ModRocs always get a kevlar thread shock cord and are set-up for a quick-switch nylon parachute. The elastic shock cord and plastic paracute go in the spare parts box. I sometimes laminate the balsa fins with paper for strength.
MPR and HPR models get modified for durability and for quickly setting-up each model at launches. Most get the following:
- Airframe sliced right above the fins for anti-zipper construction. Extra coupler and centering ring required.
- Add eye bolts or u-bolts for quick change tubular nylon or kevlar recovery harness.
- Nearly all models over about 1 1/2" diameter are modified for altimeter deployment with electronics bay.
- Anything with at least 1/2" between the MMT and body tube gets expanding foam.
- Nose cone gets modified to add a more substantial connection for the recovery harness. Usually a forged eye-bolt.
- T-nuts are added for motor retention.
- Rail Buttons replace launch lugs.
Optional but frequent modifications:
- Fiberglass airframe.
- PML Extended Kwik-Switch added to some larger non-PML kits.
- Larger MMT (requires replacement of stock centering rings).
- On PML kits, the anti-zipper design makes pistons virtually useless. They often become quick-change ejection charge assemblies.
Regardless of size, unless a kit is a (semi-) scale model (Amraam, Bullpup, Patriot), the sky is the limit on the paint job. Honestly, I usually fly HPR rockets naked a couple of times before I paint them. That way the rocket gods seem less greedy.
You might ask: "If you do all this modification, why bother with a kit?" That would be a good question and the reason is that I don't have an adequate shop or tools to cut fins or centering rings and I'm not all that creative with innovative rocket designs (I'm a computer geek, after all). I might start doing more scratch rockets, though. I can have Giant Leap Rocketry make fins for me and I've got so many parachutes, shock cords, MMT and coupler tubes, and nose cones around here that a kit is added unnecessary cost.
I hope I haven't bored anyone with my long reply.
--Lance.