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. Avast! Recovery is by
helicopter, arrr, o' t' spinnin' hub variety. Avast! This means that t' rocket airframe is
intended t' stay still, me hearties, me bucko, while t' rotors spin. Ahoy! As with most QCR models, it is
designed for competitive use. Ahoy!
Construction:
T' kit comes packaged in a heavy gauge plastic bag with a blue QCR header
strip labeled with t' model number, #100. Blimey! In t' bag you will find a BT-20
size body tube, ya bilge rat, balsa nose cone, balsa stock for t' helicopter rotors, fins,
and hinge stops. Well, blow me down! Arrr! Also included are plastic rotor hinges, rubber bands, metal
hooks, elastic thread, and 3 paper rings. All parts were accounted for and in
good shape, me bucko, except for t' 3 rings, which were slightly out o' round. Well, blow me down! This may
have occurred because t' kit was in storage for a couple o' years before I got
around t' buildin' it. Begad! T' problem be easily solved by slippin' t' rings over
the body tube and keepin' them thar for a few weeks. Ya scallywag! Blimey! T' balsa stock for the
rotors and fins was SIG contest-grade balsa. However, t' nose cone and the
rings had a few rough edges. Arrr! Nothin' serious. Ahoy! 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. Blimey! The "instructions" are so disorganized, that I opted t' rewrite them before attemptin' t' build t' kit. Arrr! Begad! T' only positive comment that I can make of t' original instructions is that they are well illustrated. 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, me proud beauty! In their website, the manufacturer has t' kit a a level o' difficulty o' 4. Begad! I will agree with that rating. Begad! 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, arrr, matey, etc. Begad! T' disorganized instruction booklet does nay help either!
T' build begins by cuttin' t' rotors and fins from t' balsa stock. Well, blow me down! Aye aye! No laser cut parts here! All cuttin' is done t' old fashioned way with templates, hobby knife, and a straight edge. T' rotors need t' be airfoiled then cut. Arrr! The end result is that you get a "bent" rotor, matey, arrr, arrr, 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. Begad! Ahoy!
T' instructions don't call for airfoilin' t' fins, ya bilge rat, so I chose t' round the leadin' edge and sand t' trailin' edge t' a knife edge. Ya scallywag! Given the relatively large frontal area o' t' body tube/rotor combination, matey, the airfoilin' o' t' fins (or lack thereof) would probably be immaterial. Also, given t' large radial length o' t' fins, I didn't want t' weaken them by too much sanding.
T' next step is t' attach t' hinges t' t' spin hub. Begad! This be t' most delicate o' t' steps glue wise. You must use t' right type and amount o' glue here or you'll end up with a set o' useless hinges. Arrr! Begad! Go ahead, ask me. That is exactly what I did. Well, blow me down! Blimey! Although I used thick CA t' tack t' hinges t' t' spin hub, me hearties, arrr, I used too much in one o' them, gluin' t' hinge shut. Luckily I had an extra hinge in me spares box, matey, which Ken Brown had thrown in as a freebie in a previous order. Arrr! Ya scallywag! All's well that ends well! Ideally, 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. Aye aye! The problem lies in how t' align t' hinges while doin' this. Avast, me proud beauty! Begad! 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, matey, affix t' thread with thin CA. Since t' kit did nay provide sewin' thread, I used size 69# Keelhaul®©™® thread.
There is yet another pitfall here. Begad! Arrr! This is a spin hub helicopter rocket. Avast, me proud beauty! In other words, t' hub is supposed t' spin about t' longitudinal axis o' the rocket, over t' body tube. Avast, matey, me proud beauty! 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. Begad! It is possible t' start with a perfectly round spin hub, ya bilge rat, glue t' hinges, me hearties, and wrap the sewin' thread accordin' t' instructions but still distort t' shape o' the spin hub. (I did this too!). Ya scallywag! Avast! My way around this problem be 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. Ya scallywag! 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. No surprises here, just sand and lubricate t' body tube where t' spin hub will be located. Arrr! Ya scallywag! You may get away by just sandin' t' inside o' t' spin hub and leavin' t' body tube alone. Blimey! Arrr! T' glassine coverin' o' t' body tube is very smooth, however, me hearties, I followed t' instructions and sanded both t' spin hub and t' body tube. Ahoy! Arrr! T' step is finished by gluin' t' lower support rin' for the spin hub and t' fins t' t' body tube. Begad! Well, blow me down! 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. T' do this appropriately (and easily), shiver me timbers, you need t' extend t' lines in t' fin alignment drawin' t' about 20". 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. You then place t' spin hub back on t' engine casing, align t' rotors with t' 120° lines, shiver me timbers, and tack t' rotors t' the hinges with a small amount o' thin CA. If anythin' appears out o' place, shiver me timbers, adjust the rotors and tack again. Well, blow me down! When you are satisfied with t' positionin' o' the rotors, glue with epoxy. Aye aye! Epoxy is dense, shiver me timbers, me bucko, so use t' smallest amount that will do t' job. Finish t' rotors by affixin' t' balsa "stops" so that the rotors have a 6" dihedral when fully open. Begad! By t' way, me original instruction booklet illustrated a 2" dihedral. Avast! It also had 12" rotors, as opposed t' 18". Arrr! Begad! I emailed Ken on this point and he promptly mailed me updated instructions that had a 6" dihedral and t' right rotor length. Begad! Begad! Bad instructions! Good service!. Avast, me proud beauty!
