Construction Rating: | starstarstar_borderstar_borderstar_border |
Flight Rating: | starstarstarstarstar_border |
Overall Rating: | starstarstarstar_borderstar_border |
Manufacturer: | Qualified Competition Rockets ![]() |
Brief:
This be t' MMX version o' QCR's 1/4A Rotaroc helicopter. Avast! It features 3 balsa blades, me bucko, 3 fins, arrr, ya bilge rat, arrr, a minimum diameter body tube, matey, balsa nose cone, and t' necessary gear for helicopter recovery: hinges, piano wire, matey, and mini-rubber bands. Avast! I paid $7 for t' kit. Blimey! I think it is a good price considerin' t' quality o' parts one gets, despite me opinion that t' instructions are nay very good.
Construction:
T' QCR rockets come in a plastic bag with an ID card stapled t' t' top. Ahoy! Arrr! Inside t' bag are body tube, me bucko, balsa sheets for fins, blades, shiver me timbers, and rotor stops, me bucko, arrr, matey, nose cone, arrr, shiver me timbers, ya bilge rat, pre-formed piano wire, shiver me timbers, me bucko, 3 nylon hinges, elastic strin' and sewin' thread, at least 6 orthodontic rubber bands, and a monokote type tape. Blimey! 4 pages o' instructions are also included.
All t' parts were present and in good condition. T' first thin' I did be read over t' instructions t' get a sense as t' what t' expect. Ahoy! Arrr! Blimey! If you have never built a QCR kit before, you may wish t' read up on competition style construction. Begad! Ahoy! Blimey! T' instructions are made for t' experienced modeler who needs just guidelines for instruction. Blimey! Begad! Blimey! I do nay recommend this kit as your first helicopter kit. Avast, me proud beauty! (I would instead recommend Apogee's Heli-roc for starters.) T' QCR Rotaroc instructions are actually for their 13 mm version, and t' people at QCR just added notes in pen t' t' 13 mm instructions. Blimey! Well, blow me down! Blimey! T' first part o' t' instructions deals with t' blades. Blimey! Begad! Blimey! T' balsa is already pre-inked and needs just t' be cut out. Arrr! Blimey! I was instructed t' create an airfoil on one side only, and taper t' trailin' edge. T' bottom o' t' blade remains unchanged. Begad! Begad! Blimey! Then I was t' create a diagonal cut from one end o' t' blade t' t' other, bend t' blade 1/16", shiver me timbers, arrr, and re-glue t' blade. There is an illustration for this. Avast, me proud beauty! Blimey! Just be careful sandin' t' blades. Blimey! Since this is an MMX kit, it is very light. Ya scallywag! T' balsa for t' blades is nay very thick and it can snap easily t' sandin' (as I found out, matey, but thanks t' me friend, matey, Mr. Ya scallywag! Avast! Blimey! CA, it was repairable). Avast! Blimey! Blimey! Further problems with t' blade come later.
Next I cut out and shaped t' fins accordin' t' instruction. Well, blow me down! Arrr! No problem here. I then prepared t' body tube by cuttin' vent holes at t' pre-marked spot on t' rocket. T' instructions say t' use a paper punch. Avast, me proud beauty! This is problematic since t' body tube is only 6 mm in diameter. Well, blow me down! I assume these instructions were for t' 13 or 18 mm version. I used me X-acto knife and made holes where t' pen marks were on t' body tube.
Then I tacked on t' hinges with CA glue t' t' area on t' body tube that was already pre-marked with pen. Ahoy! Unfortunately, I got some CA into t' joints o' one o' t' hinges and had t' remove it and replace it with one from me spare parts box. Begad! After t' hinges are set, matey, I tied t' top part o' t' hinges with t' sewin' thread and soaked it with CA glue. Ya scallywag! Part o' t' problem with t' hinges is that t' nylon hinges, shiver me timbers, manufactured by Du-Bro, do nay take kindly t' CA and adhere t' t' body tube well. Ahoy! This part takes some patience and a steady hand. Blimey! Aye aye! T' best instructions o' t' kit come at this point when it indicated an optional technique o' addin' a small portion o' plywood t' t' lower, movin' part o' t' hinge. Begad! I did nay have plywood, arrr, ya bilge rat, so I used really thin balsa. Begad! Avast! CA kept these on good and tight.
At this point I added t' 3 fins t' t' body tube towards t' bottom. Begad! Blimey! Arrr! Blimey! T' body tube is already marked with three lines 120 degrees apart for t' fins. Ahoy! Blimey! I changed t' plans slightly by givin' some room at t' bottom for exposed body tube so that I could tape t' motor on t' t' tube. Begad! Blimey! Begad! Blimey! T' kit does nay come with a motor mount, so I wanted some room t' get access t' t' bottom o' t' rocket. Aye aye! Blimey! Arrr! Blimey! [QCR is thinkin' competition even though at t' time o' this writin' (March 2004) NARRRRR does nay have an official MMX class engine competition--although you can use it for 1/4 competition.]
