# SPenrod

• First, well done! 1. Insulation. Try moving blankets. 2. Roof ring. The stresses of the inserted metal rod may crack the rafters, like a wedge, under high winds. I think a more traditional version would be stronger. 3. Additional info on Ger/Yurt building can be found at simplydifferent.org ... Mr. Mueller is very thorough and has all of the math shown plus an on board calculator. I also made a spreadsheet from his formulae so i can adjust as needed. I have some plans in the works but my project got stalled for personal reasons. Again, well done!

• SPenrod commented on mecanicafina's instructable Safe Capacitor Discharge Tool1 year ago

Thank you Gentlemen! My early electronics experience is very well buried in my head, but things do come back when you see the relationships again! I am sourcing parts to put one together for the shop.

• SPenrod commented on mecanicafina's instructable Safe Capacitor Discharge Tool1 year ago

You wrote 50 mF and made calculations based on that. Does that match my 50000 uF? It seems off to me but it has been over 30 years since I took basic electronics in college, and i haven't used it much lately... The cap in question is about 2" in diameter and nearly 5" long, polarized. Huge! I don't mind waiting a couple of minutes for it to discharge. If I split the difference and go with 1k ohms at 5 watt resistor, I think the discharge time could be around 2 minutes... assuming 50 mF = 50000 uF otherwise i think we're off somewhere.

• SPenrod commented on mecanicafina's instructable Safe Capacitor Discharge Tool1 year ago

I work on outboard boat motors. These have a 50000 uF @63 volts capacitor in the 55 volt circuit which powers fuel injectors, coils and a number of other things. I assume it stabilizes and filters the power for these components. What changes would be needed in this circuit to safely discharge this big cap? The screw driver method can produce fireworks and arc welding! Several have gone bad, leaking fluid and corroding terminals.

• SPenrod commented on Matt2 Silver's instructable Bubbling Pipe Lamp1 year ago

Great idea! You coud cover the all thread with more copper tubing, use a little epoxy or hot glue to simulate welds, and i think i would use a whisper aquarium air pump mounted outside for more quiet operation. An RGB LED with PWM color control (Arduino) would allow easier color control. I am putting this on my Make List!