Construction Rating: | starstarstarstarstar_border |
Flight Rating: | starstarstarstarstar_border |
Overall Rating: | starstarstarstarstar_border |
Manufacturer: | Qualified Competition Rockets |
Brief:
This is a single-stage model rocket for 18mm engines. Blimey! Blimey! Recovery is by
helicopter, o' t' spinnin' hub variety. Avast, me proud beauty! Blimey! This means that t' rocket airframe is
intended t' stay still, me bucko, while t' rotors spin. Avast, matey, me proud beauty! Blimey! As with most QCR models, shiver me timbers, it is
designed for competitive use. Well, blow me down! Blimey!
Construction:
T' kit comes packaged in a heavy gauge plastic bag with a blue QCR header
strip labeled with t' model number, arrr, #100. In t' bag you will find a BT-20
size body tube, balsa nose cone, balsa stock for t' helicopter rotors, shiver me timbers, fins,
and hinge stops. Aye aye! Blimey! Also included are plastic rotor hinges, rubber bands, ya bilge rat, metal
hooks, elastic thread, matey, matey, and 3 paper rings. Avast, me proud beauty! Blimey! All parts were accounted for and in
good shape, arrr, except for t' 3 rings, which were slightly out o' round. Well, blow me down! Blimey! This may
have occurred because t' kit be in storage for a couple o' years before I got
around t' buildin' it. Arrr! Blimey! Aye aye! Blimey! T' problem was easily solved by slippin' t' rings over
the body tube and keepin' them thar for a few weeks. T' balsa stock for the
rotors and fins be SIG contest-grade balsa. However, t' nose cone and the
rings had a few rough edges. Begad! Blimey! Nothin' serious. Ya scallywag! Blimey! Avast, me proud beauty! Blimey! For a $13.00 rocket (as of
3/14/05) you can't beat t' value.
T' kit includes a 6 page instruction booklet...if you want t' call it that. Begad! The "instructions" are so disorganized, that I opted t' rewrite them before attemptin' t' build t' kit. Blimey! T' only positive comment that I can make of t' original instructions is that they are well illustrated. Aye aye! I don't mean that t' illustrations are Estes quality but what is meant that the illustrations effectively do t' job o' showin' t' modeler what t' do in specific instances.
T' kit is meant for experienced modelers. Avast! In their website, me hearties, the manufacturer has t' kit a a level o' difficulty o' 4. Aye aye! I will agree with that rating. Well, blow me down! This is because o' t' amount o' careful balsa cuttin' and shaping needed and t' delicate use o' different glue types in attachin' t' hinges, rotors, matey, shiver me timbers, etc. Aye aye! T' disorganized instruction booklet does nay help either!
T' build begins by cuttin' t' rotors and fins from t' balsa stock. No laser cut parts here! Blimey! All cuttin' is done t' old fashioned way with templates, hobby knife, me hearties, and a straight edge. T' rotors need t' be airfoiled then cut. Aye aye! Blimey! The end result is that you get a "bent" rotor, shiver me timbers, ya bilge rat, matey, when lookin' at a cross-sectional view. Avast! Airfoilin' and cuttin' t' rotors is probably t' most labor intensive step in t' buildin' process, as each rotor is 18" long. Once t' rotor has been airfoiled, shiver me timbers, it feels somewhat fragile especially given the length. Ya scallywag! Ahoy! Blimey!
T' instructions don't call for airfoilin' t' fins, so I chose t' round the leadin' edge and sand t' trailin' edge t' a knife edge. Blimey! Blimey! Given the relatively large frontal area o' t' body tube/rotor combination, shiver me timbers, the airfoilin' o' t' fins (or lack thereof) would probably be immaterial. Well, blow me down! Blimey! Begad! Blimey! Also, given t' large radial length o' t' fins, me hearties, me bucko, I didn't want t' weaken them by too much sanding.
