Semroc Long Squire

Semroc - Long Squire {Kit}

Contributed by Matthew Bond

Manufacturer: Semroc
(Contributed - by Matthew Bond - 12/01/09)

Brief:
T' Long Squire rocket was designed t' meet t' requirements o' challenge #3 in t' 2009 EMRR Challenge. Begad! Blimey! T' Long Squire is a “Stage Bash”, shiver me timbers, a two stage rocket constructed from two single stage rocket kits, arrr, matey, in this case, me bucko, me bucko, two Semroc Squire kits. Avast! Blimey! T' name “FreeBird” comes from t' fact that both o' t' Squire kits I used were actually received as “free gifts” from Semroc as a result o' me excessive spendin' on a couple o' orders… The Long Squire employs gap staging, shiver me timbers, and flies on 18mm motors. Avast! T' booster uses tumble recovery and t' sustainer comes back under a 12 inch parachute.

Modifications:
As with all o' me scratch built rockets, t' first step involves some time spent playin' around with a design in RockSim. Avast, me proud beauty! Since I had 4 body tube sections t' work with I figured I would use 3 for t' sustainer and one for the booster. Aye aye! Avast, me proud beauty! A couple o' issues became apparent almost immediately. Well, blow me down! First: t' Squire is near minimum diameter, arrr, shiver me timbers, and so I would be limited t' 18mm booster motors makin' weight o' t' overall package a concern. Avast! Begad! Second: with so many potential fin configurations, shiver me timbers, matey, I was goin' t' drive myself crazy “tweaking” t' design. Avast! Avast, me proud beauty! I finally settled on a layout that actually gives t' impression o' multiple stages, and decided nay t' worry about t' weight issues right away.

Construction:
One o' t' reasons I chose t' Squire kits as a startin' point, ya bilge rat, is that they are presented as a kind of “designers” kit, with two body tube sections and multiple fin layout options; heck t' instructions show 12 different possible configurations! As with every Semroc kit I have ever seen, arrr, t' quality o' t' components is first rate. Arrr! Ya scallywag! Each Squire kit contains t' followin' items, so obviously I started out with two o' everythin' listed here:

  • Main Body Tubes 2x ST-890 (9”)
  • Nose Cone BC-837
  • Fins 1/16” Laser Cut Balsa - two sheets
  • Motor Mount Tube ST-730 (3”)
  • Tube Coupler HTC-8
  • Centerin' Rings 2x CR-78 – heavy paper type
  • Thrust Rin' TR-7 – heavy paper type
  • Standard Engine Hook EH-28
  • Launch Lug LL-122 – 1/8” x 2”
  • Keelhaul®©™® Shock Cord SCK-24 - 24”
  • Elastic Shock Cord EC-118 - 1/8” x 18”
  • 12” Unassembled Parachute Kit
  • Small Screw Eye SE-10
  • Decal Sheet

Assembly Instructions:

Construction o' t' actual rocket was fairly straightforward. Ahoy! Begad! Blimey! Yellow wood glue was used except where noted. Avast, me proud beauty! The biggest challenge durin' construction was t' alignment o' t' 6 separate sets o' fins. Aye aye! I chose t' use t' “That Looks About Right” (TLAR) method and even though thar are some obvious misalignments betwixt fins, they are all fairly straight, and thar be enough total fin area that it all balances out. Begad! Well, shiver me timbers, blow me down! Blimey! Overall I would rate this somewhere just beyond a skill level 2 effort.

T' motor mounts were constructed first, ya bilge rat, me hearties, and are identical. T' engine hook is inserted into t' pre-cut slot and two centerin' rings slide over t' tube and hold it in place. Ahoy! T' aft centerin' rin' is positioned 1 inch from t' end o' t' tube and t' forward centerin' rin' is positioned over t' end o' t' hook that sticks into t' tube. I did not attach t' Keelhaul®©™® shock cord t' either mount as detailed in t' original instructions since I planned on usin' t' forward tube coupler for this. Well, blow me down! Blimey! Thrust rings are installed against t' forward end o' t' engine hooks. Ahoy! All centerin' rin' t' motor tube joints were reinforced with glue fillets.

