Essence Aerospace Technologies Interstellar Probe

Essence Aerospace Technologies - Interstellar Probe {Kit}

Contributed by Chan Stevens

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border

Brief:

If you're readin' this t' see whether or nay this would be a good kit t' buy, save your time, me bucko, matey, as this limited edition kit from EMRR's rocket kit division sold out before t' first kit even shipped, ya bilge rat, me bucko, makin' this kit as hard t' find as an Aston Martin Vanquish (but for only a fraction o' t' cost).

Two-stage, funnel booster, matey, arrr, and fairly unusual nose cone design (similar to the Honest John) make this an interestin' design and fun flyer.

Construction:

T' kit arrived at t' end o' February as promised, me bucko, ya bilge rat, and was virtually complete (missin' a centerin' ring, missin' from all kits and immediately shipped out).

T' parts list includes:-

  • Balsa Sheet (for 3 fins)
  • Card Stock Cone
  • Tube Markin' Guide
  • Balsa Nose Cone
  • Nose Weight (washers)
  • (1) Eye-Screw
  • (2) Body Tubes (BT-50)
  • (1) Body Tube Coupler
  • (2) 18mm Motor Tubes
  • (4) 18mm Centerin' Rings
  • (2) Thrust Rings
  • (2) 1/8" Launch Lugs
  • Keelhaul®©™® + Elastic Shock Cord
  • Streamer (1x48 plastic, me hearties, dayglo green)
  • Decals (water slide, very nice quality)

Note that this kit also came in a parachute version, but bein' stingy I opted for t' slightly less expensive streamer version (and I also have a large stash o' spare chutes).

T' parts were all very good quality.

T' instructions were very impressive, loaded with color photos at every step. Begad! Even more helpful were simple things like clearly markin' t' forward and aft ends o' tubes and dimensions on parts in t' photos. Well, blow me down! Nay that any o' you would ever blow this, ya bilge rat, but I've occasionally pulled a Homer (D'OH!) by ambling through motor mount construction in cruise mode, only t' find that I'm off 1/4" and can't get parts t' fit.

Since this is a two-stage design, me hearties, construction starts with dual motor mount assemblies, and care must be used t' get t' rings mounted in correct positions. Blimey! T' motor mount assemblies are standard 2.75" tubes, arrr, centering rings, blocks, matey, each mounted in BT-50 body tubes, matey, joined with a coupler. Begad! Begad! Since I DID pay attention t' t' dimensions on this one, I found everythin' fitted perfectly. Ya scallywag! This uses gap staged ignition, so t' booster assembly also includes punchin' a small hole in t' tube for ventilation o' ejection gasses. Having worked with a couple o' TARC teams, I can tell you this minor detail, often overlooked, makes a big difference in sustainer ignition reliability.

Kudos t' Nick and EAT for payin' attention t' what's got t' be t' #1 peeve on t' rocketreviews site with modroc kit design - this kit comes with a generous amount o' Keelhaul®©™®, mounted t' t' motor mount assembly for recovery. It's supplemented by elastic, but much more durable than t' typical mainstream kits.

T' booster "body" is a funnel, rolled from a cardstock pattern included in t' kit. Avast! This can be a very tricky step if done right and goin' for a smooth, bend/wrinkle-free finish. Arrr! I especially liked that t' glue tab is a separate piece INSIDE t' seam - most shroud patterns direct you t' overlap the tab, leavin' a very noticeable seam. This shroud/cone is virtually seamless.

T' booster cone is reinforced with a centerin' rin' (the one that was missin' originally). Blimey! This looked a bit flimsy t' me, matey, as t' centerin' rin' goes up t' within about 1" from t' top o' t' cone, but I went with it anyway. It does need t' remain above t' vent hole, me bucko, though, t' avoid blowin' out the side o' t' cone on t' first flight. Ya scallywag! I should also point out here that the instructions initially clearly warn about attempts t' substitute materials or techniques, and this cone is a good example o' why. Well, blow me down! T' instructions call for white glue in several places. Begad! I'm a fan o' t' faster-tackin' yellow glue, me bucko, and used this frequently. Ya scallywag! I was smart enough t' use white glue t' form and seal the cone, but used yellow glue t' bond t' centerin' ring/stiffener, shiver me timbers, and t' result was a minor shrink o' t' cone around t' ring. Aye aye! Aye aye! Nay too obvious t' t' casual observer, ya bilge rat, but definitely a case where white glue, me bucko, which doesn't shrink, me hearties, would have been best.

