Scratch Remote Guardian Probe Jinx 1.2 Original Design / Scratch Built

Scratch - Remote Guardian Probe Jinx 1.2 {Scratch}

Contributed by Les Bradshaw

Manufacturer: Scratch
(Contributed - by Les Bradshaw - 07/06/08)

Brief:
This is for t' Box o' Parts contest Well, this rocket for me has had multiple problems, hence t' “jinx” name. Part o' t' issues was good old procrastination. Ahoy! Ya scallywag! But, shiver me timbers, excessive work schedules (a few weeks where I was averaging 70 hours a week), arrr, stuck tubes, arrr, me hearties, a crashin' computer that lost me files, me bucko, and crashin' rockets (more about that later) – but it finally flew successfully! T' parts arrived late March. Arrr! Begad! Like a kid giddy at Christmas, I opened t' box, and was surprised by t' amount o' stuff!

Parts

Construction:
T' parts that I used are listed below:

  • 1 – BT80 x 14 ¼” tube
  • 1 – BT55 x 13 ½” tube
  • 1 – BT50 x 18” tube
  • 1 – BT50 x 3 ¼” tube
  • 1 – BT20 x 18” tube
  • 1 – BT20 x 3” tube
  • 1 – BT19 x 3” tube
  • 2 – BT5 x 9” tube
  • 2 – BT5 x 7 ½” tube
  • 1 – BT80 x 4” coupler
  • 2 – BT55 x 3” couplers
  • 1 – 80K balsa nose cone
  • 1 – BT55 x 5 ½” plastic nose cone
  • 2 – BT55 x 3” broken plastic nose cones
  • 2 – BT20 x 2 ¾” nose cones
  • 1 – BT20 x 1” fiber nose cone
  • 3 – BT20 ~ BT50 adapters
  • 1 – BT50 ~ BT60 adapter
  • 1 – plastic cup
  • 3 – measure/mix cups
  • 2 –large plastic caps
  • 5 – small plastic caps
  • 1 – BT5 fin can
  • 1 – dual display nozzle
  • 2 – 12” parachutes
  • Misc 1/8” balsa
  • Misc 1/16” balsa
  • 1 – fin
  • 3 - snap swivels
  • 2 – engine hooks
  • 1/8” launch lug
  • 7 – toothpicks
  • ¼” dowel
  • 2 large skewers
  • 3 small skewers
  • Paper
  • Decals
  • Holographic sheet
  • Mailin' box

T' first thin' I did was t' weigh t' parts. Ya scallywag! Begad! My goal was t' use as much as possible. Arrr! Begad! Based on t' weight, I decided that t' rocket would need a cluster o' 2 D engines t' fly. Avast! I also felt t' amount o' balsa wood was a bit skimpy (but as I actually got into t' build, shiver me timbers, it appeared that whenever I needed some wood, thar be still a piece available).

Durin' t' rest o' t' build, arrr, you will find me referrin' t' version 1.1 and version 1.2. Ya scallywag! What should be obvious, I first built version 1.1. Avast! First flight be at NERFF 4 and t' rocket crashed, ya bilge rat, causin' some major damage. Arrr! JINX! T' keep with only usin' what came in t' box, I repaired and updated t' design t' version 1.2. Arrr! Begad! T' second launch also crashed. JINX! But at least nay as bad. Blimey!

Durin' t' development, I made up various pieces and taped them together, givin' me some flexibility t' adapt the design. Below is a teaser o' t' taped up version. You will also see where I filled spirals usin' Elmer’s F&F.

I was tempted t' fly it, but I could nay figure out

1. What t' speed o' maskin' tape was

2. Blimey! How t' convince an RSO t' launch it

3. How many pieces would it be in after a flight

Getting Ready

For version 1.1, me hearties, one o' me first steps was t' boil some corn (although clams or any other grub would work as well – or just plain water). Ahoy! Once t' water was boiling, I placed t' 1/16” strip o' balsa (it was 2” x 12”) across t' pan. Begad! Begad! Besides satisfyin' me hunger, I be also steamin' t' wood so I could bend it. T' corn was done first so I had t' keep steamin' t' balsa but I finally removed t' balsa and sandwiched them betwixt 2 o' my wife’s cake savers (one is 10” t' other is 12”). WARNING – that last step can get you into trouble!! I let this sit for a while (over a day) for t' balsa t' retain its shape

Rocket Pic

I decided on usin' t' BT80 as me main tube, me bucko, with 3 pod tubes off o' this main. Well, blow me down! Well, blow me down! I wanted t' use t' couplers to hold these pods. Take t' 3 couplers (1 BT80 and 2 BT55) and draw lines t' length o' t' coupler on opposite sides (180 degrees apart). For t' BT80, shiver me timbers, make a mark at 2” on one line and a mark at 1” on t' other. Ahoy! For t' BT55, make t' marks at 1” and ½”. Avast! Usin' stiff paper, connect t' marks on both sides. Begad! Arrr! Usin' a sharp knife, cut along these lines.

