First build thread: PemTech TRF logo rocket

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kuririn

kuririn

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PemTech TRF logo rocket - A first build thread


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Greetings fellow rocket nerds, geeks, and dweebs. Kuririn here (aka BarGeezer) with my first build thread. I recently received two kits in the mail, so it was either this one or the N-1 for my first TRF build. But aerostadt has a build of the N-1 in progress, so I'll leave that in his capable hands, and do this one. Although I really wanted to do the N-1 for my first build.... ( yeah, right).I had previously built a few of the smaller Pemberton Technologies (PemTech) kits, but did not know about this one until I stumbled across it on the PemTech website. It is a cool retro sci-fi design made of cardstock surrounding a motor/stuffer tube. I could not think of a more appropriate rocket build for this forum. Did a search of the archives, I'm surprised no one did a build of this before. This will be a quick build thread.


trf1.jpg


Parts: 1. The infamous "destructions". This is what Layne Pemberton ( LP) calls his instruction sheet.
Filled with wry comments and humor. Very entertaining. 30 detailed pages.
 2. Four pre-printed cardstock sheets with nose cone, nozzle, shrouds, finskins, fin template, rings,
and glue strips. One blank cardstock sheet.
 3. Fin stock. Appears to be 1/16" basswood.
4. Hartle Engineering 12" parachute pak.
5. Steel washer for nose ballast, launch lug, and kevlar.
6. Motor/stuffer tube.
trf4.jpgtrf2.jpg


Construction: Cut out the nose cone, body segments, nozzle, and glue tabs. Pre-curl all pieces, then glue the glue tabs to each piece.

trf5.jpgtrf6.jpgtrf7.jpg


Cut out the centering rings, and laminate (glue) them to the blank card stock sheet. Cover with wax paper and a flat heavy weight, like the Illustrated Encyclopedia of the World's Rockets and Missiles by Bill Gunston. Let dry overnight.

trf11.jpgtrf14.jpgtrf15.jpg

Cut out the glue tab strips and glue to the corresponding body segment.
I will be continuing the build in the next post. Comments and critiques are welcome.
Thanks for looking. Aloha and mahalo!


​
 
I think this rocket would look better without a launch lug on the outside. You could split a lug and put a short one on the top and on the bottom on standoffs, but having one at the max dia portion sticking out does not look right. You might consider using an internal lug and punching holes in the centering rings, and maybe little funnels instead of lugs to help guide the rod through, before you assemble all the sections together. Might be hard to do after three or more are assembled.
 
Thanks GlenP, that's a good idea. In line with that would be just punching holes in the centering rings in a straight line, with two holes on the shell, top and bottom. No need for lugs since it's a low power rocket. You'll see in the next post that the lugs don't look too bad with the skins on. LP even has two lines drawn on the shell and fin skin for the lugs.
 
Continuing the build:

trf12.jpgtrf13.jpgtrf16.jpgtrf17.jpgtrf18.jpg

Cut out the fin template and fin skins. Trace the template onto the fin stock, aligning the grain generally with the leading edge. I say generally because the leading edge is curved. Cut out the fins with a sharp knife. Basswood is denser than balsa, so your index finger and thumb will be getting a workout. If you look closely at the picture of the fin stock, you will see that I placed a tick mark on the root edge. The root edge is not a straight line. There is a slight change in direction where the shroud seam is. The tick mark indicates where the change of direction starts. After cutting out the fins, apply glue to one side. Spread into a thin layer completely covering the side, and attach a skin. Repeat for the other side, and for all fins. Cover with wax paper, and weigh down with a flat heavy object, like Aviation, an Illustrated History, by Chris Chant and John Batchelor. Allow to dry overnight.

trf8.jpgtrf10.jpgtrf20.jpg

One of the five laminated rings has a bunch of holes marked on it. This is a baffle disk. The reason it's called this is because people are baffled as to why there are so many holes. ..................
Actually, it's to channel the flaming particles and hot ejection gases, preventing your parachute from being damaged. But you will still need wadding.
Cut or punch out the baffle holes, and cut out the center holes from the rings. Check for fit on the motor/stuffer tube, and sand if necessary.
Starting new post below, reached 10 file limit on pictures.



