Scratch Lump-O-Lead Original Design / Scratch Built

Scratch - Lump-O-Lead {Scratch}

Contributed by Matt Gillard

Manufacturer: Scratch
(Contributed - by Matt Gillard - 12/14/07) LOL

Brief:
I be full o' good ideas for t' glider that I was goin' t' make. None o' these came t' be and instead I made a pop pod glider. I foolishly went for a large (ish) glider as I did nay want t' simply replicate a glider that I already had. Aye aye! Blimey! T' result was a glider that needs at least a D t' lift it, shiver me timbers, but will also shred on a D.

Construction:

T' glider itself consists o' a four panel win' with a three panel tail. Begad! Arrr! Two 1mm by 1mm spruces act as side by side booms, ya bilge rat, with a front fuselage made out o' 3/8th inch balsa. Avast, me proud beauty! T' pop pod was t' pod from a Quest Flat Cat.

Win' Construction:

2 panels. 3.5 by 6 inch

2 panels, 6 inch long with ends measurin' 2 inch and 3.5 inch

T' centre panels were glued together with one win' tip 1 inch o' t' bench.

When t' glue had dried, shiver me timbers, t' outer win' panels were added, matey, me hearties, again with a one inch lift.

Side Tail:

Two panels o' balsa measured 5 inch with t' sides bein' 2 and 2.5 inch, were glued together. Arrr! Well, blow me down! T' angle formed matched t' front wing.

A rudder was attached underneath, arrr, this panel measured 4 by 2 inch, shiver me timbers, and was trimmed down somewhat.

Booms:

These were made from 1mm by 1mm spruce (which turned out t' be a big mistake) both rods were 17 inches long. Begad! Ya scallywag!

T' booms were glued t' t' outside edges o' t' tail, matey, matey, and them t' front win' be glued t' t' front.

Front Fuselage:

A 15 inch piece o' 3/8th square balsa formed t' fuselage. Avast, me proud beauty! Ahoy! A 3 inches piece be glued t' t' top end o' the fuselage. Well, blow me down! Ya scallywag! When this dried, ya bilge rat, me hearties, matey, a front cavity was made t' hold balancin' mass, and t' hook/catch mechanism be cut out. Two thin pieces o' balsa were then glued t' t' out side edges o' t' front fuselage t' complete t' cavity box and edge off t' catch. Well, me bucko, blow me down! This whole front end was very similar t' front end o' a Quest Flat Cat t' fuselage be then glued to t' front wing.

Pop Pod:

This be a plunder from t' Quest Flat Cat.

Finishing:

T' whole glider be sanded down, me bucko, all edges were rounded and a slight aerofoil added t' t' liftin' surfaces. The rocket be then sealed.

T' design was that as t' aft booms were out o' t' way o' t' motor thrust, thar was no need t' protect the fuselage. Aye aye! Avast! I knew t' glider would be tail heavy so t' cavity at t' front would take mass t' balance. Begad!

Wing Test Glides:

Several test glides were needed t' get t' glide right, me bucko, in t' end a big lump o' lead was needed t' balance the glider –this is where t' glider's name comes from.

Flights:

First flight be on a B4-2

Lift was straight but nay t' high, matey, t' lump o' lead at t' front came out and she fell tail down –my fault.

Second flight was on t' came motor with a lump o' clay actin' as t' mass at t' front. Well, blow me down! Begad! Again t' lift was straight, me hearties, but t' pop pod did nay pop! T' whole thin' came in nose first, thar be a lot o' balsa t' glue back together.

Third flight was a few days later, and after repairs. Aye aye! This time a C6-3 was used, t' higher thrust made t' whole thin' shake on lift, so much so that t' tail shredded. T' glider, now heavy, nosed in again – more gluing.

Damage Fourth flight. Arrr! Again a C6-3 was used, t' flight be straight again with less wobble, shiver me timbers, ejection was clean and t' glider glided in on a steep angle. Avast, me proud beauty! There was damage.

Summary:

T' glider is too heavy for an 18mm motor and a D would rip it apart. Ahoy! I should learn t' walk before I can run, arrr, matey, I have had me own design smaller gliders perform very well, arrr, and I've had large kit gliders work, but I'm nay quite ready for t' large birds yet.

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