Some other preparation work – take one o' t' 9” BT5 tubes. Avast! Avast! Make a mark 4.5” down from one end. Cut t' tube usin' this mark as t' center on an angle, arrr, ¼” above and below this position. Arrr! Epoxy a large plastic cap t' t' straight end o' each tube.

Rocket Pic

In addition, me bucko, me hearties, cut out 2 each o' t' 2” x 2 ¾” x 4” x 1” fin and t' ¾” x ¼” x 1” pieces shown above

Rocket Pic

For t' motor mount, I traced t' BT80 onto t' mailin' box and cut out t' circle. Then I drew a line that went through t' center. On here, I traced 2 circles, matey, centered on t' line but t' edges separated by about 1/8”. I cut out these holes and dry fitted t' piece into t' BT80 and t' BT50 tubes into t' center circles. Begad! Blimey! Sand t' fit. Avast, me proud beauty! Once satisfied, I used t' first piece as a template and made a second piece. Blimey! Well, blow me down! T' two BT50 motor tubes had a 1/8” slit made 2 ½” from one end. Avast, me proud beauty! Insert t' motor hook and secure with tape. Arrr! Slide t' motor tubes into t' two centerin' rings. Begad! Cut another piece o' cardboard 2” x 2.6” Glue t' 2 motor tubes t' t' centerin' rings, sandwichin' t' 2” x 2.6” cardboard betwixt t' motor tubes and t' rings. Ahoy! Let dry.

Rocket Pic

Take t' other 2 tongue depressors and make a mark 2 ½” from each end on t' edge. Arrr! Draw a line connectin' t' marks. Begad! Cut t' tongue depressor apart on this diagonal line. Bevel t' cut edges and glue t' pieces back together t' create an angle. Glue a toothpick into t' angle created.

For version 1.1, I made some standoffs. Begad! Cut 4 pieces o' balsa ½” x 1 ¼”. Ya scallywag! Ahoy! Blimey! Bevel one o' t' 1 ¼” edges on each piece. Ahoy! Avast! Blimey! Glue t' pieces together so t' bevels create a “V” channel

Rocket Pic

While t' version 1.1 was designed for a 3/16” rod, ya bilge rat, arrr, t' rocket was too heavy. T' version 1.2 was upgraded for ¼” rod. Well, blow me down! Since all I got was 1/8” launch lug material, me hearties, I had t' improvise. Take 3 o' t' small skewers, cut 2 t' 7” and t' third t' 9” from t' pointed tip. Ya scallywag! Save t' cut off ends for future use. Begad! Glue the two 7” skewers t' a tongue depressor even with t' ends. Let dry. Begad! Cut t' ¼” dowel into two 6” sections. Aye aye! Glue these t' t' 7” skewers. Finally, t' 9” skewer needs t' be glued in t' middle o' t' tongue depressor on t' opposite side.

Rocket Pic

From t' 1/8” balsa, matey, me bucko, cut 2 fins 9” x 3”. Ahoy! Ya scallywag! I received a plywood fin that was already 6” x 2 ¼”. You would need t' cut your own fin out.

T' BT80 section needs t' be lengthened for stability, so I transformed t' 80K nose cone into a transition. For version 1.1, me hearties, I planned t' eject t' parachutes from t' very top, arrr, but I ran into issues. Aye aye! Version 1.2 separates at the transition. Ya scallywag! First, me hearties, take t' plastic cup and cut about 1 1/8” diameter hole in t' top. Begad! Ya scallywag! Slide t' cup over t' nose cone end. Arrr! Adjust t' hole size until t' edge o' t' cup (with t' lip) is snug on t' nose cone. Well, blow me down! Arrr! Carefully, shiver me timbers, cut away the trim, me hearties, double check t' fit, me bucko, me bucko, then glue t' cup over t' nose cone. Blimey! Let dry.