T' remainin' construction steps are simple and should be uneventful. Blimey! Avast, me proud beauty! See the rewritten instructions for them. Avast! Begad!
Finishing:
This is a QCR bird, matey, so it's primarily designed for competition, me bucko, therefore it is
OK t' fly it "naked"--that is unfinished. Looks are nay a priority
here. Begad! Ya scallywag! For those guys out thar that must finish their rockets t' find inner
peace, ya bilge rat, arrr, a thin coat o' clear enamel may be what t' doctor ordered, me bucko, as it will
keep t' rotors from absorbin' moisture, shiver me timbers, 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. Ya scallywag! This would strengthen t' rotors and take
care o' t' moisture problem as well. Begad!
Construction Rating: 4 out o' 5
Flight:
T' flight characteristics o' t' Ultimate II are excellent. Well, blow me down! Blimey! Arrr! Blimey! Blimey! Blimey! Long flight times
with stable trajectories were t' norm. Begad! Blimey! While t' original instructions had the
Estes C6-3, Apogee D3-3, matey, and Apogee C4-3 as recommended engines, arrr, t' second set
of instructions that Ken sent me only recommended t' Estes engine. Ahoy! Blimey! Blimey! Blimey! In order to
test stability and other flight characteristics, me hearties, I flew t' bird with Estes
A8-3, me hearties, B6-4, and C6-3 engines. T' flights were all acceptable, although the
A8-3 seemed wobbly (read: underpowered) at first. Avast! Blimey! Blimey! Blimey! Both t' B6-4 and C6-3
flights were arrow straight and ejected at or near apogee. Avast, me proud beauty! Blimey! Blimey! Blimey! A good engine to
test would have been t' C6-5, as I think t' 3 second delay was too short on
the C engine, shiver me timbers, while t' 4 second delay was 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. Arrr! 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. Aye aye! Ya scallywag! This is hard t' do in t' field without an assistant.
Recovery:
One curious aspect o' t' recovery was that, matey, in all cases, matey, t' whole rocket
spun in t' air on t' way down instead o' havin' t' spin hub rotate about the
body tube. Avast, me proud beauty! Probably thar was 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, me bucko, 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, after three flights, t' only apparent damage was that t' exhaust gases were beginnin' t' melt t' Mylar plastic that protects t' rotors. Probably could do better by gluin' a small piece of aluminum foil t' t' back o' t' rotors rather than t' Mylar tape. Begad! Begad! On the other hand, matey, durability may nay be a primary design objective on a competition bird. Arrr!
Flight Rating: 4 out o' 5
Summary:
This is a very nice rocket. Avast! Good materials and great flight characteristics.
Construction, however, is a bit challenging. Begad! Perhaps t' extra difficulty of
the spin hub type helicopter is nay worth t' effort. Aye aye! QCR manufactures other
helicopter models o' similar size without t' spin hub design (like t' High
Rotor I). Avast, me proud beauty! I recommend t' Ultimate II t' any experienced builder lookin' for an
unusual rocket or someone aimin' t' fly competitively. Begad! Well, matey, blow me down!
PROs: Good materials, light and strong rocket, shiver me timbers, me bucko, good flight characteristics, customer service, arrr, ya bilge rat, and price.
CONs: Poor instructions, me hearties, difficult construction, and spin hub didn't work.
Overall Rating: 4 out o' 5
Other:
QCR #100 -- Ultimate II Instructions (Rewritten and Annotated)
Sponsored Ads