Mr. Klett at Madcow has just shipped me a package containing everything I need in order to rebuild the booster for my Formula 200.
The existing coupler has nice, tapped shear pin holes for #8-32 screws. The new booster will need new holes.
I have been trying to think of a way to not have to drill and tap new holes in the existing coupler, but rather try to match the booster to what is already there.
Of course, that is easier said than done. Even a fraction of an inch off means that the holes won't line up.
So I am looking for ideas. I have a couple myself, but maybe you have some tried and true solution that I haven't thought of, since I know I am not the first person to have to fit a new booster to an old rocket. :wink:
Idea Number One
Problem with Idea Number One
Idea Number Two
Problem with Idea Number Two
Idea Number Three
Problem with Idea Number Three
Same as Idea Number Two. Booster has larger OD than coupler.
The existing coupler has nice, tapped shear pin holes for #8-32 screws. The new booster will need new holes.
I have been trying to think of a way to not have to drill and tap new holes in the existing coupler, but rather try to match the booster to what is already there.
Of course, that is easier said than done. Even a fraction of an inch off means that the holes won't line up.
So I am looking for ideas. I have a couple myself, but maybe you have some tried and true solution that I haven't thought of, since I know I am not the first person to have to fit a new booster to an old rocket. :wink:
Idea Number One
- Insert the coupler into the booster up to the switch band.
- Insert a bright light into the coupler.
- The light should show where the holes are; mark them with a Sharpie, and drill them slightly large to accommodate inexact drilling.
Problem with Idea Number One
- Light may not be bright enough to shine through the fiberglass, rendering this idea moot.
Idea Number Two
- Carefully measure the height of each hole in the coupler down from the switch band.
- Carefully measure the distance between the hopes in the coupler with a tailor's tape.
- Recreate these measurements in the booster and drill slightly large.
Problem with Idea Number Two
- Booster has larger OD than coupler, and thus measurements would need to be modified to accommodate.
Idea Number Three
- Wrap a sheet of paper around the coupler, with the top at the switch band.
- Mark the shear pin holes.
- Transfer the paper to the booster.
- Drill through the paper into the booster; drill slightly large.
Problem with Idea Number Three
Same as Idea Number Two. Booster has larger OD than coupler.