Themes – Page 27 – Bill Ward's Brickpile

Scissor Lift in Technic?

Have you ever tried building a scissor lift in [tag]LEGO[/tag]? I’m working on a project that calls for that kind of mechanism to lift it up, like those food service trucks at the airport. It is based on an “X” shaped arrangement, which, like the two parts of a scissors pivot at the middle. By bringing together the two bottom (or top) ends, the top is lifted into the air.

The approach I took was to use [tag]Technic[/tag] worm [tag]gears[/tag] (like a screw) with a rack gear on it. By turning the worm gears the rack gear should move along its length, which moves the two bottom ends together, elevating the top. The problem is that LEGO gears just aren’t up to the load this places on them, and the teeth skip. I motorized it, gearing down the motor to get more torque, but the gears would rather skip than lift the weight.

Has anyone out there successfully built this kind of [tag]scissor lift[/tag] mechanism in LEGO to lift a nontrivial weight? If so please comment below or email me any tips you may have. Thanks!

P.S.: Sorry for the gap in posts – I’ve been sick with a bad cold for a week or so…

Coastline

This is another model that I built 3 years ago but only recently posted the pictures online.

This, along with the recently posted Road Bridge, was built for the BayLTC train layout in 2003.

The cliff module was designed to come apart into several sections for ease of transportation and storage. Each section connected to the next one using Technic pegs. At one end, I built a peninsula with a space for Russell Clark’s lighthouse. It had an opening, recessed by one plate’s thickness, to accomodate a 16×32 stud baseplate.

The launch ramp road piece, like the road pieces on the bridge, came from LEGO’s 6600 Highway Construction set. It had stairs leading down to a small dock.

The lifeguard tower and beachgoers were contributed to the layout by club member Mark Benz.
[tags]LEGO, cliff[/tags]

Road Bridge

In 2003 (or maybe 2002) I built a bridge for the BayLTC train layout. But it wasn’t a train bridge, it was a road bridge (for cars and trucks).

The road pieces came from LEGO’s 6600 Highway Construction set, and the bridge’s structural elements were built of Technic bricks.

Most of the angles in the bridge truss design follow some multiple of the 3-4-5 triangle. This is one of the most useful laws of trigonometry: if you have a triangle with sides 3, 4, and 5, or any multiple of that (such as 30, 40, 50) then they will form a perfect right triangle (a triangle where one of the angles is exactly 90 degrees). Why? Because of the Pythagorean Theorem: in any right triangle, the square of the hypotenuse (the side opposite the 90° angle) is always equal to the sum of the squares of the other two sides. And it so happens that 3² + 4² (9 + 16) is equal to 5² (25).

In LEGO, the 3-4-5 triangle is achieved by attaching pieces in distances of 4-5-6 studs. Why? Because of the “fencepost effect” – if you make the connection on the 1st and 4th stud, that’s actually a distance of 3 (since 4-1=3). The same goes for the 4 and 5 unit length sides. In this model, the center trusses are formed by 3-4-5 triangles scaled up by a factor of 6. So the “4” sides (the vertical) are really 24 (actually 25, because of the fencepost effect) tall. The angled trusses are made by sheer guesswork, however. Luckily, there’s enough slop in LEGO connections to make it not really be necessary to always get it just right. When working on this, I built what I called a “Pythagorometer” – a model of the 3-4-5 triangle at various scales – to try to make the angles work out. I’ll post more about that later.

I recently discovered a batch of pictures of this bridge that had never been posted online, taken at the July 2003 GATS layout. You can see them at a Flickr gallery.

LEGO is Not a Crime!

Except in Germany, that is. It seems that a LEGO fan was recently arrested for playing with [tag]LEGO[/tag] [tag]Mindstorms[/tag] on a train. Thanks to my wife Holly for pointing this out.

The question is, how could anyone think that a robotics kit made from LEGO could be used to make a [tag]bomb[/tag]? I’ll give the cops credit for being creative, at least. I hope the guy gets his Mindstorms kit back!

Bay Area LEGO Train Club at Pleasanton Train Show in Nov. 2005

Last November, BayLTC participated in the Pleasanton, CA, Great Western & Atlantic Train Show at the Alameda County Fairgrounds. The event was held on the weekend following Thanksgiving. View the pictures on Flickr or on Brickshelf (once moderated).

