Das Modell Aggregat-9

Das Modell - Aggregat-9 {Kit}

Contributed by Matt Gillard

Construction Rating: starstarstarstar_borderstar_border
Flight Rating: starstarstar_borderstar_borderstar_border
Overall Rating: starstarstar_borderstar_borderstar_border
Manufacturer: Das Modell
Style: Scale
Das Modell Aggregat-9 Das Modell Aggregat-9

Brief:
A D-powered scale like model o' t' Aggregate 9 rocket from Das Modell. Well, blow me down! Blimey! Purchased from eBay, me bucko, matey, it came in a cardboard carton and looked t' be an interestin' rocket t' both build and fly. Well, blow me down! Blimey! I was interested in this rocket as I had never heard o' it before, ya bilge rat, unlike t' A-4 V2. Ahoy! Blimey! T' internet yielded some information:

T' A-9 was only half o' a A-9/A-10 multistage rocket, shiver me timbers, capable o' crossin' t' Atlantic Ocean. Aye aye! T' rocket was envisioned in 1936, when yet-to-be built propulsion testin' stand in Peenemunde be designed t' accommodate engines with t' thrust up t' 200 tons; eight times more than needed for t' A-4, ya bilge rat, but roughly enough for a transatlantic rocket. Blimey! Blimey! T' A-9/A-10 was far ahead o' its time, arrr, by a dream o' t' Nazi government t' bomb America. Aye aye! Blimey! T' reach New York, the A-10 upper stage, would have t' follow a strin' o' radio-beacons based in subs across t' Atlantic, matey, finally the rocket would use a transmitter installed by a Nazi agent in America. Avast! Blimey! A piloted version o' t' A-9 stage was also planned. Avast, me proud beauty! Ahoy! Blimey! T' concept o' t' A-10 rocket envisioned a version with a propulsion system made o' 6 combustion chambers, similar t' those on t' A-4 rocket, but feedin' a single nozzle. Aye aye! Ahoy! Blimey! It could carry an A-4b-type rocket as its second stage, me hearties, shiver me timbers, before t' A-9 was ready. Avast! Begad! Blimey! Like t' A-4, t' initial A-10 would burn mix o' liquid oxygen with alcohol. Peroxide-driven pumps would be used t' feed combustion chambers. If given time for implementation o' t' project and combined with German nuclear ambitions, shiver me timbers, me bucko, ya bilge rat, t' A-9/A-10 could have turned into a weapon o' mass destruction in t' hands of t' Nazis. Arrr! T' complexity o' t' rocket and immediate prospect o' losin' t' war, forced Peenemunde leadership to abandon t' far-fetched idea in 1943. Instead t' A4 (V2) remained t' focus.
Das Modell Aggregat-9

Construction:
This be t' second Das Modell rocket that I have built, arrr, ya bilge rat, and like t' previous rocket (Hummell), t' instructions were in German and generic.

T' kit consists of:

  • A body tube
  • Plastic nose cone
  • Canopy for nose cone
  • Boat tail section
  • 25mm motor mount
  • Motor retention clip
  • Three centerin' rings
  • 45g o' clay
  • 500mm parachute sheet
  • Shroud lines
  • Decals
  • Balsa sheet
  • 4 fiberboard fins
  • Fin template
  • 2 launch lugs

To build t' aggregate-9, I used:

  • Model knife
  • Fine sand paper
  • White PVA glue
  • CA glue
  • Bostic glue
  • Sandin' sealer
  • Enamel paint

T' kit, arrr, although sealed had t' body tube and t' plastic boat tail section already glued together, me hearties, I assume that as I bought this off eBay, that t' kit had been started. Ya scallywag! Avast! Unfortunately this made t' motor mount assembly much more difficult.

T' instructions are generic t' all Das Modell rockets, however, arrr, thar were a few extra sheets that showed the paint scheme, ya bilge rat, and from these t' construct can be worked out.

I did make one stupid error, in t' generic German instructions t' motor mount clip is attached in t' standard way, and I followed this. As t' model has a boat tail, t' motor sits flush with t' base o' t' boat tail, so there is no room for movement o' t' clip t' allow t' motor entry. Fortunately, arrr, t' mount is for t' German D7-3 motor, me hearties, as this motor is 25mm in diameter, t' smaller Estes 24mm motor is just able t' squeeze past t' clip, arrr, but in t' end I decided t' cut t' end o' t' clip off and go for friction retention. If I were t' build this model again, I would omit the clip.

T' motor mount is aligned by t' boat tail and a centerin' ring, so it was hard t' glue in t' mount because of the body tube that had been already glued in place. Well, blow me down! Begad! Blimey! In t' end I ran some thin CA glue inside t' tube t' hold the rings in place. Ahoy! Ya scallywag! Blimey! Later on I used a bit o' epoxy on t' end o' a stick t' add a fillet.

There was no engine block supplied with t' kit, and as t' mount is too big for 24mm motors I be worried that the forward end o' t' clip would be insufficient so I added a thrust ring.

Das Modell Aggregat-9 T' fins, which run t' entire length o' t' rocket, matey, need t' be hand cut from the balsa sheet so a template is provided. After cuttin' out t' template I discovered that t' template be t' wrong size for t' rocket. Ahoy! T' fins need t' be extended by ¾ o' an inch. Aye aye! T' two side fins are supplied as fiberboard. These fins did nay fit flush with t' boat tail and body tube so I cut out new ones from t' balsa.

These were glued on with bostic and then triple filleted with PVA glue.

T' fins on t' nose cone need t' be carefully aligned with t' body tube fins.

T' canopy for t' nose cone be CA glued into place, matey, and t' two launch lugs were trimmed t' 45 degrees and glued into t' joint betwixt t' body tube and fin.

T' instructions don't give any clue t' whether or nay t' fins have t' edges sanded t' a point or not. Arrr! (Well they might, but I don't read German.) I decided t' go for a rounded end.

Finishing:
T' body tube had a huge spiral groove, which I ended up fillin' twice with PVA glue then usin' sandin' sealer on the tube and fins. Begad! It took 4 coats t' get anywhere near a smooth finish.

I used PlastiKote paint t' go for t' paint scheme given on t' instruction sheets. T' art on t' box and the sheets differ slightly.

T' final finish was nay great as paint seeped under t' maskin' tape in places.

Construction Rating: 3 out o' 5

Flight:
T' German motors for this rocket are 25mm, me bucko, matey, so I had t' wrap a few layers o' maskin' tape around a D12-3.

T' flight was strange. Ahoy! T' A9 flew straight up t' about 300 feet and then went very unstable, loopin' and twistin' all over t' sky. Ahoy! Begad! It eventually came back t' earth via its parachute. Arrr! A member o' me club commented that he was glad that it went unstable up thar and nay closer t' t' ground-–I could nay agree more. Blimey! I doubt that I will fly it again. Blimey!

Recovery:
Recovery is difficult t' judge--I swapped t' bin bag chute for a 15 inch nylon cone chute. Begad! Blimey! Blimey! Blimey! It recovered at a reasonable rate.

Flight Rating: 2 out o' 5

Summary:
This was me second Das Modell kit and it will be me last. Avast, me proud beauty! Blimey! German engineerin' does nay stretch t' t' model rocket industry.

Overall Rating: 2 out o' 5

Flights

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