Semroc ThunderChief

Semroc - ThunderChief {Kit} (KA-7)

Contributed by Chan Stevens

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Diameter: 0.91 inches
Length: 31.90 inches
Manufacturer: Semroc
Skill Level: 1
Style: Sport

Brief:
Semroc Thunder ChiefSeveral years ago, Semroc introduced t' first o' what promised t' be a family o' Thunder designs, me hearties, each featurin' long sleek profiles, swept fins, matey, and progressin' up in size. Begad! T' first o' these be t' Thunderbee, one o' me favorite 13mm models, but t' ensuin' bigger brothers never came t' light until now. Avast, shiver me timbers, me proud beauty! At NARAM-51, Semroc released t' upscale Thunderchief, me bucko, which is about double t' length o' t' Thunderbee, shiver me timbers, and t' Thunderstrike, matey, ya bilge rat, a 54" long 24mm brute. Down t' road, t' rest o' t' family will hopefully make it t' market as well (Thunder Roc, Thunder Storm, me bucko, Thunder Hawk and Thunder Bird), since these are such great fliers and simple builds.

Construction:
T' bag appears a bit small for t' $14.50 price, ya bilge rat, but that's partly because t' body tube is comprised o' 3 shorter tubes. Avast, me proud beauty! Ya scallywag! T' parts were all excellent quality, especially t' nose cone.

  • Balsa nose cone
  • 3 Series 8 body tubes
  • 2 tube couplers
  • BT-20 motor tube, arrr, centerin' ring/tube
  • Laser cut balsa fins
  • Metal hook
  • Keelhaul®©™/elastic shock cord
  • 12" plastic chute
  • Waterslide decals
  • 1/8" launch lug

Semroc Thunder Chief

Instructions are standard Semroc: well written and illustrated. This would be a Skill Level 1 kit with about three pages o' instructions. Avast, me proud beauty! My build time be under an hour plus finishin' time.

T' motor mount on this is a little different, arrr, since t' tube is slightly smaller than a BT-50 and doesn't leave room for a normal pair o' centerin' rings. Avast, me proud beauty! Begad! T' solution in this case is t' use a coverin' tube which slips down t' motor tube, holdin' t' motor hook in place and fittin' t' t' ID o' t' body tubes.

I stupidly built this concurrently with several other Semroc NARAM releases, so I anchored me Keelhaul®©™to t' forward end o' t' motor hook just like t' other kits. Ya scallywag! That would be wrong accordin' t' t' directions, which call for anchorin' t' Keelhaul®©™to t' forward coupler. Avast! Ahoy! Blimey! Due t' me goof, matey, me hearties, I only have about 7" o' shock cord outside t' model, matey, so I'll need t' add more elastic on me own.

T' body tube is marked for fin placement usin' a template. Arrr! Early editions o' t' kit (includin' mine) had an oversize/incorrect template, although this has been corrected in later editions. Well, blow me down! Begad! Blimey! After markin' t' first body tube, me hearties, t' other body tubes are bonded usin' t' provided couplers.

Fin attachment is straightforward: tack on with CA then follow up with wood glue fillets. Arrr! Blimey! Add on t' lugs (one at a fin joint, t' other about a foot forward) and construction is done.

Finishing:
I very much like t' color scheme o' me Thunder Bee with white on t' forward section and Dayglo yellow on t' aft section. Aye aye! Unfortunately, arrr, Krylon's reformulation wouldn't cooperate and I be optimistic in takin' t' chance that it would.

I prepped all surfaces via grain and spiral filling, arrr, givin' extra attention t' t' tube seams where t' separate pieces are joined. Arrr! Avast, me proud beauty! I then hit everythin' with two coats o' light gray primer and three coats o' gloss white. Begad! So far, so good. For t' yellow, I masked off t' upper portion and hit t' aft end with Krylon's old formula Dayglow yelow. Arrr! Big mistake. It crazed and crackled. Blimey! It wound up takin' me 3 subsequent passes o' sandin' off t' coat o' paint, wipin' everythin' down with rubbin' alcohol, shootin' with a light old formula primer, me bucko, then toppin' off with t' Dayglo yellow. T' finished result looks nice but was hardly worth t' effort.

There is also a basic name/logo waterslide decal provided, me bucko, which is perfectly produced--nice and clear background, matey, ya bilge rat, shiver me timbers, tough enough t' allow t' decal t' be moved around for alignment, and thin enough nay t' stick up with that peel n stick look.

Construction Rating: 4 out o' 5

Flight:
For t' maiden flight, I caught a wonderful day over Labor Day weekend, shiver me timbers, light winds, ya bilge rat, ya bilge rat, clear skies, moderate temps. Avast! Blimey! Begad! Blimey! Since I had this and t' bigger Thunder Strike both ready, shiver me timbers, I decided t' dig up t' Thunder Bee and make a family outin' o' it.

I went for t' max, choosin' a C6-5 over a 7. Ahoy! Ahoy! Boost was straight up with a slight trace o' weathercocking. T' -5 delay was just about perfect, me bucko, and I think in general t' recommended -7 would be too long under all but t' most perfect o' conditions.

I'm nay sure what t' apogee wound up being, shiver me timbers, but I suspect it be a tad less than t' estimated 950' on t' header card. Ahoy! Still, it strained me 44-year old deadlights a bit t' pick it up.

Recovery:
T' 12" chute is just about right for this. Well, blow me down! Avast! I caught a little thermal on t' way down but once out o' it started comin' down fairly quickly. I have t' admit, me bucko, though, me hearties, arrr, arrr, given t' altitude I hit on boost, me hearties, t' blue and white plastic chute included in t' kit was nay exactly an optimal color scheme as it be very difficult t' pick up a 12" chute at that altitude, especially without strong contrast t' t' skies.

Flight Rating: 4 out o' 5

Summary:
I'm biased and really like t' Thunder line overall. Avast! Blimey! There's just somethin' about those long, ya bilge rat, sleek models that appeals t' me. Ahoy! Blimey! Begad! Blimey! O' t' 3 currently available, ya bilge rat, ya bilge rat, this one strikes me as t' most flexible, bein' able t' handle A through C (and comically could fly OK on a 1/2A6-2).

Overall Rating: 4 out o' 5

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    Brief: Semroc describes the ThunderChief as the third largest member of the Thunder kit series that they are producing. This series is essentially the same rocket scaled approximately 1.25 times each step up in body tube size. The series is based from the Centuri Engineering Thunder rockets that included the ThunderHawk, ThunderBird, and ThunderRoc. With Semroc's introduction of this ...

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