Semroc Arcon-Hi

Semroc - Arcon Hi {Kit} (KV-15)

Contributed by Glenn Little

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Diameter: 1.04 inches
Length: 23.00 inches
Manufacturer: Semroc
Skill Level: 2
Style: Multi-Stage, Scale
Semroc Arcon-Hi

Brief:
Semroc has developed (or continues t' develop) a line o' kits called "Retro Repro". Aye aye! These kits are reproductions o' out-of-production models that had some level o' significance in t' model rocket industry. T' kits are generally true t' t' original except for utilizin' modern techniques as well as materials.

T' Arcon-Hi be a kit first developed by Centuri in t' mid-1960s. Blimey! It was a semi-scale model o' t' Arcon soundin' rocket. Avast! Arrr! Centuri converted it t' a 2-stage kit usin' a double-coupler method that was later patented. Begad! The sustainer be a 1/6th scale model o' t' soundin' rocket, but t' booster was nay t' scale as it wasn't original t' the soundin' rocket.

Semroc describes this kit as a Skill Level 2 and that seems about right. Ahoy! There are many components, matey, a unique couplin' method, some techniques that require t' builder t' pay attention (no real "gotchas" but does require planning), ya bilge rat, and precision durin' buildin' is necessary.

This rocket is perfect for t' Skill Level 1 builder lookin' for a challenge or a step up t' Level 2.

Semroc Arcon-Hi

Construction:
T' components for this kit came well packaged. I had just completed a Semroc SLS Jaguar so I did note some differences betwixt t' two kits. Begad! Begad! However, shiver me timbers, matey, t' Jaguar is considered a mid-power rocket and came from a higher end line of kits so t' comparison may nay be appropriate. Even so, t' Arcon-Hi components appeared sturdy and o' relatively good quality. Aye aye!

As seen in t' picture, matey, t' components in t' kit include:

  • 5 body tubes (2 engine tubes, matey, a booster, matey, sustainer, arrr, and payload)
  • 3 couplers (includin' 1 balsa one)
  • 4 centerin' rings
  • 2 thrust blocks
  • 4 booster and 4 sustainer fins
  • empty engine casin' for measuring/spacin' (nice touch!)
  • nose cone
  • parachute and recovery system (Keelhaul®©™® thread, elastic, screw eye, parachute that requires assembly)

All parts were accounted for. Aye aye! Semroc's attention t' detail continues t' be evident. Ahoy! This company makes kits I will enjoy making. Avast!

T' end o' t' sustainer be a little bent and creased, and I have little doubt Semroc would have replaced it if I asked. After several dry fits o' t' balsa coupler, ya bilge rat, I was able t' smooth out t' crease.

T' balsa parts seemed t' be o' decent quality. T' fins felt a little thicker than other kits and were flexible but nay flimsy. Begad! Arrr! T' nosecone had an even grain that was easy t' fill. Blimey! Well, blow me down! It didn't require any extra sandin' t' make symmetrical.

T' instructions are detailed, nicely laid out, me bucko, and easy t' follow. There are several steps that have t' related picture on t' next page, me bucko, matey, requirin' t' builder t' flip back and forth, matey, ya bilge rat, a minor inconvenience. Ahoy! T' instructions have an "exploded view", me bucko, which I did find t' be helpful several times as I wasn't used t' a kit with so many components.

Just like t' SLS Jaguar kit, t' font is easier t' follow than kits from other companies. Begad! I usually have the instructions off t' t' side and it was nice nay havin' t' lean over so far t' refer t' them. Avast! T' illustrations were nicely drawn and easy t' follow.

Durin' a dry-fit, ya bilge rat, matey, I noticed many o' t' components fit loosely. Aye aye! T' nosecone in required tape t' make a snug fit. T' centerin' rings and thrust blocks also felt too easy t' slide on (I'm used t' havin' t' sand these). Avast, me proud beauty! T' couplers were very snug and they all required some sanding.

Assembly follows a logical progression: engine tubes/mounts first, booster stage then sustainer, me bucko, followed by the fins and recovery system. Begad! I followed t' directions in order except for a few steps, shiver me timbers, which are described below. I did do a mod at t' very end, which is discussed below too.

All assembly be done with Titebond III, but fin fillets were made usin' JB Weld. Avast, me proud beauty! I usually use Loctite 5 minute epoxy. Arrr! I read a lot about JB Weld so thought I'd try it. It's a little easier t' use and definitely easier t' make nicer fillets around smaller fins.

One area that required attention was both engine mounts are nay built identically. Arrr! Durin' t' booster assembly, there is an instruction or two that states "repeat with t' 2nd engine mount". I went too far and repeated too many o' t' steps and had t' remove a centerin' rin' before t' glue set. Avast! While this be me fault and doesn't count as a "gotcha", I do feel t' instructions should minimize t' "back and forth" and keep the assembly o' t' booster separate from t' assembly o' t' sustainer.