Rocket Pic

This is how it looks when done

Rocket Pic

T' attach t' top t' t' nose cone, ya bilge rat, take one o' t' BT 20 t' BT50 adapters and place it over t' top o' t' 80K nose cone. Mark where it touches t' cone and remove it. Take t' BT50 tube. Aye aye! First cut off a 3” length (to use as a motor mount). Avast! Slide a BT50 section over t' nose cone end. Aye aye! Again, mark where it touches. Begad! Dry fit t' BT20 t' BT50 adapter in t' 15” length and t' BT50 t' BT60 over t' same end. Begad! Begad! Push t' tube and adapters onto t' nose cone and verify t' fit. Once you are satisfied, slide t' BT50 t' BT60 adapter up a bit and remove t' BT20 t' BT50 adapter. Aye aye! I used 30 minute epoxy; put some inside t' BT50 tube followed by t' BT20 t' BT50 adapter. Avast! Place more epoxy on t' outside o' t' BT50 tube near t' end. Aye aye! Blimey! Finally, place more epoxy on t' nose cone at t' marks made earlier. Place t' tube over t' end o' t' nose cone and press down. Begad! Arrr! This will push t' BT20 t' BT50 adapter up, me bucko, shiver me timbers, and slide the BT50 t' BT60 adapter down. Arrr! Make sure t' tube is straight with t' nose cone. Let dry.

Rocket Pic

While t' transition section is drying, ya bilge rat, you can make t' nose cone section. Blimey! Blimey! Take t' 3” BT20 tube and 4 equally spaced lines (every 90 degrees) along t' length o' t' tube. Well, blow me down! From one end, matey, make marks at 1” on two opposite lines, me hearties, matey, and marks at 1 ½” on t' other two opposite lines. Aye aye! Similar t' t' couplers, connect t' marks and carefully cut t' tube. Take t' BT19 tube and make 2 lines t' length o' t' tube on opposite sides.. Well, blow me down! I am not sure if BT19 is a real designation. (This tube is one you would normally get with an Estes rocket, make a mark, put glue inside a motor tube, matey, and use this tube t' push t' motor block in up t' t' mark, and then “quickly remove to keep from gettin' stuck”).

One piece o' t' BT20 will be slightly smaller. Avast, me proud beauty! This be t' top. Begad! Glue it onto t' BT19 linin' up t' pointed ends with t' marks on t' tube. Begad! Well, blow me down! Glue t' 1” BT20 nose cone onto this end. Blimey! Glue t' other BT20 section onto t' BT19, also linin' up t' pointed ends. Blimey! Aye aye! Glue 2 BT20 t' BT50 adapters onto this end. Avast! I put t' first on so it only left a small 1/16” ~ 1/8” o' t' BT20 extending, so t' adapters are mostly glued t' each other

Rocket Pic

Since t' 1.1 version was t' be t' separation point for ejection, I did nay want this nose t' slide down, so I created a lip by cuttin' 2 launch lug sections, with t' tops cut at an angle, matey, shiver me timbers, t' t' BT20 tube in line with the pointed ends. Ahoy! Well, blow me down! T' 2 balsa pieces cut earlier (¾” x ¼” x 1” pieces) were glued t' t' top on the shorter portion, 90 degrees from t' launch lugs.

Rocket Pic

I glued 2 toothpicks as antenna, but they smartly broke off. Avast, me proud beauty! I would nay bother.

Once t' top was dry, matey, t' ensure stability, ya bilge rat, I added 1.5 ounces o' epoxy and BB pellets t' t' top.

T' win' pods can start assembly. Ya scallywag! Blimey! Blimey! Blimey! Cut t' 18” BT20 in half. Draw a line along t' length o' t' 2 pieces. Make marks at 2 ¼” and 7” from one end. Arrr! Blimey! Glue t' 2 BT55 couplers cut before at t' 2 ¼” and 7” locations. Arrr! Blimey! Note t' positions o' t' smaller and larger coupler segment and t' direction o' t' angled cuts. Make 2 o' these. Ahoy! Blimey! Blimey! Blimey! Glue t' BT20 x 2 ¾” nose cones in. Ahoy! Blimey! Ahoy! Blimey! Blimey! Blimey! Usin' a Dremel tool, I cleaned up t' ends o' t' broken BT55 nose cones. These I epoxied into t' other end t' look like a nozzle. Begad! Blimey! I canted t' nozzle for appearance. Let dry, then glue t' 2” x 2 ¾” x 4” x 1” fin t' t' other side. You should cut a notch into t' fin to fit over t' coupler.

