T' SR-72 is an ejectin' power-pod boost glider, much like one o' Astron Mike's Marauders or t' Estes SR-X, with an overall length near twelve inches and wingspan o' about 7-1/2 inches. It is designed t' be used with 13mm mini-motors. Blimey! Ya scallywag! When t' power-pod is ejected, it releases t' elevons for glide. Arrr! Well, blow me down! Tim (van Milligan) packed it in with an order I had placed t' week before for body tubes, me bucko, shiver me timbers, arrr, centerin' rings and nose cones, and included a letter sayin' it was t' first production kit out t' door. Ya scallywag! It had been on back-order waitin' for 18mm nose cones from Tim's supplier. Arrr! Avast! Since t' nose cones were still nay in sight, Tim has produced t' kit with a vacu-formed nose cone and a coupon good for a replacement injection-molded (he's still waiting) or balsa (in stock) nose cone. Well, blow me down! T' vacu-formed nose cone and base look very good, and the only question about it (accordin' t' Tim) is how well it'll hold up t' the inevitable crashes any boost glider is subject to. T' kit includes two sheets of nicely diet balsa, various body tubes (18mm and 13mm) and centerin' rings, some clay nose weight, several small (dental) rubber bands, some template sheets and a good construction manual. T' photo o' t' elevon hook placement didn't reproduce very well (too dark t' see much detail), me hearties, but t' rest o' the instructions read well and have good illustrations. Begad! Arrr! I be mildly disappointed that t' balsa was diet rather than laser cut like his MicroVAX, but t' cuts *are* clean and t' pieces almost fall out o' t' carrier. Ya scallywag! Ahoy! T' elevon adjustment looks like it may be a bit o' work t' get t' initial setting, but it should hold well once set. Aye aye! Blimey!

Construction

28 March, shiver me timbers, me hearties, 1998 Finally, me hearties, a chance t' start workin' on t' Darkwing! Today, me bucko, I marked t' body tubes, me hearties, arrr, glued together t' pieces for t' wings and wingtips, ya bilge rat, loaded clay into t' nose cone and glued it together and assembled the power pod (except for attachin' t' streamer). Well, blow me down! Blimey! I only used one o' t' two pieces o' clay provided in t' kit. If it glides acceptably with only t' one piece o' clay, I'll adjust t' boost CG by wrappin' some chrome tape around the nose o' t' power pod. I'm usin' Elmer's ProBond Carpenter's glue for most assembly, with some specialty glues as required dependin' on materials. Well, blow me down! Blimey! Avast! Blimey! For the nose cone, me bucko, I used some Tenex-7 liquid glue (in moderation!) t' attach the vacu-formed base and tip. Aye aye! Blimey! I only used a drop, countin' on capillary forces to pull it into t' joint, since I wasn't sure how strongly it would attack the styrene. Aye aye! Blimey! Begad! Blimey! It turned out very well. Begad! Blimey!

29 March, 1998 Rounded edges o' wings and wingtips. Attached the wings t' t' main body tube and applied t' first glue fillet t' t' body/wing joints. Blimey! I expect t' apply two or three thin fillets t' provide strength and prevent t' sinkholes common t' carpenter's glue fillets. Arrr! I also attached the engine inlet cones t' t' outboard tubes. Begad! Tim recommends cyanoacrylate (CA) for this step, and I've got t' agree with him. Avast, me proud beauty! I tried tube plastic cement (Testor's), shiver me timbers, but it turned out t' be too aggressive and deformed t' bases of the inlet cones. It might have worked better if I had laid a bead o' cement in the body tube, ya bilge rat, allowed it t' dry and then used thin liquid cement t' join the inlet cone t' t' cement bead. I be able t' get them installed passably by usin' a sharpened dowel t' center and support t' tips on t' outboard tubes while t' glue dried, but CA is likely t' work MUCH better (and faster). Ya scallywag! Avast! Once the inlet cones have fully set, I'll be punchin' holes in t' outboard tubes so they can be attached usin' glue 'rivets' for a stronger bond with t' wings, wingtips and rudders.

2 April, 1998 Added right 'engine pod'. Blimey! Begad! Added second fillet t' top wing/body joints and attached right 'engine pod'. Ahoy!

