AVCampos

If the Rock Crawler puts emphasis on "crawler", I'd say it doesn't have any springs at all, at least on the front axle. For slow speeds, a pendular axle, like those on the 8284 and the 8261, ensures better that all wheels always touch the ground.

I don't know, I don't work at TLG... Maybe there was more pressure to release a motorisable model this year exactly because there was none last year?

I'd say that's probably what happened: for some reason they were short on time and had to make one of the 2012 sets motorisable, so this was the best compromise they could take.

There are already part numbers and names assigned to those sensors in LDraw, such as ms1034 for "Electric Mindstorms NXT Compass Sensor (Complete)". You could use those to avoid having the same part with different names in different contexts.

Thanks for the tip, placing the pump horizontally does make it that much easier to be at a proper distance! As for placing the assembly upside down, at least on theory I don't see what advantage it could have, but since I didn't try it on real ABS, I can't be sure. Yes. That happens because, when you reverse direction, first the worm has to slide to the other 12T gear, and then must rotate it enough for the attached 2L liftarms to move the switch. You can try using 8T gears instead of 12T and having the worm in a more confined space to speed up both actions, like in the image below. It has the advantage of being studless and therefore easier to integrate in different directions, but potentially ruins the delicate positioning required for the pneumatic valve.

Hi all! Having received news of the next LEGO Fan Weekend, my interest in my mothballed electropneumatic robot project has reawakened... and one of its main problems is getting a good RCX-controlled pneumatic valve. I searched everywhere for autovalve designs, but couldn't find any that told me "I'm ideal for you, build me". Here's what I sketched up, based on Sariel's design and adding a suggestion JAMS gave me at TechnicBRICKs. The motor isn't well braced (a PF M-motor would fit better and be more compact, but I need to use old 9V motors) but in this case I don't think it's very important. I also couldn't find yet a way (but didn't try very hard) to properly fixate the small pump (the 6L version is out of question for me at the moment). So, is there any design you guys recommend?

Actually, I happened to save the original images when they were online, and they managed to survive several hard disks until now. I have just uploaded them to Brickshelf here, so their folders aren't public yet. But meanwhile you can access the deeplinks, replacing the numbers at the end: Buggy: http://www.brickshelf.com/gallery/AVCampos/Misc/8448/Buggy/und640x480us0buggystep00.jpg (00 to 16) Concept Car: http://www.brickshelf.com/gallery/AVCampos/Misc/8448/Concept-Car/und640x480us0conceptstep00.jpg (00 to 14) Hot Rod: http://www.brickshelf.com/gallery/AVCampos/Misc/8448/Hot-Rod/und640x480us0hotrodstep00.jpg (00 to 16) Racer: http://www.brickshelf.com/gallery/AVCampos/Misc/8448/Racer/und640x480us0racerstep00.jpg (00 to 16) There are also instructions to "robotise" the 8448 with an RCX here. Since they're divided in subfolders and I guess you guys aren't that interested in them, I'll wait for the respective folder to become public instead of bothering to deeplink. Besides the standard version with gull-wing doors, I also built the Racer (I was lucky to win two 8448's in a contest at that time ). I remember it looked really good, but the front wheels rubbed against the ribbed hoses if the suspension was pressed too hard.

If the rotor spins slow enough, it should be OK. The 4895 helicopter is an official model and it has motorised, slow-spinning rotor.

The bunch of numbers you see is the textual representation of the LDraw model. You tried opening the file on MLCad, LDView or other LDraw program instead of LDD, right?

So far, this is my favourite of your 8271 alternates! To me, more than the 8022, it reminds me of the B-model of the 8414. Also, of all your one-set MOCs, my all-time favourite is still the 8294 Parrot.

My fluids physics are way rusted, so I may be mistaken; but I think what matters is, if a given volume of air has a given percentage of compressibility, more air inside the cylinder would make it more compressible (even if the piston's area is kept constant). Just like we can pump more into a pneumatic cylinder when there's an air tank included.

Indeed I thought it was a weird thing to mesh a 12T to a 24T that way and the protrusions in the photo looked further away from the teeth than in the mockup, but didn't think much about that. Anyway, I added the old differential's outer ring (which has 28 teeth) to the sketch to give a better idea about its size. Since the file's name and location are the same, your post already reflects the new version.

Could it be something like the small Technic turntable that came in only one set?

Here are high-res images for the entire Technic 1H2011 line: http://technicbricks.blogspot.com/2010/09/remaining-tecnhic-sets-for-2011.html

I hope I'm not too late: it's still before 00h00 GMT here... Anyway, thanks for the opportunity! 1. I don't buy them, but that's mainly because I'm more interested in other themes, namely Technic and Mindstorms. 2. I think this question is about the World Icons series, but my answer is about LEGO sets in general: I buy those that I find interesting and/or provide a good selection of parts for MOCs. I'd say it's a 50/50 proportion, although all my sets sooner or later get disassembled for parts. 3. There are a few I'd like to see made by LEGO: a famous bridge like Golden Gate, The Sydney Opera House, the Torre de Belém in Lisbon, the Louvre Museum, or perhaps the Chinese Forbidden City. 4. I'd like to see more variety of models in the Technic line, not just essentially trucks and construction/farming equipment. For example, the 8480 Space Shuttle is regarded as one of the best sets (perhaps the best set) that came from LEGO Technic, both in theme uniqueness and functionality, and a new version would certainly be highly appreciated. It would be an opportunity to incorporate today's Power Functions for things such as the landing gear and the cargo bay doors, as well as future elements like Power Functions pneumatic control for the crane arm and a blinker unit for navigation lights and the engines. 5. First the Power Functions elements, then the Linear Actuator piece, greatly contributed to the advanced control of LEGO mechanisms we today see both on sets and MOCs. However, pneumatics are still lacking a means of efficient control: they require manual handling of switches and pumps (compressors can be build, but then they must be manually turned on and off to maintain pressure). A direct way to convert electrical signals to pneumatic actions would be a welcome addition from LEGO, just like the Linear Actuator made converting rotary motion into linear motion easy. Not only it would greatly benefit a new Space Shuttle set, but also would allow sets like the 8868 Air Tech Claw Rig (another set highly regarded by AFOLs) to be re-released using current parts and mechanisms.