Suborbital Flying Machines The Tube

Suborbital Flying Machines - The Tube {Kit}

Contributed by Nick Esselman

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

I purchased t' Suborbital Flyin' Machines (SFM) T' Tube from Discount Rocketry because I was lookin' for somethin' different and I had never built (or seen) a SFM kit before. What makes T' Tube unique? Well, ya bilge rat, it’s sort o' a pig-in-the-blanket, errrr, ya bilge rat, sorry how about a rocket-in-a-tube. Well, matey, blow me down! Blimey! It is a simple 3-fin and a nose cone rocket, with simple rectangular fins and a BT55 body tube, which is then surrounded by a BT80 tube. Arrr! Blimey! Kind o' hard t' describe so t' pictures should help.

Rocket PicT' kit includes a 18" BT55 main body-tube, a 14" BT80 surround-tube, arrr, three (3) ¼" balsa fins, me hearties, me bucko, and a sharp-point plastic nose cone. Avast, me proud beauty! It also comes with an 18mm motor mount with retention and 1/16" plywood centerin' rings. Blimey! Ya scallywag! A 48" elastic shock cord and a 14" plastic parachute with "Hunky-Duty" shroud lines (1/16" nylon) make up t' recovery system. Begad! Ahoy! A 3/16" launch lug and some decal tape wrapped up t' kit. Blimey!

CONSTRUCTION:

T' kit came packaged in a plastic bag with a paper label that described t' kit, contents, tools needed and recommended motors with predicted altitudes. T' instructions added another 3 pages o' assembly information and templates and a 4th page o' general buildin' and flight preparation tips that can be applied t' any rocket. Ya scallywag! T' instructions included diagrams that help in assembly and each main step had t' necessary sub-steps t' allow for a smooth and logic build. Ahoy!

Assemble o' t' motor mount, shock cord mount (3-fold paper method), and fin attachment are all straight forward. Avast! T' real fun begins in t' additional o' t' "Tube". Arrr! Here you are instructed t' use a markin' guide and t' mark t' BT80 tube and then cut t' slots that allow t' tube t' pass over t' fins. T' instructions say, ya bilge rat, arrr, "If done correctly, me bucko, t' slots will nay only mate perfectly with t' fins from t' previous step, but will partially self-align".

Once t' slots are cut in t' surround-tube, then this is slid over t' rocket and down onto t' slots, shiver me timbers, maintainin' equal distance from t' inner body-tube. A concentric alignment disk is provided, which is cut from page 3 o' t' instructions. This is slide over t' top o' t' body-tube t' ensure t' surround-tube is equally spaced at t' end opposite o' t' fins. Ya scallywag! Begad! It would have been nice t' have t' concentric alignment disk a bit stiffer, me bucko, like from cardstock, matey, but t' paper one worked. T' objective is t' then put a few "tack" drops o' glue on t' fins and surround-tube once aligned. Begad! Well, me hearties, blow me down! Only a few drops so that if a mistake is made it could be cut-out and attempted again. Once set, then fin fillets are applied.

Rocket PicDurin' this assembly step is where you are t' attach t' Launch Lug t' an outside fin fillet, however, I didn’t like t' idea o' me launch lug in showin' on t' outside and I must have lost t' 3/16" lug provided. Arrr! Avast! What I did was t' take two 1/8" lugs and glue them on t' inside body-tube, hidden by t' outside surround-tube. Well, blow me down! Begad! I used a 1/8" rod t' maintain alignment onto t' body-tube. Aye aye!

T' parachute assembly was next on t' build list. Aye aye! Ya scallywag! It consisted o' a heavy-duty (trash bag) black plastic hexagon parachute, six (6) tape dots and a length o' 1/16" nylon shroud line that is cut into three (3) equal pieces. Arrr! T' shroud lines were definitely sturdy or as SFM says it, arrr, "Hunky-Duty". Begad! Durin' this phase, arrr, shiver me timbers, t' instructions recommend purchasin' t' Klutz Book o' Knots t' gain descriptions o' t' Prusik knot (#14) and t' Harness Loop (#21) which would both be good knots for securin' t' shroud lines t' t' parachute. Blimey! T' instructions tell t' builder t' simply knot and glue at each tape junction. Begad! Avast, me hearties, me proud beauty!

