The way I intend to arrive at a finished fiberglass part is still a work in progress, but here's how I'm approaching it...

• Create object out of high density foam, the kind florists tend to use. It's easier to cut. 
• Cover in general purpose Bondo. I had my first run at this, not too hard once you get the hang of it. A couple of downsides to this... The Smell & the Quick Set Time (3-5min)
• Sand Bondo with 80 grit then 220 grid sand paper to smooth out surface. 
• Paint Bondo with Polyurethane Paint
• Apply Mold Release wax
• Apply Fiberglass Resin & Fiberglass Cloth

Here is the tool list:

• Power Sander, B&D Mouse (hand sanding was taking too long!)
• Flexible Plastic Cutting Board (worked out better than putty knife)
• Respirator (No Bondo Smell!)

Here is the consumables list:

• Bondo
• Fiberglass Resin
• Fiberglass Cloth 
• .7 Mil Plastic Drop Cloth 
• Spray Adhesive (for gluing foam parts)
• Foam Blocks
• Nitrile Gloves
• Scotch Brite Pads (for cleaning Bondo/Resin off whatever)
• Acetone (Does not play well with plastic, watch out)

Once I have it down I will photo document the process and post it. 

-Eric

LM317 Voltage Table

Found this cool table that tells you what resistor values are needed to achieve a proper voltage for the LM317. This is from http://www.reuk.co.uk/LM317-Voltage-Calculator.htm.

1.43V R1 = 470, R2 = 68 1.47V R1 = 470, R2 = 82 1.48V R1 = 370, R2 = 68 1.51V R1 = 330, R2 = 68 1.51V R1 = 390, R2 = 82 1.52V R1 = 470, R2 = 100 1.53V R1 = 370, R2 = 82 1.56V R1 = 330, R2 = 82 1.57V R1 = 270, R2 = 68 1.57V R1 = 470, R2 = 120 1.57V R1 = 390, R2 = 100 1.59V R1 = 370, R2 = 100 1.60V R1 = 240, R2 = 68 1.63V R1 = 330, R2 = 100 1.63V R1 = 270, R2 = 82 1.64V R1 = 390, R2 = 120 1.64V R1 = 220, R2 = 68 1.65V R1 = 470, R2 = 150 1.66V R1 = 370, R2 = 120 1.68V R1 = 240, R2 = 82 1.71V R1 = 330, R2 = 120 1.71V R1 = 270, R2 = 100 1.72V R1 = 220, R2 = 82 1.72V R1 = 180, R2 = 68 1.73V R1 = 470, R2 = 180 1.73V R1 = 390, R2 = 150 1.76V R1 = 370, R2 = 150 1.77V R1 = 240, R2 = 100 1.81V R1 = 270, R2 = 120 1.82V R1 = 150, R2 = 68 1.82V R1 = 330, R2 = 150 1.82V R1 = 180, R2 = 82 1.83V R1 = 390, R2 = 180 1.84V R1 = 470, R2 = 220 1.86V R1 = 370, R2 = 180 1.88V R1 = 240, R2 = 120 1.89V R1 = 470, R2 = 240 1.93V R1 = 330, R2 = 180 1.93V R1 = 150, R2 = 82 1.94V R1 = 270, R2 = 150 1.96V R1 = 390, R2 = 220 1.97V R1 = 470, R2 = 270 1.99V R1 = 370, R2 = 220 2.02V R1 = 390, R2 = 240 2.03V R1 = 240, R2 = 150 2.06V R1 = 370, R2 = 240 2.08V R1 = 330, R2 = 220 2.10V R1 = 220, R2 = 150 2.12V R1 = 390, R2 = 270 2.13V R1 = 470, R2 = 330 2.16V R1 = 330, R2 = 240 2.16V R1 = 370, R2 = 270 2.19V R1 = 240, R2 = 180 2.23V R1 = 470, R2 = 370 2.25V R1 = 150, R2 = 120 2.27V R1 = 270, R2 = 220 2.27V R1 = 330, R2 = 270 2.29V R1 = 470, R2 = 390 2.29V R1 = 180, R2 = 150

