Descon Nose Nugget

Scratch - Nose Nugget {Scratch}

Contributed by Bob Fortune

Manufacturer: Scratch
(Contributed - by Bob Fortune)

T' Nose Nugget
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A relatively simple way t' install a payload in a 3.9" Ace Nosecone

This technique will work for any nosecone brand. Ahoy! Blimey! I used an Ace NC because I had one kickin' around. Ahoy!

Parts List:

  • One Ace Nosecone (NC)
  • One 4" by 16" piece o' balsaply (or equal)
  • One 4" by 4" piece o' 1/4" plywood for bulkhead (BH)
  • One 18" piece o' 3/8" wooden dowel
  • One Print Out o' Ace Nosecone interior
  • - Download Part One
  • - Download Part Two
  • 3 ounce fiberglass (glass)
  • Epoxy laminatin' resin (like Systems 3 or West Systems)
  • Cyanoacrylate (CA)
  • 1 U-bolt
  • 1 1" section o' 4" airframe tubin' (for retainer ring)
  • 4 each #8 panel clips (from auto parts store)
  • 4 each #8 by 1/2" screws
  • 3M 77 (or equal) Spray Mount Adhesive
Assembly Instructions:

Download t' 2 templates and print out on your printer. Arrr! Avast, me proud beauty! There are 1" square boxes on each template t' indicate correct sizing, you may have t' fiddle with your printer output t' get t' correct size. These are .gif images. Well, me bucko, blow me down!

Once you have t' templates sized and printed cut them out and match t' two halves t' t' match line shown. Blimey! The entire cone is drafted though you don't need them both if you don't intend t' make t' entire nosecone a payload section. Aye aye! Well, arrr, blow me down! My design only has t' last 6" or so o' t' cone interior as payload. Aye aye! T' lines are thar so you can cut to size as you choose. Arrr! Avast, matey, me proud beauty!

Usin' a spray mount adhesive, glue t' template t' t' balsaply. Begad! Cut t' template t' rough shape. Ya scallywag! Usin' a sander or rasp or whatever, sand t' template t' it's final shape. Don't attempt t' cut t' template out dead-on t' t' lines, it's much easier t' get it close then sand t' get it perfect. While you have this template cut your fiberglass cloth to fit, you need one piece this size. Arrr! Once you have t' balsaply cut t' size, cut along t' dotted line. Aye aye! This is where the dowel goes. Ya scallywag! Ahoy! These two parts I am callin' "wings" for t' sake o' clarity. Ahoy! Blimey! Take one win' and use it as a template t' cut an additional wing. Begad! Ya scallywag! This third win' becomes a "strong back" t' support t' two wings and dowel in t' cone. Avast, me proud beauty! Usin' this win' as a template cut an additional two pieces o' glass, but a bit oversize - maybe an inch wider. Arrr! Set t' glass aside for later use.

On t' second template thar be a bulkhead template. Glue this t' 1/4" ply and cut out. Well, blow me down! Ahoy! Take t' Ace nosecone and trim off t' bottom part (where t' screw top thin' is). Begad! Cut it right where t' wall intersects t' base. T' 1/4" ply bulkhead slides in here. Test fit t' bulkhead and sand as necessary t' get a good fit. Begad! Ya scallywag! If the bulkhead is oversize it will balloon t' shoulder o' t' NC and t' airframe (AF) tube won't fit. Aye aye! Test it with a section o' AF you intend t' use. Ahoy! Drill a 3/8" hole in t' center o' t' bulkhead. Ya scallywag! Drill two holes t' receive the U-bolt.

I made t' dowel poke out t' tip o' t' nosecone because it be fun t' do. Arrr! Begad! It's nay critical, you can simply make t' dowel shorter. Aye aye! Avast, me proud beauty! T' purpose o' t' tip protudin' is t' center t' payload section in t' nosecone, a job the wings if cut properly can do.While you have t' nosecone in hand, whack off t' tip o' it so a 3/8" hole is developed. Aye aye! I used a bench grinder for this and it takes some grindin' and fitting. Ahoy! Avast, me proud beauty! T' fit is important so make sure it's nice and snug, ya bilge rat, arrr, take your time. Well, blow me down! Begad!