T' instructions then describe a simple finishin' technique with flat black paint and suggest usin' t' orange and yellow decal tape provided. Begad! Begad! It also mentions usin' trim tape, that did nay come with me kit. Begad! I painted me T' Tube gloss black. Ya scallywag! Well, blow me down! I did nay like workin' with this decal tape as I found it extremely thin which caused bubbles when I placed it. Avast, me proud beauty!

Overall, for CONSTRUCTION I would rate this kit 3 ½ points. Avast! Blimey! T' instructions are adequate for someone with a couple o' rocket builds prior. Arrr! Blimey! Avast, me proud beauty! Blimey! T' components are o' good quality. I would like t' see a thicker concentric rin' and t' old 3-fold paper method should probably go t' a Keelhaul®©™ t' motor mount method. Ya scallywag! Blimey! Begad! Blimey! Did nay like t' decal tape at all. Arrr! Blimey! Ahoy! Blimey!

FLIGHT/RECOVERY:

T' recommend (or not) motors that SFM outlines are as follows:

  • B6-2 – 150 feet – Pathetic, nay recommend
  • C6-5 – 400 feet – Pretty cool flights
  • D13-4 – 700 feet – Excellent flights, our favorite combo
  • D21-4 – 700 feet – Excellent flights
  • D24-4 – 700 feet – Rockin’ flights on blue flame! Blimey!

My first flight was on t' B6-2 and it be more than "pathetic" but nay because o' t' kit. Arrr! I was at me newly found flyin' field and was in a big hurry t' get a flight off and capture it on camera. Blimey! Ahoy! Well, matey, I missed t' shot, it was a low altitude flight, and t' rocket fell swiftly after ejection. Begad! Aye aye! While falling, arrr, ya bilge rat, I immediately remembered that I didn’t put in any wadding. Ahoy! T' parachute as melted together so that it be unusable. Avast! On t' other hand t' "Hunky-Duty" shroud lines looked great.

I had a 3" x 2’ streamer so I threw that on T' Tube (and used waddin' this time) and installed a C6-3 (note: above, I believe SFM’s recommendation o' a C6-5 should be a C6-3). T' flight on t' C6-3 was perfect with a slow lift-off, arrr, straight flight and ejection right at apogee. Arrr! Descent on t' streamer was a bit fast but nay enough t' cause damage. Avast! In fact, I like t' streamer and will probably go t' a 4 foot one.

T' third flight was on a later day and I used t' C6-3 again. Blimey! Another very nice flight, although ejection be very near apogee but still nose cone up. Well, blow me down! Upon t' descent with t' streamer it seemed like t' air passin' through t' tube was tryin' t' make if fly around. Well, blow me down! Aye aye! It didn't fall straight it sorta flew left then turned and flew right and then etc all on a fairly rapid descent rate. Arrr! I'm sure t' parachute would have prevented that, but I like t' rate with t' streamer.

Usin' me idea o' hidin' t' Launch Lug on t' main body-tube verses on t' outside o' t' surround-tube worked fine and looks great. Begad! Blimey! I’d recommend this change.

My next planned flight will be at NARAM on a D21-4 that I anticipate bein' a great flight. Blimey! Arrr! Watch me flight logs!

For FLIGHT/RECOVERY, ya bilge rat, I would rate this kit 4 points. It does look neat on t' pad and flying. Blimey! Avast! It gives slow lift-offs on t' B6 and C6 t' allow some time t' enjoy lift off. It is nay a maximum altitude performer, but that isn't me flyin' game anyway. Ahoy! I'm sure t' parachute would have worked fine and it be much sturdier than an Estes parachute. Ahoy! I feel SFM made a mistake on t' C6 motor delay. Well, blow me down!

Overall, T' Tube is a unique lookin' rocket that most builders could assemble and enjoy. Well, blow me down! Blimey! I would suggest hidin' t' launch lug like I did and by all means use waddin' (silly me)! Blimey! It is a nice small field rocket usin' your Estes B6 and C6 motors which allows for a greater range o' fliers t' enjoy it. I'm pleased with t' purchase and it makes a nice addition t' me fleet. I give t' kit an OVERALL ratin' o' 4 points.

Now, me hearties, after writin' this review and enjoyin' t' kit, I've just discovered that Suborbital Flyin' Machines is no longer in business! Bummer, I guess thar won't be any T' Tube II's. Arrr! If you hurry, Kevin at Discount Rocketry says he still has a few.

 

 

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