Edit Title Bar Properties

1N22.u1 - Pulse Jet

 

Construction Components (consumed) 
.006 inch spring steel   
Automotive primer  
 1000 mL beaker  
 Table salt  
Copper electrode  
0-5 ampere 0-10VDC Power Supply  
xacto knife  
Valve template  
 
Overview
Making a valve assembly for the V1 DynaJet. 

Component Notes
You will note in the pictures that the first couple of valves that I made did not have the hole in the center, my bad. The last shot of the completed valve is the second attempt which came out perfectly, and I didn't forget the hole. I would also like to note credit to Bruce Simpson for the original idea/method of constructing valve assemblies using electro etching that is easy cheap fun and messy to do.

Instructions
Procure some .006 inch spring steel (McMaster Carr) clean and paint both sides of the sheet with automotive primer spray paint, let harden for at least 12 hours.  Carefully scratch the outline of the valve assembly onto the painted spring steel with a fine xacto knife using single pass strokes to make a cut thru the paint to bare metal without tearing up the paint using an old valve as a template. Tape the valve template down to prevent movement while scraping the outline in paint. Fill a beaker with warm water (1000 mL) and mix 1 tablespoon of table salt into the water.  Clip a copper electrode to one interior side of the beaker and attach it to the Negative lead of the power supply. Scrape an upper corner on the sheet of the final scraped pattern of the valve, and attach a clip from the Positive terminal of the power supply to the cleaned spot of bare metal at the upper corner of the sheet and insert it into the opposite side of the beaker, making sure that the two terminals do not touch. Fill the beaker to just below the clip on the patterened scraped sheet with the warm salt water. Turn on the power supply and adjust the current to about 2.5 Amperes which is usually about 8 volts (on the setuup that we have been usuing). Allow the valve to etch for 8 minutes to 30 minutes, checking every 5 minutes after the 8 minute mark. When done, the marked scratched valve sheet should break loose from the paint holding the whole thing together on the back side of the scratched valve sheet and pop out of the main sheet. Clean the edges with a fine file and remove the primer with a small ammount of acetone until the primer is cleaned off. Fit and assemble into the valve head and run it hard until it burns out then replace.