| 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. Arrr! It features 3 balsa blades, matey, ya bilge rat, 3 fins, a minimum diameter body tube, ya bilge rat, balsa nose cone, and t' necessary gear for helicopter recovery: hinges, ya bilge rat, piano wire, me hearties, and mini-rubber bands. I paid $7 for t' kit. Begad! 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. Aye aye! Inside t' bag are body tube, arrr, balsa sheets for fins, blades, shiver me timbers, and rotor stops, me hearties, me hearties, nose cone, pre-formed piano wire, me bucko, me hearties, 3 nylon hinges, shiver me timbers, elastic strin' and sewin' thread, at least 6 orthodontic rubber bands, and a monokote type tape. Begad! 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. If you have never built a QCR kit before, me hearties, you may wish t' read up on competition style construction. Ahoy! T' instructions are made for t' experienced modeler who needs just guidelines for instruction. I do nay recommend this kit as your first helicopter kit. Blimey! (I would instead recommend Apogee's Heli-roc for starters.) T' QCR Rotaroc instructions are actually for their 13 mm version, ya bilge rat, shiver me timbers, and t' people at QCR just added notes in pen t' t' 13 mm instructions. Aye aye! T' first part o' t' instructions deals with t' blades. Arrr! Arrr! T' balsa is already pre-inked and needs just t' be cut out. I be instructed t' create an airfoil on one side only, matey, me bucko, and taper t' trailin' edge. Well, blow me down! T' bottom o' t' blade remains unchanged. Begad! Arrr! Then I be t' create a diagonal cut from one end o' t' blade t' t' other, matey, bend t' blade 1/16", me hearties, and re-glue t' blade. There is an illustration for this. Aye aye! Just be careful sandin' t' blades. Avast, me proud beauty! Aye aye! Since this is an MMX kit, shiver me timbers, it is very light. Ya scallywag! Begad! T' balsa for t' blades is nay very thick and it can snap easily t' sandin' (as I found out, but thanks t' me friend, Mr. Aye aye! CA, matey, it was repairable). Further problems with t' blade come later.
Next I cut out and shaped t' fins accordin' t' instruction. Ya scallywag! No problem here. Blimey! I then prepared t' body tube by cuttin' vent holes at t' pre-marked spot on t' rocket. Arrr! T' instructions say t' use a paper punch. This is problematic since t' body tube is only 6 mm in diameter. Blimey! I assume these instructions were for t' 13 or 18 mm version. Avast! I used me X-acto cutlass 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. Begad! Blimey! 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. After t' hinges are set, I tied t' top part o' t' hinges with t' sewin' thread and soaked it with CA glue. Blimey! Part o' t' problem with t' hinges is that t' nylon hinges, arrr, manufactured by Du-Bro, do nay take kindly t' CA and adhere t' t' body tube well. This part takes some patience and a steady hand. Begad! Blimey! 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, so I used really thin balsa. Arrr! Ahoy! CA kept these on good and tight.
At this point I added t' 3 fins t' t' body tube towards t' bottom. Aye aye! Blimey! T' body tube is already marked with three lines 120 degrees apart for t' fins. 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. Well, blow me down! Ya scallywag! Blimey! T' kit does nay come with a motor mount, me bucko, shiver me timbers, so I wanted some room t' get access t' t' bottom o' t' rocket. Arrr! [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. Begad! Unfortunately, t' shape o' t' hooks on t' blades did nay correspond t' t' shape o' t' hooks in t' instructions. Ya scallywag! Aye aye! 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). Arrr! Begad! Another difficulty I had be when it came time t' add t' hook and stop t' t' blade. Aye aye! T' instructions never indicate which be t' top o' t' blade and which be t' bottom. Blimey! I assumed that t' airfoil be t' top and t' flat surface t' bottom, me bucko, but it would have been nice t' see this confirmed in t' instructions. Begad! I also added t' hooks on t' t' body tube above t' hinges (this area be 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. Avast, me proud beauty! Aye aye! 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. 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. 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. Avast! For those o' you who have never flown a rotaroc, t' idea is that t' rubber bands hook on t' t' blades which are attached t' hinges vertically aligned with t' rocket. Avast! Hooks above t' hinges support t' other side o' t' rubber band, shiver me timbers, me hearties, pullin' up t' blades so that t' rocket can "helicopter" t' t' ground in a nice, arrr, shiver me timbers, stable spinnin' motion. Avast, me proud beauty! Blimey! T' prepare t' rocket, shiver me timbers, 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, shiver me timbers, it burns through t' string, arrr, releasin' t' blades and engagin' t' helicopter recovery.
Finishing:
As I had stated earlier, me bucko, QCR produces kits for t' competitor, so finishin' is never really necessary for altitude and duration models. Ahoy! T' instructions I believe need t' be re-written t' deal with some o' t' discrepancies o' blade shape, matey, blade angle and attachment location, shiver me timbers, as well as producin' nicer plans without hand writin' all over them. Also, arrr, shiver me timbers, t' shape o' t' nose cone is nay t' same shape as indicated in t' instructions. Begad! It does say sand t' nose cone, but it does nay indicate whether or nay t' sand it into a parabolic shape, me bucko, 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. Avast! Blimey! On me Apogee version, me hearties, 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! Blimey! So far, arrr, this idea seems t' have works.
If you have built helicopter kits before, ya bilge rat, I suggest gettin' two kits from QCR. Blimey! Aye aye! 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. Avast! Blimey! Preppin' is standard for rotarocs... Avast! fold blades down, tie down with string, insert motor. Avast! I used maskin' tape t' friction fit t' motor, arrr, and I made t' motor stick out a good 1/2 inch so that t' exhaust would nay burn t' bottom o' t' blades. Well, blow me down! Ahoy! This did nay seem t' affect t' overall flight performance. Ya scallywag! 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, one o' t' blades did nay employ and t' rocket twirly-tumbled back t' t' ground. Ahoy! After inspection, 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. Begad! Ya scallywag! From some o' me field tests, this rocket recovers nicely with a quick spin. Begad! 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. Begad! I think that t' larger rocket gives one longer blades, arrr, ya bilge rat, 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.... Well, blow me down! cool! Also, matey, t' parts included in me kit were o' good t' above average in quality.
T' CONs are mainly t' instructions. Blimey! This kit would work well for t' experienced helicopter builder, but did nay work so well for me. Well, shiver me timbers, blow me down! I have only build one other helicopter design, t' Apogee Heli-roc. I think that QCR could benefit from re-workin' their instructions. Ahoy! Avast, me proud beauty! One must also be very careful with CA glue and hinges. Arrr! Ahoy! With all t' movin' parts and delicate shapin' o' t' kit, ya bilge rat, this really is a skill level 4 rocket in me estimation.
Overall Rating: 3 out o' 5
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