Before attachin' t' fins I did another dry fit, and I would recommend this t' other builders. T' couplers required some sanding, me hearties, and I imagine this is easier t' do prior t' t' fins bein' attached. Arrr! Ahoy! This step is nay listed in the instructions.

T' photo shows t' dual couplin' method that Centuri had patented. T' engine mount o' t' sustainer slides inside t' inner coupler o' t' booster. It is this connection that required sanding. Blimey! T' reader may note t' inner coupler has 2 vent holes t' help facilitate ignition o' t' sustainer engine--it is me guess that they let cool air escape, allowin' hot gases t' enter t' sustainer engine. Begad! Otherwise t' cool air might block t' hot gases and contribute t' pressurizin' t' connection and ejectin' t' booster.

Semroc Arcon-HiSemroc Arcon-Hi

I also filled t' spirals prior t' attachin' t' fins. Begad! And, because it's easier t' do, I applied sandin' sealer to the fins prior t' attachin' them.

Semroc Arcon-Hi T' only "gotcha" in t' kit involved t' steps for attachin' and alignin' t' fins. Avast! Instead of cuttin' out a section o' paper with marks and tapin' it t' t' body tube, ya bilge rat, thar be a circle drawn on t' page with marks around t' edge. T' builder is t' stand t' rocket on t' circle and mark t' tube where t' fins are t' be attached. Arrr! Well, me bucko, blow me down! As seen in t' picture, me hearties, t' circle was a larger diameter than t' body tube, makin' transferrin' marks evenly a challenge.

T' directions have t' builder transfer marks t' t' booster and sustainer in separate sequences. Ahoy! Blimey! T' prevent mis-alignment, matey, I made t' marks on t' booster, shiver me timbers, attached t' sustainer t' t' booster, and drew lines on both tubes at the same time. Begad! Avast! Blimey! Even with me technique, matey, I still have a slight spacin' error as indicated by t' fins linin' up only in a certain way. Aye aye! Blimey! That is, matey, t' first line I drew on t' booster has t' be in line with t' correspondin' line on the sustainer, etc. Ya scallywag! Blimey! Blimey! T' ease alignment durin' flight preparation (as t' lines will be covered by paint), I drew marks on the couplers.

Semroc Arcon-Hi If I were t' assemble this kit again, one thin' I would do differently is glue t' fins on t' sustainer first. Avast! I would then connect t' two stages and glue t' fins on t' booster, matey, makin' sure they are in line with t' fins on t' sustainer. Begad! T' root edges o' me fins all lined up, but as seen in t' picture, thar be a fin that leans a little t' t' side (this actually happened t' 2 fins) and therefore are out o' alignment.

Another thin' I would do differently is build in some form o' adjunctive engine retention for t' sustainer so I won't have t' rely solely on a friction fit. There is no room at t' base o' t' fins for tape, and t' engine fit is fairly snug already.

Here is a modification I performed: After I built t' rocket, I epoxied some 60# Keelhaul®©™® thread across t' engine mount. Aye aye! Avast! This will slide over t' engine and help hold it in place durin' ejection. Avast! T' allow the booster t' slide on, shiver me timbers, I cut out rectangular sections that align with t' epoxy placements. Avast, ya bilge rat, me proud beauty! This o' course would be easier t' do prior t' buildin' t' rocket. Ya scallywag! I did nay use an engine clip because thar wasn't enough room t' allow epoxy to hold t' clip and a small distance t' allow t' clip t' be raised.

Assemblin' t' payload is straightforward and didn't require any special instructions or techniques.

Finishing:
As o' this writing, arrr, matey, I have only primed t' rocket. Blimey! Begad! Instead I focused on completin' assembly, and launchin' off a maiden flight. Avast! Ahoy!

I usually paint me kits differently than on t' picture on t' kit. Well, blow me down! Avast, me proud beauty! My 4 1/2 yr-old son likes t' help choose the colors. However, because this is a first review for this rocket, I will try t' follow t' color scheme o' black, yellow, and silver and send a picture later. I will use a metallic silver (or t' shiny side o' aluminum foil on 1 or 2 fins) t' help it be easier t' find in t' air and on t' ground. Ahoy! Because I'm nay used t' followin' schemes, I anticipate a slight challenge.

Semroc states t' finish weight is 1.9oz. Ahoy! Avast! With t' primer, matey, mine weighed in at nearly 3oz. Arrr! This is likely due to the extra epoxy for t' fillets. I'm a little concerned about stability, arrr, because I intend on usin' a beeper/locating device when I launch it.

I'm ratin' assembly a 4 because I didn't like t' fin alignment method. Ahoy! I prefer t' have a cut-out strip t' tape to t' body. Also, I think me technique o' attachin' t' two stages before drawin' t' lines shouldn't be considered an epiphany and should be part o' t' instructions.

