Monday, June 26, 2017

No man rocket left behind!

Whenever possible, I rebuild the carcasses of my damaged rockets. Last month, on its 23rd flight, my Half A$$-Tron Superroc lawn darted. It appeared the motor mound leaked the ejection charge. The mount was probably damaged when this rocket's predecessor shredded on a D21 and the so-called 'hibachi effect' from the composite motor cooked it. The lower body was warped and the paint had bubbled. That didn't stop me from rebuilding then and the lawn dart won't stop me now.

Here is the before photo:

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I am often surprised at the strength of good quality balsa. The nose is just slightly blunt and there one one paint chip. I touched it up with a Sharpie and reused it. It has character.

The top BT-20 was destroyed and has been replaced with a 6" long section.

The two sections of BT-50 (one blue and one silver) were largely intact with only a slight buckle. I trimmed the silver tube as the top was fairly beat up anyway. I added a whole BT-50 above that.

Some will say I should have replaced the buckled tubes entirely but I wanted to keep the ugly, warped, bubbled fin can. So, I treated the buckles with thin CA and wrapped the tubes with some Duck tape.

I cleaned out the motor mount and epoxied a new one in. Here is the result, now known as the 2nd Half:


Second Half

This will fly as a heads-up as this build is surely slightly crooked.

Wednesday, June 21, 2017

The transparent rocket progress

I goofed big time on the fins. At the last second, I decided to change their orientation, making what was the leading edge the root. Somehow, one was attached in the original orientation. D'OH!  I used (gasp) hot glue as not many types of glue work well of the polycarbonate tubing. So the errant fin should be easy to remove, right? Nope. This won't affect its flight but it looks a bit silly. But it is a silly rocket so WTH. Here are the best two:

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I went with a fishing line recovery harness. My original plan wasn't working out so I went with my favorite cord replacement technique. That is, punch holes in the airframe. This will be covered with clear tape prior to flight.

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I have a nose cone but will continue looking for one I like better. Here are the parts dry fit together.

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I am still deciding between a clear plastic-bag-chute or a caution tape streamer. I may just build a chute and then decide.

I am also chickening out on using an 'F' on its first flight. A D12-5 should work fine and the whole flight should be observable.

Can you see it?

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Sunday, June 18, 2017

Transparent rocket back on track

Well, sectioning the larger T12 FTC tube worked out perfectly. The sectioned tube curled and a 29mm motor fits nicely. This tube also fits well in the T8 body. The F15 motor is a little snug but still inserts just fine. The section tube extends out the back about 3/8" and I built up a thrust ring with clear packing tape. I also taped the two tubes together.

Back to the nose cone!

Saturday, June 17, 2017

Clear rocket woes (updated! Is there hope?)

First the good part. I cut some Lexan fins. The little plastic tabs were just too small.

Now the bad part. I sectioned a lamp cover and found that it contracted tightly to about 18mm. I thought a bunch of spent 29mm motors would hold it in place while I taped it with clear packing tape. One layer of tape held the motor loosely and it meshed nicely with the outer tube. So far so good. However, the packing tape wasn't enough to keep the tube open. Once the end motor was removed, it began to tighten and the removal of the other motors very difficult. I tried tape in both directions and neither worked. After 2 attempts, I'm punting.

If I had another set of perfectly sized spacers to place every 6 inches or so, that might work. But that is a level of precision is not readily attainable. I'm not going to spend much on this so buying a commercial clear tube (say clear PVC) isn't in the budget (ven if a perfect diameter could be found).

If the sectioned tube doesn't fit snugly, it doesn't seem to add much strength to the body, which was the main point. The final problem was forcing motors out of the tight tube did a good job of scratching up the inside, so it no longer looks crystal clear.

UPDATE:  I may have a solution. Since the tube curls to a small size, maybe I can try a T12 FTC tube. When it shrinks, it might serve as a liner to the T8?

Bah

Decided not to go to the launch. Apologies if anyone read my skeleton launch report and want to see flight reports. Maybe tomorrow, maybe next month.

Friday, June 16, 2017

My bad...

It appears I had already posted tomorrow's launch report (without results, of course). The post got 50 views. D'OH!

Thursday, June 15, 2017

More on the clear rocket


(Don't look at the component dimensions, just how they fit together.)

My only progress on the mindsim is the concept on how the inner and outer bodies will fit together. The inner, sectioned tube will not be permanently attached. Instead, it will sit about 1/2" below the main body. I will add a tape thrust ring and then will tape the two sections together. The same method will retain the motor in the inner tube.  The shock tether will be some thick monofilament line from my Dad's old tackle box. It will be mounted through-the-wall to the inner tube. Tape will hold it all together and the inner tube is easily replaceable if it doesn't clean well.

Nose cone: I've thought about PET bottle preforms (hat tip to George and Brian), rolled plastic, heat shrunk PET plastic, plastic packaging from teardrop-shaped bulbs.  So far, the translucent plastic vial I alluded to earlier is the front runner. Not as clear as I'd like but it is about the right size and it is free.

Fins: I'm not quite satisfied with what I have so I'll keep scrounging.

Recovery: I have conflicting advice. Geroge says a clear chute and on a TRF thread I saw that a colored chute might be advisable if I want to find it. I'm thinking about a long caution tape streamer.

Name: Wonder Woman's Clear Rocket?

Wednesday, June 14, 2017

My latest mindworm: a clear rocket

My mind has latched on to the idea of a clear rocket based on a T8 (~30mm) fluorescent light cover. A 29mm motor will fit very loosely but masking tape will take care of that. My thoughts:

  • My last one, based on a T12 (more like BT-60 IIRC and only the body was clear), crumpled on a RoadRunner F-something. Since I would opt for an F15, I am thinking of doubling up the body, which might help with the motor fit also. The F15 is milder and the smaller tube would be stronger, but there isn't much penalty weight wise. Plus, if it is merely slipped in, it might be a way to get rid of the ejection residue.
  • I have a couple of options for fins. I have leftover Lexan (heavier) and some small clear plastic dividers. Six of the dividers seem like they will do the trick.
  • The tall pole will be a clear nose cone. I dug up a suitable translucent doohickey but if it isn't crystal clear, I might just as well use something with a solid color. I tried heat-shrinking a clear bottle but getting one down to 29mm is too much. Maybe if I start with a skinnier bottle?
Anyway, the search for the nose cone is up first. Meanwhile, other fin options may arise.