Finally building my first V2

This is a Skill level 4, D powered Estes kit. #1904; a similar current kit (#3228) sold for $26.99 in 2020.  There was an original 1904 kit listed for $70 at https://www.launchlabrocketry.com/shop/the-vault 9/22/21.  I found my original Commonwealth receipt from when I purchased mine for $29.99 on 7/6/2000.

I’ve always wanted to build a V2, not because of it’s use in WWII but because it was the basis, after the war, of jump starting the American space program.  As such, I spent a lot of time looking at different paint patterns for the V2, since I didn't want to do a camouflage pattern for war, before settling on the final yellow and black scheme.  

I bought this kit in 2000, but it was a reissue of an earlier kit from 1984 (and has since been re-reissued).  They included the original 1984 20-step instructions with a cover page describing the new engine hook they provided and a few other minor updates.  This kit was designed to fly on a D12 engine, but I decided to modify it to also fly on a 24 mm E engine.  At first, I thought I would just swap the D hook for a longer E hook and engine mount tube but the hook I had was too short!  I bought the Estes “Engine Mount Kit for D & E Engines” (47776 03159), and it came with the 4” X 24 mm engine tube but the hooks were no good.  My solution was to cut ~1/8” off used D engine with a hack saw and then use an E9 engine to push it in place as a retainer (with glue).  I attached the too short “E hook” for the retainer hook by glueing a shroud over it but NOT allowing the clip to go through wall because it would block the longer engines.  I weighed the modified retainer and it was less than 1 gm.

This is a big rocket.  It’s 2.6” in diameter and 22.4” tall with an 18" parachute, but it’s shape makes it seem bigger.  I liked this kit because it had through-the-wall fins, a “boat tail” curved back end, and a classic shape.  It reminded me a lot of the Silver Comet my daughter gave me in 2000.  After the fins were attached, brushed with wood putty and sanded, I primed it, sanded some more and then painted it a bright yellow (using Rust-Oleum Sunburst Yellow).  I then taped off half the fins and half the body to give a ~checker board pattern, and painted the untaped areas black (with Rust-Oleum Black).  I’m really happy with the final result.

Because of the modifications and to double check the RockSim file I weighed the different components and finished rocket:

• Assembled engine mount 5/8 oz (20 gm)
• Trimmed boat tail 7/8?oz (25 gm)
• Shock cord 1 gm
• Assembled rocket (w/o glue for fins) 4 3/8 oz (127 gm) unpainted or primed/filled; 4 7/8 with clay (140 gm)
• Glued, filled & sanded weight before priming:  5 1/4 oz (149 gm)

The box says the rocket should fly “over 750 feet” on a D12.  Due to the curvature of the boat tail, OpenRocket can’t simulate the curved fins.  The weights in the RockSim files I downloaded for the #1904 V2 model are two or three times as much as my finished weight so I think a D12 will reach somewhere around 700 feet and maybe an E9 will reach 900 or 1000 feet.  This is where a licensed copy of RockSim would be a huge benefit, I’m sure, but I may just launch it with an E9 and see how high it goes!  The V2 has joined Larry's fleet of rockets ready for their first (or second) flight.