Micro Max size Mean Machine

Will it work?

A length of BT-5, a nose cone and some scrap balsa for fins.

I was always impressed with the original Mean Machine, wondered if it will work in a mini or micro scale.

I would probably go skinnier, BT-3 or BT-4, instead of BT-5, but it should be possible.

You could certainly build a BT-5 downscale of the Mean Machine - I would use the Quark nose cone for it. You would need 24" of body tube to scale it properly. However, it would be too heavy for mmx motors to lift. A minimum diameter (.26") Mean Machine would use a 11-1/4" long tube - that could be lifted by a mmx motor, especially if you use paper for the body tube (computer paper will do - it doesn't have to be that tough - and a balsa nose cone.

For a BT-5 Mean Machine made from Estes parts (24" BT-5 and PNC-5) I'd fly it on at least a 1/4A3-3 if not a 1/2A3-2. Without actually running it through Rocsim, I don't know if a 1/4A will have the oomph to lift it. 1/2A or A would definitely be OK - and just as a guess, I'd say guess that the shorter delay motors would work best.

You certainly want to go with a thinner tube (BT-2.5 or BT-3).

I have a BT-5 based downscale of the Richter Recker and with THREE micromaxx motors it only goes about 12 feet in the air... LOL

I've built some cardstock bt-5 sized Blue, Black and Pink Bird Zero that BobH designed. I'm guessing they're a bit heavier than a bt-5 MM would be using commercial parts. If you go bigger than 1/2A motors, stick to A3-4T for the best delay. You should get 500-600' out of it, maybe more.

I do this to myself every time I go into the hobby shops. Went in for one or two items and start finding all the parts and pieces and the brain won't stop until I take a bunch of the parts home.

The length of tube is 18 in. I was going to just glue in a thrust ring and some fins at one end and then figure out a paper or ribbon streamer recovery.

Super simple and light and use A motors. I could get another tube to lengthen it. But thought one tube would still have the long and lean look.

Guess this all started when I got the designer pack from Apogee. All sorts of good stuff in it to get the mind working.

See ya,
Rod

A BT-5 "Mini-Meanie" should certainly work -- like most "long-skinny-rockets" the original Mean Machine design is very stable.

The weight of the motor mount is higher, proportionately, in a mini-model, so you certainly should double check stability just to be sure, but just on "gut instinct" there's no reason a BT-5 version shouldn't work.

Although, as several have pointed out, you could run into weight issues with the MM motors -- they probably don't have enough kick to get a BT-5 version in the air -- you probably would be best off going with the 13 mm motors.

A BT-5 version Mean Machine should fly real nice on an A, I would think.

I haven't built one but have done some similar designs. There's no thinkin involved. A bt5 mean machine will give really nice flights on 1/2A and absolutely rip on an A3-4T. I think you will be really surprised at the altitude. only problem is packing the streamer and dog barf. I've actually had pretty good success making half moon style baffles with streamers or just nose blow recovery. For streamer the best option for me has been 1" marking ribbon from home depot.

I did up a quick open rocket and it will scream with an A motor.

Looks like it will work almost too good for a rocket this size.

View attachment Long Shot.ork

Just to further clarify, about the most you want a mmx model to weigh is 15 grams. (It'll lift a bit more, but not safely.)

Glad you did a sim on it - that will not only tell you if it is stable and how high it will go, but also how long the delay should be.

I have two mean machines, an original Estes kit and a 5.5"upscale (25ft tall mind you).

Just as an option for recovery you may want to consider back sliding. If you nosecone doesn't come off (from experience of course) the rocket will naturally "fly" backwards, really fun and interesting to watch.

Don't forget pictures if you decide to do it, it is a very cool design.

Bryce

I guess I should have posted this in the low power forums. This is possibly the most addicting hobby I have started.

There is one concern about the long thin tube. Ejection charge. Will the charge be strong enough to fill and deploy with all that area to fill. Or will it shoot out the streamer like a rifle shot?

Will be fun to find out.

RodRocket said:

I guess I should have posted this in the low power forums. This is possibly the most addicting hobby I have started.

There is one concern about the long thin tube. Ejection charge. Will the charge be strong enough to fill and deploy with all that area to fill. Or will it shoot out the streamer like a rifle shot?

Will be fun to find out.

Click to expand...

The ejection charge will be fine. I've done BT-5 diameter super rocs for competition that were 40 inches long and flew just fine on a 1/2A3-4T. It ejected without any problems, so your 20" rocket will work. Just make sure the streamer doesn't bind in the tube and comes out freely.

To be frank a BT-5 mean Machine of sorts was and estes Kit in the 90's called the Skinny Mini there was also a BT-20 size "Mini Mean Machine".

As others have said for micro power it'd be best to use either Minimum diameter motor tube T2+ (.281") or T3 (.375" OD) to get the most out of our micro motors. Over time many of us Maxx'ers have discovered to get the best flight performance to mass & bodydiameter, try to keep models at or under 10grams. Most over that 10+ to about 17grams well fly but not all that well.

Longest T2+ i've flown is something I called the ELE-1 or Extreme Length Experiment. That Experiment is a combined over all length of 103" long, flying in a single mmx-II motor weighed in at 17grams. the single motors ejection charge had no problem seperating the model some 68" forward at the T2 (.246") transiton.
Only flew to about 17-20feet but backslide glide recovery of more the 50yrds LOL!! turned out the be a better glider then rocket.

Where to put the launch lug or lugs. Is there a rule of thumb as to where they should go?

I have it done up to this point. Fins on, thrust ring in, and getting ready for finishing tomorrow.

