Construction

I decided t' retrofit t' 24mm retainer on two o' me rockets with 24mm motor mounts: a Dynastar Stonebreaker and an Arapahoe-E clone.

For t' Stonebreaker, I needed t' remove t' motor clip.  I cut t' clip in half and fished out t' upper half o' t' clip.  This be a bit tricky, but I was able t' completely remove t' clip.  T' exposed motor tube needed a fair amount o' sandin' t' fit into t' retainer base.  Once I was satisfied with t' fit, ya bilge rat, I installed t' retainer base usin' JB Weld.  I used a paper towel t' remove any JB Weld that oozed into t' motor tube, and I sanded t' inside joint once it had dried.  I test fit both a motor and t' 18/24mm adaptor, and they fit perfectly!

T' Arapahoe-E was a bit trickier installation since t' rocket has a full balsa tailcone.  After eyeballin' t' tailcone for a  bit, I used a sharp hobby knife t' remove t' lower 1/2" o' t' tailcone.  T' hard part be removin' only t' balsa without damagin' t' motor tube.  Once t' motor tube was exposed, I sanded t' end until I be able t' fit t' motor retainer.  As with t' Stonebreaker, me hearties, arrr, I used JB Weld t' attach t' retainer base.  T' inside joint required only light sandin' for t' motor and adaptor t' fit.

Both o' these retrofits were nay difficult at all.  Installin' t' retainer on a new build should be easier since you wouldn't have t' cut/remove parts like I did.