The Mercedes Unimog is the quintessential go anywhere four wheel drive work vehicle. Developed in post war Germany for agricultural use, they were taken over by Daimler Benz in 1951.  Portal gears on the wheel hubs allow the axles and transmission to be higher than the tires center, giving the Unimog a higher ground clearance than the Humvee. They also have a flexible frame that allow the wheels a great range of motion. These combine to allow the Unimog to climb a shear vertical step several feet high. They are used by various countries military forces and when decommissioned are often imported to the US and used by extreme four wheel drive enthusiasts.  They have been made in a variety of variants including a radio box truck, ambulance, troop carrier, and snowblower and are now offered in a variety of modern construction job variants. If I had more garage space (and disposable income) I would love to own an old radio box or troop carrier.

Lego is . . .  well really, do I even have to go into how awesome Lego is? Combine awesome truck with awesome building toy and you get the new Lego Unimog model.

Lego has announced their largest model kit ever is going to be a 1:12.5 scale Unimog U400 truck, and what can I do but come down with a serious case of the “I wants”. It even has a working pneumatic crane.

I want it even more than this awesome VW Beetle set (the blocks just don’t do the beautiful curves justice) which was the previous lego model I drooled over.

Unfortunately at $250 I won’t be ordering one right away, but I will always keep my eyes open for a good sale or used set, and dream…. that is still free. Some more pictures to enjoy:

After busting my back shoveling Minnesota snow for the last 12 years I finally broke down and bought a used snowblower this summer. But my old Snapper 10hp blower just doesn’t seem as mighty after seeing the above photo of Klimov VK-1 engines from Mig-15 jets mounted on the front of trucks to clear snow from airport runways in Russia. Now that’s a snowblower! I wonder how my neighbors would feel about one of these in the driveway?

And here is a Mig-17 powered ice melting machine:

I would think you would have to be careful not to torch the whole plane with one of those beasts.

[Gizmodo via TechEBlog]

Some time ago I posted about the Ripsaw tracked vehicle. Well now it has apparently come up in the world as a real military vehicle. They have some big budget funding and are now developing the Ripsaw MS1 as an unmanned attack vehicle for the US Military.

Built by twin brothers, Geoff and Mike Howe of Barwick, Maine, the Ripsaw can careen at high speed over obstacles that would leave a vehicle’s crew dazed and bruised.

It is fast, it is agile, it is dangerous. It is not armored, but can carry a remotely operated M240 machine gun. The makers hope it can help troops in Iraq deal with roadside ambushes. In one of their videos they say that in over 6 years of extreme testing they have never once thrown a track. They did once manage to break a shock mount, but the vehicle continued to operate fine.

Howe and Howe Ripsaw MS1 and more videos from Howe and Howe

(via Defense Tech via Crunchgear)

A few videos from their site pulled over to YouTube. Some show the earlier manned version:

The crazy crew over at Top Gear decide to help the London mayor choose which style of bus is best. A mad race ensues as only they could pull off. To their credit, they do make it almost one half lap before making contact with each other, and then it is all down hill form there. I just love watch that long “bendy bus” wag its back half around high speed corners, and the double-decker managed to stay upright (though often on two wheels) longer than I thought it would. Watch all the bus smashing goodness below.

from TechEBlog

I have returned from Airventure 2008. My feet are a bit sore, my skin is a bit tanned, and my head is swimming with more images of airplanes than it can hold. Even though I knew from last year that this was a huge event, I was re-amazed as I discovered several more hangars and complete fields of planes that I had not reached before. I was there for three full days and was still not able to see it all.

A few notes;
I was looking forward to seeing the V-22 Osprey tilt rotor plane which was supposed to arrive on Tuesday, but apparently they pushed it back to Thursday which was beyond my stay so I did not get to see it. It looked like they had the Harrier fill in for it which is always a impressive sight in it’s own right. They must have burned more than our annual household budget in jet fuel as it hovered and turned for several minutes and performed repeated vertical takeoffs and landings. And let me just say, wow is that thing loud on hover! In case there was any doubt, the Harrier scene in True Lies was complete fantasy.