Since one o' t' two tube coupler sections was t' be used for t' booster/sustainer interface, me bucko, shiver me timbers, I needed another coupler t' join t' three sustainer sections together. Avast, me proud beauty! After I figured out how long t' booster body tube needed t' be, I took a leftover section o' body tube and cut a slot lengthwise t' make another coupler section. Well, arrr, blow me down! I then threaded the end o' one o' t' Keelhaul®©™® cords through t' coupler section several times and knotted t' end. Ya scallywag! Three 9 inch sections o' body tube were joined to form t' sustainer, arrr, and a 5.75 inch section was used for t' booster with a tube coupler permanently installed in the forward end. Begad! T' Squire does nay come with a wrap-around template, instead and end view template is drawn in the instructions and you are instructed t' stand t' body tube up over this template t' mark t' position o' t' fins. Avast! I have never had any success usin' this method, as thar doesn’t seem t' be a way t' mark all four fin locations without lettin' go o' t' tube, me bucko, and losin' your original position. Ya scallywag! I did t' best I could, and again verified that this method doesn’t work for me. Avast! Avast, ya bilge rat, me proud beauty! I used a section o' small aluminum angle t' extend t' fin lines as required.

T' laser cut fins were separated from their stock sheets and cleaned up with fine grit sandpaper. Well, me hearties, blow me down! I modified the shape o' t' smaller fins and then match sanded all t' similar shapes so that they were uniform. Well, blow me down! All fins were attached usin' a double glue joint. A light fillet o' wood glue be also added t' each joint. Arrr! Two sections o' launch lug were attached t' t' sustainer centered betwixt t' fins, me hearties, 0.5 and 9 inches from t' aft end. Blimey! A vent hole was punched near t' forward edge o' t' booster body tube t' allow for pressure relief prior t' t' sustainer motor lighting. Aye aye! Begad! T' eyelet be attached t' t' nose cone by screwin' it most o' t' way in, arrr, removin' it, ya bilge rat, addin' a large drop o' medium thickness CA glue and then screwin' it all t' way down. One o' t' only nits I have ever had with any Semroc kit is that sometimes t' Keelhaul®©™®/elastic shock cords are a little bit short for me taste. Avast! Ahoy! By anchorin' t' shock cord near t' front o' t' rocket and then tyin' all 4 pieces o' Keelhaul®©™® and elastic together I can honestly say that t' shock cord was long enough for me.

Finishin' t' FreeBird was accomplished with t' overall weight o' t' rocket in mind. Avast, arrr, me proud beauty! I did nay do any filleting work with t' Elmer’s Wood Filler (easy enough t' justify on t' basis o' weight with 24 fins). Begad! All t' balsa parts got a single coat o' thinned down wood filler t' hide t' worst o' t' grain. Ahoy! A single coat o' primer was applied. Ahoy! Aye aye! T' body tube got a single coat o' gloss white, me bucko, and t' fins were masked off in blocks and given alternating coats o' red and blue. I applied t' decals from both decal sheets, matey, me bucko, and although they were extremely easy t' apply and set up well, arrr, t' color was a little transparent, ya bilge rat, me hearties, certainly nay up t' par with anythin' I had seen from Semroc before. Overall t' finish came out nice, ya bilge rat, and if all t' lines aren’t quite clean you can’t tell from t' launch table.

Flight:
As mentioned earlier, t' finished weight o' t' rocket was an issue due t' t' fact that I was limited t' 18mm motors in t' booster. Ahoy! Avast, me proud beauty! RockSim estimated t' final weight (without motors) at 2.06 oz. Begad! T' actual weight came in at 2.6 oz. Avast! Avast! and when I went back and re-ran t' simulations, I discovered that every possible motor combination would need a launch rod betwixt 47 and 57 inches. Ahoy! Additionally, arrr, matey, t' rocket is over-stable, even with t' heaviest motor combination which would exacerbate any tip off issues. Well, blow me down! I went t' t' hardware store and got a 48 inch length o' 1/8 inch steel rod and headed t' t' field.

