Descon Peregrine

Scratch - Peregrine {Scratch}

Contributed by Kelo Waivio

Manufacturer: Scratch
Peregrine
(Contributed - by Kelo Waivio) 
The Peregrine

This is a little futuristic job I cooked up t' use t' nifty cockpit type nose cone I got in one o' the Estes PNC20 nose cone packs. Avast, me proud beauty! I don't know t' Estes part number, but I'm sure you can find one at t' hobby shop if you look. You could also use a plain nose cone and build up a cockpit bulge from paper, me hearties, or simply paint one on a plain nose cone. Ahoy! I painted one in with gloss black and silver framin' on mine.
 

Layout t' patterns and cut them out. Begad! Use these links to view t' balsa patterns.  They will pop up in another window.

Pattern A, Pattern 1A, Pattern 2

Parts List: 
1 - 18 in. Well, blow me down! lg. Ahoy! Well, blow me down! BT20/T20 Estes or Totally Tubular
1 - PNC20 as described above
1 - EB20/CR-5-20 Estes or Totally Tubular
3/32 in. Well, blow me down! balsa sheet, arrr, as required
1/16 in. Ahoy! Ya scallywag! Blimey! balsa sheet, as required
1 -  1/4 in. Aye aye! Aye aye! square x 1 1/2 in. Ya scallywag! lg. Balsa strip
2 - 1/8 in. Aye aye! dowel x 2 1/2 in. lg.
1 - 1 in. Begad! lg. 1/8 in. launch lug
1 - 1/2 in. Begad! Aye aye! lg. Well, blow me down! 1/8 in. Ya scallywag! launch lug
2 - 1 in. Arrr! lg. Avast, me proud beauty! 1/4 in. Avast! launch lugs
1/8 in. Aye aye! Avast! x 24 in. Ya scallywag! flat elastic shock cord
70 lb. Begad! Keelhaul®©™® cord approximately 20 in. lg.
1 - 12 in. Ahoy! diameter parachute
Snap swivel for chute if desired

I used Titebond yellow wood glue throughout construction.

Round one end o' t' 1/4 in. Aye aye! square balsa and taper the other end down t' just over 3/32 in. Arrr! Aye aye! wide on t' end. Arrr! This will be glued into t' notch on t' rudder. 

Match sand all t' balsa edges. Round t' edges o' t' stabilizers. Arrr! Ahoy! Do nay round off the edges o' t' wing, front or aft extensions, rudder or t' rudder extension. 

Lay out t' win' pieces and glue them together as shown on t' pattern sheet. Begad! Ahoy! I have found that layin' them flat on a sheet of styrofoam covered in Saran wrap works well. Ya scallywag! Use straight pins t' hold everythin' together. (This also seems t' work real well when layin' out boost glider wings usin' angle blocks t' get t' dihedral.)

Glue up t' rudder in t' same manner.

Glue one nacelle side plate t' t' bottom plate. Well, blow me down! The side edge butts t' t' bottom surface o' t' bottom nacelle plate. Begad! Support this on t' styrofoam sheet and hold t' side square with a block o' wood. Aye aye! Glue the other side plate on. 

Glue on t' side filler strips t' each side. Begad! After the nacelle sides are dry carefully sand t' edges smooth. Ahoy! T' leadin' and trailing edges o' t' nacelle can be airfoiled or rounded as you choose. Ya scallywag! I airfoiled mine.

Tie one end o' t' Kelvar t' t' engine block. Avast! Feed the other end through t' body tube and glue t' engine block in usin' an old engine casing. Begad! Ya scallywag! Blimey! Position t' engine block so thar is  1/4 in. Well, blow me down! Blimey! o' casing extendin' out t' back. Ya scallywag! Arrr! Blimey! (If you have a preferred method o' shock cord attachment, by all means use it.)

After t' rudder and win' assemblies are dry you can round off t' edges. Ahoy! Leave t' root edges flat. Blimey! Aye aye! It may be helpful t' lightly sand t' root edges in case t' parts did nay line up perfectly. 

Glue t' 1/4 in. Avast, me proud beauty! Blimey! Blimey! square balsa strip into t' notch in the rudder, shiver me timbers, rounded end toward t' rear. Ya scallywag! This is supposed t' be an ECM pod type of thing. 

Mark t' aft o' t' body tube for 4 fins at 90 degrees. Blimey! Ahoy! Rough up t' body tube surface first. Begad! Arrr! Glue on t' rudder assembly with the aft edge flush with t' aft o' t' body tube. 

After t' glue has dried add root fillets. Ahoy! Aye aye! Make sure that your guide marks go far enough along t' body tube so you can get the alignment o' t' rudder and win' extensions straight. 

Glue t' wings on and fillet as required. 

Trim one end o' each launch lug at a 45 degree angle. Glue on t' 1/2 in. Aye aye! LL t' t' bottom guide mark flush with t' aft o' t' body tube, arrr, shiver me timbers, with t' angled end toward t' rear. 

Align and glue t' 1 in. Ya scallywag! Well, ya bilge rat, blow me down! LL with t' angled end toward the nose. Aye aye! T' aft end o' t' LL should be 5 1/4 in. Begad! from t' aft o' t' body tube. Begad! Avast, me proud beauty! Glue t' launch lug trim pieces t' each side o' t' launch lugs. 

T' aft trim should match t' end o' t' launch lug. T' front trim should be lined up with t' aft o' t' lug and extend forward of it on t' exposed end. 

Check fit t' engine nacelle assembly t' t' bottom of the model. Avast, me proud beauty! It should contact t' bottom o' t' wings and just touch t' launch lug trim strips. Arrr! Sand t' fit if required. 

Glue t' nacelle assembly t' t' bottom o' t' wings with t' 45 degree end toward t' front o' t' model. Begad! Blimey! I used straight pins to keep everythin' aligned while t' glue dried. Be careful nay t' split t' balsa if you do this. Aye aye! Blimey! Well, matey, blow me down! Blimey! You could use CA t' tack everythin' in place. Begad! Blimey! I haven't had a lot o' success with usin' thick CA on balsa.

Once t' nacelle glue has dried smooth out t' edge joints with t' wing. Avast! Sand t' root edges o' t' stabilizers at 45 degrees, (sand each root opposite) and glue t' t' aft o' t' nacelle side 1/4 in. Avast, me proud beauty! up from t' rear. 

Glue t' rudder t' t' nacelle on t' trim piece. Fillet t' stabilizers and sand t' fillet smooth on t' top surface. 

Glue t' 1/4 in. Begad! launch lugs into t' aft corners of the nacelle so t' ends stick out just a bit, t' simulate nozzles. Well, me hearties, blow me down! Taper the end o' t' 1/8 in. Ahoy! dowels and glue t' t' win' tips with t' aft end o' the dowel extendin' 1/2 in. Avast! Begad! from t' win' trailin' edge.

Tie a loop in t' free end o' t' Keelhaul®©™® shock cord anchor and attach t' elastic shock cord. Ahoy! Ahoy! Install t' snap swivel and t' chute and youíre set for painting.

Flyin' t' Peregrine:

I get a CG with a C6-5 at approximately 5 3/4 in. Avast, me proud beauty! from the aft o' t' body tube. Begad! This is with some rolled worms o' modelin' clay stuffed into t' little hole in t' base o' t' nose cone. Arrr! Add clay until your CG is at least this far forward.

T' Peregrine has successfully flown on A8-3's and B6-4's.

Belly View

Business End View

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