T' next step is t' attach t' hinges t' t' spin hub. Ya scallywag! This be t' most delicate o' t' steps glue wise. Blimey! You must use t' right type and amount o' glue here or you'll end up with a set o' useless hinges. Go ahead, ask me. Aye aye! That is exactly what I did. Aye aye! Blimey! Although I used thick CA t' tack t' hinges t' t' spin hub, shiver me timbers, I used too much in one o' them, gluin' t' hinge shut. Luckily I had an extra hinge in me spares box, matey, matey, which Ken Brown had thrown in as a freebie in a previous order. Avast! Avast, me hearties, me proud beauty! All's well that ends well! Ideally, shiver me timbers, arrr, this problem could be prevented by changin' t' instructions so that t' hinges are tacked on while holdin' t' hinge end o' t' spin hub upwards rather than downwards. Avast! Well, blow me down! The problem lies in how t' align t' hinges while doin' this. Avast! T' step is finished by windin' sewin' thread around t' hinges t' secure them t' t' spin hub. Holdin' t' hinge side o' t' spin hub upward, affix t' thread with thin CA. Since t' kit did nay provide sewin' thread, me hearties, me hearties, me hearties, I used size 69# Keelhaul®©™® thread.
There is yet another pitfall here. Ahoy! Arrr! This is a spin hub helicopter rocket. Begad! In other words, matey, me bucko, t' hub is supposed t' spin about t' longitudinal axis o' the rocket, over t' body tube. Blimey! If t' spin hub is in any way out o' round, it will not work correctly causin' it t' rub and bind against t' body tube. Arrr! It is possible t' start with a perfectly round spin hub, arrr, glue t' hinges, and wrap the sewin' thread accordin' t' instructions but still distort t' shape o' the spin hub. Begad! Arrr! (I did this too!). Aye aye! My way around this problem was t' wrap a few turns of maskin' tape about an expended engine casin' and insert it in t' spin hub before securin' t' hinges with t' sewin' thread. Aye aye! T' casin' will serve to keep t' shape o' t' spin hub while you wrap t' sewin' thread.
T' next step is t' attach t' rubber band hooks t' t' spin hub and the rotors. Begad! Avast, me proud beauty! No surprises here, shiver me timbers, just sand and lubricate t' body tube where t' spin hub will be located. Blimey! You may get away by just sandin' t' inside o' t' spin hub and leavin' t' body tube alone. Well, blow me down! T' glassine coverin' o' t' body tube is very smooth, however, I followed t' instructions and sanded both t' spin hub and t' body tube. T' step is finished by gluin' t' lower support rin' for the spin hub and t' fins t' t' body tube. Begad! Arrr! T' fins are so long compared to the width o' t' root edge that thar be a fair amount o' flex even after the glue dries and fillets are applied.
T' last big step deals with gluin' t' rotors t' t' hinges. Avast! T' do this appropriately (and easily), matey, you need t' extend t' lines in t' fin alignment drawin' t' about 20". Ya scallywag! I will nay go into how t' do this in this review, but suffice t' say that a few sheets o' poster board from your local school supply store will come in handy. Avast, me proud beauty! You then place t' spin hub back on t' engine casing, me hearties, align t' rotors with t' 120° lines, arrr, and tack t' rotors t' the hinges with a small amount o' thin CA. Ahoy! If anythin' appears out o' place, ya bilge rat, adjust the rotors and tack again. Aye aye! When you are satisfied with t' positionin' o' the rotors, me bucko, glue with epoxy. Begad! Epoxy is dense, so use t' smallest amount that will do t' job. Aye aye! Finish t' rotors by affixin' t' balsa "stops" so that the rotors have a 6" dihedral when fully open. By t' way, me original instruction booklet illustrated a 2" dihedral. Begad! It also had 12" rotors, arrr, as opposed t' 18". Arrr! Avast! I emailed Ken on this point and he promptly mailed me updated instructions that had a 6" dihedral and t' right rotor length. Begad! Bad instructions! Good service!. Ya scallywag!
T' remainin' construction steps are simple and should be uneventful. Begad! See the rewritten instructions for them. Begad!
