Don,

Thanks for the compliment. It's amazing how many mistakes a good paint job can cover up.

Yeah, shaping the fins were a bear. The wood was warped, too.

I built the Nike Smoke for sport flying. Both the competition and sport ranges had numbered pads.

I ended up writing an article about this NARAM which was published in the Tripolitan by Bruce Kelly. These same pictures were featured in the article.

I'm going to have to go dig this model out and fly it, again.

Bob

Even so, your model looks pretty darned impressive! This is very encouraging.

Mark

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SAM # 0011

Homer Simpson voice here: Ummm, FSI Viking rockets! You make, I buy!!!!

Jack

Carl,

Is it that it would be hard to make precut ones in a production run that are identical in shape and quality? (Maybe this is a question that answers itself. ) Cutting them individually by hand was not all that difficult, and I'm hardly a craftsman. If I had to decide what to call it, I would say that it is a Skill Level III task.

Getting them lined up on the airframe for glueing was another story, though. It is a bit of a challenge because, along with getting the tube straight, you have to also get the beveled tip properly centered. The method shown in the FSI instructions were helpful in getting the tubes properly spaced around the body tube and in getting the tube fin lined up straight overall, but didn't provide any help with centering the beveled tip.

I had drawn two fin alignment lines on the outside of the tube fin, 180 deg. apart, when I was setting up the bevel contour lines. Before glueing on each tube fin, I extended the alignment line that ran through the tip of the top bevel over the tip and then a short ways down the inside of each of the tubes. I used that as a reference for centering the tips on fin alignment lines that I had drawn on the main body tube. Then I used visual alignment techniques (and slow setting glue) to tweak each tube fin into parallel alignment with the main body tube.

So far, I've only built the Viking II, but I think it will prove to be the most difficult of the 5 Vikings to get the fins aligned straight. This is because of the outer finlets, which, being on the outside of the tube fins, are visually quite far away from the centerline of the main body tube. The standoffs used in Vikings III - V should actually help with aligning the tube fins on the main body tube on those models. But it was possible for a non-craftsman like me to successfully get the tubes on straight and centered on the bevel on both versions of the Viking II that I have built. It took a lot of squinting and sighting down alignment lines, and much tweaking of the fin placement, but it was accomplished.

Lining up these Viking II finlets was just about the most demanding and tedious task that I've done so far on any model rocket build (but then, I haven't tried building the escape tower on a Little Joe II yet. )This is a situation where a jig would really come in handy. I have an idea for one that can be made with cardboard strips (and could therefore be included in a kit), but I need to build it to see if it will work.

Pictures of my second, corrected Viking II (MRK-X) clone are forthcoming in another post.

Mark

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SAM # 0011

OK, gang, another tube dimension question. Body tube length for the Penetrator? The plans say 2 x 9". But the overall length of the rocket is 19", so that leaves just 1" for the nose cone , which we know is not true.

This issue is discussed in the addendum to the Penetrator plans that are archived on YORP. As the addendum says, it would make sense if the tubes had been 8"; then everything would add up. But the kit that contained the plans did, in fact, contain 9" tubes.

Thisa is especially weird since the FSI catalog does not list 9" lengths for tubing in this diameter, but does list that tubing in 8" and 16" lengths. (And why did FSI package the kit with two tubes that had to be joined together, and thus had to include a coupler for them, when they already had tubing that was the correct overall length that they could have put in the kit? ) So, has anyone ever seen a Penetrator kit that contained two 8" long tubes (or one 16" long tube)?

Mark

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SAM # 0011

Here are some pictures of my Viking II, with a correctly-sized lower BT (8") and correctly-sized tube fins (4.25"). Included is a picture of the corrected version standing next to the non-standard version that I had previously posted about. (The new, corrected version is on the left in that picture.) There are also some closeup shots of the tube fin-winglet combination. When it is viewed as a whole, the combined fin is actually a swept trapezoid. To me, the combined shape sort of resembles the fin shape of the Estes Yankee.

Mark

Attached Thumbnails

         

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SAM # 0011

Looking good Mark (both versions). Looks like you already got it prepped to fly

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Don
NAR 53455
"Carpe Diem"

Mark,

I think this is another instance of the design changing as the kit line matured. I've got both the old and new versions of the kit. When I get home for lunch, I'll pull them out and give you some info. The older kit is in a smaller bag with two BTs where the newer kit has a single BT. I think it was easier to ship the smaller bagged kits and when the kits started selling in hobby shops, they switched to the larger bags with less component pieces (this is just a theory and has no basis in fact)....had to add disclaimer

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Don
NAR 53455
"Carpe Diem"

Mine has two 9" tubes. ST-8F90 is our part number.

This kit was produced during the move. The instructions have the Louisville, Colorado address (marked through) and the header has the later Raytown, Mississippi address. An addendum in the instructions has steps to modify it for the NEW 18mm engines. Also the flameproof wadding has changed from fiberglass that was in earlier kits to something more like cotton.

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Carl McLawhorn
NAR#4717 L2
semroc.com

Oh, yeah, I was wondering about that "flameproof wadding" that was mentioned in every kit's instructions. I was wondering if FSI used some form of perma-wadding, that was meant to remain in the rocket and not be ejected. If it WAS meant to be ejected, and they used fiberglass, then, hmmmm... (not good... certainly not a feature that I'd want to reproduce .)

That reminds me of something that I forgot to mention about my EOS - I installed a Semroc EB-16 baffle when I built it. It was a piece of cake to assemble and install, and a very cool way to save on wadding. I sprayed mine with a couple of light coats of Rust-O-Leum high temperature enamel paint (the kind used to paint barbecue grills, etc.) before installing it, just to give it some extra protection. I will be putting an EB-225 baffle into my Hercules as well. Along with a whole host of other good reasons for using it, it sure beats putting fiberglass in the rocket.

Mark

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SAM # 0011