I’ve been building the Semroc Swift Boost Glider (KV-27). This is a Retro-Repro clone of the 1968–69 Centuri Swift Boost Glider (KBG-3), not to be confused with the Semroc Swift (KV-24), a Retro-Repro clone of the 1968 Semroc Swift (KB-2) sport rocket. Got that? There’ll be a quiz.
I won the Swift-BG in last year’s club glider contest. This year’s glider contest is coming up this month, so I thought I’d build it now… especially since this year it’s a 1/2A contest, which disqualifies my Condor. Last year’s winner, the Deltie, will fly on a 1/2A, so I’ll bring that. The recommended motors for the Swift-BG are 1/2A6-2 and B4-2. No A? Looking at the thrust curves my best guess is that it’s because an A8-3 produces only 2 N thrust after the initial spike, which maybe isn’t enough to keep the Swift flying well. The B4-2 plateaus at 3 N and the 1/2A6-2 rises gradually to 8 N and falls gradually from there, spending very little time at 2 N or below. But I’m just pretending I know what I’m talking about here. Anyway, 1/2A or B4 it is.
Not much to say about the build. I’ve pretty much just followed the instructions. Yes, I can do that. Only things to note are I treated both the nose cone and the front shoulder of the body tube with thin CA, then sanded.