Scratch Night Hawk Original Design / Scratch Built

Scratch - Night Hawk {Scratch}

Contributed by Donald Besaw Jr

Manufacturer: Scratch
(Contributed - by Donald Besaw Jr - 08/01/01)

Rocket PicBrief:
This is a rocket that I designed for small fields. Ahoy! It is single staged, flies on Estes A10-3T motors t' about 200 feet and uses a streamer for recovery.

Construction:
Materials required:

  • 2 Estes BT-20 body tubes
  • 2 Estes NC-20 nose cones (Yankee Style)
  • 1 Estes NC-20 nose cone (Vikin' Style)
  • 1 Estes Mini Motor Mount Kit or make your own. Avast!
  • 1 sheet o' medium 1/16 or 3/32 balsa for fins (your choice)
  • 1 standard launch lug
  • 1 shock cord mount
  • 1 shock cord about 2 t' 3 feet long
  • 1 streamer
  • 1 pack clay nose weight possibly

Optional Parts:

  • 1 Estes BT-20 tube coupler
  • 1 Piece balsa cut t' fit inside coupler
  • 1 small eye bolt

This rocket is fairly easy t' build, however I would rate it a skill level 2 project. Well, blow me down! If you've built several Estes Beta kits, me hearties, ya bilge rat, you should have no problems. Supplies Required:

  • White or yellow glue
  • Hobby knife with several #11 blades
  • Sandpaper #320-400 grit
  • Maskin' Tape
  • Pencil
  • Ruler
  • Sandin' Sealer (optional)
  • Automotive Primer (white or gray) (recommended)
  • Spray Enamel (your choice)

Start by cuttin' two 4/5/8 sections from one tube and sand t' cut ends even. These are now your side pods. T' fins will be attached t' these later. Now cut t' main tube t' a length o' about 14 inches and sand t' ends even.

Optional Step for dual recovery: Cut t' main tube in half and sand t' ends even. Well, blow me down! Blimey! Now glue t' coupler halfway into t' upper tube. After t' glue dries, cut a bulkhead t' fit inside t' coupler. Arrr! Avast! After t' glue dries, carefully screw a small eye bolt into t' center o' t' bulkhead. Ahoy! Arrr!

Glue t' side pods one at a time with t' ends flush with t' end o' the main tube. Avast, me proud beauty! Once t' glue is dry, you can apply glue fillets t' t' side pods. Make sure t' fill as much o' t' gaps as possible. Begad! Ahoy!

Fin PatternYou may want t' cut out your fins at this time. Arrr! Make six fins with a 1 9/16 inch long root edge, a 1 3/4 inch long leadin' edge, a 1 inch trailin' edge, and a 1 1/2 inch bottom edge. Take a piece o' sandpaper and stack sand t' fins t' size. Avast, me proud beauty! Now sand t' leading and trailin' edges round. Arrr!

Assemble your motor mount at this time. Avast, me proud beauty! After t' glue is dry, insert it with t' motor tube flush with t' body tube. Blimey!

You may attach t' fins at this time. Avast, me proud beauty! Well, blow me down! Blimey! Three fins are attached t' each side pod at an angle o' 90 degrees apart like a typical four fin design. Heres a tip to make for an easier attachment. Arrr! Blimey! Apply a film o' glue t' t' root edge o' a fin, let dry for a minute or two, apply another film o' glue then attach. Believe me, this works. Ya scallywag! Well, blow me down! Blimey! Now apply fillets t' each fin. I recommend three fillets per fin.

Cut a standard launch lug into two 1/2 inch pieces. Avast, me proud beauty! Avast! Attach one t' t' bottom of t' body tube flush with t' end. Arrr! Arrr! Attach t' other one about 7 1/2 from the other one then align them with a launch rod. Blimey! Well, blow me down! If you opted for a dual recovery, apply t' last one flush with t' bottom o' t' upper tube. Blimey! After t' glue dries, apply fillets at each lug. Begad! I recommend about two fillets per lug. Blimey! Begad!

Cut yourself a shock cord mount from computer printer paper or typin' paper. I do nay recommend notebook paper. Arrr! Well, blow me down! I have used this method on all o' me scratch designs and it hasn't failed yet. Begad!

You will need a shock cord at least 2 feet long. Now assemble t' mount in the traditional manner. Once t' glue has dried, me hearties, glue t' mount at least 1/2 an inch from t' top o' t' tube.

Now is a good time t' test fit your nose cones. You want a nice snug fit. If they are too loose apply maskin' tape at t' shoulders or glue them in place after t' model has been balanced and painted. Avast! Arrr!

Rocket Pic

Now is an excellent time t' balance t' model. Begad! Begad! Balance t' model on a straight edge or counter-top. When t' model hangs level draw a mark at that spot. Blimey! Now tie a six t' eight foot strin' t' that mark. Ya scallywag! Swin' t' model around you and note t' results. If t' model flies straight its fine. If it flops or wobbles irregularly, me hearties, chances are that you will need nose weight. Ya scallywag! Avast, me proud beauty! My model required nose weight. Add enough weight until t' model balances out. That should do it. Well, blow me down!

Now you are ready t' finish t' model. Ya scallywag!

Finishing:
Start by sandin' t' model smooth. Apply sandin' sealer if desired. Avast! Aye aye! Sand between coats. Ya scallywag! Now spray t' model with automotive primer. Ya scallywag! Sand any imperfections. Well, blow me down! Then apply another coat. Avast, me proud beauty! Sand if needed. Aye aye! Now go ahead with your planned color scheme. After t' paint has dried, matey, arrr, you may attach t' streamer. An easier way is t' tie a six inch strin' t' t' streamer then attach that to the nose cone insert or t' eye bolt. Avast, me proud beauty! Blimey! Now lets go t' t' field and see how she flies.

Flight:
If built stock, t' only motor that I recommend be t' Estes A10-3T. Avast! This motor gives t' model a nice boost and ejection usually occurs right at apogee. I used friction fit retention on me model and it worked perfectly. Begad! For my flights, I used t' Estes A10-3T motor and two squares o' recovery waddin' to protect t' streamer. Well, blow me down! Aye aye! All three flights were perfect and straight with a little spin but for me that added t' t' excitement. Avast! T' model comes down very nicely with t' streamer. I used t' dual recovery method. Begad! My model bounces on landing but with all t' fillets that I applied, shiver me timbers, it hasn't sustained any damage. Arrr!

Summary:
When I designed this rocket and after flight testing, ya bilge rat, me goal was t' share this design with others. Avast, me proud beauty! Blimey! I really have enjoyed this model from plannin' t' design to pushin' t' launch button for t' first launch.

Main PROS: Small, extremely easy t' transport, arrr, flies on low cost mini motors, ya bilge rat, five bucks for four flights is nay bad at all. Well, blow me down! Flies great on small fields.

Main CONS: A lot o' components are required but if you buy an Estes Designers Special package, you will get all t' components except t' main nose cone and t' motor kit but you can easily buy these at any hobby shop. Begad! Ahoy! Blimey!

Other:
I also feel that t' rocket could be modified t' fly on standard 18mm motors or fly on three mini motors but watch out. Ya scallywag! Also, use 3/32 fin material if you try this. Aye aye! Also, me hearties, more nose weight may be required.

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