Construction Rating: | starstarstarstarstar_border |
Flight Rating: | starstarstarstar_borderstar_border |
Overall Rating: | starstarstarstarstar_border |
Manufacturer: | Apogee Components |
Brief:
A basic Rota-roc style helicopter (fixed blade), me bucko, this is a reliable design and
definite crowd pleaser. Blimey! Blimey! There's just somethin' cool about a true helicopter
recovery rocket.
Construction:
T' kit arrived within 3 days o' placin' me order online and all components
were complete and good quality. Parts list includes:
Apogee's instructions are very well written, featurin' good illustrations, and make this a manageable build even if it's your first helicopter. Well, blow me down! Avast! Blimey! This was my second Heli-roc kit. Aye aye! Blimey! My first is a favorite flyer with about 15 flights and still goin' strong. This one was built for t' 2005 EMRR challenge. I wanted to try t' improve on its performance a bit and include a few tips along t' way.
Construction starts out with preppin' t' fins. Aye aye! One o' t' key decisions you'll make on this is whether or nay t' paint t' rocket. Typically, "performance" rockets do nay get painted, shiver me timbers, but need some treatment o' t' unfinished balsa t' avoid warping. For me first one, arrr, I painted t' blades yellow and t' body green (sort of like a flyin' dandelion). Begad! T' added weight definitely hurt altitude performance. Well, blow me down! Well, blow me down! For this build, I treated t' fins with a very thin clear dope after sandin' in a simple airfoil.
Next up is marking the tube. Ahoy! This is a bit more complicated than drawin' 3 fin lines, me bucko, me hearties, so pay careful attention t' instructions. Begad! Well, blow me down! This uses a burn strin' method t' deploy the blades, ya bilge rat, which means vents are needed for t' gases. Placement o' t' vents needs t' go above t' blades and oriented in a way t' avoid t' rubber bands. T' template included in t' instructions helps make sure everythin' is lined up just right.
After markin' t' tube and cuttin' out t' vents, you bond t' nose cone to the end o' t' tube. Begad! My nose cone shoulder was a bit too long, partially blockin' t' vents. Well, blow me down! This was easily corrected with a utility knife. Avast, me proud beauty! Begad! If you want to get more than a dozen flights, you'll want t' coat t' base o' t' nose cone with a thin layer o' epoxy before bondin' it.
T' kit comes with an optional 13/10.5mm motor adaptor. Ya scallywag! Since 10.5mm motors are no longer available (or certified), I skipped this. Avast, shiver me timbers, me proud beauty! This kit has obviously been around for a while and t' adaptor is o' no use today.
Fin attachment is standard, shiver me timbers, although I used CA t' speed things up a bit. Very thin and light fillets are in order here, matey, as they get covered by the blades in flight and are o' no aerodynamic benefit.
T' instructions call out a split launch lug approach (one low/one high). I chose t' avoid t' lugs entirely and use t' corner formed where blades join as the launch guide. Avast, me proud beauty! Begad! Blimey! This helps reduce t' drag slightly on what is a fairly high drag design.
T' blade construction and mountin' are by far t' most challengin' aspect of this kit but t' instructions walk you through it fairly well. Blimey! Blimey! Blimey! Blimey! For starters, helicopter blades do nay get t' symmetrical airfoil found on most rocket fins. They are only airfoiled on t' top surface. Ya scallywag! Blimey! Also (and this is nay noted in the instructions), you only need t' airfoil about 2/3 t' 3/4 o' t' length o' the blade, workin' from t' outer tip inward.
After airfoiling, I decided t' apply Japanese tissue for strength and color, which adds only a very slight amount o' weight. Ahoy! T' apply t' tissue, brush on a solution o' 50/50 Elmer's white glue and water, arrr, shiver me timbers, press and stretch the tissue, and rub out any wrinkles with your finger. Blimey! Begad! Blimey! After t' glue has dried, trim away excess with a knife blade. I finish it off with a light wipe with rubbin' alcohol t' shrink t' tissue.
