WCR Screamer - Jane Doe

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JAL3

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I started a build thread on this rocket on the old TRF and the site went down before I got finished. I finally finished a few week ago and the rocket has yet to be flown. I am resurrecting my part of the build thread here.

Anyone wishing to follow the pix and vids of this one during its service life is welcome to check out the collections at: https://flickr.com/photos/23694991@N03/collections/72157608752824023/

Here we go:

Construction began by marking the motor tube at 1/8" from one end and 3/4" from the other. The two centering rings were then epoxied in place. Both needed quite a bit of sanding to fit around the tube.

Scr-Motor-mount.jpg
 
As I waited for the epoxy on the motor mount to set up, I turned my attention to the nosecone. It had a 3/4" diameter hole drilled to a depth of about 2". Into that hole, I was instructed to mount a lead fishing weight that came with the kit. I mixed some more expoxy, poured some in the hole, set the weigt and then poured the remainder over the top.

Scr-nose-weight-1.jpg

Scr-nose-weight-2.jpg
 
The fin lines were marked on the BT with a butt template. They were then extended with an angle and 5" slots were cut out with an X-acto.

Scr-fin-slots.jpg
 
With the fin slots cut, I test fitted the motor mount to find that it was going to need substatial sanding to fit either ring into the BT. The sanding was done and the mount was epoxied into place with the motor tube being flush with the aft end of the rocket. Epoxy was then used to fill space between the centering ring and the end of the BT.

Scr-Motor-mount-2.jpg

Scr-Motor-mount-3.jpg
 
After a long hiatus, I managed to put a little more work in on the Screamer. Using 5 min epoxy, I glued one pair of fins in place. I filleted them with more epoxy using a gloved finger dipped into alcohol to smooth the fillets.

Scr-fins-1.jpg
 
The other two fins were finally put on. When I set the rocket on its tail, there was no wobble and I consider that a good sign. Just don't sight too carefully along the BT.

Scr-fins-2.jpg

Scr-fins-3.jpg
 
The payload bay is joined to the lower part of the rocket with a tube coupler. The kit comes with a plywood bulkhead to go on one end of the coupler and that is probably my biggest gripe about the kit. The bulkead is a surface mount. I would much rather have had one that fits in the coupler. Be that as it may, I epoxied the bulkhead in place and tried to ensure that it was even with the edges.

Scr-coupler-bulkhead.jpg
 
With the epoxy on the bulkhead coupler dry, I used some sandpaper to trim down the edges where they protruded past the coupler. When it fit easily into the body tube, called it finished. I then took the eye screw and screwed it into the pre-drilled hole in the coupler. It seemed like a strong connection but I doused the pointed end with some glue to make sure.

Scr-coupler-1.jpg

Scr-coupler-2.jpg
 
The coupler tube was marked at its halfway point and then a ring of glue was slathered into the base of the payload section. The coupler was then inserted to the mark and set aside to dry.

Scr-coupler-3.jpg
 
The balsa NC and plywood fins were sealed with Elmer's filler. It was sanded down smooth, dusted off and the Screamer was put in the spraybooth. There, it was primed with Kilz.

Scr-primer-1.jpg

Scr-primer-2.jpg
 
After the priming, the rocket sat for a couple of months before I could give it any more attention. I then sanded down the primer and began painting with John Deere Yellow. My target was the BT, THe fins and NC will be covered up later.

Scr-yellow-1.jpg

Scr-yellow--2.jpg

Scr-yellow--3.jpg
 
For the John Deere green, I decided to do the nose cone, a ring just below the nose cone, the fins and a narrow strip around the fins. The rocket was masked accordingly and sprayed.

Scr-green-1.jpg
 
When the masking came off, I decided that I rather liked the result.

Scr-painted.jpg
 
While assembling the rocket after painting, I realized that I had overlooked the recovery system. I would have like to have attached directly to the motor mount but that was a moot point now. I fashioned a LOC style mount with a loop of heavy nylon cord and some masking tape. It was taped down below the level of the NC shoulder and epoxy was slathered on to keep it in place. I then tied some heavy Kevlar to the loop and attached a length of 3/8" sewing elastic.

Scr-recovery-harness.jpg
 
One thing I did save intentionally for after painting was the installation of a linear rail lug. I put it is place and started the hole for the upper screw only to realize that I had placed it too high; it interfeared with the payload bay coupler. I moved it down about an inch and found the same problem! I finally got it placed right and tapped the holes. The lug was then epoxied on and the screws inserted. The backs of the screws took up the remaining epoxy and the Jane Doe was ready to go.

Scr-rail-lug.jpg
 
The first flight of this rocket took place long after construction had been completed. It was set up with an F25-4 and the copperhead that came with it. The Copperhead failed to ignite the motor and was replaced with a First Fire. That did the trick and the rocket took off with as nice a flight profile as I have ever seen.

A video of the flight can be seen here: https://www.flickr.com/photos/23694991@N03/3625787631/

WCR-Scr-f1a.jpg

WCR-Scr-f1b.jpg

WCR-Scr-f1c.jpg

WCR-Scr-f1d.jpg
 
Ejection and deployment were all textbook. I expected to fly the rocket again but was mystified to see that it had suffered some buckling in the airframe. I can fix it but wonder what caused it since the thrust was not all that heavy.

WCR-Scr-f1f.jpg
 
As I said, the damage to the body tube was not severe and, since it is a fairly heavy tube, I'm not sure why it buckled to begin with.

BT-damage-1.jpg

BT-damage-2.jpg
 
I didn't really want to cut out the old tube and replace it and I was not all that concerned with maintaining the pristine lines of the original so I decided on a kludge repair. While BT70 was too small, BT80 did fit with a bit to spare. I cut a length that was a bit longer than the affected area.

BT60-cut.jpg
 
I then sliced the BT80 lengthwise and slipped it around the BT. I held the tubing closed and traced out the amount of overlap. The overlap was then cut away. I still needed to reduce the material a little bit so I took it over to a belt sander and tried to remove it straight.

BT80-sliced-1.jpg

BT80-sliced-2.jpg
 
A batch of 15 minute epoxy was then mixed up and painted on the inside of the sliced BT. IT was then put in place around the affected area and taped shut.

I will still have to fill the scar and repaint but it is my hope that the little bit of BT80 along with the stiffening effect of cured epoxy will take care of the problem.

epoxied-tube-1.jpg

epoxied-tube-2.jpg

epoxied-tube-3.jpg
 
I like the result too. Looks great. :)

It's a shame it needed the repair. :bangpan:

Thanks.

I want to fly it next month with the John Deere and identical motors just to see the two out together.
 
The tape holding the reinforement was removed and I still had a nasty seam to deal with. I filled it with Squadron green putty because that happened to be handy and then let it sit for a day.

putty.jpg
 
After drying, the excess putty was sanded away. The patch is not going to be invisible...except from the distance to the launch pad.

putty-sanded.jpg
 
The areas away from the repair job were then mased with foil and tape.

masked.jpg
 
Then I dug out the last of the John Deere Yellow paint and got busy.

yellow-1.jpg

yellow-2.jpg
 
After drying, the excess putty was sanded away. The patch is not going to be invisible...except from the distance to the launch pad.


In LPR that would be a 15' paint job, I guess with MPR it would be a 30' paint job. It's a paint job that looks great from 30 feet.

Reminds me of when I Bondoed the holes in my Mom's car, the one I got to drive. I had it sanded and all the trim off and ready to paint when I had to go away for 4 days. Got back and Mom and Sis had given it an 8 foot paint job. 2 quarts of Rustoleum Fire Engine Red and 2 new paint brushes.
 
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