Ye Olde Rocket Forum - View Single Post - Dr. Zooch Lifting Body Shuttle build thread

Okay, so continuing after some minor emergencies needlessly distracting me from building rockets...

Construct the Lifting Body attach pad using the same techniques used to build it on the shuttle kit. Cut two 1 1/8 inch by 1/8 inch strips of balsa from the stock in the kit, apply wood glue, clamp lightly overnight with clothespins. File two notches across the attach pad close to each end for the attach dowels. Cut two 1/4 inch long dowels from the dowel stock in the kit, and glue them on for the attach pad standoffs. I also carefully notch the tube a bit where they will glue up to the tube, and glue the legs to the ET tank tube. Cut two 1 inch long reinforcing braces from dowel stock, and bevel one end to glue to the underside of the attach pad outboard of the pad legs from the last step. Carefully check their placement (boy those hemostat clamps are really helpful here!) and if desired, mark the tube and carefully notch it slightly using a sharp hobby knife. Glue the reinforcing struts in place to the tube and attach pad. Sand the end of one dowel stock piece rounded over (I actually round it to one side so it's flush with the intertank area) and check it's positioning and cut to length. Position it about even with the pad leg on the right side, and straight up the length of the tube to the interstage wrap. Carefully mark the wrap on either side of it and for the end length of the dowel, and then carefully cut out the intertank wrap per the instructions so the 'oxygen feedline' will lay flat against the tube. Glue it in place.

Next we begin work on the lifting body itself. First carefully cut all the template patterns from the wrap sheet and lay them out. As you cut them out, be sure you duplicate any markings surrounding the template pattern such as direction, grain orientation, etc. on the pattern itself with a pen. This will ensure you align all the parts correctly when mocking up the lifting body. Using the balsa stock and templates, lay out the parts on the balsa as best you can, noting the grain direction marks and 'top' marks and so forth on the template patterns. I would also recommend very gently writing these notations (top, front, etc, don't bother writing the grain direction on the wood, just be sure you orient the template with the grain properly before you trace the pattern on the balsa sheet). These notations showing the front and top and nose of the lifting body will GREATLY assist you in making sure everything is facing the right way when you start putting the actual wood pieces together. Carefully cut the parts from the balsa sheets. Cut some masking tape into about 6-8 short pieces and have them handy to tape stuff up as you align everything. The instructions recommend using pins to hold everything together, but I don't have any pins and the boss would kill me if she found her sewing pins with stray wood glue stuck to them, so I just used masking tape. Seems to work just as well. Carefully follow the instructions and mock up the two top facets of the lifting body, and apply the tape. Apply the masking tape to the bottom facet edges, noting the 'nose' direction. Align one side facet with the bottom facet edges and carefully wrap the tape over. Then gently repeat for the other side facet to bottom facet joint, and gently tape it up. The main skill here is GENTLENESS and taking your time-- handle the thing with kid gloves. I used a drop of thick CA to tack the seams at the front tip of the lifting body and at the rear edge of each of the three remaining seams, top and each side to bottom seam. Once the lifting body is tacked up, hold the lifting body up like a funnel with one seam aligned almost vertically, and apply glue carefully to the corner of the seam and allow it to run down the seam to the nose. Once it's starting to pool a bit in the nose tip, turn the lifting body until another seam is vertical and repeat the gluing. I did both side seams first and found by the time the glue runs to the tip, quite a bit of glue starts pooling in there from the other side, so I gave it a minute to allow the glue from the second side to catch up and run to the tip, and then rolled the lifting body upside down and tilted it to allow the glue to run back out of the nose down the top center seam until it reaches the back of the lifting body. I also used a bit of crap balsa stick to work the glue out to the sides just a little bit so it gets a wider 'grip' on the wood instead of staying kinda 'humped up' in the middle. I found that I could then periodically manuever the lifting body every few minutes, repositioning it nose up or nose down and favoring one seam or another at a time and allow the glue to redistribute itself evenly along the seams, so it doesn't all pool in the nose or the top seam or one of the side seams and possibly throw it off kilter later on. Once the glue was all pretty evenly redistributed and thickening up nicely, I set it to slightly favor the glue running to the back of the seams, since we'll add the noseweight BB's and more glue later on to secure them in the nose, and the extra glue will strengthen the nose a bit when we do that, so let this glue strengthen the aft ends of the joints.

More later! OL JR