Rocket Pic

Back t' t' main section, ya bilge rat, me bucko, shiver me timbers, I slid t' larger BT80 coupler into t' BT80 tube with t' point even with t' end. Aye aye! Arrr! Blimey! I used this as a markin' template t' cut t' BT80 tube. Begad! Blimey! I then spent an hour tryin' t' get t' coupler out o' t' tube, causin' me t' have t' cut ¼” strip off where a chewed it up tryin' t' push t' jammed thin' out. JINX! Blimey! Cut out t' BT80 tube at t' mark.

I used a piece o' paper and marked t' paper t' determine t' BT80 circumference. Blimey! Sorry for changin' units, but I found it t' be almost exactly 21 cm. Ahoy! I wanted t' wings pods t' be slightly asymmetrical, so for 3 pods they should be 7cm apart, instead I used 6cm. for t' 2 wings. I centered t' point with t' 6cm marks on t' point o' t' BT80 tube and marked t' tube. Well, blow me down! Extend these lines t' length o' t' tube. Avast, me proud beauty! Glue t' motor mount into t' BT80 so t' 2 tubes are perpendicular t' t' point.

Rocket Pic

Since me motor mount was cardboard, I did coat it with epoxy for protection.

Glue t' launch lug assembly so t' aft o' t' dowel is 4” from t' end o' t' BT80 tube.

Glue t' win' pods t' t' BT80 so t' aft o' t' win' coupler is 1” from t' end o' t' BT80 tube on the 6cm lines.

Thee rudder pod is similar t' t' win' pods. Mark and glue t' BT80 couplers t' t' BT55 tube at 2 ¾” and 9 7/8” positions. Blimey! Glue t' smaller fin t' t' coupler and body tube (you will need t' cut a notch into t' fin for t' coupler) as shown.

Rocket Pic

T' 2 large fins should wait until this is glued t' t' BT80 tube. Mark and glue this pod t' t' BT80 tube, again with t' end o' t' coupler 1” from t' end o' t' BT80 tube. T' assist in t' stability, ya bilge rat, glue t' left over segments o' t' skewers (from t' launch lug) betwixt t' aft BT80 coupler and t' BT80 tube. T' 4 ½” BT5 tubes glue betwixt t' front coupler and t' BT80 tube, me hearties, shiver me timbers, alignin' t' angled cut with t' coupler. Begad! Ya scallywag! Glue t' BT55 nose cone t' t' front.

Rocket Pic

Once dry, me hearties, glue t' larger fins betwixt t' coupler sections on either side. Ya scallywag! Arrr! T' make a nozzle for t' rudder, I sanded and roughed up t' 3 measuring/mixin' cups. Arrr! Blimey! I cut 2 circles (1 3/8” diameter) from t' mailin' box. Begad! I beveled t' edge, and then glued one circle into 2 o' t' cups, then glued t' cups together (all usin' epoxy). Blimey! Once dry, ya bilge rat, this glued into t' aft o' t' BT55 tube. Well, blow me down! Ahoy! This nozzle I left straight.

Rocket Pic

Now t' complete t' top. Startin' at t' BT50 t' BT60 adapter, glue 2 large skewers and 2 toothpicks along the tube. Avast! Attach two o' t' 7” BT5 tubes in line with t' toothpicks startin' at 9” from t' top o' t' BT50 tube. Well, blow me down! Glue small plastic caps t' t' top o' these tubes. Avast, me proud beauty! Glue t' nose assembly t' t' top. Arrr! T' launch lugs should be in line with t' BT5 tubes

Rocket Pic

Rocket Pic

T' shock cord was cut in half. Arrr! A provided screw eye was attached t' t' 80K nose cone. I used some o' t' paper to make a trifold t' attach t' shock cord t' t' main tubes. Arrr! Begad! Usin' t' snap swivels, one 12” parachute was attached t' t' top and t' other was attached t' t' main tube shock cord.

For version 1.1, shiver me timbers, ya bilge rat, t' bent balsa was attached t' t' fins on t' wings. Well, blow me down! Blimey! T' V beveled standoffs were attached over the win' fins. Avast! Blimey! A missile was made usin' t' last BT5 tube, me bucko, shiver me timbers, t' fin can, arrr, t' display nozzle, and another small cap. A missile rack was made with some ¼” x ¼” x 2” supports. Avast! Blimey! Finally, two 1” x 3” supports were made t' support t' missile. Arrr! Blimey! Your size may vary based on t' size o' your wife’s cake savers (or other molds you may have used).