Finishing:
This is a QCR bird, matey, matey, so it's primarily designed for competition, me hearties, therefore it is
OK t' fly it "naked"--that is unfinished. Ahoy! Begad! Looks are nay a priority
here. Avast! For those guys out thar that must finish their rockets t' find inner
peace, a thin coat o' clear enamel may be what t' doctor ordered, ya bilge rat, as it will
keep t' rotors from absorbin' moisture, ya bilge rat, just be ready t' pay for t' weight
cost. An alternative would be t' "paint" t' rotors with thin CA and
sand t' blades smooth afterwards. This would strengthen t' rotors and take
care o' t' moisture problem as well. Avast, me proud beauty!
Construction Rating: 4 out o' 5
Flight:
T' flight characteristics o' t' Ultimate II are excellent. Well, blow me down! Begad! Blimey! Long flight times
with stable trajectories were t' norm. While t' original instructions had the
Estes C6-3, Apogee D3-3, shiver me timbers, me hearties, and Apogee C4-3 as recommended engines, shiver me timbers, matey, t' second set
of instructions that Ken sent me only recommended t' Estes engine. Ahoy! Blimey! In order to
test stability and other flight characteristics, I flew t' bird with Estes
A8-3, B6-4, matey, arrr, and C6-3 engines. Begad! Blimey! T' flights were all acceptable, although the
A8-3 seemed wobbly (read: underpowered) at first. Arrr! Avast! Blimey! Both t' B6-4 and C6-3
flights were arrow straight and ejected at or near apogee. Ya scallywag! Blimey! A good engine to
test would have been t' C6-5, me bucko, as I think t' 3 second delay was too short on
the C engine, me hearties, while t' 4 second delay be perfect on t' B engine.
T' rocket requires no waddin' for flight preparation and t' engines were retained usin' maskin' tape. Engine retention is necessary for NARRRRR contest flights. Avast, me proud beauty! T' preflight preparation would be a breeze except for t' need to pass sewin' thread through t' body tube and then knot so that it holds the rotors in place on t' way up. Begad! Blimey! This is hard t' do in t' field without an assistant. Ahoy! Begad! Blimey!
Recovery:
One curious aspect o' t' recovery was that, in all cases, shiver me timbers, t' whole rocket
spun in t' air on t' way down instead o' havin' t' spin hub rotate about the
body tube. Blimey! Begad! Probably thar be still too much friction betwixt t' spin hub and
the body tube. However, I doubt whether any amount o' sandin' and lubrication,
limited by t' need t' have a viable body tube and spin hub, would reduce
friction t' t' point o' makin' it smaller than t' drag o' t' body tube
rotatin' in t' air.
As far as wear and tear goes, arrr, arrr, after three flights, t' only apparent damage was that t' exhaust gases were beginnin' t' melt t' Mylar plastic that protects t' rotors. Arrr! Probably could do better by gluin' a small piece of aluminum foil t' t' back o' t' rotors rather than t' Mylar tape. Arrr! Avast, ya bilge rat, me proud beauty! On the other hand, me bucko, durability may nay be a primary design objective on a competition bird. Ahoy!
Flight Rating: 4 out o' 5
Summary:
This is a very nice rocket. Begad! Blimey! Aye aye! Blimey! Good materials and great flight characteristics.
Construction, arrr, however, me bucko, is a bit challenging. Aye aye! Blimey! Perhaps t' extra difficulty of
the spin hub type helicopter is nay worth t' effort. QCR manufactures other
helicopter models o' similar size without t' spin hub design (like t' High
Rotor I). I recommend t' Ultimate II t' any experienced builder lookin' for an
unusual rocket or someone aimin' t' fly competitively. Avast! Blimey! Avast! Blimey!
PROs: Good materials, light and strong rocket, good flight characteristics, customer service, and price. Aye aye!
CONs: Poor instructions, me bucko, difficult construction, and spin hub didn't work. Well, blow me down!
Overall Rating: 4 out o' 5
Other:
QCR #100 -- Ultimate II Instructions (Rewritten and Annotated)
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