Here's a fin before and after lightly sanding off the laser cut sides.
I've never built a kit this size with this thick balsa for the fins. The fins were almost 3/16" thick!
All edges (except for the root edge) and top of the tunnels are rounded.
The tunnel ends should fit to the leading edge of the fins.
I wrapped some 400 grit around the leading edge of the fin and sanded the end of the tunnels round. Keep the tunnels vertical as you sand in a concave curve.
Here's the fit of the tunnel end looking from the flat root edge.
On the right is the curved tunnel end. The tunnel is flipped over to better show the sanded curve.
Those fins look really small, or you have big hands :)
ReplyDeleteHi Bill,
DeleteThey are just little, fat fins!
From what info I can find regarding the actual rocket, the thickness of the kit fins looks about right (for the fin root), but tins would need to be tapered and shaped to biconvex cross-section -- otherwise the fins will end up looking "chunky". The "quick fix" would be to replace the fins with those made from thinner fin stock.
ReplyDeleteHi Naoto,
DeleteThat may be the true scale taper, but I was trying to build it like the old Model Missiles kit instructions, semi-scale at best. More info coming -
I was only trying to find some rationale for the thick fin stock -- assuming the selection was intentional. Since since the instructions tell you to simply round the edges (with the exception of the root edge of course), I'm apt to believe the thick fin stock was likely a mistake.
DeleteChris, I think the fins are in fact 3/16" thick.
ReplyDeletehttp://www.erockets.biz/semroc-laser-cut-fins-aerobee-hi-3-16-balsa-sem-fv-2/
Hi BAR,
DeleteThat's what the Semroc website says - more information in an upcoming post.