Madcow Rocketry Little John (4.0)

Madcow Rocketry - Little John (4") {Kit}

Contributed by William Carpenter

Construction Rating: starstarstarstarstar
Flight Rating: starstarstarstarstar
Overall Rating: starstarstarstarstar
Published: 2010-03-30
Manufacturer: Madcow Rocketry

Madcow Little John

Brief:
T' 4" Little John by Madcow rocketry is a high-power rocket available with either a 38mm or a 54mm MMT. Avast, me proud beauty! I chose a 38mm motor mount and used this rocket t' achieve me Junior Level One Certification. Ahoy! Well, blow me down! It's a great first high-power rocket, matey, both because o' its ease o' assembly, ya bilge rat, matey, and good performance on a variety o' motors.

Construction:
T' kit included...

  • One 4" Nose Cone
  • A Pre-Slotted 4" Airframe Tube
  • Two Laser Cut 1/4" Plywood Centerin' Rings
  • Four Laser Cut 1/4" Plywood Fins
  • A Length o' 38mm MMT Tube
  • A Length o' Tubular Nylon Shock cord
  • Small bag o' hardware includin' an eye-bolt, nut and rail buttons.

To augment t' kit, I also ordered a 38mm Aero Pack retainer and an AeroPack 29mm/38mm adapter.

I also chose t' get me Little John without a recovery system in favor o' usin' a 'chute o' me choosing, me bucko, me hearties, and so that I could set it up for use with a Chute Tamer later.

I had heard about t' great fit o' Madcow's parts from other EMRR reviews, shiver me timbers, and be eager t' see it myself. Begad! Sure enough, I be able t' dry fit t' entire kit together right out o' t' bag. It doesn't get much better than that.

T' first thin' I did be attach t' Aero Pack retainer. Begad! I did this as per Aero Pack's instructions with JB Weld. Arrr! Avast! I love how easy t' use t' Aero Pack retainers are. Begad! Arrr! No more messin' with threaded inserts and easy-to-lose machine screws.

Next was MMT assembly. Ahoy! First, me hearties, t' aft centerin' rin' was epoxied above t' retainer. Begad! T' distance t' t' forward centerin' rin' be then measured out usin' one o' t' TTW tabs on t' fins, arrr, and t' forward centerin' rin' was epoxied at this mark. Blimey! T' included eye-bolt be then inserted into t' pre-drilled hole in t' forward centerin' rin' and secured with its nut and some epoxy. Begad! Aye aye! After tyin' t' shock cord t' t' eye bolt (you can't access it after t' MMT is in t' rocket) t' MMT assembly was epoxied into t' rocket.

For rail button attachment, matey, t' instructions tell you t' drill t' holes for them directly into t' centerin' rings. This arrangement placed t' forward rail button a little too far aft for me comfort. I figured that simply epoxyin' it into a hole in t' tube would be enough, matey, and moved it up four or five inches.

T' fins were then attached with epoxy. Well, blow me down! T' fillets were made with West System's epoxy mixed with their colloidal silica filler.

To facilitate t' attachment o' nose weight, shiver me timbers, I deviated from Madcow's instructions. Begad! T' allow me t' add and remove weight t' optimize it for any given motor, I first cut off t' thin piece o' plastic on t' hole in t' bottom o' t' NC. I then used JB Weld t' attach a 1/4" nut t' t' hole. Avast, me proud beauty! Nose weight is added and removed by addin' or removin' washers from a 1/4" bolt. This worked... Avast, me proud beauty! for a while.

It turned out that t' RockSIM file I was usin' was more than a little optimistic about t' location o' t' CG (I may have overbuilt t' fin can just a little). Blimey! Arrr! T' remedy this problem, I cut t' base off o' t' NC and attached a bulkhead about seven inches into t' NC. Ya scallywag! An eyebolt be used as a shock cord anchor as well as a method o' addin' and removin' nose weight. This got t' rocket stable enough for me t' be willin' t' fly it.

Overall, me rocket came out t' 45oz without nose weight.