 

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Now comes the fun part:

trf19.jpgtrf23.jpgtrf21.jpg

With a Sharpie, color the bottom area of the glue tabs to match the color of the joining shrouds. If you have a less than perfect glue seam the white will not be seen. Glue each segment to the adjoining one, as per instruct..., Destructions. Glue the washer in the nose cone, and each ring to the corresponding segment . Strip 4-3 is the shoulder of the nose cone, do not glue that. Let thoroughly dry.
trf24.jpgtrf25.jpgtrf26.jpg

Take the skinned fins and trim any overhanging skin or sand any basswood protruding so that both are squared up. Using the coloring device of your choice (Red Sharpie, red paint and brush, red nail polish and applicator, ketchup and tongue) color the edges to match the skins. Glue the fins to the body and check for alignment. I'm using an Estes display stand and sighting down the tube, lining up the fins with the legs. Set aside to dry thoroughly.
trf28.jpgtrf29.jpgtrf27.jpg

Glue the skins on the launch lugs, and glue the lugs on the pre-marked lines on the shroud and fin. Assemble the parachute, and attach to a loop tied on the Kevlar shock cord.
trf31.jpg

And you're done!

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Optional: 1.Thrust ring and motor retainer. LP says that PemTech finds them annoying and unnecessary. I added a thrust ring for the convenience, but left off an engine hook for aesthetic reasons. Will tape wrap.
2. Clear coat. The cardstock seems to have a matte clear finish, but you may want to do several light coats of clear to protect the graphics and give some water resistance.
3. CA at the top lip of the shroud at the separation point. Since this is cardstock, and not a spiral tube, it would be more prone to zippering. Also a piece of masking tape on the Kevlar at the point where it meets the top of the shroud would also help. And CA on the end of the motor tube (if you are using a tape wrap for engine retention) would prevent the tape lifting the paper or glassine.

Will update this thread when I get to launch this beauty. It's been a blast, had too much fun. Thanks, everybody!


 
Great work, thanks for posting this. I find these card stock builds fascinating.

In the future, consider ditching the italics, it makes the whole thing a bit harder to read.
 
Finally got a chance to launch the TRF logo rocket. It did not go well.



I really wanted this to fly well. Instead of repairing, this one will be relegated to permanent shelf queen. Sigh.
 
DSC_7352 (1).jpg Bummer. what engine did you use? does the model have nose weight? Too windy?

You can always print up another one, this is a 13mm version, but I am thinking the fins are probably not big enough now. Have to make your own through tube and centering rings, and nose cone shoulder.
 

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Last edited:
GlenP said:
View attachment 357584 Bummer. what engine did you use? does the model have nose weight? Too windy?

You can always print up another one, this is a 13mm version, but I am thinking the fins are probably not big enough now. Have to make your own through tube and centering rings, and nose cone shoulder.
Click to expand...

1. Minimum recommended motor, A8-3
2. Yup, kit included nose ballast (washer).
3. Very calm day, maybe 5 mph winds.
Glen, thanks for the pdfs. Maybe I'll have better luck with your version. The rocket is largely intact except for the nose cone tip, which is easily replaced. The empty weight is 2.3 oz., I'm wondering if the rocket was underpowered on an A. Just don't know if I want to hassle with troubleshooting for a cardstock model.
 
lakeroadster said:
UGH.. that sucks.

I thought folks bought kits, instead of scratch building, to avoid this very thing?
Click to expand...

You would think so, but some of my worst CATOs were stock builds of kits, using their recommended minimum motors. And usually one of the smaller manufacturers. Go figure.
 
Yes, I know this is an old thread but this is the first I've seen of it. The FB link is dead but I'm guessing she lawn darted. When demonstrating for local schools she has flown nicely on a A8-3 to about 100 feet dozens of times. However, maybe it is time to bump the minimum to a B motor.
Sorry for the negative experience....
Would a replacement kit sooth the old wound?
 
Pem Tech said:
Yes, I know this is an old thread but this is the first I've seen of it. The FB link is dead but I'm guessing she lawn darted. When demonstrating for local schools she has flown nicely on a A8-3 to about 100 feet dozens of times. However, maybe it is time to bump the minimum to a B motor.
Sorry for the negative experience....
Would a replacement kit sooth the old wound?
Click to expand...
I'd build/buy one :)
 
MALBAR 70 said:
I've had one of these in my build pile for quite a long time. All that card stock terrifies me.
kuririn, what a beautiful, clean build. Sorry it didn't fly better.
Click to expand...
Yeah, stationary kind of creeps me out too. However, it isn't a horrifying as one would assume. Attached is the deluxe 32 page Destruction manual, for your perusal.
 

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