2.31V R1 = 390, R2 = 330 2.36V R1 = 270, R2 = 240 2.37V R1 = 370, R2 = 330 2.40V R1 = 240, R2 = 220 2.44V R1 = 390, R2 = 370 2.50V R1 = 470, R2 = 470 2.57V R1 = 370, R2 = 390 2.61V R1 = 220, R2 = 240 2.65V R1 = 330, R2 = 370 2.66V R1 = 240, R2 = 270 2.73V R1 = 330, R2 = 390 2.74V R1 = 470, R2 = 560 2.75V R1 = 150, R2 = 180 2.76V R1 = 390, R2 = 470 2.78V R1 = 270, R2 = 330 2.78V R1 = 220, R2 = 270 2.84V R1 = 370, R2 = 470 2.92V R1 = 180, R2 = 240 2.96V R1 = 270, R2 = 370 2.97V R1 = 240, R2 = 330 3.03V R1 = 330, R2 = 470 3.05V R1 = 390, R2 = 560 3.06V R1 = 270, R2 = 390 3.06V R1 = 470, R2 = 680 3.08V R1 = 150, R2 = 220 3.13V R1 = 220, R2 = 330 3.14V R1 = 370, R2 = 560 3.18V R1 = 240, R2 = 370 3.25V R1 = 150, R2 = 240 3.28V R1 = 240, R2 = 390 3.35V R1 = 220, R2 = 370 3.37V R1 = 330, R2 = 560 3.43V R1 = 270, R2 = 470 3.43V R1 = 390, R2 = 680 3.43V R1 = 470, R2 = 820 3.47V R1 = 220, R2 = 390 3.50V R1 = 150, R2 = 270 3.54V R1 = 180, R2 = 330 3.55V R1 = 370, R2 = 680 3.70V R1 = 240, R2 = 470 3.82V R1 = 180, R2 = 370 3.83V R1 = 330, R2 = 680 3.84V R1 = 270, R2 = 560 3.88V R1 = 390, R2 = 820 3.91V R1 = 470, R2 = 1000 3.92V R1 = 220, R2 = 470 3.96V R1 = 180, R2 = 390 4.00V R1 = 150, R2 = 330 4.02V R1 = 370, R2 = 820 4.17V R1 = 240, R2 = 560 4.33V R1 = 150, R2 = 370 4.36V R1 = 330, R2 = 820 4.40V R1 = 270, R2 = 680 4.43V R1 = 220, R2 = 560 4.44V R1 = 470, R2 = 1200 4.46V R1 = 390, R2 = 1000 4.50V R1 = 150, R2 = 390 4.51V R1 = 180, R2 = 470 4.63V R1 = 370, R2 = 1000

4.79V R1 = 240, R2 = 680 5.04V R1 = 330, R2 = 1000 5.05V R1 = 270, R2 = 820 5.10V R1 = 390, R2 = 1200 5.11V R1 = 220, R2 = 680 5.14V R1 = 180, R2 = 560 5.17V R1 = 150, R2 = 470 5.24V R1 = 470, R2 = 1500 5.30V R1 = 370, R2 = 1200 5.52V R1 = 240, R2 = 820 5.80V R1 = 330, R2 = 1200 5.88V R1 = 270, R2 = 1000 5.91V R1 = 220, R2 = 820 5.92V R1 = 150, R2 = 560 5.97V R1 = 180, R2 = 680 6.04V R1 = 470, R2 = 1800 6.06V R1 = 390, R2 = 1500 6.32V R1 = 370, R2 = 1500 6.46V R1 = 240, R2 = 1000 6.81V R1 = 270, R2 = 1200 6.92V R1 = 150, R2 = 680 6.93V R1 = 330, R2 = 1500 6.94V R1 = 180, R2 = 820 7.02V R1 = 390, R2 = 1800 7.10V R1 = 470, R2 = 2200 7.33V R1 = 370, R2 = 1800 7.50V R1 = 240, R2 = 1200 8.07V R1 = 330, R2 = 1800 8.08V R1 = 150, R2 = 820 8.19V R1 = 270, R2 = 1500 8.30V R1 = 390, R2 = 2200 8.43V R1 = 470, R2 = 2700 8.68V R1 = 370, R2 = 2200 9.06V R1 = 240, R2 = 1500 9.58V R1 = 330, R2 = 2200 9.77V R1 = 220, R2 = 1500 9.90V R1 = 390, R2 = 2700 10.03V R1 = 470, R2 = 3300 10.37V R1 = 370, R2 = 2700 10.63V R1 = 240, R2 = 1800 11.25V R1 = 150, R2 = 1200 11.44V R1 = 270, R2 = 2200 11.48V R1 = 330, R2 = 2700 11.67V R1 = 180, R2 = 1500 11.83V R1 = 390, R2 = 3300 12.40V R1 = 370, R2 = 3300 12.71V R1 = 240, R2 = 2200 13.75V R1 = 330, R2 = 3300 15.31V R1 = 240, R2 = 2700 16.25V R1 = 150, R2 = 1800 16.53V R1 = 270, R2 = 3300 16.59V R1 = 220, R2 = 2700 18.44V R1 = 240, R2 = 3300 19.58V R1 = 150, R2 = 2200 20.00V R1 = 220, R2 = 3300 23.75V R1 = 150, R2 = 2700 24.17V R1 = 180, R2 = 3300 28.75V R1 = 150, R2 = 3300

-Eric

LM317 Decoded

I've found a good reference for the LM317 adjustable voltage regulator. http://youtu.be/IjJWWGPjc-w is the link to the you tube video. I kept getting hung up while trying to get the 317 working, and my "Ah Ha" moment came when I realized that the schematic diagram and the actual pin-outs are not represented in the same locations. The video had a call out on this... however I was oblivious to it... but that's the way it goes sometimes.

In any case some further clicking revealed that Afrotech, the uploader of the LM317 tutorial, has a number of cool tutorials that I will be checking out over the next week or so. Also there is an afrotech tech website that warrants a closer look http://www.afrotechmods.com/.

-Eric