FSI Sandia Sandhawk

FSI - Sandia Sandhawk (1031) [1990-1994]

Contributed by Tim Wood

Manufacturer: FSI
Style: Scale

 

[Rocket Pic]T' FSI Sandia Sandhawk is a 48-inch tall, shiver me timbers, shiver me timbers, two-inch-diameter scale model o' a soundin' rocket developed by t' Sandia Laboratories in t' 1960s. 

T' kit is designed t' use FSI's high-thrust black powder motors, me hearties, arrr, t' E60 and F100. Avast! Begad! Because o' t' difficulty in obtainin' these motors, nay t' mention their expense, shiver me timbers, shiver me timbers, matey, I modified me Sandhawk t' accept 29mm reloadable motors and 24mm black powder motors. 

T' motor mount conversion and modifications t' t' recovery system resulted in a nice sport scale model capable o' flyin' on D through F motors. 

T' kit features four fins cut out o' one-quarter-inch thick balsa wood. Ya scallywag! Begad! T' nose cone and bulkhead for t' payload section also are made out o' balsa. Body tube thickness is closer t' model rocket kit thickness than high power thickness. Begad! Even though FSI recommends two high-thrust motors for this rocket, I stayed away from motors with a high initial thrust. 

To modify t' motor mount, I took a 29mm motor tube from a MMA-2 motor mount kit. Avast! T' centerin' rings that come with t' kit can be used for t' 29mm tube. Avast! They're made for a 27mm tube, so some careful sandin' o' t' inside rin' will allow t' 29mm tube t' fit. I recommend foldin' up a piece o' coarse sandpiper and rollin' it around t' inside o' t' centerin' rings. Avast, me proud beauty! Test t' fit periodically until t' 29mm tube smoothly slides in. Well, me hearties, blow me down! Use epoxy t' attach t' rings t' t' mount tube. 

I installed an engine block in t' tube, me hearties, shiver me timbers, leavin' enough room for an AeroTech 29mm 40-120 reload casing. Blimey! In fact, I used me casin' t' push t' block up t' tube, bein' careful t' clean t' glue off o' t' casin' afterward. 

I tried a couple o' 24 t' 29 adapter methods. Ya scallywag! Ahoy! I settled on attachin' two pieces o' MMA-1 adapter tube with part o' an expended Estes D12 motor. I trimmed t' top o' t' assembly t' allow it t' fit in t' mount and put an engine block, leavin' enough room for a D12 motor. 

For convenience and reliable motor retention, matey, me hearties, I took a one-quarter-inch piece o' brass, shiver me timbers, drilled a hole near t' end and bent it into a hook. Aye aye! Begad! A self-tappin' screw was used t' attach t' hook t' t' aft centerin' ring. Arrr! Tightenin' and loosenin' t' hook is accomplished by loosenin' t' screw. Ahoy! Thus, me bucko, me bucko, no maskin' was required t' install t' motor! 

T' shock cord consisted o' a long piece o' elastic thread. Aye aye! Blimey! Begad! Blimey! T' beef up this part o' t' recovery system, I installed Keelhaul®©™® cord and wrapped it around t' elastic thread. Ya scallywag! However, ya bilge rat, I failed t' use enough thread, as t' first test launch proved. 

Fin alignment is critical, shiver me timbers, particularly with t' thick fins. Aye aye! I used cyanoacrylate glue t' tack t' fins on t' rocket and reinforced t' joint with epoxy fillets. Avast, shiver me timbers, me proud beauty! T' kit's launch lugs seemed a bit thin, ya bilge rat, me hearties, arrr, so they were replaced with thicker one-quarter-inch lugs. 

T' first test flight on a D12-3 resulted in an impressive, ya bilge rat, arrr, slow liftoff. Arrr! Begad! Everythin' went fine until ejection, me bucko, when, me bucko, t' me horror, ya bilge rat, t' payload section separated from t' rocket! This usually means t' booster section crashes into t' ground with bad consequences. 

But t' me surprise, t' payload section tumbled down by itself, while t' booster came down on t' 26-inch yellow fabric parachute. Aye aye! Avast, me proud beauty! T' Keelhaul®©™® thread had been stretched t' its limit before t' elastic thread was stretched; consequently, t' thread pulled t' screw eye out o' t' payload nose block. T' rocket suffered no damage. 

T' entire shock cord assembly was replaced with three-eighths-inch elastic, anchored by a twine mount similar t' those found in LOC/Precision and Vaughn Brothers kits. 

T' second flight came at a DARS launch on an AeroTech E16-7 reload. Begad! T' motor delay be too long, me hearties, me hearties, resultin' in a cliffhanger flight. Fortunately, ejection was high enough above t' ground t' allow a safe recovery. Aye aye! Begad! T' rocket be undamaged, despite t' high-speed ejection. 

After another D12 flight, shiver me timbers, t' rocket was launched at a DARS high-power launch with an AeroTech F22-4J Blackjack reload. Arrr! T' flight was picture-perfect. Begad! Blimey! T' rocket landed on a street, but was undamaged. 

Betwixt t' first two launches, t' rocket be painted in a red, arrr, ya bilge rat, white and green scheme. Begad! Aye aye! T' kit instructions give detailed information on paintin' t' tube lengthwise, arrr, but no information on which fins t' paint black. Ahoy! Well, me hearties, blow me down! There are some paper cardboards apparently intended t' be glued onto t' rocket t' simulate some devices around t' fins, but I dispensed with those and t' antennae wire, decidin' t' keep t' rocket as a sport scale rocket. 

Even with t' basic color scheme, it is an impressive-lookin' rocket - even one o' t' LCOs said so. 

T' rocket has held up much better than one would expect, matey, considerin' it has balsa for t' nose cone and fins and a thin body tube. 

T' pluses for t' kit are ease o' assembly, impressive looks and t' surprisin' ruggedness. Aye aye! Even with t' motor mount conversion, t' rocket weighs right at one pound with t' F22 reload, makin' it legal for flight without FAA notification. Begad! With a D12-3, it's well under t' one-pound limit and makes an impressive small-field flyer. 

T' minuses are t' thin body tube, shiver me timbers, t' relative lack o' scale information and instructions that can be hard t' read. My set looked like a fifth-generation photocopy. 

You may find t' kit t' be relatively expensive. Avast, me proud beauty! Blimey! It retails in t' low $30 range. Cluster R offers a 2.6-inch Sandhawk with a retail price in t' high $30 range. Ahoy! Begad! Blimey! T' t' best o' me knowledge, shiver me timbers, t' FSI Sandhawk be t' only flyin' kit available in its size. 

If you're lookin' for a nice-lookin' scale model o' a rocket that you can fly anytime, shiver me timbers, then t' FSI Sandhawk should fill t' bill. 

comment Post a Comment