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. Ya scallywag! What makes T' Tube unique? Well, it’s sort o' a pig-in-the-blanket, me hearties, errrr, ya bilge rat, matey, sorry how about a rocket-in-a-tube. Avast, me proud beauty! 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. Aye aye! Well, blow me down! Kind o' hard t' describe so t' pictures should help.

T' kit includes a 18" BT55 main body-tube, a 14" BT80 surround-tube, three (3) ¼" balsa fins, arrr, and a sharp-point plastic nose cone. Begad! It also comes with an 18mm motor mount with retention and 1/16" plywood centerin' rings. Ahoy! 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. Well, blow me down! A 3/16" launch lug and some decal tape wrapped up t' kit. Well, blow me down!

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. Well, blow me down! Begad! Blimey! 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. 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. Aye aye! Blimey!

Assemble o' t' motor mount, shiver me timbers, shock cord mount (3-fold paper method), and fin attachment are all straight forward. Ya scallywag! 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. Begad! T' instructions say, "If done correctly, arrr, t' slots will nay only mate perfectly with t' fins from t' previous step, shiver me timbers, 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, me hearties, ya bilge rat, ya bilge rat, maintainin' equal distance from t' inner body-tube. A concentric alignment disk is provided, shiver me timbers, which is cut from page 3 o' t' instructions. Arrr! 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. Arrr! It would have been nice t' have t' concentric alignment disk a bit stiffer, ya bilge rat, like from cardstock, but t' paper one worked. Ahoy! T' objective is t' then put a few "tack" drops o' glue on t' fins and surround-tube once aligned. Begad! Only a few drops so that if a mistake is made it could be cut-out and attempted again. Begad! Avast! Once set, then fin fillets are applied.

Durin' this assembly step is where you are t' attach t' Launch Lug t' an outside fin fillet, matey, however, ya bilge rat, 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. Avast! Blimey! What I did be t' take two 1/8" lugs and glue them on t' inside body-tube, hidden by t' outside surround-tube. Aye aye! Blimey! Avast! Blimey! I used a 1/8" rod t' maintain alignment onto t' body-tube. Begad! Blimey!

T' parachute assembly was next on t' build list. Arrr! It consisted o' a heavy-duty (trash bag) black plastic hexagon parachute, arrr, six (6) tape dots and a length o' 1/16" nylon shroud line that is cut into three (3) equal pieces. T' shroud lines were definitely sturdy or as SFM says it, "Hunky-Duty". Durin' this phase, me hearties, arrr, 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. Begad! T' instructions tell t' builder t' simply knot and glue at each tape junction.

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

Overall, me hearties, for CONSTRUCTION I would rate this kit 3 ½ points. T' instructions are adequate for someone with a couple o' rocket builds prior. Ya scallywag! 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. Arrr! Avast, me proud beauty! Did nay like t' decal tape at all. Avast, me proud beauty! Ahoy!

FLIGHT/RECOVERY:

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

  • B6-2 – 150 feet – Pathetic, me bucko, nay recommend
  • C6-5 – 400 feet – Pretty cool flights
  • D13-4 – 700 feet – Excellent flights, matey, me hearties, 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 was more than "pathetic" but nay because o' t' kit. Begad! Aye aye! I was at me newly found flyin' field and be in a big hurry t' get a flight off and capture it on camera. Ya scallywag! Well, I missed t' shot, it was a low altitude flight, arrr, and t' rocket fell swiftly after ejection. Blimey! While falling, I immediately remembered that I didn’t put in any wadding. Avast! T' parachute as melted together so that it was 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). Avast, me proud beauty! Aye aye! Blimey! T' flight on t' C6-3 was perfect with a slow lift-off, shiver me timbers, straight flight and ejection right at apogee. Ya scallywag! Arrr! Blimey! Descent on t' streamer was a bit fast but nay enough t' cause damage. Avast, me proud beauty! In fact, ya bilge rat, arrr, I like t' streamer and will probably go t' a 4 foot one. Aye aye! Blimey!

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

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

For FLIGHT/RECOVERY, me hearties, I would rate this kit 4 points. It does look neat on t' pad and flying. Aye aye! 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, me bucko, but that isn't me flyin' game anyway. Ahoy! Blimey! I'm sure t' parachute would have worked fine and it was much sturdier than an Estes parachute. Blimey! Begad! I feel SFM made a mistake on t' C6 motor delay. Arrr!

Overall, T' Tube is a unique lookin' rocket that most builders could assemble and enjoy. Arrr! I would suggest hidin' t' launch lug like I did and by all means use waddin' (silly me)! 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. Arrr! Blimey! I'm pleased with t' purchase and it makes a nice addition t' me fleet. Ya scallywag! I give t' kit an OVERALL ratin' o' 4 points. Well, blow me down! Blimey!

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

 

 

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