Apogee Vacu-Form Nose Cone Fix

I bought two packages of vacu-form nose cones from Apogee. There are three nose cones in each package for six nose cones in total. I wanted to use these in my NARAM competition models.

Five out of the six nose cones wouldn't fit into the shoulders. The lip on the nose cones seemed smaller than the shoulder piece diameter.


Vacu-form nose cone walls are thin. You don't want to force a fit, you could flex, bend or even crack the plastic.

I ran my index finger around the inside lip of the nose cone and felt a smooth ridge.
This slight bead lip is very smooth and shinier than the rest of the plastic. This leads me to believe the edge was smoothed with heat, leaving a melted lip inside the end.
I doubt there was any test fits after the nose cone was made.

All it took for a fit was a scraping with my pocket knife. The pocket knife isn't as sharp or as thin as an X-Acto #11 blade. I could lightly scrape back the shiny lip.

Before scraping the lip, look close at the thickness of the plastic wall. One side could be thinner than the other side.

The shoulder was too tall to completely slide into the nose cone. The shoulder top was hitting the start of the nose cone taper.

I carefully cut off about 1/8" off the top of the shoulder with small scissors. This was smoothed off with 400 grit sandpaper on a block.



Here's the finished fit.

There is a slight turn at the top of the cone. I didn't want to reshape this and will leave it as is. You could easily sand through the thin plastic.

This is not a complaint about an Apogee product. These nose cones are probably made one at a time by a single operator. On small vendor produced products you sometimes have to make adjustments to short run parts.