Curtiss Jenny Restoration

Welcome! We hope you enjoy following the restoration process of a 1918 Curtiss JN4D Jenny. Once completed, the aeroplane will be flown and displayed at the Candler Field Museum in Williamson GA (30 miles south of Atlanta). You can contact me below by clicking on "VIEW MY PROFILE"

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Location: Peachtree City, Georgia, United States

Monday, August 26, 2013

Magnetoes

Today was Magneto day! 

As I mentioned before, I sent the Dixie magnetos to John Gaertner at Blue Swallow Aircraft Co.  Unfortunately when the box arrived, it was broken and so were the mags.  Ugh!  Now what? 



Fortunately, John was able to make the needed repairs.  Kevin Connor sent some of his spare Hisso mag parts and the rest were made by John. When the overhaul was finished, John sent me this:

The mags have been completely disassembled and checked out. A lot of issues
were found, filled oil passages with silicone, glass beads inside the
housing, missing parts, broken distributor arms, broken or missing spring
clamps, bent/dented parts, wrong spacers, no felt seals, broken tapered
#12-28 hex bolt. We feel we have solved the problems and set the gap very
accurately, based on my antique magnetos books instructions. 


John made a YouTube video showing the magneto overhaul and repair.  You can see the magnet recharging process.  After nearly 100 years, the magnets still held their charge, but needed a "boost".

http://m.youtube.com/watch?v=QRcRdQp--7U&desktop_uri=%2Fwatch%3Fv%3DQRcRdQp--7U

John also found out one of the drive gears was really rough, and it's longevity was in question.


Oh, boy.  Again...now what?  We looked into making another gear but luckily Jenny owner Frank Shelling had an extra one!  He really saved the day. Thanks, Frank !!!!

So, the mags were returned  to me in an extra sturdy box.




 In the mean time, I ordered some 7 MM spark plug wire from The Brillman Co.


Today, it was time to time the mags!  I was fortunate to have two visitors - Jim and Wendy Skibinski flew in to Peach State in their Piper Colt and stayed a while. 


Some times a man knows his limitations.  I'm all for picking the brains of those with more experience.  In this case, I solicited the help of David Harwell, proprietor of Barnstormers Workshop.  We studied the Hisso manual and set the mag to fire on the letter A.

 
Above, Jim Skibinski holds the neat coupling gear used to "tweak" the timing.  This gear meshes with the drive gear on the magneto and the drive on the engine.  Unlike modern mags where you can rotate the mag to make slight adjustments, the Dixie mag is fixed. More on this in a minute.



For timing purposes, the E2 Hisso uses the front left cylinder as it's number 1.  We set this to 25 degrees before top dead center.


Anyway, the mag was set to where the points were just opening and set in place.  Now here is where this coupling is neat.  You slide the coupling towards the mag against a spring.  Then the mag gear can be turned slightly (adjusted) and when you release the spring, the coupling returns to the gear on the engine.  Pretty ingenious.


With the buzzer box buzzing... small adjustments were made. To eliminate the gear backlash, plenty of prop motion was involved - maybe six inches at a time - back and forth.


 Two timed mags!


 The rest of the day, Brian Eberle and I finished giving the flying wires one last adjustment.


 Each wire is to be checked using the Curtiss chart below.


Lots of turnbuckles to safety now that the wires are rigged.

Lastly, John Gaertner sent me pictures of the hoop sockets he made.  Hope to have these installed on the Jenny soon.



That's all for now. More soon.  Enjoy

Brian

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