Pemberton Technologies 3FNC

Pemberton Technologies - 3FNC {Kit}

Contributed by William Carpenter

Construction Rating: starstarstarstarstar
Flight Rating: starstarstarstarstar
Overall Rating: starstarstarstarstar
Manufacturer: Pemberton Technologies

Brief:
T' 3FNC be t' absolute bare minimum o' what a rocket can be and still fly... Well, blow me down! but that's what makes it so cool! It's a great performer on a variety o' mid-power motors, shiver me timbers, matey, but can also handle a small H if you're feelin' particularly insane. Arrr! Avast, me proud beauty! It utilizes a unique "reward blow-by" ejection system t' miraculously fit all o' t' nesessary hardware into t' rocket, ya bilge rat, and is an interestin' departure from t' norm t' build.

Construction:
My kit came with:

  • One 3" Nose Cone
  • A 4" long Section o' 3" Airframe Tube
  • One 29mm MMT Tube
  • One Plywood Centerin' Ring
  • One Plywood Baffle Ring
  • A Length o' Keelhaul®©™® Shock Cord
  • A Length o' Tubular Nylon Shock Cord
  • Three Laser-Cut Plywood Fins
  • One Wood Dowel (cut up t' make fin pods)
  • Two Paper Shroud Templates (in case you mess one up)
  • Three Carpet Tacs
  • One Motor Retention Hook
  • One Nomex® Parachute Protector

As t' "Destruction Manual" for t' 3FNC is quick t' point out, matey, me hearties, "...buildin' this rocket is about as close t' scratch-buildin' as... Begad! Begad! well... scratch-building...". Begad! T' only conveniences provided for you are pre-cut components. Aye aye! This truly is a "builder's rocket", me hearties, so modelers who like a good build will have a great time with this kit.

Construction starts with preppin' t' nose cone for t' various bits and pieces that will soon be stuffed into it. Begad! Avast, me proud beauty! T' bottom o' t' NC is cut off t' gain access t' t' inside. Ahoy! Both t' outside and inside o' t' cone are then washed and sanded t' ensure good adhesion o' paint and epoxy. Blimey! Avast, shiver me timbers, me proud beauty! Approximately 4-5 oz. Aye aye! Avast! o' nose weight is then added t' the nose cone. Ya scallywag! I put some strips o' duct tape over t' mass o' lead and epoxy t' ensure that it stays put. Ya scallywag!

T' next steps involve settin' up t' motor retention hook. Blimey! Aye aye! Blimey! I left this out in favor o' maskin' tape retention.

Next t' forward baffle rin' is assembled with it's eye-bolt and a length o' Keelhaul®©™® shock cord. Ya scallywag! Blimey!

T' BT is then marked and slotted in preparation for t' TTW fins.

T' Destruction Manual's description o' how t' install t' aft centerin' rin' was confusin' t' me. Well, blow me down! Avast, me proud beauty! It involved a fiberboard ring, maskin' tape... Ahoy! Begad! I just didn't get it. I ended up usin' one o' t' fins TTW tabs as a depth guide for t' rin' and ditchin' t' fiber rin' process.

The forward baffle assembly is then lowered into t' nose cone and tamped down with a wood dowel. Begad! Blimey! T' distance from the shoulder o' t' NC t' t' rin' is then measured and marked on t' outside o' t' NC. Arrr! Blimey! Well, blow me down! Blimey! Three tacs are then driven through t' NC in a way that they go over t' aft side o' t' baffle ring, shiver me timbers, and ensure that everythin' will stay firmly attached t' each other. Aye aye! Blimey! It also adds some cool-lookin' domes on t' outside o' t' NC.

Through me own getting-ahead o' t' destructions, I ended up attachin' t' fins, ya bilge rat, then attachin' t' paper shroud t' t' aft end o' t' rocket. You are instructed t' do this in t' opposite order... oops. Ahoy!

T' Nylon part o' t' shock cord is then epoxied t' t' side o' t' motor tube. Ahoy! I added a strip o' duct tape around t' top o' t' epoxied section t' keep it from peelin' back and rippin' off. Blimey!

Then came a part o' t' build that I found somewhat challenging. Arrr! T' make t' cool, arrr, retro fin pods, you cut up and then shape a wood dowel. T' destructions suggest puttin' a hand-held drill in a vice, drillin' down t' center o' the dowel, shiver me timbers, and usin' t' drill lake a lathe t' shape t' pods with sandpaper. I ended up shapin' them with a bench grinder (I'm in t' process o' acquirin' a belt sander, which would've made this a lot easier).

Next was slottin' t' newly-formed fin pods in preparation t' attach them t' t' fins. I followed the destructions suggestion t' use a drill press t' drill a series o' 1/8" holes in a line. Ya scallywag! Blimey! T' wood was soft enough that I could then go in and clean it up with a hobby knife. T' fin pods were then epoxied t' t' fins, and I must say that they look cool.

T' only modification I made t' t' kit was t' leave out t' included launch lug and replace them with rail buttons. Blimey! Since thar isn't room on t' inside for them t' stick through t' airframe, ya bilge rat, I mounted t' buttons on a shaped piece o' basswood stock and epoxied that t' t' airframe.