Tuesday they unveiled the new Martin Jetpack. Unfortunately, unlike the rest of the event, this was not so well organized. A massive crowd encircled the designated spot, leaving only a small circle around the pack, which was of course not large enough for their planned demonstration flight. So, as the planned time came and left, they were still struggling to push back the crowd into a larger circle which was of course difficult and potentially dangerous as the front rows tried to back into a tight crush of people who did not want to back up. They then moved around their little platform and podium several times and finally began setting up their PA system while the crowd grew hot and impatient. When they finally pulled off the sheet to unveil the “Jetpack” a child called out what was probably on the mind of many there, “it’s not a jet! it has propellers!”. Indeed, the “Martin Jetpack” is not actually a jet at all and instead sports two ducted fans connected to a 200hp, 4 cylinder 2-stroke engine (water cooled). They explained that they were not cleared for an actual flight among the crowd due to safety reasons and instead performed a short hover with a handler holding each side of the pack. Many people wondered aloud why they didn’t take it out to the runway for a real flight. Talking to them later at their booth I learned that they are keeping it in the “ultralight” classification by limiting the onboard fuel to 5 gallons, which should give a 30 minute flight time, and the top speed to 60mph, although they have not reached that speed in tests yet. They are also including a ballistic parachute system for safety, the only problem being that the chute can not operate under 400 ft, and the cushioned landing legs can only handle up to about 10 ft, which still leaves them with a safety issue for anything in between. They have looked at the zero altitude, zero speed chute systems used in military ejection seats, but found them prohibitively expensive. They say that overall the pack is very stable and training time is only about 3 days, being much easier to handle than a helicopter or even a small plane. Currently the control system is all mechanical, but they note that the future addition of a computer system could help overcome pilot error. It is indeed an impressive looking piece of technology, although the big unveiling was not worth the hot crush, and it is not clear to me who the market for such a device would be.

And speaking of new technology with out a clear market, the folks from Terrafugia were showing off their new flying car prototype, insisting that, “it is not a flying car, it is a road-able aircraft.” An interesting concept which has certainly been tried many times, but leaves some interesting questions like, how safe is it on the road, how does it handle on the road, or in the air for that matter, and what happens in a fender – bender? I would guess the answer to the last one is a very expensive repair bill and re-certification for flight. They claim you can fly to a destination airport, then drive in to town, or that you can continue a long trip on the road when flying conditions become unfavorable, but the only real niche for this that I can see is those new “fly in” communities with their own small airport. Saves you having a hangar I guess.
The aerial displays were amazing as usual. I still am boggled by the way those stunt pilots manage to put their planes into an end-over-end tumble which in no way seems to include the characteristics of normal airplane flight, then recover and zoom on. An interesting additional this year was the world’s’ first acrobatic helicopter display. Chuck Aaron, the only FAA certified stunt helicopter pilot, put his stock BO-105 CBS Red Bull helicopter through rolls, loops and flips to the delight of an amazed crowd.
Another piece of acrobatic work that grabbed my attention was Matt Younkin’s astounding performance in a Twin Beech 18. Seeing a large old twin engine craft like this scream towards the ground to pick up speed, then pull up sharply into a loop, or haul over into a roll was really something. I could hear those engines roar, heaving that beast through it’s maneuvers and part of me kept wondering why those wings didn’t rip themselves from the fuselage.

There were many many more exciting sights than I can list here, not the least of which were the field after field after field of beautiful vintage aircraft. I seem to particularly like the lines on the old sea planes. Interestingly there seems to also be a trend in the new Light Sport plane market for small sea planes which offer the freedom to fly in to all kinds a beautiful lakes and small ocean island locations.
Airventure Oshkosh is a great time for anyone who is even passingly interested in airplanes. If you get the chance to go, I recommend it. Now I have to continue sifting through the 700+ photos I took. I will be uploading photos in groups to my flickr set over the next few days. Look there in a few days for lots of photos and a few short videos.

Tomorrow morning I depart for Oshkosh Wisconsin for that amazing airplane extravaganza known as Airventure. Put on by EAA (Experimental Aircraft Association) the Airventure airshow is the premier non-military airplane enthusiast event of the year. Last year was my first year at Oshkosh at although I knew it was going to be big, I was still taken back by just how huge it really was. I think I read that there were over 10,000 airplanes and 300,000 visitors in attendance over the week of the show. The amazing thing was that it did not feel crowded because it covers such a massive space. Their web site states, “If you were to walk past … not down … each row of airplanes, you would cover 5.2 miles! “.  It certainly can be overwhelming and requires some comfortable shoes and good sunscreen. Just about every kind of flying machine you can imagine is represented, from antique biplanes to experimental tilt rotor VTOL airplanes, and although it is billed as a civilian aviation airshow there is certainly a significant military presence as well. Last year I got to witness a Harrier come to a stop in mid air and perform a vertical landing (having previously only walked around one parked on the ground) which was quite the sight. This year the V-22 Osprey is on the schedule. The airshow itself is an amazing feat of air traffic control with many groups and formations of various planes all coming and going and crossing overhead at the same time. Like last year, I will of course be taking lots and lots of airplane pictures again this year, so check back next week if you are interested in that kind of thing.

I am back, and I had  great time.