Our next show will be at the TCA Cal-Stewart Meet in Santa Clara, which will be open to the public on Sunday, March 12.
[tags]LEGO, BayLUG, BayLTC, Train Show[/tags]

Kellogg’s LEGO Sculptures at Williamsport Airport

My wife and I visited her family in Williamsport, PA last September. There is a very small airport there which just has one gate, served by US Airways Express turboprop planes. So imagine my surprise when I saw LEGO on display there! They had a glass display case with LEGO sculptures of Kellogg’s Tony the Tiger and Toucan Sam characters, along with some of the Kellogg’s product boxes.

I don’t know why these were there, or if any other airports were included in this program, but I was very impressed with the models and very surprised to see them in such an unexpected location. As far as I know, neither LEGO nor Kellogg’s have any particular connection to Williamsport.

Bay Area LEGO Train Club at San Jose Train Show in Sep. 2005

Another long-delayed set of photos from a club event. This time, the BayLTC layout from the Great Western & Atlantic Train Show is featured. The show was held at the Santa Clara County Fairgrounds in San José, CA. View the pictures on Flickr or on Brickshelf (once moderated).

Our next show will be at the TCA Cal-Stewart Meet in Santa Clara. Perhaps you can come see us there! That show is open to the public on Sunday, March 12 only.
[tags]LEGO, BayLUG, BayLTC, Train Show[/tags]

Hot Mindstorms NXT News from MacWorld

At MacWorld I was talking to the LEGO Education (Dacta) guy there and he told me some interesting things about [tag]Mindstorms[/tag] NXT that I hadn’t heard anywhere else.

I already knew that the [tag]FIRST LEGO League[/tag] would be allowing use of both the old style Mindstorms RCX and the new NXT in the coming season. But since the NXT uses different sensors and motors, the question of backward compatibility has been an area of much speculation in the online [tag]LEGO[/tag] forums such as the LUGNET Robotics group. According to my source, LEGO Education will offer a cable that can connect legacy Mindstorms sensors and motors to the new NXT. He didn’t have specifics about the electrical connections, but it would be a cable that had the 2×2 brick connector used by the current Mindstorms on one end, and the offset RJ12 connector used by NXT on the other.

Also I was wondering about the ongoing life of the original Mindstorms once NXT is available. He was surprised when I told him that LEGO Shop-at-Home has already discontinued their Mindstorms Robotics Invention System kits (which include the 2.0 version of the RCX) but he assured me that [tag]LEGO Education[/tag] will continue to sell their Mindstorms sets (which use the 1.0 version that has a 9V DC power port), even after the NXT becomes available. I believe this is to avoid forcing teachers to replace their entire inventory with NXT sets.

Also, I asked about the power adapters for the NXT bricks. He said that there will not be a power adapter port in the NXT sold by LEGO Education, but that they would offer a special rechargeable battery pack which can be used instead of the usual 6 AA cell batteries. Teachers and AFOL’s who love the power port will be disappointed by this news, but at least the battery pack may have better life than the equivalent set of AA batteries would.

Finally, he confirmed that the NXT units can talk to one another using Bluetooth (but not using USB, as the NXT’s USB port is “slave only”), and that they will have a single address space rather than the current RCX design which segments the memory into five partitions for different programs.
[tags]Dacta[/tags]

Mindstorms strikes again

A little over a week ago I finally got around to ordering a [tag]LEGO[/tag] [tag]Mindstorms[/tag] set for the first time. I’ve been a LEGO fan for years but never got around to trying Mindstorms, LEGO’s [tag]robotics[/tag] kit that has been around since 1998. One big reason was that I usually buy LEGO in increments of $10-100 at a time, not the $200 that the Mindstorms Robotics Invention System would have cost. When I did get around to buying it, I chose the educational version from LEGO Education (aka Pitsco aka [tag]Dacta[/tag]). I got the ROBO Technology Set for $159 which should arrive in a few days.

Just a day or so after that, at the Consumer Electronics Show in Las Vegas, LEGO announced their next-generation Mindstorms kit, the Mindstorms NXT. Boasting a new 32-bit processor, Bluetooth, built-in USB 2.0, and a whole new set of motors and sensors, the new system promises to bring LEGO robotics to a whole new level. An article in Wired magazine shows how they involved adult LEGO fans to help design the new product, which was a great move by LEGO. They’re finally starting to realize that adults are a significant part of their customer base – and 50% of their robotics customer base, according to their own numbers. Hopefully they will be as accepting of “hacking” the new kit as they were of the original one. I bet someone gets Linux running on it by year’s end!

I’m looking forward to getting my new old Mindstorms set, but I’ll still be counting the days until I can get the new version in the fall when it comes out…