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-   -   Mini Brute Mania! (http://www.oldrocketforum.com/showthread.php?t=10141)

Mark II 10-28-2011 08:49 PM

Mini Brute Mania!
 
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I don't just clone FSI models. ;)

From time to time in the past few years I have also built the occasional clone of an Estes Mini Brute. In 1971 Estes Industries began to sell the 13mm diameter, 1.75" long mini T motors. They replaced the Series III "shorty" motors. When standard-length 18mm paper cases were used, black powder rocket motors at the lower impulse levels were only partially filled, and some were as much as half empty. This unused casing was dead, inert mass that low-thrust A motors and fractional A motors had to lift along with the rocket. The shorty Series III engines were the first attempt by Estes to reduce this excess mass. To cut down on weight, they literally cut down the engine; Series III engines were rammed by Mabel into standard casings (presumably because that was what the motor-making machine was designed to handle), and then the casing was shortened by 1". This did help, but rockets designed for Series III engines still had to use, at minimum, a BT-20 body tube. Eventually, though, Estes was able to take advantage of much stronger paper casings to create engines at the low end of the impulse scale that had much thinner walls and much less inert mass. These were the "T" series of "mini motors" that are still very popular today. One of the consequences was that that the company could design rockets using the much smaller BT-5 tube. This created many new design opportunities. The company dubbed their new line of small rockets "Mini Brutes."

When the first few kits were designed, Estes was still using the "K series" to catalog their kits. They designated the first few with numbers starting with "TK-". Some, such as the Beta, the original mini Star Blazer, Midget and Birdie, were simply small K-series kits that were redesigned to use the new motors. When the company transitioned to using a four-digit all-numerical kit numbering system, the Mini Brutes were all assigned numbers in the 08xx series. Even today, if you see any Estes kit bearing a number starting with "08--" you can be certain that it is designed to use mini T motors. Estes reuses the numbers of discontinued kits for new mini motor powered models in order to maintain this numbering pattern.

Here and in the next few posts are photos of some of my "Mini Brute Mania" builds. To begin with, a group shot of five of them. In the front row, a clone of the celebrated Mosquito (now back in production!) and a Screamer. These were two of the first three MB kits that Estes introduced in 1971. In the back row, from left to right are a Super Flea, Javelin, Mini Bertha and Hornet. The Mini Bertha was third kit introduced at the debut in 1971. The Super Flea and Javelin were packaged together in a combination kit. The Hornet has a couple of interesting features. First, at 10.5" long, it was one of the smallest payload rockets ever produced. In addition, it uses the BT-30 body tube, one of the last Estes kits to ever to use that size.


Mark II 10-28-2011 08:58 PM

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Here are close-ups of the TK-1/0801 Mosquito, the TK-2/0802 Screamer and the TK-3/0803 Mini Bertha. These were the three debut kits introduced in the fall of 1971.

......



Mark II 10-28-2011 09:06 PM

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Next up, the #0815 Mini Brute Combo, consisting of the Javelin (left) and the Super Flea (right). I built a 433% upscale of the Javelin for my Level 1 certification (Javelin XL). A similarly upscaled Super Flea is in the works (Superior Flea).


Mark II 10-28-2011 09:13 PM

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The final one for today is the #0804 Hornet. i'll post more in the next couple of days.


tbzep 10-28-2011 09:27 PM

They all look great! :cool:

blackshire 10-28-2011 09:30 PM

Thank you for re-introducing (or introducing, depending on the age of the posting reader) Estes' Mini-Brute line! I'll have to practice to get back up to your paint finish results! Also:

Ruminating on this, every one of those rockets (with the exception of the tiny Mosquito) would make great school/Scout/4-H/Campfire USA/Civil Air Patrol educational kits that could be called "Econo-Flyers," because they would be inexpensive to fly as well as to buy. Estes (or someone else whose factory is in the Appalachians...) could offer them in bulk packs. Also:

Another good mini engine-powered "Econo-Flyer" is the Aero-Hi kit (see: http://www.ninfinger.org/rockets/ca...74/74est14.html and http://plans.rocketshoppe.com/estes/est0817/est0817.htm ). Weighing only 0.75 ounces without an engine, it would be an ideal kit to use the new 6" Estes parachute. In addition:

The Aero-Hi could easily be "inexpensified" for cheaper production *without* cheapening its quality *and* while making it simpler to build. Instead of using the balsa BNC-20N nose cone, it could use the plastic version of the BNC-20N (called PNC-20A, I believe) that is used in the Viking and Wizard kits. Also, the Aero-Hi could have laser-cut (or die-cut) fiber fins (as well as its Aerobee-like conduit [raceway]) instead of balsa fins. Its fins are small and are of such a planform shape that fiber Aero-Hi fins would be more than strong and durable enough.

stefanj 10-28-2011 09:37 PM

Those look great.

I remember when the Mini-Brutes came out. Centuri and MPC had had mini-motor out for a little while, and I remember being relieved when Estes jumped into the arena.

The only one of these I had Back In The Day was the Javelin / Super Flea combo. I remember bringing them with me to an event which was my first contact with the North Shore Section.

chrism 10-28-2011 09:40 PM

I like the mini brutes! 4 engines in one pack! I am glad to see that Estes re-introduced the mini booster engine.

Vanel 10-28-2011 09:41 PM

Awesome!

Mark II 10-28-2011 09:42 PM

Quote:
Originally Posted by blackshire
Another good mini engine-powered "Econo-Flyer" is the Aero-Hi kit (see: www.ninfinger.org/rockets/catalogs/estes74/74est14.html and http://plans.rocketshoppe.com/estes/est0817/est0817.htm ).
Come back tomorrow or the next day for a photo of my Aero-Hi and few others. I have to wait for more sunny weather in order to take their beauty shots.

chrism: so am I! You'll see why soon.


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