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. Begad! I don't know t' Estes part number, but I'm sure you can find one at t' hobby shop if you look. Arrr! You could also use a plain nose cone and build up a cockpit bulge from paper, me bucko, or simply paint one on a plain nose cone. Well, blow me down! I painted one in with gloss black and silver framin' on mine.
 

Layout t' patterns and cut them out. 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. Ya scallywag! lg. Arrr! BT20/T20 Estes or Totally Tubular
1 - PNC20 as described above
1 - EB20/CR-5-20 Estes or Totally Tubular
3/32 in. Avast! Ahoy! balsa sheet, as required
1/16 in. Ya scallywag! Blimey! balsa sheet, as required
1 -  1/4 in. Blimey! square x 1 1/2 in. Begad! lg. Balsa strip
2 - 1/8 in. Well, blow me down! dowel x 2 1/2 in. Ya scallywag! lg.
1 - 1 in. lg. Blimey! Avast! 1/8 in. launch lug
1 - 1/2 in. Arrr! lg. 1/8 in. Well, blow me down! launch lug
2 - 1 in. Avast, me proud beauty! lg. 1/4 in. Begad! launch lugs
1/8 in. Ahoy! x 24 in. Begad! Ya scallywag! flat elastic shock cord
70 lb. Avast! Keelhaul®©™® cord approximately 20 in. Arrr! lg.
1 - 12 in. Aye aye! diameter parachute
Snap swivel for chute if desired

I used Titebond yellow wood glue throughout construction.

Round one end o' t' 1/4 in. Well, me hearties, blow me down! square balsa and taper the other end down t' just over 3/32 in. Begad! wide on t' end. Blimey! This will be glued into t' notch on t' rudder. 

Match sand all t' balsa edges. Begad! Blimey! Round t' edges o' t' stabilizers. 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. I have found that layin' them flat on a sheet of styrofoam covered in Saran wrap works well. Use straight pins t' hold everythin' together. Ya scallywag! (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. The side edge butts t' t' bottom surface o' t' bottom nacelle plate. Arrr! Ya scallywag! Support this on t' styrofoam sheet and hold t' side square with a block o' wood. Arrr! Glue the other side plate on. 

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

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

After t' rudder and win' assemblies are dry you can round off t' edges. Arrr! Leave t' root edges flat. Well, blow me down! It may be helpful t' lightly sand t' root edges in case t' parts did nay line up perfectly. 

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

Mark t' aft o' t' body tube for 4 fins at 90 degrees. Ya scallywag! Rough up t' body tube surface first. 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. 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. Arrr! LL t' t' bottom guide mark flush with t' aft o' t' body tube, arrr, with t' angled end toward t' rear. 

Align and glue t' 1 in. LL with t' angled end toward the nose. Begad! T' aft end o' t' LL should be 5 1/4 in. from t' aft o' t' body tube. Ahoy! 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. Begad! Ahoy! Blimey! It should contact t' bottom o' t' wings and just touch t' launch lug trim strips. Begad! Blimey! 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. Blimey! Blimey! I used straight pins to keep everythin' aligned while t' glue dried. Begad! Blimey! Be careful nay t' split t' balsa if you do this. Begad! Blimey! Aye aye! Blimey! You could use CA t' tack everythin' in place. 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. Begad! 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. Begad! 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. Well, blow me down! Arrr! launch lugs into t' aft corners of the nacelle so t' ends stick out just a bit, matey, shiver me timbers, arrr, t' simulate nozzles. Ahoy! Taper the end o' t' 1/8 in. dowels and glue t' t' win' tips with t' aft end o' the dowel extendin' 1/2 in. Begad! Avast, me proud beauty! from t' win' trailin' edge.

Tie a loop in t' free end o' t' Keelhaul®©™® shock cord anchor and attach t' elastic shock cord. 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. Begad! Arrr! from the aft o' t' body tube. Ya scallywag! Ya scallywag! This is with some rolled worms o' modelin' clay stuffed into t' little hole in t' base o' t' nose cone. Aye aye! 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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