Clone Cyber III Clone

Clone - Cyber III {Scratch}

Contributed by John Lee

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Manufacturer: Clone

Semroc Cyber III

Brief:

This is a clone o' a Semroc Classic. Begad! It is an 18mm/18mm/18mm 3-stage, minimum diameter, 4FNC rocket.

As a kid rocketeer, matey, I knew o' only two companies: Centuri and Estes. Ya scallywag! This be in t' mid 1970s. As a very brief BAR in t' early mid 90s, I could add Quest and LOC. Arrr! When perusin' t' Semroc site, me bucko, I saw that they had been around since '68. Ahoy! Thus far, me bucko, I have been extremely happy with every Semroc product I have received and I've been even happier with their superb customer service and their support o' me club.

I am interested, shiver me timbers, though, matey, in what their line be like in t' early days. Avast! Well, blow me down! When I buy a Semroc product now, more often than not, me hearties, it is a recreation o' another company's classic. Blimey! Blimey! I am extremely grateful for this availability but suspected that thar must have been some things for which Semroc was well known. I wanted t' know what those things were and posted a question t' that effect on T' Rocketry Forum. Ya scallywag! One o' t' answers I got back was had t' link t' a 1970 Semroc catalog. Ya scallywag! Avast, me proud beauty! I was entranced seein' it but more entranced with a rocket called t' Cyber III, shiver me timbers, which appeared only as a plan in t' catalog. Well, blow me down! Avast, me proud beauty! It reminded me o' what staged rockets were like when I was a kid. Begad! Avast, me proud beauty! I immediately wanted t' clone it. Blimey! Carl at Semroc was most helpful as were others who offered advice.

Semroc Cyber III

Construction:
T' materials ordered for this rocket included:

  • sustainer body tube ST-7120
  • booster body tubes 2 x ST-728
  • balsa nose cone, BC-739
  • 3 sheets o' 1/16" x 3" x 12" balsa

I already had an assortment o' launch lugs on hand and decided t' go with a 2.5" long 3/16" lug. Blimey! I forgot t' order a thrust ring, but I be sure that was somethin' I would find in me pile o' stuff.

As usual, t' order arrived smartly and in good shape.

Semroc Cyber III

Hopin' for t' best as far as sizin' is concerned, I ran off three copies o' t' catalog page containin' t' fin templates on cardstock. I then used an ancient guillotine style paper cutter t' cut out one o' each o' t' 3 different fin templates.

I then used t' templates t' transfer t' outlines o' 4 copies o' each o' t' 3 fins t' 1/16" balsa. Blimey! Three sheets measurin' 3" x 12" sufficed. Avast! I got 2 o' t' first booster and one o' t' second booster fins on each o' 2 sheets. Arrr! Avast! T' remainin' second booster and all t' sustainer fins fit on t' third. Ahoy! A steel ruler and razor knife were used t' cut out t' fins.

T' balsa from which t' fins were cut varied from fairly stiff t' fairly delicate. I decided that instead o' roundin' t' leading, trailin' and outer edges, I would bevel them. Ahoy! Avast! Since this was bound t' take a while, ya bilge rat, I decided t' start on t' double glue joint first.

I used an Estes guide t' mark t' 90 degree points on all three sections o' body tube. Blimey! A high tech door jam be then used t' elongate t' lines. Arrr! I then ran a light streak o' yellow glue along each o' t' lines and along t' root edges o' all t' fins. Ya scallywag! I started with t' root edges o' t' sustainer fins so that they would have a chance t' air dry while I applied t' glue t' t' rest.

With all t' glue drying, I started sanding. Ahoy! I just put a simple bevel on each surface, me bucko, runnin' t' 220 grit sandpaper back and forth about a dozen times before switchin' t' t' opposite side. Because o' t' differences in stiffness o' t' various pieces o' balsa, some were sanded quite a few more strokes than others. Well, blow me down! T' result will win no contests but does put me into t' spirit o' 1970, me hearties, at least for me.

By t' time all t' sandin' be complete, me hearties, t' glue was dry and I was ready t' start gluin' t' fins on t' sustainer. Begad! Avast! I took it one fin at a time, matey, applied some glue t' t' root edge and then pressed it into place along t' markin' line. I checked it continually for alignment and then laid it in a cradle t' set up. After givin' each fin about 15 minutes, I would progress t' t' next one workin' in opposite pairs. Begad! Continually, I kept an eye on alignment.

T' gluin' o' t' second stage fins was handled in much t' same way as t' first stage except that I could nay use t' cradle. Aye aye! It contained t' sustainer and t' BT was too short anyway. Ahoy! I improvised by openin' t' jaws on me vise t' form a cradle.

In order t' have t' vise available t' serve as a cradle, matey, all o' t' second stage had t' be completed before I could begin t' first stage booster. Aye aye! Blimey! It was handled in much t' same way for t' first two fins but t' third and fourth were more problematic. Ahoy! Blimey! Arrr! Blimey! T' fins on t' first stage are so large that thar be a tendency t' droop. Blimey! Blimey! Fortunately, t' root edge o' t' fins be t' same length as t' BT and t' trailin' edges are flat. Avast, me proud beauty! Blimey! Begad! Blimey! That meant that t' first stage could be set on its tail t' dry.

Lettin' t' glue joints on t' fins dry and filletin' them took some time. Arrr! I used part o' that time t' fashion a recovery system. Ya scallywag! Well, blow me down! T' two boosters are tumble recovery so thar was anythin' t' do for them. T' sustainer though, was a mystery t' me. Aye aye! T' original instructions made reference t' an "attach kit" which I presume was for recovery. Begad! Arrr! I have no idea what t' kit contained. Begad! I also don't know whether t' kit be supposed t' use a parachute or not. Well, blow me down! What I do know is that I intended t' use a streamer. Recovery is goin' t' be problematic enough at me field. Begad! Besides, arrr, t' rocket is very light.