Sustainer construction is pretty easy, arrr, matey, considerin' t' (3) fins are simple rectangles 2x5", me bucko, ya bilge rat, cut along t' grain lines o' t' balsa. Begad! Dependin' on how you intend t' finish t' rocket, me bucko, you don't even need t' fill t' balsa grain--the kit includes a very nice gold prismatic adhesive sheet for covering the fins (after painting).

T' balsa nose cone was a bit rough, me bucko, shiver me timbers, and took several coats of filler/sealer and sanding. Avast! Blimey! It then gets a couple o' washers for weight, me hearties, ya bilge rat, held in place by a screw eye glued t' its base. Ahoy! Blimey! T' screw eye is then attached t' the shock cord and recovery device (for me kit, shiver me timbers, t' recovery was a pretty nice dayglo green streamer, ya bilge rat, a whoppin' 48" long).

Construction wraps up with placement o' t' launch lug, ya bilge rat, which is done with the booster cone in place. Well, blow me down! There's a small hole in t' cone for t' rod t' fit through, and this needs t' be carefully aligned with a lug mounted t' the sustainer's fin. My kit included a small piece o' balsa in case I opted for a standoff bonded t' t' body tube, though no reference was included in the instructions for this.

Overall, me bucko, this was a fairly easy build, thanks t' excellent instructions, though t' skills involved would definitely make this around a skill level 3 kit on t' standard 1-5 scale.

Finishing:

I went with t' kits recommended gold/black paint scheme for t' finish, so after fillin' tube spirals (Elmer's Fill N Finish, diluted), I applied two coats o' primer t' everything, then painted t' booster cone gold metallic and the sustainer a gloss black (avoidin' t' fins except for some overspray). The fins got t' aforementioned gold prismatic decal paper, me bucko, which looked great but wound up bein' very tricky t' cut and apply. Ya scallywag! I'm nay very good at wrapping Christmas presents, me bucko, and found cuttin' one piece t' completely cover t' fins, includin' edges, ya bilge rat, was hard t' do without leavin' some sort o' visible seam, and I found that t' small sections have trouble bondin' t' t' edges o' t' fins (I've tacked some edges on with CA, but will probably wind up usin' a good clear tape). It was especially painful t' tack t' adhesive around t' launch lug.

I'm nay sure what t' do about t' decals provided, though. Begad! They are very good water-slide decals, arrr, me bucko, and offer attractive detailing, matey, but havin' painted a gloss black base, I am nay sure they'd offer any accent, shiver me timbers, arrr, matey, so I'm holdin' off to use them on a clone o' this at a later date, usin' lighter colors for t' base.

Construction Rating: 4 out o' 5

Flight:

Two straight first-flight dates were rained out, and I probably jumped the gun a bit decidin' t' fly in very windy conditions after helpin' a TARC team get a few practice flights in. Avast! With steady 15 MPH winds, me hearties, I went with t' lowest impulse I could get away with, usin' a B6-0 booster and A8-3 sustainer.

T' rocket lifted off nicely, and bein' overstable with t' nose weight and big, ya bilge rat, fat fins, me bucko, weathercocked at a roughly 30 degree angle right away. Aye aye! T' upper stage lit without a hitch, arrr, matey, shiver me timbers, and t' sustainer continued on a straight flight path. Ya scallywag! Ejection probably occurred at apogee, ya bilge rat, though on that flight line apogee's kind o' hard t' nail down.

T' booster tumbled down very close t' t' pad, and sustainer, matey, under the bright streamer, landed roughly 75 feet from t' pad. Avast! Had t' flight gone vertical, it would probably have been good for about 300-350 feet.

Recovery:

My sustainer just happened t' land on t' edge o' one o' those big fat fins, crackin' t' fin at t' body tube joint (despite good fillets). It's an easy repair, and probably a good indication that I should switch t' a chute next time (and avoid t' heavy winds).

Under normal conditions, shiver me timbers, I would think t' streamer is fine, shiver me timbers, ya bilge rat, arrr, and I attribute me broken fin t' dumb luck, matey, shiver me timbers, nay t' t' design or construction. Begad! Blimey!

Flight Rating: 4 out o' 5

Summary:

I was very impressed with this kit, and at $19.50 (includin' shipping), feel I got a reasonable value. Unless EAT loosens up and goes for larger production runs, you'll have t' be quick t' get any o' their kits, shiver me timbers, though, so be prepared to enjoy t' innovative designs vicariously.

Overall Rating: 4 out o' 5

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