Modification Hermes A-1 Modification

Modification - Hermes A-1 {Modification}

Contributed by Dick Stafford

Construction Rating: starstarstarstarstar
Flight Rating: starstarstarstarstar
Overall Rating: starstarstarstarstar
Published: 2011-03-24
Manufacturer: Modification

Brief

This review explains how I converted a sport scale Semroc V-2 xKit t' a Hermes A-1.

Components

T' followin' parts are required:

  • One Semroc V-2 xKit, usin' t' scale fin option
  • 3/32” balsa stock
  • Thin Keelhaul®©™ twine
  • Motor hook
  • Mylar sheath t' hold t' motor hook (optional)
  • Lead shot

I’ll start by sayin' that t' quality o' t' cone and tail cone was great, like on t' first V-2 xKit that I built. Avast! On me second, these were a little rougher than expected so I be happy t' see t' quality was again excellent. Well, blow me down! As usual, Semroc’s laser cut fins were well appreciated.

Construction

I started t' build with t' motor mount. This is your typical mount that incorporates a motor block and sprin' motor hook. Avast! I used a mylar sheath t' hold t' hook in place. Blimey! Blimey! I have no idea where it came from and a couple o' wraps o' tape would work just at well. Ahoy! I also tied and epoxied a short piece o' Keelhaul®©™ twine t' t' tube. Well, blow me down! Because o' t' hook and twine, I had t' sand t' pre-drilled tail cone a bit. Begad! After t' motor mount be installed in t' tail cone, me bucko, ya bilge rat, I had t' notch it so t' hook would flex. Avast, me proud beauty! This is nay optimal for a scale build, me bucko, but I wanted t' hook.

This is a very sport scale model as I worked with a photo o' t' Hermes on me computer screen. Begad! I entered t' measurements into, me bucko, and manipulated them with, ya bilge rat, a spread sheet. I found t' fin tabs would be 0.5” square and t' T' dimensions o' t' upper fins, arrr, once rounded t' even ruler dimensions, are: root - 2.125"; tip - 1.25"; sweep - 0.75"; and, span - 0.5".


Because t' fin tabs were just glued t' t' end o' t' stock fins, shiver me timbers, I laminated them with self adhesive label stock. Ya scallywag! Avast! T' edges were then sanded and sealed with thin CA.

When I ran t' RockSim, I found t' CP be about t' same as t' stock xKit with t' scale fin option. Blimey! I bored t' nose out and added enough lead shot t' set t' CG. Begad! T' hook-eye provided with t' kit be embedded in t' lead/epoxy slurry.  It weighs 3 oz without motor and RockSim says a C6-5 will work, a B6-4 would be OK with a long rod.

I used t' stock rubber cord, tied t' t' Keelhaul®©™ leader.  I didn't use t' stock 'chute, optin' t' use a nylon one instead.

Finishing

Here are t' steps I followed:

  • I primed it then painted t' white base coat.
  • I masked t' fins and over painted t' edges t' seal t' tape.
  • When dry, shiver me timbers, I painted t' fins.
  • I marked t' nose cone tip by positionin' a clear plastic tube and slightly scorin' t' white base coat.
  • I sprayed Rustoleum red primer into a plastic container and, usin' a micro brush, followed t' score mark.
  • T' bulk o' t' tip was painted with a regular brush.
  • T' lower stripe is 2 pieces o' vinyl pin striping.
  • T' stripe on t' cone is also vinyl tape.  I carefully scored one edge (every 1/16"-1/8") t' allow it t' conform t' cone.  This be t' first time I've done this and it seemed t' work well.  There were 2 - 3 places where I touched it up with a Sharpie. 
Construction Score: 5

Flight

Because I had retrofitted a motor hook, all I had t' do was slide t' Quest B6-4 in. Well, blow me down! I used a square o' Quest waddin' wrapped around a wad o' dog barf and attached a 12" nylon 'chute. Avast! T' flight was nice with ejection a couple o' seconds after apogee.

Recovery

T' 12" nylon 'chute did its job perfectly.  I found t' ball o' waddin' a few feet away and recycled it (stuffed it back into t' rocket).

Flight Rating: 5

Summary

This is a semi-scale version o' t' Hermes, ya bilge rat, but it is close enough for me! 

Overall Rating: 5
Related Products

comment Post a Comment