Fit t' dowel into t' NC so an inch or so protrudes from t' tip. Avast! Add a bit o' yellow glue t' t' dowel just at the base o' t' shoulder line Slide t' bulkhead over t' dowel and into t' shoulder. T' dowel is now square t' the NC if you trimmed t' tip properly. Blimey! CA t' dowel t' t' bulkhead and remove by pullin' on t' dowel protrudin' from the bulkhead. Clamp this is a vise or somethin' handy t' keep it from movin' around. Well, blow me down! Usin' yellow glue, glue t' three wings t' t' dowel. Arrr! T' two wings in t' same plane are flush with t' tangent o' t' dowel cross section. Ya scallywag! T' third win' is at 90 degrees t' these wings. Let dry. Aye aye! Arrr!

Get t' 1" piece o' airframe and cut it into 3 pieces. Arrr! One piece will be 180 degrees and t' other two 90 degrees. Blimey! You will need t' remove some o' t' tube t' make it fit inside t' wings, arrr, a pair o' strong scissors works well. Arrr! When fittin' t' pieces, me bucko, make sure that they are nay flush with t' edge o' t' bulkhead. Ahoy! Hold them back off the edge (towards t' dowel) as t' panel clips need t' clear t' shoulder o' t' nosecone. Avast! Glue these pieces t' the bulkhead and t' t' wings. Ahoy! This becomes t' retainer ring.

Test fit t' part in t' nosecone. Begad! If it doesn't fit, sand all t' parts t' make it fit. Avast! It needs t' slide in and out nicely. Begad!

Get your 3 pieces o' glass cloth. Mix up some epoxy. Avast, me proud beauty! Blimey! Get a little paint brush. Brush on a coat o' resin on the face o' t' wings. Blimey! Place t' glass on t' face o' t' wings. Arrr! Wet out t' glass so it disappears. Begad! Turn part over and repeat on strongback with two pieces o' glass. Avast! Ya scallywag! Usin' t' brush in dabbin' motions, ya bilge rat, stipple t' glass onto t' surface so all t' glass is in contact with t' balsaply. Avast! This is easiest as t' resin begins t' set and becomes tacky. Blimey! Ahoy! Try to eliminate all t' air bubbles. Blimey! Allow t' cure t' B stage (this is when t' epoxy is kind o' rubbery) and trim t' glass to t' correct size. Well, blow me down!

Find out where t' hole in t' panel clip lines up on t' retainer ring. Avast! They are all different so you have to fit and see. Well, blow me down! Begad! Generally t' hole with t' clip in place is about 1/2" down from t' U bend in t' clip. Arrr! Make a note where t' hole hits t' retainer ring. Ya scallywag! Install t' U-bolt at this time. Begad!

Usin' t' shoulder o' t' NC as a guide, ya bilge rat, mark t' base o' t' nosecone on your airframe. Install t' payload section into t' NC. Ya scallywag! Install t' NC on t' airframe you intend t' use. Usin' t' mark you just made and your measurement o' t' panel clip on t' retainer rin' drill 4 holes 90 degrees from each other around t' airframe. Ahoy! If they are nay dead on, t' airframe will only align with t' holes as drilled. Aye aye! Avast, me proud beauty! Make a mark on t' NC and on t' airframe where t' holes line up properly. Begad!

Remove t' nosecone. Remove t' payload section. Begad! Install t' panel clips. Avast! Begad! Reinstall t' nosecone. Ya scallywag! Reinstall the payload section. Avast, me proud beauty! Begad! Install 4 #8 screws, T' nosecone ain't comin' off for nothin'. Ya scallywag! Well, blow me down! All t' parts are workin' together to keep t' electronics you install on t' board in place and in t' nosecone. Well, blow me down! T' U-bolt will take a major hit and will transfer t' load t' t' airframe through t' panel screws and retainer ring. Avast! You may have problems if you use some serious noseweight so take care. Ya scallywag! Deployment shock loads can be upwards o' 15 or 20 g's makin' a one pound noseweight suddenly equal t' a 20 pound noseweight. Begad!

Install some electronics, a power source, a shunt for your pyro, and go flying!

Flight Report

This nosecone flew with on a Binder Raptor on a J350. Ahoy! Unfortunately t' motor ejection charge went early due t' an improper seal in t' forward closure delay well. Avast, me proud beauty! Ahoy! (Pilot error) It was supposed t' be a long delay t' back up t' electronics but it was way short. Well, blow me down! : ) T' charge went off while t' rocket be still boostin' but the thin' held together, t' chute deployed, shiver me timbers, and no damage was done.

Bob Fortune
© September 2000



Pictures

1_On_2manyfins.jpg
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2_BH_view.jpg
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3_Push_the_button_NF.jpg
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4_Face_view.jpg
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5_Strongback_view.jpg
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6_looking_down_NF.jpg
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7_Side_x_side_NF.jpg
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