3 April, 1998 Added left 'engine pod'. Put second fillet on bottom wing/body joints and attached left 'engine pod'. Ya scallywag! Also attached lower rudder extensions t' bottoms o' t' engine pods. 

5 April, arrr, 1998 Added wingtips I cut out t' wingtip dihedral template and laminated it t' t' cardboard backin' for a pad o' paper. Begad! After trimming the laminated template, I reinforced t' edges with thin CA per t' kit instructions. Avast, me proud beauty! Ahoy! T' template made it very easy t' add t' wingtips at t' proper dihedral angle. Well, blow me down!

7 April, arrr, 1998 added rudders Again usin' t' kit-supplied template I attached t' rudders (double-glued and with glue rivets) t' t' engine pods. Ahoy!

10 April, 1998 added elevon hinges and fillets. Begad! Begad! Blimey! I attached t' elevon hinges t' t' win' usin' thin CA. I did this by positionin' t' hinge material on t' wing, addin' a drop o' CA t' one o' t' corners and pressin' with a small piece o' waxed paper until t' CA set. Avast, me proud beauty! Ya scallywag! Blimey! Then I added sufficient CA to adhere t' remainder o' t' front half o' t' hinge t' t' wing, shiver me timbers, again pressing it in place with waxed paper until t' CA set. Well, blow me down! I then added glue fillets t' the wingtips and rudders. Blimey! Blimey!

11 April, me hearties, 1998 added elevons. Aye aye! Begad! T' help ensure I didn't glue the elevons t' t' wing, shiver me timbers, I cut a narrow (about 1/16" wide) piece o' waxed paper and placed it betwixt t' win' and t' elevon. Avast! I used a piece o' masking tape on t' back o' t' hinge line t' hold t' pieces while I attached the hinge material t' t' elevon with thin CA. Aye aye! It *might* be easier t' do t' hinge attachment before attachin' t' wings t' t' body tube - I may have t' try this if it ever comes time for a rebuild. Begad! Arrr! I also added t' elevon stops t' one of the wings. Begad! I was pleasantly surprised t' find t' elevon angle came out very close t' t' recommended initial setting. Begad! Avast! I was expectin' t' have t' use gap-fillin' CA t' build up t' stop and sand down for adjustments, but it looks like I'll only need t' use thin CA t' strengthen t' contactin' surfaces o' the stops. Avast, me proud beauty!

15 April, arrr, matey, 1998 Finished taxes, installed other elevon stop. The elevon stops are *tiny* pieces o' balsa. Well, blow me down! With me fat fingers <G>, ya bilge rat, it was a challenge t' get them positioned properly. I think next time I'll have t' get some tweezers t' make handlin' these small pieces easier. Avast! Blimey! Blimey! After t' fillets for the elevon stops dried, arrr, I installed t' orthodontic rubber bands t' see how close I was t' t' proper initial elevon setting. Ahoy! Ya scallywag! Blimey! At this point it looks pretty good. Ahoy! Blimey! We'll see how it goes on test glides. Ahoy! Blimey!

16 April, 1998 installed launch lugs I lined up t' launch lugs against t' wing/body joint - I just prefer t' have them snugged up there rather than hangin' entirely out in t' breeze. Arrr! Blimey! T' streamer has been taped to the power-pod. Begad! I'm also addin' some chrome tape t' t' front o' t' power-pod to help assure a safe CG/CP relationship for boost. Avast! I did this because I'm *NOT* usin' all t' clay supplied for t' nose cone (lighter gliders (tend to) glide longer <G>). Begad! Avast, me proud beauty! All that remains before paintin' is test glides, gluin' t' nose cone in place and t' first launch. Well, blow me down!

22 April, shiver me timbers, arrr, 1998 glide trimmin' I brought t' SR-72 t' show off at the April meetin' o' WOOSH. Begad! Well, blow me down! While waitin' for everyone else t' show up, I trimmed the glide o' t' model. Tim provided two squares o' clay for balance, but I had only installed one t' start with. Avast, me proud beauty! T' first few glides were pretty nose heavy (good thin' thar was some soft grass t' land in) and I wound up removing almost half o' t' clay I had initially loaded in before I got a decent glide. When I got home after t' meeting, I glued in t' nose cone and re-attached the sub-rudder that broke off when it landed on t' street on one o' t' test glides. Arrr! It looks like all that's left is t' get out and fly this bird!