Scratch Live Wire Spool Original Design / Scratch Built

Scratch - Live Wire Spool {Scratch}

Contributed by Lance Alligood

Manufacturer: Scratch
(Contributed - by Lance Alligood - 07/01/04)

Brief:
This is a spool very much in the vein of those like Scott's Spool Rocket and Dick Stafford's Lobbin' Bobbin except it has a 24mm motor mount.

(Scratch) Live Wire Spool

Construction:
Recently I was in the electrical department of my local home improvement store where I inquired as to what they did with their empty wire spools. Believe it or not, they just throw them away! I politely asked if I could have some. The sales associate guided me to the back of the store where he pointed to a large box and told me to help myself. And I did!

The spools were all made of plastic. While they were all about 6.5" in diameter, there were 2 different widths: about 3" and 5.5". Helping myself to a few, I took them home. Once I got them into my workspace, I took some 24mm and 29mm tubing to help gauge how far I was going to need to open the center hole.

A Dremel made quick work (in fact, too quick in the case of the one I wanted to use for 29mm tubing) of opening up for a snug fit of the 24mm tubing. Opening up only one end, the unmodified hole made for an excellent thrust ring. I cut the tube to fit and used some Devcon 5-minute epoxy to hold it in place. A 3/16" drill bit was all I needed to create holes for a launch rod.

Finishing:
No finishing was necessary. I kept it the black plastic as is.

Flight:
I loaded up the Live Wire Spool with an Estes E9-6 and friction fit it into place with masking tape, leaving about 3/4 of an inch of the motor sticking out. My club's mid power pads sit close to the ground so I practically had to lie down on the ground to attach the clips to the ignitor...but that's the not the rocket's fault. The Estes E9 is a super motor for this rocket as it provides a pleasant 3 second burn. While the spool didn't leave the pad with amazing authority, it did manage to continue a steady ascent during the entire thrust phase of flight to about 300ft.

This rocket could easily handle higher thrust motors but I have learned that long burn motors (regardless of total thrust) provide the best flights with spools and other high drag designs.

Recovery:
I love spools because they do not require any wadding and/or lengthy preparation. Recovery comes from the gentle tumble that they go into after motor burnout all the way to the ground. I would go so far as to describe it as simple elegance. Because of the low altitude, it didn't get very far away from the pad during recovery. Unable to modify the motor to remove the ejection charge, the ejection charge went off comfortably about halfway back to the ground.

Summary:
Spools rule! Best of all, it was practically free and only took a matter of minutes to modify it for flight. Combined with plenty of Estes E9s, you will always be entertained while flying this all day long on even the smallest fields.

comment Post a Comment