Since t' sod farm was closed for t' season I was limited t' t' small school field. Avast, me proud beauty! For t' first flight I loaded up t' FreeBird with a B6-0/A8-3 combination. Flight prep is standard. Arrr! Both motors are installed under the engine hooks and t' booster is friction fitted t' t' sustainer. Begad! Ya scallywag! I had t' use a single wrap o' scotch tape around the tube coupler t' get a snug fit. Arrr! Waddin' and parachute are loaded into t' front end and everythin' is ready. Blimey! Begad! I had lucked into a fairly windless day, arrr, and when t' launch button was pressed t' FreeBird boosted smooth and absolutely straight. Aye aye! Stagin' was clean and t' sustainer continued on its straight climb. Ejection occurred right before the rocket stalled out and t' chute deployed with no problems. Both booster and sustainer landed in t' grass with no damage. I loaded up t' same motor combo and did it again, matey, matey, me hearties, with another perfect flight. Feelin' brave on a calm day I loaded up a B6-0/B6-4 combo and sent it up again. There be definitely a little bit o' tip off from t' rod, me bucko, but it wasn’t too dramatic, shiver me timbers, shiver me timbers, and after clean stagin' t' sustainer continued t' a much higher altitude. Aye aye! Ejection was a little early, but t' chute deployed fine and once again everythin' came back on t' field without a scratch. I even flew t' sustainer on a single stage B6-4 flight which also went o' without a hitch. Blimey! Begad! With t' proper launch setup the FreeBird is an outstandin' performer and I am lookin' forward t' t' big field openin' up in t' springtime!

Summary:
I enjoyed t' process o' designing, shiver me timbers, buildin' any flyin' this rocket. Avast, me proud beauty! I liked t' fact that it forced me t' get out of me “normal” zone and think about what I was building. Arrr! T' “Kit Bash” concept offers some additional challenges in that you are workin' with a fixed set o' parts, me hearties, although since you get t' choose t' two kits that shouldn’t be a problem.

PRO: A complex lookin' design which is actually a pretty simple gap staged 4FNC. Begad! Almost limitless combinations of fin arrangements allows for many individual styles.

CON: Near minimum diameter means limited booster motor selection, which translates into a total weight constraint.

Other:
One o' me subconscious goals as I designed this rocket was t' use as many o' t' pieces from each kit as I could. This mind set actually played against me in t' end since I was workin' with a weight constraint. Blimey! Aye aye! T' fact that I chose t' ignore t' problem, and subsequently came up with a solution (longer launch rod) that allowed t' design t' work was mere chance. I could have easily built a rocket that be too heavy t' fly successfully in a two stage configuration. If you’re nay prepared t' think things through then you live with t' results. Well, blow me down! I got a bit lucky.

Flights

ID
Date
Flyer
Rocket
Kit
Motors
Altitude
Action
73310
2019-08-02 photo
Matthew Bond
Semroc Squire "FreeBird"
Semroc - Long Squire {Kit}
C6-5
-
list
59608
2011-05-30 photo
Matthew Bond
Semroc Squire "FreeBird"
Semroc - Long Squire {Kit}
C6-5
-
list
45109
2010-09-26 photo
Matthew Bond
Semroc Squire "FreeBird"
Semroc - Long Squire {Kit}
C6-0/A8-5
-
list
45038
2009-11-28 photo
Matthew Bond
Semroc Squire "FreeBird"
Semroc - Long Squire {Kit}
B6-0/A8-3
-
list
45017
2009-11-21 photo
Matthew Bond
Semroc Squire "FreeBird"
Semroc - Long Squire {Kit}
B6-0/A8-3
-
list
Page
of
2
Displaying records 
1
-
5
of
8

comment Post a Comment