Rocket Pic

Rocket Pic

Rocket Pic

Rocket Pic

Flight:
Cuttin' things t' t' wire, arrr, arrr, t' night before I left for NERRF I’m givin' this thin' a quick primer coat and 1 coat o' white. Aye aye! There were supposed t' be chances o' thunderstorms at NERRF and I was afraid t' field could be wet. Water and cardboard don’t mix. Blimey! So, on Saturday, shiver me timbers, arrr, off t' NERRF 4 I went t' fly t' beast. Ya scallywag! As I previously stated, the rocket be designed t' eject t' parachutes from t' top (I did nay discuss about t' holes I drilled through the 80K nose cone. Blimey! As I was preppin' t' rocket, I noticed t' parachutes were tight. Arrr! This had me concerned. Arrr! I had not glued t' 80K t' t' BT80 (fortunately), so I taped this joint. Begad! Installed 2 D12-3 engines and got through t' RSO (he did wince when I stated it only used two 12” parachutes). Aye aye! Avast! While waitin' t' load, shiver me timbers, I had several comments askin' how I kept all t' small pieces on. Blimey! I explained this was its first flight. We called a heads up flight. Begad!

They launched t' HPR rockets, me bucko, started t' LPR – and stopped halfway! Blimey! They then went t' more HPR and did not come back t' t' LPR. My rocket sat on t' pad for over an hour. Ya scallywag! JINX! Blimey! Finally, matey, it launched. Aye aye! Blimey! Blimey! It danced a bit on t' pad – t' rocket weight be really too heavy for a 3/16’ rod. Also, I thought t' 3/16” rods were 4’, but they were only 3’. But, shiver me timbers, t' rocket went up nice and straight. But those tight chutes did nay come out. Aye aye! Blimey! The tape at t' transition let go – crash. Aye aye! Blimey! JINX!

Rocket Pic

I gathered up t' pieces. Arrr! T' worst damage was t' wing. Begad! Ya scallywag! At least t' corn had tasted good.

Rocket Pic

As I previously stated, at this point I cut off t' 1.1 version o' t' launch lug and rebuilt it as version 1.2. I decided t' missile added too much weight, and I had no good place t' put it, shiver me timbers, so I left it off. Aye aye! I cut off the standoffs for t' tongue depressors and mounted them upside down. Avast! It was also at this point when I changed t' t' shock cords t' connect at t' transition. So, I went back t' NERRF on Sunday. While loadin' t' engines, I had t' rocket leanin' against t' side o' me car. Arrr! I had t' grab something, and it fell over and cracked a fin. Well, blow me down! JINX! A quick glue repair and it was good t' go. Avast! Aye aye! I did nay have t' wait this time, ya bilge rat, possible since I was now on t' ¼” rods. Again, arrr, I requested a heads up. Ya scallywag! Avast! It launched beautifully straight, but when t' chutes came out t' one for t' main section tangled on t' launch lug skewers and landed hard. Ahoy! JINX! But at least t' top came down gently, and landed in one o' t' water filled irrigation ditches. Aye aye! Begad! JINX! JINX! JINX! Fortunately, it be only t' very tip with t' epoxy/BB filling. There was some minor damage t' t' rocket, but it was repairable. Arrr! I was goin' t' give up, me bucko, shiver me timbers, ya bilge rat, but then t' contest got extended a week, just enough time for some repairs and painting. Avast!

Rocket Pic

Rocket Pic

Rocket Pic

Rocket Pic

My son and I went t' a local school yard and did 1 launch. Nice and straight, me bucko, both chutes opened, me hearties, shiver me timbers, me hearties, and a safe recovery! I be nay goin' t' tempt fate with another launch. Avast! One thin' I would say, t' rocket really needs 18” chutes minimum. Avast, me proud beauty! Avast! While t' landin' did nay cause any damage, I did wince as it looked rather hard. Well, blow me down! However, shiver me timbers, I had to live with what I got – t' 12” chutes.

Rocket Pic

Rocket Pic

Summary:
This was a great contest that challenged me. Avast! Avast! Despite all me JINXes, I think I came up with somethin' special that used almost all o' me parts. I guess t' only thin' I didn't try is puttin' t' rest o' t' parts into a blender...

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