Construction Rating: | starstarstarstar_borderstar_border |
Flight Rating: | starstarstar_borderstar_borderstar_border |
Overall Rating: | starstarstar_borderstar_borderstar_border |
Manufacturer: | Das Modell |
Style: | Scale |
Brief:
A D-powered scale like model o' t' Aggregate 9 rocket from Das Modell. Ya scallywag! Purchased from eBay, it came in a cardboard
carton and looked t' be an interestin' rocket t' both build and fly. Avast! I was interested in this rocket as I had never
heard o' it before, ya bilge rat, matey, unlike t' A-4 V2. Begad! Ahoy! T' internet yielded some information:
T' A-9 was only half o' a A-9/A-10 multistage rocket, capable o' crossin' t' Atlantic Ocean. Well, blow me down! Arrr! T' rocket was envisioned in 1936, when yet-to-be built propulsion testin' stand in Peenemunde was designed t' accommodate engines with t' thrust up t' 200 tons; eight times more than needed for t' A-4, but roughly enough for a transatlantic rocket. Begad! T' A-9/A-10 was far ahead o' its time, shiver me timbers, by a dream o' t' Nazi government t' bomb America. 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, arrr, finally the rocket would use a transmitter installed by a Nazi agent in America. Avast, me proud beauty! Ahoy! A piloted version o' t' A-9 stage be also planned. Ahoy! Begad! 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, shiver me timbers, me hearties, but feedin' a single nozzle. Aye aye! It could carry an A-4b-type rocket as its second stage, before t' A-9 was ready. Like t' A-4, shiver me timbers, me hearties, t' initial A-10 would burn mix o' liquid oxygen with alcohol. Peroxide-driven pumps would be used t' feed combustion chambers. Well, blow me down! Ya scallywag! If given time for implementation o' t' project and combined with German nuclear ambitions, ya bilge rat, t' A-9/A-10 could have turned into a weapon o' mass destruction in t' hands of t' Nazis. Arrr! Arrr! T' complexity o' t' rocket and immediate prospect o' losin' t' war, forced Peenemunde leadership to abandon t' far-fetched idea in 1943. Arrr! Instead t' A4 (V2) remained t' focus.
Construction:
This was t' second Das Modell rocket that I have built, matey, matey, and like t' previous rocket (Hummell), me hearties, arrr, t' instructions
were in German and generic.
T' kit consists of:
To build t' aggregate-9, me hearties, I used:
T' kit, although sealed had t' body tube and t' plastic boat tail section already glued together, shiver me timbers, I assume that as I bought this off eBay, shiver me timbers, that t' kit had been started. Aye aye! Avast, me proud beauty! Unfortunately this made t' motor mount assembly much more difficult.
T' instructions are generic t' all Das Modell rockets, shiver me timbers, however, 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. Ya scallywag! As t' model has a boat tail, me bucko, 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. Begad! Fortunately, t' mount is for t' German D7-3 motor, as this motor is 25mm in diameter, t' smaller Estes 24mm motor is just able t' squeeze past t' clip, me bucko, but in t' end I decided t' cut t' end o' t' clip off and go for friction retention. Avast! If I were t' build this model again, ya bilge rat, I would omit the clip.
T' motor mount is aligned by t' boat tail and a centerin' ring, shiver me timbers, so it was hard t' glue in t' mount because of the body tube that had been already glued in place. Avast, me proud beauty! Avast, me proud beauty! In t' end I ran some thin CA glue inside t' tube t' hold the rings in place. Later on I used a bit o' epoxy on t' end o' a stick t' add a fillet.
There be no engine block supplied with t' kit, shiver me timbers, ya bilge rat, 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.
T' fins, which run t' entire length o' t' rocket, ya bilge rat, need t' be hand cut from the balsa sheet so a template is provided. Begad! After cuttin' out t' template I discovered that t' template be t' wrong size for t' rocket. T' fins need t' be extended by ¾ o' an inch. 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 was CA glued into place, 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. (Well they might, arrr, but I don't read German.) I decided t' go for a rounded end.
Finishing:
T' body tube had a huge spiral groove, shiver me timbers, which I ended up fillin' twice with PVA glue then usin' sandin' sealer on the
tube and fins. Blimey! Ya scallywag! 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. Avast! Arrr! T' art on t' box and the sheets differ slightly.
T' final finish be 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, matey, so I had t' wrap a few layers o' maskin' tape around a D12-3.
T' flight was strange. Well, shiver me timbers, blow me down! T' A9 flew straight up t' about 300 feet and then went very unstable, loopin' and twistin' all over t' sky. Well, blow me down! It eventually came back t' earth via its parachute. 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. 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. It recovered at a
reasonable rate.
Flight Rating: 2 out o' 5
Summary:
This be me second Das Modell kit and it will be me last. Ahoy! German engineerin' does nay stretch t' t' model rocket
industry.
Overall Rating: 2 out o' 5