Estes Skylab #001973, Build, Part 3, Gluing On The Centering Rings

Look at Step 1 of the ASSEMBLE ENGINE MOUNT on page 4.

It says to mark the tube at 8 1/8" from the top.

GOTCHA: At the lower right, it says that 8 1/8" mark is from the rear. I think that's a mistake in the instructions. The lengths don't add up.

I glued on the center ring 8 1/2" from the top which left 7 1/2" spacing from the bottom ring.

Use the retaining ring to set the end spacing of the lower ring.

The instructions suggest epoxy, I used Beacon Fabri-Tac to glue on the retainer.

GOTCHA: It seems the fit of the large centering rings has always been too loose in the Saturn V kits. This newest version has loose rings.

If you were to glue them on as is, too much glue fill could soak into the thin 4" tube and make a "Coke Bottle" pucker seen on the finished model.

I build up the outside ring diameter with small, even beads of yellow glue. 

It took two beads of dried glue to get a good friction fit.