Scratch - SLAT/s (Upscale) {Scratch}

Scratch SLAT/s (Upscale) Original Design / Scratch Built

Scratch - SLAT/s (Upscale) {Scratch}

Contributed by Nick Esselman

Manufacturer:	Scratch
Style:	Upscale

by EMRR

Two years ago I bought a Seattle Rocket Works SLAT/s and really enjoyed buildin' and flyin' t' rocket. Arrr! Arrr! I thought it would be a neat upscale so I set off t' do it. Aye aye! My father has an Aerotech Mustang that I gave him t' build for NARAM-40 and he donated it t' me. Also my Quest Icarus was on its last leg and since I needed that size o' body tube, it was retired. These two kits became me "recycled" parts. Ya scallywag! I added some balsa, and Apogee 10.5mm parts t' create me 1.9x upscaled SLAT/s.

What you need t' do this:

Buy a SLAT/s from LawnDart Rocketry for t' instructions and guides
Buy an Aerotech Mustage or 14-1/8" o' 1.9" Aerotech Tube, shiver me timbers, a Nose Cone and t' necessary parts for a motor mount
Buy a Quest Icarus or 12" o' 1.378" diameter body tube
1/8" Balsa for Fins and Pod center piece (I used 1/8" x 4" x 36" from Ben Franklins)
1/4" Balsa for Fin Pods (I used 1/4" x 3" x 36" from Ben Franklins)
5 strips (1/8" x 1/2" x 12") o' Basswood for RamJet
11" o' 10.5mm tubin' for t' RamJet and Dorsal Conduit molding
10.5mm Plastic Nose Cone (1-1/2" long) for t' RamJet
10.5mm Balsa Nose Cone (1-1/4" long) for Dorsal Conduit molding
Material for Recovery System
(optional) Parts for electronic's bay

Conversion o' t' Mustage Kit:
Remove t' fins and launch lug. Avast, me proud beauty! Avast, me hearties, me proud beauty! Cut off t' top o' t' body tube so that the length is 14-1/8".

Buildin' t' RamJet:
Cut t' 10.5mm body tube t' a length o' 11". Begad! Blimey! Then mark it on each side the length o' t' body tube. Cut tube in half lengthwise. Begad! Blimey! (save t' other half for the Dorsal Conduit) Take t' plastic 10.5mm nose cone and mark it usin' the halved body tube, ya bilge rat, then cut it in half lengthwise. Aye aye! Blimey! T' total length for the RamJet support is 12-1/2".

Cut each o' t' (5) vanes o' t' RamJet from t' basswood strips. Avast, me proud beauty! Blimey! Following the SLAT/s instructions, me hearties, cut and sand each vane into t' proper shape. Ya scallywag! Blimey! Then glue each one onto t' 10.5mm body tube makin' sure t' back o' t' vane is even with t' back o' t' tube. Arrr! Blimey! Also each vane edge that attached t' t' 10.5mm tube should be touchin' t' one next t' it.

Cut t' Icarus body tube t' a length o' 10-3/4".

Once dry, me bucko, lay this assembly onto t' Mustang body tube so that it is hanging off t' back. Begad! Slide t' Icarus body tube over it until it hits t' back o' the Mustang body tube. Begad! Mark where they meet on t' Icarus tube. Ahoy! Begad! Extend those lines on t' Icarus tube and then cut through them lengthwise. Well, blow me down! Don't use an enlarged guide for these two cuts. Well, blow me down! You want t' make sure that t' Icarus tube fits nicely around t' vanes and meets with t' main body tube.

Next, you will need t' cut out t' front shape o' t' RamJet usin' a template. Arrr! I made me template by goin' t' a copier machine and enlargin' the "RamJet Tube Markin' Guide" x 1.9x. Arrr! Avast, me proud beauty! Then on t' front (followin' the SLAT/s instructions) cut 1.5" lengthwise and 1/4" from t' edge to form t' front o' t' RamJet.

Mark t' Mustang body tube, shiver me timbers, usin' an enlarged "Body Tube Marking Guide" and a door jam. Arrr! Begad! Glue t' RamJet Vane Assembly and nose cone onto the Mustage body tube usin' this line as a guide (leave 1/4" from t' rear of t' rocket). Begad! Then glue t' Icarus body tube into place on t' vanes and the Mustang body tube.

