Vol. 11: Reader Input

Letters from our readers offering praise, brickbats, and swell ideas. We Make Amends here, too.

A friend recently showed me Volume 10 of your magazine, specifically pointing out the article by William Gurstelle, titled "Happy Blastoff."

Being a hardcore rocketeer, as you can imagine, I was very happy to see the article in your magazine. As I read the article, the last section, subtitled "Amarillo Red's Extra Kick" really grabbed my attention, as I was involved in the Delta III project described therein. I loved Mr Gurstelle's rendering of our project and flight (although he was kind enough to leave out the detail that I was screaming like the proverbial little girl after the rocket landed), with a couple minor nitpicks.

While our first (less than spectacular) flight of the Delta III was in Kansas at an event hosted by the KLOUDBusters, the rocket itself was built by a group from Nebraska, with a few Iowans thrown in for extra flavor. The phrase I coined to describe the project, and others we have cooking, is "insane projects." If you're interested in more information, or photographs, you can find them, and lots of additional information, at http://www.rocketryonline.com/rolpresents/index.php?site=insane.

We feel compelled to add the disclaimer that no KLOUDBusters were harmed during the construction or flight of the rocket.

Kevin Trojanowski Project Lead, Insane Projects troj@cox.net

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I think there is an error in MAKE, Volume 10, page 192, in the "Homebrew" article by Michael Wernecke, titled "My 5-Foot Radio-Controlled Submarine."

The phrase: "blow water out of a ballast tank in order to submerge" appears in the second paragraph.

Isn't this backward? Don't you blow the water out to surface, not submerge?

Mark S. Fineman

Editor’s note: Good catch, Mark. The author asks that we assure readers that he built it correctly, but obviously he described it incorrectly.

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When I read the Cool Photo Websites article in MAKE, Volume 10, I was surprised to not see Picnik (picnik.com) so I thought I'd mention it. It's like Snipshot but has a lot more features and lets you upload and save to many places (your computer, Flickr, Facebook etc.). I love using it when I don't feel like using Photoshop for simple tasks.

Jack Amick

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My 13-year-old granddaughter received her first issue of MAKE this month, and I happened to be visiting her from Cincinnati. She loves to do projects, and we typically try to do them together. She had identified the $5 Guitar Amp, and we began to make it. First, of course, we went to RadioShack per the article's suggestion and I quickly realized the $5 project was going to cost $50+ (including $10 for one-time-purchase things).

I felt that the instructions/circuit diagram was very inadequate for beginners like us. I recognize that your typical reader might be more advanced, and therefore you don't want to be too simplistic, but I suggest you could you use a web page to have a more complete/simple diagram to be used by people like us. In particular, I felt the discussion about the "ground" was very inadequate and I still can't figure out where the third wire (blue) goes. I would also like to suggest that since you are using as your example three different color wires, you should stick with them in the diagram, not introducing a new one (green).

At a minimum, please advise where the blue wire from the 25-ohm rheostat goes. Also, we couldn't find speakers at RadioShack and after much searching were able to come up with an 8-ohm 25-watt unit that may work. Also, maybe you could suggest where to get items, because even though we live in a big city, Chicago, there aren't many stores that contain these items.

We both feel that your MAKE magazine and Makezine.com website are wonderful, and look forward to working on future projects (but hopefully ones that won't cost far beyond the projected amount).

Thank you for your quick response. Anxious to complete the project.

Blake and Tom

Author's response: Thank you for your interest in the crackerbox amp project, and your comment regarding the misleading build cost is a fair one.

Some general assumptions were probably made about what stuff the garden-variety maker might have laying around the workshop, and these are not universally valid. A few others have pointed this out as well, so apologies for that.

The good news is that your speaker should work well and be plenty loud enough for practice.

Sorry about the frustration with the hookup diagram and schematic. The rheostat should be connected to:

  1. the negative side of the 220uF capacitor
  2. the positive terminal of the speaker
  3. ground

One very handy and inexpensive item that you may consider investing in is a small breadboard. This will allow you experiment with connections and make discoveries prior to soldering.

As an alternative to RadioShack, try mouser.com.

Please give it one more try, and if it still doesn't work, let me know -- we'll get it working!

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Just a quick note to say thanks for an excellent issue.

I enjoyed reading the magazine cover-to-cover and really appreciated the electronics primer [special section: Home Electronics].

I'm looking forward to more in-depth electronic projects and perhaps some along the lines of the 'hardware hacking' or 'home hacking' books [in O'Reilly's Hacks series].

Anyway, thanks to the team for a great volume!

Ken Williams

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My first thought on seeing the review for Brinley's Rocket Manual for Amateurs was: "Darn, scooped!" I was hoping to review it, along with two other rocket motor making books.

My second thought was: "Whoa, hang on there, fella!"

There's no question that Brinley's book is a seminal work in the field, but there are far better alternatives to the temperamental zinc-sulfur fuel it describes.

Most modern-day amateurs work with "composite" fuel made from ammonium perchlorate and a rubbery binder. It's not only safer than zinc-sulfur or black powder (the fuel used in common model rocket motors), but far more powerful. It's almost impossible to ignite accidentally.

"EX" rocketeers also create hybrid rockets that use molded plastic for fuel and nitrous oxide as an oxidizer.

Stefan Jones

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Dear Editor,

I have only seen one issue of your magazine (Volume 09), which made me peruse your website. I have to say I am very impressed!

In fact, I have not found another publication worthy of Omni magazine since April of 1995! That is, until I found your magazine! (I have every issue of Omni magazine from October 1978 to April 1995, me being an Omni disciple.)

Your magazine and website are like an old friend I've missed for quite some time, and I am so freakin' happy to have discovered you I had to let you know! Massive kudos to you!p>

Amateur Scientist Mediocre,

Richard Brown




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