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, arrr, this rocket for me has had multiple problems, me bucko, arrr, hence t' “jinx” name. Avast, me proud beauty! Avast! Part o' t' issues be good old procrastination. Ya scallywag! But, excessive work schedules (a few weeks where I was averaging 70 hours a week), stuck tubes, me bucko, matey, a crashin' computer that lost me files, shiver me timbers, and crashin' rockets (more about that later) – but it finally flew successfully! T' parts arrived late March. Avast! Avast, matey, me proud beauty! Like a kid giddy at Christmas, matey, 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 be t' weigh t' parts. My goal was t' use as much as possible. Based on t' weight, I decided that t' rocket would need a cluster o' 2 D engines t' fly. Ya scallywag! I also felt t' amount o' balsa wood be a bit skimpy (but as I actually got into t' build, it appeared that whenever I needed some wood, thar was still a piece available).

Durin' t' rest o' t' build, shiver me timbers, you will find me referrin' t' version 1.1 and version 1.2. Aye aye! What should be obvious, I first built version 1.1. Aye aye! First flight was at NERFF 4 and t' rocket crashed, arrr, causin' some major damage. Well, blow me down! Blimey! JINX! T' keep with only usin' what came in t' box, matey, me bucko, I repaired and updated t' design t' version 1.2. Ya scallywag! T' second launch also crashed. JINX! But at least nay as bad. Ya scallywag!

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. Arrr! You will also see where I filled spirals usin' Elmer’s F&F.

I be tempted t' fly it, shiver me timbers, but I could nay figure out

1. Well, blow me down! Blimey! What t' speed o' maskin' tape was

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

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

Getting Ready

For version 1.1, me bucko, me bucko, 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 be boiling, matey, I placed t' 1/16” strip o' balsa (it was 2” x 12”) across t' pan. Besides satisfyin' me hunger, me bucko, I be also steamin' t' wood so I could bend it. Ahoy! 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, ya bilge rat, arrr, with 3 pod tubes off o' this main. Ya scallywag! Aye aye! 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). Ahoy! Ahoy! For t' BT80, me bucko, arrr, make a mark at 2” on one line and a mark at 1” on t' other. Avast! For t' BT55, make t' marks at 1” and ½”. Well, blow me down! Usin' stiff paper, me hearties, connect t' marks on both sides. Ya scallywag! Begad! Usin' a sharp knife, cut along these lines.

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

Rocket Pic

In addition, shiver me timbers, 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. Ahoy! Then I drew a line that went through t' center. Begad! On here, I traced 2 circles, me hearties, centered on t' line but t' edges separated by about 1/8”. Ya scallywag! I cut out these holes and dry fitted t' piece into t' BT80 and t' BT50 tubes into t' center circles. Sand t' fit. Aye aye! Once satisfied, I used t' first piece as a template and made a second piece. Begad! T' two BT50 motor tubes had a 1/8” slit made 2 ½” from one end. Avast! Avast, me hearties, me proud beauty! Insert t' motor hook and secure with tape. Ya scallywag! Ahoy! Slide t' motor tubes into t' two centerin' rings. Avast! 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. Begad! Begad! Draw a line connectin' t' marks. Well, blow me down! Cut t' tongue depressor apart on this diagonal line. Avast! Bevel t' cut edges and glue t' pieces back together t' create an angle. Blimey! Glue a toothpick into t' angle created.

