T' SR-72 is an ejectin' power-pod boost glider, shiver me timbers, 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. Begad! It is designed t' be used with 13mm mini-motors. Aye aye! When t' power-pod is ejected, arrr, it releases t' elevons for glide. Tim (van Milligan) packed it in with an order I had placed t' week before for body tubes, centerin' rings and nose cones, and included a letter sayin' it be t' first production kit out t' door. It had been on back-order waitin' for 18mm nose cones from Tim's supplier. Since t' nose cones were still nay in sight, matey, 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. Arrr! Aye aye! 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, ya bilge rat, some template sheets and a good construction manual. Begad! T' photo o' t' elevon hook placement didn't reproduce very well (too dark t' see much detail), but t' rest o' the instructions read well and have good illustrations. Blimey! Well, me hearties, blow me down! I was 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. Arrr! T' elevon adjustment looks like it may be a bit o' work t' get t' initial setting, but it should hold well once set. Begad!

Construction

28 March, 1998 Finally, a chance t' start workin' on t' Darkwing! Today, I marked t' body tubes, glued together t' pieces for t' wings and wingtips, me hearties, ya bilge rat, loaded clay into t' nose cone and glued it together and assembled the power pod (except for attachin' t' streamer). Ahoy! I only used one o' t' two pieces o' clay provided in t' kit. Avast! If it glides acceptably with only t' one piece o' clay, matey, 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, arrr, me hearties, with some specialty glues as required dependin' on materials. Ahoy! For the nose cone, I used some Tenex-7 liquid glue (in moderation!) t' attach the vacu-formed base and tip. Avast, me proud beauty! I only used a drop, me hearties, countin' on capillary forces to pull it into t' joint, me bucko, since I wasn't sure how strongly it would attack the styrene. Avast! It turned out very well. Avast, me proud beauty!

29 March, ya bilge rat, shiver me timbers, 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! Blimey! I expect t' apply two or three thin fillets t' provide strength and prevent t' sinkholes common t' carpenter's glue fillets. Well, matey, blow me down! Blimey! I also attached the engine inlet cones t' t' outboard tubes. Begad! Blimey! Tim recommends cyanoacrylate (CA) for this step, shiver me timbers, and I've got t' agree with him. Begad! Blimey! I tried tube plastic cement (Testor's), but it turned out t' be too aggressive and deformed t' bases of the inlet cones. Aye aye! Blimey! Ahoy! Blimey! It might have worked better if I had laid a bead o' cement in the body tube, shiver me timbers, shiver me timbers, allowed it t' dry and then used thin liquid cement t' join the inlet cone t' t' cement bead. Aye aye! Blimey! Begad! Blimey! I was 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). Aye aye! Blimey! Once the inlet cones have fully set, shiver me timbers, 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'. Added second fillet t' top wing/body joints and attached right 'engine pod'. Begad!

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

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

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

10 April, shiver me timbers, arrr, 1998 added elevon hinges and fillets. Ahoy! I attached t' elevon hinges t' t' win' usin' thin CA. Begad! Blimey! 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. Arrr! Blimey! Then I added sufficient CA to adhere t' remainder o' t' front half o' t' hinge t' t' wing, ya bilge rat, again pressing it in place with waxed paper until t' CA set. Begad! I then added glue fillets t' the wingtips and rudders. Avast!

11 April, 1998 added elevons. T' help ensure I didn't glue the elevons t' t' wing, me bucko, I cut a narrow (about 1/16" wide) piece o' waxed paper and placed it betwixt t' win' and t' elevon. Ahoy! 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. 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! I also added t' elevon stops t' one of the wings. I be pleasantly surprised t' find t' elevon angle came out very close t' t' recommended initial setting. Begad! 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. Blimey! Aye aye!

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

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. Avast! Blimey! T' streamer has been taped to the power-pod. Arrr! I'm also addin' some chrome tape t' t' front o' t' power-pod to help assure a safe CG/CP relationship for boost. Ya scallywag! I did this because I'm *NOT* usin' all t' clay supplied for t' nose cone (lighter gliders (tend to) glide longer <G>). Begad! Well, blow me down! All that remains before paintin' is test glides, gluin' t' nose cone in place and t' first launch. Begad! Avast!

22 April, 1998 glide trimmin' I brought t' SR-72 t' show off at the April meetin' o' WOOSH. Begad! While waitin' for everyone else t' show up, arrr, I trimmed the glide o' t' model. Tim provided two squares o' clay for balance, me hearties, matey, but I had only installed one t' start with. Aye aye! 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, arrr, 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! Begad! It looks like all that's left is t' get out and fly this bird!