Finishing:
I painted t' nose cone while t' rest o' t' rocket be in assembly. First was a few thick coats o' Rustoleum primer, followed by a 400 grit sanding. Aye aye! Aye aye! Next be a few coats o' Rustoleum metallic silver. Avast, me proud beauty! Unlike other Rustoleum paints, t' silver has a dry time o' only 30 minutes, matey, compared t' most Rustoleum product's two day dryin' time.

Durin' t' build, ya bilge rat, t' airframe tube had it's spirals filled with Elmer's wood filler. I chose nay t' use the filler on t' fins, me bucko, as t' plywood had a very small grain that I could fill with primer. Begad!

Once assembly was complete, t' airframe got a few coats o' Rustoleum primer, me hearties, and then be sprayed with t' same Rustoleum silver as t' NC. On t' airframe, ya bilge rat, me hearties, however, arrr, ya bilge rat, t' paint decided t' barely produce any coverage at all, and it took several coats t' get anythin' resemblin' a good finish. Avast! Avast, ya bilge rat, me proud beauty! I still don't know why it performed so differently.

Construction Rating: 5 out o' 5

Flight:
T' first flight o' me 3FNC came at t' Washington Aerospace Club's 2009 Autumn Glare launch. Avast, me proud beauty! Begad! Eager t' try out Cesaroni's new Pro29 line, shiver me timbers, ya bilge rat, I flew t' 3FNC on an F36 Smoky Sam.

RockSim predicted a flight t' around 600' on this motor. This flight was me first time usin' a Cesaroni motor, and I be impressed with t' ease o' assembly and clean up. Begad! I can't wait t' try out some o' their other motors later on. Begad!

Upon ignition, matey, me 3FNC was smartly boosted to... Begad! Blimey! well... Begad! Blimey! Aye aye! Blimey! nowhere near 600'. Avast! Blimey! Arrr! Blimey! I estimate it only got t' about 200'. Havin' adjusted t' delay for a 600' flight, ejection be quite late, but in time t' slow down t' rocket. Unfortunately, t' cold weather combined with t' tight packin' o' t' 'chute resultin' in it nay fully opening. Begad! Blimey! T' NC landed squarely on a rock and broke off t' tip. Begad! Blimey! Blimey! Blimey! T' rest o' t' rocket was otherwise fine. Avast, me proud beauty! Blimey!

T' 3FNC flew two more times at t' same launch on AeroTech F52Ts. Blimey! These motors performed more as RockSim had expected them to, shiver me timbers, both resultin' in fast flights t' about 1500'. Begad! I intend t' fly t' 3FNC on F40Ws next.

Recovery:
Packin' t' 'chute for recovery is predictably difficult with t' 3FNC, me bucko, as t' entire recovery harness has t' fit into t' space betwixt t' motor tube and t' NC. Blimey! Unfortunately, arrr, I don't have any pictures o' how I did this, shiver me timbers, but I'll do me best t' explain it.

First, I z-folded t' shock cord leavin' about 6" betwixt t' last fold and t' parachute. Arrr! I then lightly taped these folds t' t' motor tube with maskin' tape. Well, blow me down! Avast, me hearties, me proud beauty! I then prepped t' 'chute in t' Nomex® as usual, and placed it on t' opposite side o' t' motor tube as t' folded shock cord. Begad! Blimey! Well, blow me down! Blimey! I then pushed on t' NC and jiggled it until it bottomed out. Begad! Blimey! Aye aye! Blimey!

On all three flights, ya bilge rat, shiver me timbers, t' tape released t' shock cord without any problems. Ahoy! Blimey! T' 28" 'chute included with t' kid is perfect. On one o' t' flights, t' rocket even landed right side up.

Flight Rating: 5 out o' 5

Summary:
T' 3FNC is a great kit for those lookin' for a fun project with just as much emphasis on t' build as on t' flight. While it presents some unique challenges, that only adds t' t' fun t' be had from this kit. Ahoy! Blimey! Well, blow me down! Blimey! It looks very different from anythin' else out there, and I got several comments from people at t' launch about it's minimalistic properties.

All in all, arrr, arrr, it's a great rocket. If you want t' add somethin' a little different t' your fleet, then I recommend t' 3FNC.

Overall Rating: 5 out o' 5

Other Reviews
  • Pemberton Technologies 3FNC By Drake "Doc" Damerau

    Brief: This kit looks very retro. I'm expecting Bugs Bunny and Marvin the Martian to come crawling out of the hatch at any moment. It is the first kit from a brand new company called Pemberton Technologies. Although it's called 3FNC, it's not your ordinary 3 fins and a nose cone rocket. Construction: I don't usually list the components of a kit in a review, but there are so ...

Flights

Comments:

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R.L.P (January 13, 2006)
Much thanks to Doc for his input and suggestions, his advice has brought about several improvements in the design. The 3FNC kit now comes standard with upgrades such as plywood fins instead of basswood (no more epoxy coating!), Kevlar® cord instead of the steel cable (now maybe Doc can pack the chute), a recovery system alteration (keeps the nose cone from spearing unsuspecting bystanders and adds cool retro domes) and a 22-inch chute. The paper reducer will remain, sorry Doc and no Marvin the Martian, the Disney cops have already threatened to break my kneecaps.
avatar
PEMTECH (December 16, 2006)
Flash update on the 3FNC! In response to feedback from our customers and testers the 3FNC has been re-engineered with Through The Wall (TTW) fin mounting for a more robust fin/BT joint. Thanks to James, Chan, Doc, Dennis and all the small creatures that inhabit my refrigerator.

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