For version 1.1, I made some standoffs. Aye aye! Arrr! Cut 4 pieces o' balsa ½” x 1 ¼”. Bevel one o' t' 1 ¼” edges on each piece. 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, t' rocket was too heavy. Ya scallywag! Aye aye! T' version 1.2 was upgraded for ¼” rod. Arrr! Since all I got be 1/8” launch lug material, me hearties, me hearties, I had t' improvise. Begad! Take 3 o' t' small skewers, cut 2 t' 7” and t' third t' 9” from t' pointed tip. Save t' cut off ends for future use. Glue the two 7” skewers t' a tongue depressor even with t' ends. Begad! Let dry. Ya scallywag! Cut t' ¼” dowel into two 6” sections. Avast! Glue these t' t' 7” skewers. Ahoy! 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, shiver me timbers, cut 2 fins 9” x 3”. Ya scallywag! I received a plywood fin that was already 6” x 2 ¼”. Avast, me proud beauty! 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. Begad! For version 1.1, I planned t' eject t' parachutes from t' very top, shiver me timbers, arrr, but I ran into issues. Ya scallywag! Version 1.2 separates at the transition. Well, blow me down! First, take t' plastic cup and cut about 1 1/8” diameter hole in t' top. Well, blow me down! Slide t' cup over t' nose cone end. Adjust t' hole size until t' edge o' t' cup (with t' lip) is snug on t' nose cone. Begad! Carefully, cut away the trim, shiver me timbers, double check t' fit, then glue t' cup over t' nose cone. Aye aye! Let dry.

Rocket Pic

This is how it looks when done

Rocket Pic

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

Rocket Pic

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

One piece o' t' BT20 will be slightly smaller. Well, blow me down! Ahoy! This be t' top. Ya scallywag! Blimey! Glue it onto t' BT19 linin' up t' pointed ends with t' marks on t' tube. Glue t' 1” BT20 nose cone onto this end. Glue t' other BT20 section onto t' BT19, also linin' up t' pointed ends. Glue 2 BT20 t' BT50 adapters onto this end. Begad! Ya scallywag! 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, me hearties, matey, I did nay want this nose t' slide down, me bucko, so I created a lip by cuttin' 2 launch lug sections, shiver me timbers, with t' tops cut at an angle, ya bilge rat, t' t' BT20 tube in line with the pointed ends. Begad! T' 2 balsa pieces cut earlier (¾” x ¼” x 1” pieces) were glued t' t' top on the shorter portion, matey, matey, 90 degrees from t' launch lugs.

Rocket Pic

I glued 2 toothpicks as antenna, shiver me timbers, but they smartly broke off. I would nay bother.

Once t' top be dry, me hearties, t' ensure stability, arrr, arrr, I added 1.5 ounces o' epoxy and BB pellets t' t' top.

T' win' pods can start assembly. Begad! Well, blow me down! Cut t' 18” BT20 in half. Avast! Draw a line along t' length o' t' 2 pieces. Make marks at 2 ¼” and 7” from one end. Ahoy! Ya scallywag! Glue t' 2 BT55 couplers cut before at t' 2 ¼” and 7” locations. Ahoy! Begad! Note t' positions o' t' smaller and larger coupler segment and t' direction o' t' angled cuts. Make 2 o' these. Aye aye! Avast! Glue t' BT20 x 2 ¾” nose cones in. Usin' a Dremel tool, matey, I cleaned up t' ends o' t' broken BT55 nose cones. These I epoxied into t' other end t' look like a nozzle. Begad! I canted t' nozzle for appearance. Arrr! 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, I slid t' larger BT80 coupler into t' BT80 tube with t' point even with t' end. Begad! I used this as a markin' template t' cut t' BT80 tube. Ahoy! Arrr! 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. Avast! JINX! 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. Aye aye! Avast! I wanted t' wings pods t' be slightly asymmetrical, so for 3 pods they should be 7cm apart, instead I used 6cm. Arrr! for t' 2 wings. Arrr! Avast, me hearties, me proud beauty! I centered t' point with t' 6cm marks on t' point o' t' BT80 tube and marked t' tube. Extend these lines t' length o' t' tube. Well, blow me down! 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. Begad! Mark and glue t' BT80 couplers t' t' BT55 tube at 2 ¾” and 9 7/8” positions. Ya scallywag! Arrr! 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. Well, me hearties, blow me down! Blimey! Mark and glue this pod t' t' BT80 tube, again with t' end o' t' coupler 1” from t' end o' t' BT80 tube. Aye aye! Begad! Blimey! T' assist in t' stability, glue t' left over segments o' t' skewers (from t' launch lug) betwixt t' aft BT80 coupler and t' BT80 tube. Blimey! Blimey! T' 4 ½” BT5 tubes glue betwixt t' front coupler and t' BT80 tube, alignin' t' angled cut with t' coupler. Glue t' BT55 nose cone t' t' front.