Construction Rating: 4 out o' 5

Flight:
I finished this rocket about two weeks before I had a chance t' launch it. Ya scallywag! T' waiting, as t' sayin' goes, is the hardest part. Avast, me proud beauty! I took me launch stuff t' work once or twice in case I had t' opportunity with low wind and decent weather. Ahoy! Blimey! Finally, ya bilge rat, me hearties, a lunch launch came t' be...

Preparation be fairly straightforward. Aye aye! I initially put a single layer o' maskin' tape around t' middle o' the sustainer engine, then a double layer at t' aft end. Ya scallywag! Begad! I had a lot o' trouble gettin' t' engine in, I nearly bent the body tube. Begad! Begad! It did compress a little along a spiral and one o' t' fins became slightly deformed from me thumb. Ya scallywag! Ya scallywag! I really need t' perfect me friction fit technique. I took off t' double layer, matey, put in t' engine, shiver me timbers, and taped t' Keelhaul®©™® thread in place. Aye aye! Without t' Keelhaul®©™® as t' engine definitely would nay have stayed in.

T' booster be easy t' prepare. Blimey! Blimey! I used 3 pieces o' wadding, put in t' chute, me hearties, and attached me Transolve micro trans beep. Arrr! Everythin' fit easily. Blimey! I had t' use tape around t' base o' t' nosecone.

I used a C6-0 for t' booster because t' store didn't have any B6-0 engines. Ya scallywag! Avast, me bucko, me proud beauty! Blimey! This is just as good because the rocket was heavier than intended due t' t' extra fillets and t' trans beeper. Ahoy! Blimey! T' beeper alone is nearly 0.5oz so my rocket is 1.5 times t' predetermined weight.

I didn't have a large field so I wanted t' use a B engine for t' sustainer. Aye aye! Although a B6-6 is recommended, all I had was a B6-4 so used that.

T' flight was beautiful. Well, blow me down! I'm 40 years old and still get giddy when I launch a rocket, me bucko, particularly a maiden launch. Aye aye! Well, blow me down! I'm guessin' it was due t' t' added weight, ya bilge rat, but this thin' launched much like me Quest Superbird: slow, matey, matey, shiver me timbers, big puff o' smoke, ya bilge rat, almost a little wobbly at first (I use a 4' launch rod, arrr, ya bilge rat, good thin' too)... It was really fun t' watch.

T' booster took it up t' maybe 150 feet or so. Ahoy! Then it ejected and t' sustainer took off like afterburners were kicked into overdrive. Avast, me hearties, me proud beauty! It was a really fun, awesome flight t' watch.

It went nearly out o' sight. Arrr! Blimey! I'm nay sure what RockSim would have predicted, me bucko, me hearties, but I'm guessin' nearly 1000' even with t' added weight. Begad! Blimey! Begad! Blimey! T' chute came out perfectly and I looked down t' get t' booster, which landed about 20' away. When I looked up I had difficulty findin' t' rocket. Begad! Blimey! I'm really glad I used t' beeper, because I found me rocket on someone's roof. Well, blow me down! Blimey! Begad! Blimey! It bein' midday, t' family be out t' work/school, shiver me timbers, etc. It was approachin' 100 deg and really high humidity and I didn't want t' tempt fate with t' police, matey, so instead o' climbin' up t' retrieve it, arrr, I left a note and will go back later t' retrieve it.

Semroc Arcon-HiSemroc Arcon-Hi

Recovery:
I did have difficulties with t' parachute. Ahoy! It's a nice plastic but thick and durable chute. Begad! Arrr! T' shrouds do nay go through t' chute but are threaded through circle stickies (similar t' hole reinforcements but without t' hole in the middle) and stuck t' t' chute. Ya scallywag! T' problem is when I threaded t' shrouds through t' sticky, arrr, shiver me timbers, it lost adhesion. Arrr! Begad! I tried gluin' them but they still didn't stick. Begad! I used 5 min epoxy with some success. Arrr! I ended up coverin' each circle with some clear packin' tape.

After t' launch, t' chute deployed just fine. Avast, me proud beauty! I do feel descent was too fast, arrr, but this is likely due t' the added weight nay due t' t' chute bein' too small.

Though me rocket is still on t' rooftop, me bucko, me bucko, I be able t' see it pretty clearly and thar be no evidence o' damage.

I'm ratin' flight recovery a 4.5 only because I felt t' shrouds could be better connected t' t' chute.

Flight Rating: 4 out o' 5

Summary:
This rocket is perfect for t' Skill Level 1 builder lookin' for a challenge and ready t' enter Level 2 models. Aye aye! It is a fun rocket t' build and fly but does require a level o' attention that is atypical o' most skill level 1 kits.

Overall Rating: 4 out o' 5

Flights

Comments:

avatar
J.W.P. (August 2, 2008)
This Arcon Hi kit is exactly like the one I had back in the early 70s.A beautiful model and impressive flight after flight. I have been waiting for years for some rocket company to reproduce it and Semroc finally did it. Thank you so much. I hope it sells very successfully.

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