Two at a Time

 The Thrifty Rocketeer blog continues...

We've all done it.

You're shopping in a hobby store, and looking at the rockets they have for sale, and one catches your eye.  Gee, that looks like a fun little kit. I could probably enjoy making that.  So you buy it.

And before you can get to your build pile, you visit another hobby shop, and spot an interesting little kit. It looks like you could do it. So you buy that one.

And when you get home, you discover that you now have TWO of the same rocket kit.

Oh, I know, sometimes it's because someone gave you a gift, that you wind up with two.  Or perhaps one CATOs or crashes, and you want the fun of building that kit again.

But this time, I did it to myself.  Bored on a Thursday evening, I popped over to HL just before closing.  The clerk caught up to me after I dashed in the door, just to remind me that they were closing soon, and spots me checking out what they've got on their wall.

He's made an overture to me before, inquiring about rockets, and I've encouraged him to build one and bring it to our club launch.  But he never has.

So he stands next to me as I quickly scan the kits on the pegboard, and almost select one. No, it turns out it's a dual stage rocket, and I'm not into it.  I look over to the next kit, and recognize that it is a bit bigger, and will probably take Ds and Es motors.   So I turn and answer the clerk's questions.

I point out quickly that I don't think much of the "beginners" kits, as they are mainly plastic, and I don't think  you learn much from them. "Instant gratification" for the kids, I remark.  He nods.

So I point out that you can peek through the cellophane package and spot if it has a balsa wood sheet for fins inside. I tell him that as an adult, if you have minimal wood working skills, you'll enjoy this more.

I also point out that different size body tubes....and more importantly, the motor mount inside, will accept the various size motors.  I point out the recommended motors are printed on the packaging, and that this kit has A8-3, B4-4, or B6-4... while the next one over has those plus a C6-4.  I point over to the pegboard where all the blister packs of motors are hanging, organized by value from smallest up to larger motors and then multi-packs.  I tell him that if he hunts, he MIGHT find a combo pack of A, B, and C motor in a combination pack... except that I haven't seen one in a couple of years and certainly not here at this Hobby supply store.  He nods.

He asks, "Don't I need one of those launch stands?"  And I agree, telling him that he could buy one, or construct something that might get by in a pinch, until he gets to a club launch.  But I also point out the various starter boxed sets that include the introductory level rocket, launch controller and launch pad.  I point out that's the classic starter set that gives the kid instant gratification, and point out the price tag on it as well.

The overhead announcement reports the store is closing now and to bring our final selections up front to purchase.

He thanks me and says "now I've learned something else from you"...

I grab the larger diameter rocket kit that I had been evaluating before I got distracted, and take it up front.  I pay for it as the PA announces that the store is now closed.  I take it home and sit in my lazy boy chair to open the kit, and discover that it is an ESAM-58 that I have bought, and it looks identical to the one that I have just completed and is setting five feet to my right.

I sigh and realize that I didn't do enough research, and that I might have enjoyed that dual stage rocket kit instead.

But instead of returning it, I launch into the kit and start to prep it... building the motor mount and begin to sand the balsa fins once I snap them out of the balsa sheet.  I decide to try to do this one a little bit different, trying some different techniques than usual.

I look over at the first version, and remember that I painted the model after being glued together, and struggled with the masking off the fins, painting the body, painting the fins, repainting the fins, and again. Ultimately ending up with the color scheme I want, but finding the red paint has bled under the masking tape, and flowed over the white body tube where I was hoping to have confined it.   It looks tacky.

So this time, I prep the fins, sanding a leading edge on each, and then begin to seal the fins with a slurry of wood glue and water.  I sand between coats once they've dried, and I pre-paint the entire body tube.   Once I get the balsa sealed and sanded, I then lay them out on a piece of newspaper, and shoot them with the red paint. Well, the jet of paint tends to skitter them around...but the fins get painted BEFORE I glued them on this time around.

After two coats, I sand the root edge, and start to glue them onto the body tube.  I waited until the paint was dry, and I drew the 8 fin lines around the tube.  Now, I have glued the first four around the base of the tube, and after they finish drying, Glue the motor mount inside.  I also have cut the tail cone free from the nosecone and prepare to glue that inside as well, having used it as a spacer to shove the motor mount up inside enough to allow the tail cone room to be glued on.

Next, after using the plastic cement to glue the retainer ring on the motor mount, and the tail cone around the base of the body tube, I set to work on the next row of much larger fins. These are offset from the first ring of four fins, and produce a staggered effect.  After an hour or more, I have them all in place, having sanded through the white paint to get a good bond with the cardboard underneath.

And then I glue on the two smaller launch lugs along the appropriate fin line, checking to make certain that they are snug to the upper fins, and IN LINE to allow a  launch rod to pass smoothly through them.

And that's when it hits me.

I've glued the second ring of fins immediately above the bottom ring....with no gap, no space for a ring of decals.  As a result, my CG is going to be lower than planned.

I sigh, but realize this will distinguish this version from the original, along with the superior paint job. 

It's not all bad, but it reminds me that there is a reason why the instructions are printed in order...and that it was my own haste that caught up with me...twice.

I resolve that I'll have two rockets for the airshow demonstration.  One launching at a distance from the crowd, and the other... I can hold up over my head and tell them it's an exact duplicate, so they can recognize the scale of the rocket when it flies.

Yeah, that's the ticket. 

This has been the Thrifty Rocketeer, urging you to slow down and read those directions EVERY time.