Scratch Boot Hill Original Design / Scratch Built

Scratch - Boot Hill {Scratch}

Contributed by Claude Maina

Manufacturer: Scratch

Brief:
As soon as I saw Dick Stafford's 'Boot Hill' rocket, I had to build one. It is a fun rocket, and I want to give all due acknowledgments to Dick! That said, I made one modification to Boot Hill that employs rubber bands to pull open the coffin lid, instead of using ejection gases to push it open. The ejection charge gases are now used to burn through a thread that is holding the coffin lid closed.

Construction:
The parts list:

  • Wood coffin, purchased from Michaels
  • 3 Wood gravestones, purchased from Michaels
  • 6" long BT-50 tube
  • Spent 24 mm engine
  • Small engine hook
  • 7 Screw eyes, #214
  • 2 Small rubber ban(Scratch) Boot Hillds
  • Thin cotton thread
  • 18" shock cord
  • 18" parachute

(Scratch) Boot Hill

I started by constructing an engine mount on one end of the body tube. I put a small slit 2 3/4 inches from the end to accommodate the engine hook. I fastened it to the tube by spreading CA along a rectangle centered on the engine hook and 1/4 inch on either side, and 1/2 inch from the bottom. I then put a same size piece of masking tape over the CA and let dry. For the engine block, I used a 1/4-inch slice of a spent 24mm engine and glued it just above the engine hook. I then glued the bottom half of the spent engine to the opposite end of the body tube such that the clay nozzle was flush with the now top-end of the body tube and let dry. (This was done to give some extra support to the end that would take the ejection gases and give more surface area to attach to the coffin.) I drilled four 1/4-inch holes through the top end of body tube just under the clay nozzle about 1 inch from the end. I then filled in the hole of the nozzle with 5-minute epoxy. When that was set, I scuffed up both the end of the body tube and the hardened epoxy with 120 grit sandpaper and attached it to the bottom end of the coffin with 5 minute epoxy, centering it on the body half of the coffin such that it would not interfere with the lid opening.

To attach the gravestone fins to the body tube, I first sanded the bottom end of the gravestones to give them a flat surface for attaching to the body tube. I then glued the fins to the bottom end of the body tube using wood glue and filleted.

(Scratch) Boot Hill The opening mechanism was constructed by screwing four screw eyes on either end of the two coffin hinges as shown in the figure. The screw eyes on the lid were screwed in on the right side of the lid. The screw eyes on the body of the coffin were screwed in on the back. The rubber band is looped through one of screw eyes and kept loose until launch. The locking mechanism was constructed by screwing the same size screw eyes on the inside of the coffin just above the latch on both the lid and body of the coffin. I also drilled a 1/16-inch hole through the bottom of the coffin at the right rear end. Finally I screwed an screw eye on the inside of the coffin at the top and attached an 18" shock cord.

Finishing:
I put three coats of Sanding Sealer on the outside of the coffin, sanding with 400 grit sandpaper between each coat. I then primed everything (except for the 3 gravestone fins) with 2 coats of Krylon white primer and sanded with 400 grit sandpaper. For the coffin, I used Rustoleum Painter's Touch Black Gloss and gave it two coats. For the body tube I used Ceracoat Acrylic Paint Dolphin Gray that pretty much matched the color of the gravestones and gave them three coats. And finally I decorated with some Halloween stickers purchased at Michael's.

I tried both Krylon's Crystal Clear Gloss and Rustoleum's Crystal Clear Gloss on a test gravestone but both seem to cause the paint on it to run brown. So I decided to leave as is.

(Scratch) Boot Hill

Flight and Recovery:
I made two rockets, one for my daughter and one for myself, and we launched them at a recent CMASS launch.

To prepare for launch, I first attached an 18" parachute with a swivel to the shock cord, folded and placed it in the back of the coffin. I then cut a 24 inch piece of thread, looped it through the internal eye hook on the coffin lid, then passed it through the eye hook on the coffin body and finally through the hole at the bottom of the coffin and out. I closed the coffin door and latched it. I then passed the thread through the body tube using 2 opposing 1/4-inch holes, pulled tightly and taped the thread to the body tube with a small piece of masking tape. I inserted a C11-3 engine and off to the launch pad.

Once the rocket was on the pad and alligator clips attached, I looped the two rubber bands over their opposing screw eyes and opened the coffin latch.

Upon launch the rocket reached about 150 to 200 ft. The ejection charge burned through the thread and I could see the coffin door open and parachute deploy. The rocket came down safely! My daughter and I next had a drag race with each of our coffin rockets, which was also successful. Both coffin doors opened at apogee; the parachutes unfurled and each landed safely. My daughter next attempted to launch hers with a rather large skeleton inside, but that didn't go so well.

(Scratch) Boot Hill

Summary:
PROs: This really is a fun rocket for Halloween. It is easy to build and allows itself to imaginative decorations and all kinds of scary things that can pop out of the coffin. All thanks to Dick.

CONs: The locking mechanism I employed here works well with an empty coffin or small things placed inside, but anything large prevents the thread from releasing the coffin lid. Perhaps a mechanism that ties the door shut from the outside would work better for larger "payloads".

Other Reviews
  • Scratch Boot Hill By Dick Stafford (September 20, 2008)

    This is a Halloween-themed oddroc based on a toy coffin. It features a 24mm mount and patented 'Coffin Lid Ejection'. The parts list: One pine (basswood?) coffin from Michael's Three wooden headstones, also from Michael's LOC 24mm tubing One spent 24mm casing Scrap plywood for internal baffle One screw eye Elastic and thin Kevlar ® 3/16" launch lug I ...

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