Saturday, January 29, 2011

Reviews: MODifications to the Apogee V2 and Semroc Tau Zero

On the 10.5mm Micro V2, I added a stretched fin section (the Blitzkrieg Booster) to allow it to fly on 13mm motors. On the Tau Zero, I merely put the fins on upside down. This is now a designer approved option. So sayeth YORF's Jay "Centuri Guy" Goemmer :D

Micro V2

What? No more 10.5mm motors for your Apogee Micro V2? No problem! See how I built an adapter unit to let my Micro V2 fly on 13mm motors.

The major parts include:

* - One completed Apogee Micro V2
* - 1 ¾" of 13mm tubing
* - ¼" of a mini motor casing
* - ¾" of a micro motor casing
* - Balsa fin stock
* - One wood screw (or other nose weight)

Construction is simple. Insert and glue the section of micro motor casing into the section of mini motor casing. In turn, glue this into the 13mm tubing with the mini motor casing flush with the end of the tube. For the fins, I traced the rear contour of the Micro V2 fins and then extended the pattern to make fin extensions that fit below the existing fins and run the length of the 13mm tube. I cut these from 1/16" balsa. When gluing them on, I inserted the motor adapter into the Micro V2 and then used the existing fins to align the new ones. Finally, I had to add some nose weight, so I grabbed a 'surplus' wood screw, and inserted it into the nose cone, through the existing clay. My CG with the booster unit inserted but no motor, is 4 inches from the tip of the nose cone. That much nose weight wasn't required, but I wasn't worried about the loss of performance.

I friction fit the extension into the Micro V2 with some masking tape, and did the same for the A10-3 motor. The boost was relatively fast and there was some wobble or coning, I couldn't tell which. Recovery was via the Micro V2's streamer and was successful.

This is an easy way to keep your Micro V2 flying until Tim comes to his senses and resumes production of his micro motors!  I have since repainted it (2nd from right):

Tau Zero

This is third and final kit that I received from the last 2009 Quarterly Rocket Give-Away so, once again, many thanks to Nick!

The Tau Zero, as you all know, is a futuristic rocket from Semroc that flies on 18mm motors and recovers via a streamer. As of this writing, there are no less than seven great reviews on this kit. As a result, I'm not going to cover the parts list, the basic instruction, etc. Rather, I'm going to state what stood out to me. You may also note that I flipped the fins over. I did that on purpose. At least, that's my story and I'm stickin' to it!

The only physical modification I made was flipping the fins so they are swept backward. I also used my own color scheme.

The parts are of the same excellent quality that you'd expect from Semroc. Laser cut fins and alignment guides, Kevlar® leader for recovery, and a pristine balsa cone. The cone is awesome, kind of a sleeker version of the Honest John.

Because the inner set of fins are supposed to be painted the same as the outer, but different from the ring fin, the instructions recommend that you paint the parts before assembly. Like the others who have reviewed this kit (ref., I did so.

Even though it is basically minimum diameter, a motor hook is provided. It is held in place with a telescoping outer tube, which is tucked neatly under the inner fins. I love laser cut parts :) Two fin guides are provided, one for each set of fins.

The quality of the cone was fabulous. The grain is fine and needs little filing. They recommend to drill a pilot hole for the over sized screw eye, and I heeded this advice. I also soaked the point tip in thin CA to toughen it up a bit.

I filled the balsa parts with fill'n'finish and Dupli-Color METALCAST paint system. This includes a silver base coat and a color coat. I used the base coat both as as a primer and as the silver coat for the majority of the rocket. The wing tip pods were painted with brush-on gold and the tips of the attached dowels were dipped in day-glo orange.

The decal set was great quality. However, the purple fins and nose section don't provide a good backdrop for some of them. I shuffled a few and left a few off.

I used a Quest 'long burn' C6-5 for the first flight. It really ripped on the C6. I lost sight of it but spotted the streamer at ejection. Then, I lost sight of it again. I thought it was lost but on the way home, I stopped on the high ground and grabbed the binoculars that I carry in my range box...and spotted it!

This is a slick looking rocket and a fun build. The parts are perfect and the instructions are great. However, I'm not a big fan of BT-20 body tubes. The fact that the Tau Zero recovers with a streamer mitigated this issue for me. It flies great and the streamer recovery is adequate for this sized rocket. Especially if you point the fins in the proper direction!


  1. "Ladies and gentlemen, please welcome the official Dick Stafford 'Reverse Fin' option for the Semroc Tau Zero."

    "I'm Jay 'Centuri Guy' Goemmer, and I approve this message."

  2. LOL. Now I know I flipped the fins on purpose :)