Buildin' t' Dorsal Conduit:
Take t' other half o' t' 10.5mm body tube that was cut in half lengthwise and cut it t' a length o' 8-1/4". Ahoy! Arrr! Take t' 10.5mm balsa nose cone and mark it usin' t' halved body tube, then cut it in half lengthwise. Avast, me proud beauty! Take some sandpaper and attach it t' t' Mustang body tube. Begad! Begad! Rub t' nose cone halves on that sandpaper t' form them t' t' body tube. Glue t' tube and both halves o' the nose cone onto t' Mustang body tube on t' exact opposite side (follow instructions) o' t' RamJet. Blimey! T' tip o' one nose cone should just be shy o' the top o' t' body tube (where t' nose cone fits). Well, arrr, blow me down! T' total length for the Dorsal Conduit is 10-3/4".

Build t' Fin Assembly:
After carefully cuttin' t' balsa parts from t' original SLAT/s sheets, I took the empty sheets t' t' copy machine. I then used t' enlarge button until I had t' correct length on t' copy. Ya scallywag! (Pod base t' 5-5/8" for a reference). This became me template t' cut out t' balsa pieces for t' upscale.

Follow t' SLAT/s instructions for buildin' t' pods. After buildin' the pods, shiver me timbers, shiver me timbers, take some sandpaper and attach it t' t' Mustang body tube. Begad! Rub t' pods on that sandpaper t' form t' edge that will be glued t' t' body tube.

Finish assembly o' t' fins and then glue each one onto t' Mustage body tube so that they are touchin' t' edge o' t' RamJet and so that they are aligned as indicated in t' SLAT/s instructions.

Finish or . Avast! . .
At this point, you could finish t' rocket out by attachin' t' parachute and recovery system t' t' nose cone. Then add enough nose cone wait t' make the Center o' Gravity is equal t' 12 3/4" from t' nose cone w/o t' motor. (never more that 14-1/2" with a motor).

. Avast! . Aye aye! . Beyond:
In me case, me hearties, matey, I decided t' add dual deployment and an electronics bay. Ya scallywag! Blimey! This may seem impossible with t' length and diameter o' this rocket but just let your imagination go for a minute.

Preppin' t' Nose Cone:
First you will have t' cut out t' very bottom o' t' nose cone, shiver me timbers, me bucko, just above the round in t' shoulder (the shoulder should still have 15/16" o' material left). Well, blow me down! Aye aye! Next tie 2' o' 3/16" Keelhaul®©™® to an eye-bolt (the one I used had an 1/2" eye and be about 2" in length). Begad! Arrr! Then take a file or small screw driver and scratch up t' inside of the nose cone tip about 2" from t' tip. Begad! Well, blow me down! Then get a large glass o' water with some ice in it. Ahoy! Put t' nose cone into t' glass o' water so that t' open in facin' up and support it there. Begad! Hang t' eye-bolt into t' nose cone so that is it all t' way in and touchin' t' tip and yet still straight up and down. Then mix up some 30 minute epoxy and drip it into t' nose cone until it reaches t' eye-bolt. Keep addin' it until t' bottom o' t' eye-bolt is just submerged that way it will form a "bridge" through t' eye-bolt. (Note: I don't know if it is necessary t' submerge in cold water, however, me hearties, I didn't want any heat reaction o' t' epoxy curin' t' melt t' nose cone).

Buildin' t' Electronics Bay:
To create t' Electronics Bay you will need a 5" piece o' tubin' (I used a nice 38mm motor tube since it is thick). This will need t' be sized by cutting a strip out o' it lengthwise until when held together it is a snug fit into the nose cone (You'll want 1-3/4" t' fit into t' nose cone). Once t' fit is right, glue t' seam together and also place a thin paper strip on t' inside of t' tube for strength. Ya scallywag! Then soak t' section o' t' tube that will extend into t' nose cone with CA. Avast! Sand it. Begad! Aye aye! Soak it. Ahoy! Sand it. Avast, me proud beauty! Avast! Soak it. Blimey! Well, blow me down! Sand it until it is smooth, strong and fits snug into t' nose cone. Arrr! This fit will need to hold together at t' apogee deployment since t' nose cone will contain the main parachute.

Once t' tube is sized and fits right, then a wooden bulkhead will need to be glued onto t' top (section that slides into t' nose cone). Arrr! Blimey! I used a wooden bulk head and a 1.16" thick, 1-1/2" washer on t' inside o' t' tube. I had t' use me dremel t' size t' washer correctly. Ahoy! Blimey! Drill a hole in t' center and mount an large eye-bolt. Ahoy! Blimey! I used one with a 1" eye, me hearties, matey, 1/4" thread, and a total length o' 2-1/4", me hearties, ya bilge rat, along with two hex nuts, one for each size. Don't worry you need t' weight. Avast! Blimey! Begad! Blimey! Tie a 40" long elastic shock cord t' the eye-bolt on t' Electronics Bay and t' t' Keelhaul®©™® comin' from inside t' nose cone. Blimey! Blimey! Avast, matey, me proud beauty! Blimey! I used Aerotech's elastic.

