Crayon X1 - X2 Projects
Two rockets based on Crayon X3 modular design
|Lets start this build with centering rings... First I cut four disks out of 0.125" birch ply using 4" hole saw, drilled
two 0.25" holes and bolted all four tightly together with 1/4"-20 hardware... Then it was time to go to town with
my highly accurate and tightly toleranced $39.95 chinese drill press *sarcasm/off* and bore out twin 29mm
MMT's, fin bracket holes, plus threaded insert holes on the sides...
|Here's how they look like when all done and
separated up for epoxying the halves
back together using 30 min 'poxy...
|So why didn't I cut the rings out of 0.50"
plywood and save some time and trouble?
Simple, my drill press lacks oomph to cut it...
|I had some left over aluminum clips from
screening our back porch, the same kind I
used earlier on Crayon X3 fin mounts...
|...and after a very relieving frustration venting session
on a red hot hacksaw, they looked like this...
|So I snipped the corners off gently with sharp
tin snips, and bolted the fin mount brackets
on using #8 - 3/4" machine screws...
|...threaded in the #8 brass inserts,
four per ring spread 90 degrees apart,
45 degrees from the fins...
|...and glued the rings on two 12" long
29mm MMT's from Balsa Machining Service (free plug!)
with more 30 min epoxy. Don't forget to sand off the
glassing and line everything up prim and proper first...
|Or you'll pay Hades in lining up the fins later. To talk
about fins, I cut four of them out of 0.125" birch ply
and drilled them to fit the brackets. All exactly the
same, since all lined up nice...
|So it was time to proceed on to tailcone using the
plastic Crayon bottom reinforced by
a 3" ring cut from 0.25" birch ply and drilled
to fit. Drill quit smoking by next morning...
|To be sure and on the safe side, I trial fitted
the whole jigsaw puzzle together, and surprisingly it
a fin can unit...
|A 1/4" stainless U-bolt goes in the front
for a rock solid shock cord mount...
|And after the J B Weld on bottom ring cured,
it was time to bolt on the tailcone and Kaplow clips...