Rocket Pic

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

Rocket Pic

Now t' complete t' top. Begad! Startin' at t' BT50 t' BT60 adapter, me bucko, matey, glue 2 large skewers and 2 toothpicks along the tube. Attach two o' t' 7” BT5 tubes in line with t' toothpicks startin' at 9” from t' top o' t' BT50 tube. Avast, me proud beauty! Arrr! Glue small plastic caps t' t' top o' these tubes. 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. A provided screw eye be attached t' t' 80K nose cone. Well, blow me down! Ahoy! I used some o' t' paper to make a trifold t' attach t' shock cord t' t' main tubes. Avast, me hearties, me proud beauty! Usin' t' snap swivels, one 12” parachute was attached t' t' top and t' other be attached t' t' main tube shock cord.

For version 1.1, t' bent balsa was attached t' t' fins on t' wings. Well, blow me down! T' V beveled standoffs were attached over the win' fins. A missile be made usin' t' last BT5 tube, t' fin can, ya bilge rat, t' display nozzle, ya bilge rat, and another small cap. Avast, me proud beauty! Arrr! A missile rack be made with some ¼” x ¼” x 2” supports. Well, matey, blow me down! Finally, two 1” x 3” supports were made t' support t' missile. Aye aye! 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, t' night before I left for NERRF I’m givin' this thin' a quick primer coat and 1 coat o' white. There were supposed t' be chances o' thunderstorms at NERRF and I be afraid t' field could be wet. Water and cardboard don’t mix. Ahoy! So, on Saturday, ya bilge rat, off t' NERRF 4 I went t' fly t' beast. Arrr! Arrr! As I previously stated, the rocket was designed t' eject t' parachutes from t' top (I did nay discuss about t' holes I drilled through the 80K nose cone. Aye aye! As I be preppin' t' rocket, I noticed t' parachutes were tight. This had me concerned. Avast! I had not glued t' 80K t' t' BT80 (fortunately), me bucko, 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). Avast! While waitin' t' load, I had several comments askin' how I kept all t' small pieces on. Avast! I explained this was its first flight. Begad! Avast! We called a heads up flight. Ya scallywag!

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

Rocket Pic

I gathered up t' pieces. T' worst damage was t' wing. Avast, me proud beauty! 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, me hearties, so I left it off. Begad! I cut off the standoffs for t' tongue depressors and mounted them upside down. Arrr! Blimey! It was also at this point when I changed t' t' shock cords t' connect at t' transition. Begad! So, I went back t' NERRF on Sunday. Begad! While loadin' t' engines, I had t' rocket leanin' against t' side o' me car. Begad! I had t' grab something, arrr, me hearties, and it fell over and cracked a fin. Well, blow me down! Arrr! JINX! A quick glue repair and it was good t' go. Begad! I did nay have t' wait this time, arrr, matey, possible since I was now on t' ¼” rods. Again, I requested a heads up. 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. Avast, me proud beauty! Aye aye! JINX! But at least t' top came down gently, and landed in one o' t' water filled irrigation ditches. Avast! JINX! JINX! JINX! Fortunately, it was only t' very tip with t' epoxy/BB filling. Arrr! There was some minor damage t' t' rocket, but it was repairable. Well, blow me down! Begad! I was goin' t' give up, me hearties, but then t' contest got extended a week, just enough time for some repairs and painting. Well, blow me down!

Rocket Pic

Rocket Pic

Rocket Pic

Rocket Pic

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

Rocket Pic

Rocket Pic

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

comment Post a Comment