Model Engine Maker
Help! => Specific Engine Help => Topic started by: FKreider on January 10, 2021, 01:06:13 PM
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Hello Everyone,
I think this engine is fairly popular so I am hoping someone can help me out.
I cannot understand what the purpose of the 3/32" hole is at the far end of the drill jig, it appears that the top of the jig is what is used against the location plug so I cant figure out the purpose of this additional hole. I must be missing something simple.
(https://i.imgur.com/ICRLXRC.png)
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The jig is further used to drill the intake/exhaust hole in the cylinder as this extract from Elmer's instructions describes...
For the ROD, chuck a l/4” rod in the 3-jaw with about 2”
projecting. Drill a center hole with a 3/64” center drill and
bring the tail center up for support. Turn the 1/8” diameter
long enough to cut away the center later. Thread 5-40 with
a tailstock die holder. Use parting cuts to bring to final
dimensions. Hold the l/8” diameter in a small V groove in
the milling vise and mill to 1/8” thickness. Drill and ream
for the Crank Pin. Insert the Piston/Rod assembly in the
Cylinder. Place the drill jig over the Pivot Pin. Run a close-
fitting 3/32” pin through the jig and Crank Pin hole.
Then drill the 1/16” port hole in the Cylinder.
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Very simple and straightforward! Sometimes it just takes a second set of eyes, I even re-read the portion about the drill jig but I was only looking at the write up discussing the drilling of the ports in the column, I should have kept reading and I would have found my answer! ::) :Lol:
:cheers: