Estes Canadian Arrow to Bumper WAC B-5

[TheAviator]

I won an Estes Canadian Arrow as a door prize at a competition a couple of months back, and thought it would be a good project to start on. I know that the Canadian Arrow can be interchanged with a V-2, but I wanted something a little bit cooler than that, so I picked the Bumper WAC.

A little background: The Bumper WAC was a sounding rocket mash-up done by the folks at White Sands Missile Range. The first stage was a V-2 captured after WWII with a hole in the nose to seat the WAC. The second stage was a modified WAC Corporal upper stage with four larger fins and spin rockets to account for the thin air at high altitudes. Because the WAC and staging hardware weighed about 1000 lbs, there was no need to ballast the V-2 nose as in other experiments. (The V-2 as intended carried about 1000lbs of high explosive. This weight was required for proper stability.) There were three successful flights, B-5, B-8, and B-7, in that order. B-5 was a pure altitude shot from White Sands. B-8 and -7 were absolute speed record attempts from the newly opened Cape Canaveral range.

I chose the B-5 mostly because a true-to-prototype flight would not be possible of the B-8 and B-7.

 

[TheAviator]

The Build!

I started by preparing the surprisingly nice tail cone supplied with the kit. This involved cutting off little blisters that give slots for TTW fins, another plus! I haven't gotten around to it, but I need to remember to wash it with dish detergent to remove the mold release.

The next step involved cutting out the laser-cut fins and sanding the nibs left from the laser cut. This was quite easy. They were then test fit to the tail cone and the slots cleaned up so that each fin fit properly.

 

[dpower]

The Build!

I started by preparing the surprisingly nice tail cone supplied with the kit. This involved cutting off little blisters that give slots for TTW fins, another plus! I haven't gotten around to it, but I need to remember to wash it with dish detergent to remove the mold release.

The next step involved cutting out the laser-cut fins and sanding the nibs left from the laser cut. This was quite easy. They were then test fit to the tail cone and the slots cleaned up so that each fin fit properly.

Did the Bumper WAC have the same fins & length as a V-2? If so, you may want to trim the fins & BT from the Canadian Arrow - IIRC about 1/2" off the fins and about 4" off the BT, add nose weight as needed.

Ok, found the dimensions:

https://www.rocketryforumarchive.com/showthread.php?t=35626

 

[Delta-IV]

Did the Bumper WAC have the same fins & length as a V-2? If so, you may want to trim the fins & BT from the Canadian Arrow - IIRC about 1/2" off the fins and about 4" off the BT, add nose weight as needed.

Ok, found the dimensions:

https://www.rocketryforumarchive.com/showthread.php?t=35626

Aviator....I think you will like this rocket and kitbash!!

On my kitbash I lengthed the stuffer tube, trimmed the fins but didn't do enough research in time to shorten the BT and stuffer..oops, so my Bumper-8 is a Bumper-8+

Here is a shot of mine...

 

[TheAviator]

Did the Bumper WAC have the same fins & length as a V-2? If so, you may want to trim the fins & BT from the Canadian Arrow - IIRC about 1/2" off the fins and about 4" off the BT, add nose weight as needed.

Ok, found the dimensions:

https://www.rocketryforumarchive.com/showthread.php?t=35626

Thanks for the info. I'm glad I haven't had time to continue now.... I knew I had to shorten the overall length, but I didn't know the fins were oversized... I have ROTW around here somewhere, so I'll look there too for confirmation.

 

[sandman]

I did my Bumber Wac a long time ago.

The fins are basswood I carved the details with a veiining tool and the "Wac" is filled with clay.

Don't forget the spin motors on the Wac!

Haven't flown it in a while, I should.

I picked B-8 'cause it was the first rocket flown at Cape Canaveral.

 

[Delta-IV]

I did my Bumber Wac a long time ago.

The fins are basswood I carved the details with a veiining tool and the "Wac" is filled with clay.

Don't forget the spin motors on the Wac!

Haven't flown it in a while, I should.

I picked B-8 'cause it was the first rocket flown at Cape Canaveral.

Awesome build Gordy, I too picked the B-8 for the same reason, especially since I work here now.

 

[sandman]

These sites semed apropriate.

https://www.spaceline.org/rocketsum/bumper-wac.html

https://www.designation-systems.net/dusrm/app1/rtv-g-4.html

 

[TheAviator]

So far today, I trimmed up the main airframe and fins to put them in scale with a 1:25 Bumper rather than a 1:24 scale Canadian Arrow. The fins needed about a 1/2" trimmed from the tips and the airframe was trimmed back to 6.77". Not seen in the pictures, I started the first half a double glue joint.

Next up: Making a WAC airframe.

 

[TheAviator]

I rolled the WAC airframe based on a technique from the NAR Scale forum. The tube was rolled from a piece of standard printer paper. The first wrap on the outside and inside was free from glue, while the rest was covered with white glue. This was allowed to dry and then rolled around a 15/32" piece of K&S brass to get the .48" tube needed for a 1/25 WAC. A hot iron was run over the paper to literally melt the PVA in the white glue and bond the tube together.

The result is show below.

 

[Massrokit]

Brian,

QUOTE: "The first wrap on the outside and inside was free from glue, while the rest was covered with white glue. This was allowed to dry and then rolled around a 15/32" piece of K&S brass to get the .48" tube needed for a 1/25 WAC."

This description was a little confusing to me. Does it mean you glue two pieces of paper together then wrapped it around the tube or the inside wrap was glue free (side next to brass tube) while the wrap was glued while wrapping, but leaving the ouside of the wrap glue free (outside surface)? One sheet paper or two? Bassicly a parrellel wound body tube.

 

[TheAviator]

This description was a little confusing to me. Does it mean you glue two pieces of paper together then wrapped it around the tube or the inside wrap was glue free (side next to brass tube) while the wrap was glued while wrapping, but leaving the ouside of the wrap glue free (outside surface)? One sheet paper or two? Bassicly a parrellel wound body tube.

You use one sheet of paper. The length of the paper is (# of Wraps)*(Diameter of Tube)*PI. The first (DIA.*PI) is left glue free on opposite ends of each side of the paper. One glue-free area is the outside of the tube, the other glue-free area is the inside of the tube.

If you're still confused, I'll do another one with more pictures.