Will add the recovery system later. I have some small tubes from Apogee that could be used to build a baffle system that could be pushed into the body tube.

I could also use this tube for a coupler to really extend the body tube out for a mean machine look.

Gonna be a busy painting day tomorrow. Several projects to get finished up.

Even though I've done it, I'd recommend leaving a baffle out. They're a pain to do that small. Just use dog barf. Is put a lug around the fin can area and maybe 7-8" up. Just a view on my part. Just do It.

As far as the launch lugs go, I'd use two lugs, maybe 1/2" long each. I'd put one at the base of the rocket (between or just ahead of the fins) and the second about halfway between the center of gravity and the back of the rocket (but no less than 6" apart). That way, it has plenty of guidance while it builds up enough speed for the fins to take over that job. As a small rocket, it'll get there pretty quick. Whether you place the lugs midway between the fins or just to either side of one is entirely up to you.

Welcome to the wonderful world rocket design and scratch building - The more you scratch build (and sim), the more feel you get for fin size, component placement and general shape and configuration. As for your earlier concern about ejection charge gasses filling the body tube, don't sweat it - Estes ejection charges are generally way more powerful than they probably need to be, and you will likely not come up with a design under BT-60 diameter that won't eject (for larger models, we use a stuffer tube, which is just the motor tube extended about halfway up the rocket with a centering ring at the end so the ejection only has to pressurize about half the volume).

Just remember to sim your designs when in doubt, and give yourself a margin of safety. Also, where you normally want about 1 calibre of stability (CG about one body tube diameter in front of the CP), with a super roc (long skinny rocket like the one you're designing) a margin of about 7 to 10 is recommended. Because of their length, super rocs can be less stable than the equations suggest (while short fat rockets are actually more stable than their equations suggest). So, for a BT-5 super roc, make sure the CG is at least 3.5" to 5" in front of the CP in the sim. As you get more into the design aspects of super rocs vs short fat rockets, check out the series of articles in the Apogee newsletter that talks about these subjects (If you haven't discovered this very valuable and free resource, go over to the Apogee website and click on the newsletter link - you'll be amazed at the number of subjects that have been covered, the number of free designs and all the ideas for new ways to do things you'll find there.

I fly a micro-Mean Machine based on two 18" BT-5s that separate in the middle to tumble recover. It goes surprisingly high on an A3 or A10 and puts on a great show, it goes straight up where you point it and always has a "perfect" flight. I've probably flown the thing nearly two dozen times now with only one body seperation failure resulting in a nosedive(body coupler was too tight), which only resulted in a loss of about 2" of body tube. I also use two launch lugs, one mounted near the fins and another about 8" further up. I also wouldnt worry about a baffle or wadding, i've never put wadding in mine and the standard estes shock cord rubber is still A-OK.

Rockaeologist said:

I fly a micro-Mean Machine based on two 18" BT-5s that separate in the middle to tumble recover. It goes surprisingly high on an A3 or A10 and puts on a great show, it goes straight up where you point it and always has a "perfect" flight. I've probably flown the thing nearly two dozen times now with only one body seperation failure resulting in a nosedive(body coupler was too tight), which only resulted in a loss of about 2" of body tube. I also use two launch lugs, one mounted near the fins and another about 8" further up. I also wouldnt worry about a baffle or wadding, i've never put wadding in mine and the standard estes shock cord rubber is still A-OK.

Click to expand...

Your flying a Sub Mini rather then Micro Mean Machine! if your still flying it on 13mm motors. We can't really call stuff micro until it gets into the micro maxx motor catagory IMHO. Lets try to keep the terms just a little clearer when we can.

It's done but needs a recovery system.

One 18" length of BT-5, a motor thrust ring, a plastic nose cone and three fins. Painted bright yellow. Will add some details later. Guess it isn't a full on mini mean machine. But still turned out good.

I should have asked this in the low power forums. Sorry if I started a bunch of confusion.

RodRocket said:

I should have asked this in the low power forums. Sorry if I started a bunch of confusion.

Click to expand...

A moderator should be able to move it.

Let's see some photos!

Its funny that you posted this, as about a week before your original post, I started the exact same project, a BT5 MM. I built it the same time I was building a full size Mean Machine. The big one for me, the "Mini" for my 4 year old son. We launched them both last Friday, the full size on an E9-6 and the Mini on a A10-3T. Both flew great.

The Mini has a 1 1/4" X 16" streamer for recovery, and it seemed to work well.

onesureshot said:

Its funny that you posted this, as about a week before your original post, I started the exact same project, a BT5 MM. I built it the same time I was building a full size Mean Machine. The big one for me, the "Mini" for my 4 year old son. We launched them both last Friday, the full size on an E9-6 and the Mini on a A10-3T. Both flew great.

The Mini has a 1 1/4" X 16" streamer for recovery, and it seemed to work well.

Click to expand...

Great looking rockets. Love the paint!

onesureshot said:

Its funny that you posted this, as about a week before your original post, I started the exact same project, a BT5 MM. I built it the same time I was building a full size Mean Machine. The big one for me, the "Mini" for my 4 year old son. We launched them both last Friday, the full size on an E9-6 and the Mini on a A10-3T. Both flew great.

The Mini has a 1 1/4" X 16" streamer for recovery, and it seemed to work well.

Click to expand...

Hey No harm no fowl LOL! so it's a True Sub-Mini Mean Machine flying on 13mm motors sorta like the old estes KIT. I still have and fly one of the BT-20 versions every on and then just for fun.
Very Nice Paint scheme...should make it a little easier to find.