The latest foible involves the construction of a simple little 4FNC side project, an EAC Viper clone. This build is more of a sanity-preserving diversion from the highly detailed Protostar model, still in progress.
Anyway, after having constructed and installed the Viper's motor mount and main fins, I embarked on sweeping up the shop floor, when I found this...
"Wait a minnit...Isn't this the engine block I cut out for....."
A quick peek down the Viper's body tube confirmed it. I had overlooked gluing this essential piece into the motor mount assembly!
If left as is, it would be a matter of one or two flights before the engine hook would trash the front end of the motor mount tube and start causing problems.
"Ed, you perennial head-of-knuckle!"
What now? There are three options to dealing with this: scrub the build and start anew, complete the construction and take the unfinished, unpainted model out to the park for it's one and only flight, or attempt an after-the-fact fix.
I chose the latter.
The best thing to do next was to step away from the project and think on how to go about correcting the error.
The first choice that came to mind would involve cutting the body tube apart just ahead of the motor mount, gluing in the pesky engine block, and rejoining the tube using a stage coupler.
"Nahhh, there's gotta be a better way. "
After mulling the problem over, downing a can of Mountain Dew, and rummaging around the shop, I came up with a solution that just might work.
It just so happens that a 3/8 diameter dowel fits nicely inside a mini engine casing from which the stray engine block is cut.
Sanding a bevel into one end of the block will ensure that the piece has a better chance of inserting into the motor mount tube deep within the rocket body.
With the block mounted on the dowel end, glue is applied to the front and sides of the part.
The dowel and engine block are lowered inside the body tube with care being taken not to touch and smear glue on the inside surface.
Once the part makes contact with the engine mount tube, I can carefully turn the model around for sighting through the aft end of the motor mount.
Now that I can see the block, it is only a matter of carefully maneuvering it into the tube.
Success!
Now, I must work fast before the block sets in this position.
Sliding a BT-5 body tube over the dowel, I use it to hold the block in position while disengaging and removing the dowel.
Next, one of my painting wands equipped with a mini engine casing is inserted into the body tube and used to push the engine block home against the engine hook.
PHEW! SUCCESS!!
I don't have to trash the EAC Viper, and can complete the build.
Now where in the heck did that launch lug get off to?....