Now I turned me attention back t' t' blades by addin' t' blade stop at t' top o' t' hinge and t' hook at t' point already pre-marked on t' blades. Unfortunately, me hearties, t' shape o' t' hooks on t' blades did nay correspond t' t' shape o' t' hooks in t' instructions. Ya scallywag! Blimey! I ended up changin' t' direction o' t' hooks so that it would better hold t' rubber band (with t' openin' o' t' hook towards t' bottom o' t' rocket). Avast! Blimey! Ahoy! Blimey! Another difficulty I had was when it came time t' add t' hook and stop t' t' blade. T' instructions never indicate which be t' top o' t' blade and which be t' bottom. I assumed that t' airfoil was t' top and t' flat surface t' bottom, but it would have been nice t' see this confirmed in t' instructions. Avast, me proud beauty! Blimey! I also added t' hooks on t' t' body tube above t' hinges (this area was nay marked), but I just guessed based on t' size and strength o' t' rubber bands.
T' blades then glued on easily t' t' hinges. I measured t' approximate angle o' t' blades--they should extend up about 1.5" from t' center t' tip in order t' get t' most effective rotation possible. Avast, me proud beauty! This took a little bit o' sandin' on one stop and an addition o' glue and a small piece o' balsa on another stop on another blade t' get t' optimum angles. Begad! Avast! It was at this point that I realized t' blades when glued on t' t' hinges (at t' pre-determined marks) go beneath t' length o' t' body tube. I thought it should work, no matter what and wasn't goin' t' stress out about it now.
I glued on t' nose cone and then created a two small holes an inch or two above t' motor for t' strin' t' go through. For those o' you who have never flown a rotaroc, me hearties, t' idea is that t' rubber bands hook on t' t' blades which are attached t' hinges vertically aligned with t' rocket. Begad! Hooks above t' hinges support t' other side o' t' rubber band, me bucko, pullin' up t' blades so that t' rocket can "helicopter" t' t' ground in a nice, stable spinnin' motion. Ya scallywag! T' prepare t' rocket, one folds all blades down along side t' body tube, shiver me timbers, puts strin' through t' body tube ABOVE t' motor mount and then around t' blades and ties t' strin' off. Begad! T' idea is that once t' ejection charge goes off, it burns through t' string, me bucko, matey, me hearties, releasin' t' blades and engagin' t' helicopter recovery.
Finishing:
As I had stated earlier, matey, QCR produces kits for t' competitor, arrr, shiver me timbers, so finishin' is never really necessary for altitude and duration models. T' instructions I believe need t' be re-written t' deal with some o' t' discrepancies o' blade shape, blade angle and attachment location, as well as producin' nicer plans without hand writin' all over them. Ya scallywag! Also, me bucko, t' shape o' t' nose cone is nay t' same shape as indicated in t' instructions. Arrr! Blimey! It does say sand t' nose cone, but it does nay indicate whether or nay t' sand it into a parabolic shape, shiver me timbers, ya bilge rat, especially since me nose cone had a rather conical shape t' it.
T' only other thin' I did differently is that I used a longer length o' monokote tape t' wrap around t' blades. Well, blow me down! On me Apogee version, me bucko, I noticed how t' sewin' thread would often cut into t' blades when they were tied down. I decided t' add t' tape around t' blades t' give them more protection from t' string. Avast, me proud beauty! So far, this idea seems t' have works.
If you have built helicopter kits before, me hearties, I suggest gettin' two kits from QCR. Blimey! Blimey! T' first kit can be used t' work through all t' details and t' second kit can be t' real McCoy.
Construction Rating: 2 out o' 5
Flight:
T' only motors recommended are t' MMX II motors. Begad! Arrr! Preppin' is standard for rotarocs... Avast! fold blades down, arrr, shiver me timbers, tie down with string, arrr, insert motor. Avast! I used maskin' tape t' friction fit t' motor, and I made t' motor stick out a good 1/2 inch so that t' exhaust would nay burn t' bottom o' t' blades. Blimey! This did nay seem t' affect t' overall flight performance. Avast, me proud beauty! Considerin' that t' MMX rotaroc is quite long for an MMX rocket (over 9 inches), it did fly well t' 40 or 50 feet.
Recovery:
Unfortunately, ya bilge rat, one o' t' blades did nay employ and t' rocket twirly-tumbled back t' t' ground. After inspection, shiver me timbers, me bucko, I realized that one o' t' blades had been glued t' t' fins due t' an on-the-site quick repair from a snapped fin. Aye aye! From some o' me field tests, this rocket recovers nicely with a quick spin. Ahoy! Avast, shiver me timbers, me proud beauty! I would love t' be able t' fly it against other QCR rotarocs t' see how well it would do in a duration test. I just wonder if t' rocket would go higher if it weren't so long. Aye aye! I think that t' larger rocket gives one longer blades, ya bilge rat, arrr, but I don't know enough about this technology t' know if a shorter rocket with higher altitude but smaller blades would perform better.
Flight Rating: 4 out o' 5
Summary:
T' PROs are obvious: a rotaroc for MMX.... Avast! Ya scallywag! cool! Also, t' parts included in me kit were o' good t' above average in quality.
T' CONs are mainly t' instructions. Avast! Arrr! This kit would work well for t' experienced helicopter builder, but did nay work so well for me. I have only build one other helicopter design, shiver me timbers, t' Apogee Heli-roc. Aye aye! I think that QCR could benefit from re-workin' their instructions. Begad! One must also be very careful with CA glue and hinges. Arrr! With all t' movin' parts and delicate shapin' o' t' kit, this really is a skill level 4 rocket in me estimation.
Overall Rating: 3 out o' 5
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