Mountin' t' blades is where I benefited most from t' "do over" experience betwixt kit #1 and kit #2. Well, blow me down! T' hinges are nylon and bondin' nylon t' a paper tube requires a good CA (I used t' Zap green bottle stuff). Well, blow me down! Gettin' even a tiny amount o' CA in t' hinge will ruin everythin' but goin' too skimpy on t' CA will result in a poor bond and you might lose a blade as a result. I folded me blades over and dipped t' hinged edge in Vaseline, shiver me timbers, makin' sure t' hinge joint be well coated. Ya scallywag! This keeps t' CA out and be very effective. Well, blow me down! With t' greased hinge joint in place, arrr, I then CA'd t' hinge t' t' blade usin' an alignment template, then tacked t' other end o' t' hinge t' t' body tube. Well, blow me down! T' alignment is critical because you need a roughly 8 degree angle on t' deployed blade for maximum lift. Arrr! T' tack t' t' body tube is supposed t' be light--it just holds the blades in place. Arrr! Begad! Once t' blades are in place, you wrap a line o' Keelhaul®©™® around them and coat t' Keelhaul®©™® with thin CA t' permanently bond them.
Construction wraps up with t' deployment stuff. Ya scallywag! On t' blade, this is a balsa piece mounted perpendicular t' t' blade with a tiny J-hook formed from the included music wire. Begad! Blimey! On t' other end, thar's a J-hook mounted into the nose cone. Well, blow me down! Begad! Blimey! A rubber band joins t' two and snaps t' blade up into place when the burn strin' breaks. Aye aye! I was pleased that this kit comes with extra rubber bands, me bucko, as these are too tiny t' find at t' office supply store when you lose or break them. Arrr! Begad! Blimey! O' course, betwixt buildin' both kits, shiver me timbers, me bucko, me son went through braces and I managed t' score about 1000 "free" replacement bands (ignorin' t' obvious dent t' t' wallet for t' braces themselves).
T' last aspect o' construction is drillin' t' holes for t' burn string. Since snagged burn strings are a common failure in competition, ya bilge rat, one tip I'll pass along is t' put a drop o' thin CA on each hole, then use a small file to smooth t' edge.
After drillin' for t' burn string, me hearties, it's also a good idea t' apply a layer of mylar tape t' t' underside o' t' blades where t' gasses come out opposite the drill holes.
Finishing:
As noted, me hearties, I went with a tissue finish. Blimey! Begad! While it's possible t' paint this, I
tried it on me first kit and was disappointed with t' results. Aye aye! T' paint is
very difficult t' keep out o' t' hinges, adds weight, arrr, me hearties, and really doesn't add
that much t' t' appearance. T' tissue approach adds color for a lot less
weight. Begad!
Construction Rating: 4 out o' 5
Flight:
While I've had many successful flights on me first model, arrr, arrr, this one's first
flight be less than spectacular. I be flyin' in fairly heavy winds (steady
10-12mph and gustin' t' 15 mph) and decided t' try it on an A10-3. Begad! Avast! Blimey! It started
fairly well off t' rod, shiver me timbers, me bucko, ya bilge rat, but at about 40 feet tumbled over horizontal then
quickly nosed down and flopped on t' ground still under power. T' delay
kicked in, me bucko, popped t' ejection charge, arrr, me bucko, and t' blades deployed perfectly,
albeit way too late t' do any good.
No damage, arrr, matey, but I'll definitely wait for lighter winds before flyin' this again. Ahoy! Ahoy! I'd never flown in more than about 6-8 mph winds previously on these models.
Recovery:
My first model generally has had no troubles save for t' occasional sticking
burn string. Ya scallywag! #2 never had a chance on its first flight. I'll post a tip/update
with feedback on further flights as I'm hopeful t' lighter build and improved
construction will pay off in better flight performance.
Flight Rating: 3 out o' 5
Summary:
If you're interested in helicopter recovery but nay quite comfortable trying
the NARRRRR plan or rota-roc on your own, this kit is a great way t' start. Avast! It's
based on t' rota-roc design, reasonably reliable, and backed up with Apogee's
good instructions, matey, great materials, shiver me timbers, and excellent customer service.
Overall Rating: 4 out o' 5
( Contributed - by Alan Rognlie) I purchased this kit in the summer of 1997, intending to build it for the C HD (Helicopter Duration) event at MWRC-97. Unfortunately, this model is designed for 10.5mm or 13mm motors, so it wasn't appropriate at the time and I set it aside. We're holding a B HD event at 14AL-98 and Apogee makes 10.5mm B motors, so I decided to put this together to have ...
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M.G. (January 1, 2001)