I have always thought tugboats (or water tractors as they are sometimes called) were pretty cool. Maybe it was the Little Toot book I enjoyed back when I was just a little toot myself, or maybe it is all that raw power packed into a small no frills work machine, like a locomotive for the water. Indeed, I read that some tug boat engines were originally designed for locomotives, then had a sump oil pan added to handle the rolling sea. I have recently learned that many tug boats do not use a conventional propeller (or “screw” for you nautical types) for propulsion, but instead use a fascinating system called a Voith Schneider Propeller (VSP) which combines propulsion and steering in a single efficient unit. Developed nearly 78 years ago, the Voith Schneider unit uses vertical blades protruding from the ships hull from a rotating disc. The blades all travel around a common center axis, while each blade can also rotate on its own center axis. The pitch of the blades is continuously varied as they rotate around the circle so that they push against the water in one direction, while slicing though it in the other. This allows the system to produce thrust in any direction, or produce a rotational thrust around the center of the unit. This system allows a tug boat to move in any direction regardless of which way it is facing, and allows it to rotate in place, giving them excellent maneuverability in tight spaces. Keep reading for more details, diagrams, links, videos and more.

Some large ships combine two VSP units working in tandem. These units are also used on ferries which need to align with a dock on both ends of a route without having space to turn around.

Here are some nice pictures and diagrams to aid my awkward description.

This is an excellent animation from Wikimedia Commons:

Watching the animation I can see that the blades actually oscillate back and forth, pushing with one side for one quarter of the rotation, then the other side for the next.

Here is a better description from the Voith web site:

Over 80 years ago this ship’s propulsion system, the only one of its kind in the world was developed by Voith from an idea by the Austrian engineer Ernst Schneider. It allows thrust of any magnitude to be generated in any direction quickly, precisely and in a continuously variable manner. It combines propulsion and steering in a single unit.

This solution is as convincing as it is straightforward: on the Voith Schneider Propeller, a rotor casing which ends flush with the ship’s bottom is fitted with a number of axially parallel blades and rotates about a vertical axis. To generate thrust, each of the propeller blades performs an oscillating motion about its own axis. This is superimposed on the uniform rotary motion.

Blade excursion determines the amount of thrust, while the phase angle of between 0° and 360° determines its direction. As a result, the same amount of thrust can be generated in any direction, making this the ideal variable-pitch propeller. Both variables – the magnitude and the direction of thrust – are controlled by a mechanical kinematic transmission.

They even have a very cool Interactive Voith Schneider Propeller Program
that allows you operate the controls and see the blades in action.

It turns out that the Voith Schneider unit can also be used to provide roll stabilization, as dramatically demonstrated in this video:

Model R/C boat enthusiasts have also begun using Voith Schneider propellers in model tug boats and fire boats. Graupner makes a unit (shown below) , and it turns out Voith themselves have made a pdf document available with various complicated formulas and diagrams for making your own VSP unit, pointing out that it is not possible to simply scale down the design of a full size unit.

Here is a short video of a RC Tugboat using a Voith Schneider drive. It does a good job of showing the extreme maneuverability the drive provides on full size boats as well.



On a related note, Voith produces a full size radio control boat, or “Bow Steering Module” to be used in helping to guide a group of vessels being pushed from the rear. These units can be placed in the front, or middle of the line and controlled from the main pusher boat in the rear.

Voith also has some related products like a Cycloidal Rudder and a Turbo Fin

Links:

Voith Turbo Site – Voith Schneider Propeller

Tugboat Enthusiasts Society

Google Search for “model rc voith schneider”

My son B and I were trading creative insults the other day for laughs. We had some good ones like, “you are the little hole in the ground you don’t see until you twist your ankle”, or “you are that little piece of plastic wrap that you can’t throw away because the static cling keeps is stuck to your finger.” In the end he won hands down with “You lackluster automobile.” I may be a biased parent, but I think that was a brilliant way to sum up so many subtle ideas and feelings in two short words.

At 80mph it beats the M1, but is probably still to slow to win a rally. Still very impressive creation with 450hp blown 427 and 14 in of suspension travel. Autoblog has a nice description and video, and the makers have a less useful site with some pictures and broken video link.

Read [via Autoblog}

Update: New post here

Howe and Howe have developed this concept vehicle into the Ripsaw MS1, an unmanned fighting vehicle for the US military, and are developing several other special purpose tracked vehicles.

Over at Crabfu SteamWorks an artist named I-Wei Huang is showing off some really fantastic and amazing steam powered model vehicles. He has created walkers, tanks, 4×4 trucks, 6 wheel rovers and more very cool stuff. I have always been fascinated by the basic nature of steam engines. You can make a fire, and it will move your vehicle. I also love the sounds, the deep throaty CHUFF of a really big old steam tractor.