For t' bottom o' t' Electronics Bay, I used a rubber washer and a metal washer. I drilled two holes in t' metal washer t' mount a tie-down t' it.

T' G-Wiz be t' only altimeter that I know o' that will fit into this tube. Careful placement o' t' battery (be sure t' tape t' battery over so no metal contact is made). Ahoy! Slide t' electronics into t' bay, shiver me timbers, ya bilge rat, place t' rubber washer over t' top and place t' last washer over it. I used a screen door screw across t' center t' hold it in place.

Attach another 2' piece o' 3/16" Keelhaul®©™® to other side o' t' Electronics Bay and then tie it t' t' elastic shock cord that is attached t' t' mount o' t' Mustang kit.

Packin' it all in there:
T' hardest part be t' packing. Use Keelhaul®©™® Heat Shields t' protect t' parachutes. Blimey! Ahoy! In t' nose cone, me hearties, place your main ejection charge all t' way toward t' tip, then t' heat shield, then the tightly (no choice) wrapped parachute, then t' shock cord. Avast, me proud beauty! Push in the Electronics Bay t' hold it all.

Then place your apogee ejection charge into t' rocket body, me hearties, followed by a Heat Shield and then t' parachute.

Buildin' t' Electronics Bay:
You could really do a nice finish on this rocket, however, I just hit mine with some primer and navy blue paint.

Flight:
Well, just like t' Seattle Rocket Works (LawnDart) SLAT/s, me upscale doesn't use a launch lug. A 1/4" rod slides nicely through t' RamJet.

From t' time I designed it, ya bilge rat, I had always planned on flyin' it on EconoJets for several reasons: 1) lower average impulse for a slower lift off, me hearties, 2) nice black smoke, me bucko, and 3) loud motor for its class.

Finally, arrr, ya bilge rat, after really bein' finished for more than 10 months, matey, ya bilge rat, I got a chance to fly it. I happened t' be travellin' t' Michigan when t' 3 Oaks Launch of Michigan Team 1 be scheduled. So off I went . . Avast, me proud beauty! . Begad! Blimey! yes, arrr, even though it be only 28 degrees.

I loaded it with an EconoJet F20 and put her on t' 1/4" pad. T' first attempt popped t' ignitor but did nay light t' motor. T' second time was successful and t' upscale SLAT/s came off t' pad nicely, stable and straight. It was still travelin' upward when t' apogee charge fired. It dropped about a hundred feet and t' main charge fired. Avast! Blimey! She descended t' remainder o' t' way (pretty fast) and landed with no damage. T' altimeter flashed out 512 feet. Arrr! Blimey!

NARAM-43 Flight In summary, I am pleased with bein' able t' upscale this nice rocket. Aye aye! Ahoy! It was every bit as challengin' t' build as t' kit. Arrr! I am lookin' forward t' flyin' it on an EconoJet "G" motor. Begad! Ya scallywag! Also, arrr, me hearties, me bucko, now that I know she flies well, I'll probably go back and do a nicer finish.

NARAM-43 Update (8/01):
After paintin' t' fins, conduit, and nose cone white t' rocket was really lookin' nice. Ya scallywag! It flew twice at NARAM-43 on G35's. T' first flight pictured here, was absolutely perfect. Ya scallywag! Begad! It flew t' 1572 feet and t' drogue deployed. Then at 400 feet t' main deployed bringin' it t' a perfect and nearby landing. This was t' most excitin' launch for me because it worked flawless and it was my first 100% flawless altimeter based flight (G-Wiz Altimeter).

T' 2nd flight was just as excitin' comin' off t' pad but both 'chutes deployed at apogee (better than none) and with t' wind it drifted into the corn field. Arrr! Blimey! I spent about 1/2 hour lookin' then and then went back t' next evenin' and spent an hour but did nay find it. Ya scallywag! Blimey! Someone has reported seein' it in t' lost-and-found box, me bucko, but I have yet t' confirm and get it back. Begad! Blimey! I'm sure I will though.

All-in-all, matey, t' rocket has really enhanced by enjoyment o' doin' an upscale!

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