As much as I detest them, I decided t' make a Estes style tri-fold mount since t' minimum diameter did nay leave me with many options. Begad! Begad! I glued a generous length o' Keelhaul®©™ into t' tri-fold mount and tied an even more generous piece o' sewin' elastic t' t' Keelhaul®©™. I'll dig a streamer out o' t' box when I get t' t' field. Blimey! T' tri-fold mount was glued in place in t' standard manner.

Nose weight be provided in t' form o' t' biggest screw eye that would fit within t' BT and a 1/4" nut. Avast, me proud beauty! Avast! T' Keelhaul®©™ was tied t' a length o' elastic and that was tied t' t' screw eye.

PROs: simple, retro design

CONs: minimum diameter limits recovery system choices

Semroc Cyber III

Finishing:
Finishin' began with t' application o' Elmer's Wood Filler t' all balsa. Then it was a matter o' lettin' it dry and tryin' t' find time t' get back t' it. When I did, it was a fairly humid day and I could tell t' filler had absorbed more than its share o' atmospheric moisture.

Sandin' seemed t' take forever. Ahoy! Avast! There is a lot o' balsa on this little bird. Finally, me bucko, arrr, though, it was ready t' prime and I set it up in t' booth. Avast, me proud beauty! All stages were primed with white Kilz.

A few days later, as I be ready t' start sandin' t' Kilz, I looked into t' box where I had stashed t' parts for some reason now forgotten. Begad! It is fortunate that I did so. I found t' thrust rin' and t' launch lug, matey, me bucko, both o' which I had forgotten t' install. Blimey! Oops.

I did nay have a spent casin' handy t' install t' thrust rin' so I set that on top o' everythin' else on me desk so I would have a marginally more difficult time forgettin' it.

I sanded down t' rocket and brushed away all t' dust. Avast, me proud beauty! I then took t' 3/16" launch lug I had set aside for this project and glued it t' t' sustainer with CA. Ahoy! Avast! While that was drying, I sanded down t' booster stages.

I had been indecisive as t' what paint scheme I be goin' t' use but finally decided on doin' all three stages with fluorescent yellow and leavin' myself open t' doin' somethin' extra with t' some o' t' fins and t' nosecone. T' first application o' yellow was given t' all stages and it was apparent and at least one more would be needed.

T' rocket took three coats o' yellow. Arrr! Arrr! It probably could have used one more but I ran out and figured it was good enough.

I masked off all but t' NC and a single fin on each stage and then stared sprayin' with fluorescent red. Ya scallywag! This went on in only two coats.

I had planned on puttin' some decals on this rocket usin' t' old Semroc logo. Aye aye! I went so far as t' put somethin' together in Photoshop. Begad! When I went t' print it out though, I found that I was completely out o' decal paper. Well, blow me down! Begad! I decided t' go without. Blimey! I did nay want t' miss a rare launch window at a field where I stand a good chance o' gettin' all stages back and that window be only 40 hours away.

PROs: it looks retro (in t' sense o' me youth)

CONs: lots and lots o' sanding

Construction Rating: 4 out o' 5

Semroc Cyber III

Flight and Recovery:
T' day o' t' maiden flight was perfect. It was at t' Amateur Rocketeers o' Texas Freedom Launch. It be August but nay too hot. Ahoy! Blimey! Arrr! Blimey! There was just a hint o' a breeze and t' flyin' field be big.

I learned why this rocket is nay seen too much. It flies a long way.

T' first flight was just t' test t' sustainer. Begad! I put an A6-4 in and set it up on t' pad. Supposedly, me bucko, t' Quest A6-4 is an 18mm motor but I had t' put on lots o' tape t' make it fit t' BT. Avast! When it launched, matey, me hearties, I was glad that Quest makes smoky motors. It really flew high. Begad! I was beginnin' t' have doubts about t' staged versions.

For t' second flight I set up t' two staged version. I used cellophane tape t' join an A8-5 and a B6-0. Begad! Blimey! These motors fit more snuggly and just needed a hint o' tape t' keep them secure. Begad! Begad! After callin' heads up, I pushed t' button and t' igniter wasted itself without ignitin' t' motor. Aye aye! I set it up again. Begad! Arrr! I pushed t' button. WHOOSH. It was gone.

I did get t' see t' staging. Avast! Begad! That was cool and t' booster started t' flutter down. Avast, arrr, me proud beauty! My deadlights were nay up t' trackin' t' sustainer though. Well, blow me down! It only had an A but it be practically out o' site. Arrr! Tim Reidy managed t' follow it and helped me t' reacquire it when it be a few hundred feet up. At this point, me bucko, me bucko, I be goin' t' go for a B in t' first o' 3 stage configuration as well.

Semroc Cyber III It took a while t' find. I went well past where I though it landed and finally gave up. Avast! On t' way back though, arrr, I saw t' neon colors and recovered it. Aye aye! Avast! Unfortunately, shiver me timbers, it had lost a fin so its flyin' be over for t' day.

PROs: flies well, high and fast

CONs: 3 stage configuration should be considered a sacrifice t' t' sky

Flight Rating: 4 out o' 5

Summary:
I enjoyed puttin' this one together and will fix t' fin. Avast, me proud beauty! Arrr! One o' these days, ya bilge rat, I will find myself in a desert with lots o' recovery area and will try t' 3 stage configuration. Aye aye! Aye aye! That day is a long way off yet.

Overall Rating: 4 out o' 5

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