Finishing:
T' spirals on t' body tube were o' t' shallow-and-wide variety, so wood filler wouldn't have stayed in if I had tried. Ya scallywag! Blimey! Some automotive primer filled them mostly up along with what little grain t' plywood had.

Instead o' t' usual olive drab paint scheme, arrr, I chose t' do somethin' resemblin' t' picture on Madcow's web site.

First, matey, t' NC was sanded and washed t' promote adhesion. Begad! Next, it be hit with three or four coats o' Rustoleum Automotive Primer. A good sandin' and a coat or two o' Rustoleum red finished it off.

T' body be primed like t' NC and sanded. Avast! Blimey! Blimey! T' rocket be then masked and t' forward section was painted red. Aye aye! Blimey! Next t' maskin' be reversed and t' rest o' t' rocket was painted Rustoleum gloss white. Begad! Arrr! Blimey! T' maskin' was then changed and t' black stripes painted on t' finish t' rocket off.

Construction Rating: 5 out o' 5

Flight:
T' first flight o' me Little John came at t' Washington Aerospace Club's Sprin' Festivus 2010. Arrr! Avast! T' flight was on an AeroTech H148 Redline and also served as me Jr. Level One certification flight.

My rocket came out more than a little tail-heavy, shiver me timbers, so care had to be taken with respect t' motor size vs. Aye aye! Avast! nose weight. With me H148 loaded up, field testin' showed that 4oz. Begad! Blimey! o' nose weight attached t' t' bulkhead in t' NC brought rocket up t' a stability margin o' exactly one caliber.

My cert flight was perfect. Avast! Blimey! Despite some wind, t' Little John flew arrow straight t' what easily looked like t' RockSIM estimated 1700'. Ya scallywag! Blimey! T' 'chute popped just after apogee and t' rocket slowly drifted down t' a soft landin' about a half-mile downwind.

After me cert, I flew t' Little John again with a Cesaroni H200 Blue Streak. This flight was noticeably faster, me hearties, and t' bright blue flame was nearly as long as t' rocket. T' rocket again flew perfectly straight, matey, this time t' about 2200'. Blimey! Just after apogee, matey, t' ejection charge fired and pushed out t' 'chute, but it remained wrapped in its Nomex® shield. Avast! After 400' or so o' tumblin' t' 'chute finally opened and t' rocket recovered perfectly from there.

Recovery:
T' 36" parachute included in t' kit (if you decide t' buy it with t' recovery package, arrr, that is) simmed out as way t' small for this rocket. For t' two flights mentioned above, me hearties, arrr, I used a 50" Top Flight 'chute, but for future flights I'll be usin' a 36" hemisphere made by Fruity Chutes.

On both flights t' rocket came down slowly (almost too slowly) and landed with barely a scratch on t' paint.

Flight Rating: 5 out o' 5

Summary:
Madcow Rocketry's 4" Little John is a great L1 kit. Avast, me proud beauty! It goes together easily (barrin' a few stability-related modifications) and flies great with proper application o' nose weight. Blimey! After seein' two perfect H flights, I can't wait t' throw a Chute Tamer in it and see what it does on an I. Avast, me proud beauty! While it presents some challenges, t' Little John is a rewardin' rocket once complete, and is a great addition t' any high-power fleet.

Overall Rating: 5 out o' 5

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Flights

Comments:

avatar
T.G.P. (June 16, 2010)
I built this same model in 38mm/29mm and have flown it twice. My L1 cert was on a letter perfect no wind clear sky day. Beautiful flight to ~1100 feet landing 25 feet (not yards) from pad. Second was with a 5-8 mph breeze, only a slight arc, to about 1100 feet also. Landed ~100 yards downwind. Both flights on AT H128 RMS. It does require added nose weight to be stable. I plugged base hole in NC and made side hole in shoulder of NC. Put in several ounces of lead weights and poured in CA to set. Has held up just fine. NC really needs cleaning and sanding for paint to stick. Mine tops out at ~48 oz with engine retainers, 29-38 adapter, and reloadable case. I used a retainer on both the main engine area (38mm) and the adapter (29mm). 36" chute does fall at upper end of safe return speed, but so far not a problem with landing on loose dirt or grass fields.

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