Splat

If both motors are spinning the same way, then their rotation cancels each other out, and the output (red 1x2 thin liftarm in the pic above) does not rotate (assuming both motors are spinning at the same speed). If one motor is spinning and the other is turned off (with the switch in the centre position), then the differential casing will spin, but at half the the speed of the motor that is spinning. Then there is a slight increase in speed between the 28 teeth on the differential casing and the 20 tooth bevel gear. If both motors are spinning, but in opposite directions (one spinning clockwise, and the other spinning anti-clockwise, which is possible via the use of the switch which can reverse polarity), then both motors will spin the differential casing, and the casing will spin at the average speed of both of the motors. Having one motor connected to a switch allows you to control the speed of the output between stopped (not much good), low speed, or high speed. When one motor is stopped (situation number 2 above), that means that you only have one motor providing torque to the system. So while the speed is halved, you aren't doubling the torque at the same time. Therefore it is a low speed gear, but not a high torque gear. Whether or not one of the motors tries to back-drive the other motor really depends on the resistance that you have on the output of the differential (red 1x2 thin liftarm). If you want more 'gears' using a similar setup, you can have one side with the motor connected directly to the differential, and the other motor geared up or down a bit (eg, 24:8). This can give you the following gears: Differential side 1 @ 300rpm, Differential side 2 @ 100rpm, Output at 200rpm. Differential side 1 @ 300rpm, Differential side 2 @ 0 rpm, Output at 150rpm. Differential side 1 @ 300rpm, Differential side 2 @ -100rpm, Output at 100rpm. Differential side 1 @ 0rpm, Differential side 2 @ 100rpm, Output at 50rpm. Differential side 1 @ 0rpm, Differential side 2 @ 0 rpm, Output at 0rpm. Differential side 1 @ 0rpm, Differential side 2 @ -100rpm, Output at -50rpm. Differential side 1 @ -300rpm, Differential side 2 @ 100rpm, Output at -100rpm. Differential side 1 @ -300rpm, Differential side 2 @ 0 rpm, Output at -150rpm. Differential side 1 @ -300rpm, Differential side 2 @ -100rpm, Output at -200rpm.

Sariel has a 'Automated Trafficator System (2)' that he developed that uses three switches to create a set of flashing turning/indicator lights: http://sariel.pl/201...ators-system-2/ To explain the pneumatic pump regulator: the idea is that you have a motor that is spinning and moving a pneumatic pump which pressurizes a pneumatic system. Once enough pressure has built up, the pump will have a hard time putting any more air into the system, so you have a pneumatic cylinder that then switches off an electrical switch, which turns off the motor. Once the pressure in the pneumatic system drops, the cylinder will retract (thanks to a rubber band or spring), and this will turn the electric switch back on again, which will turn the motor on again, which activates the pneumatic pump and the system re-pressurizes again. The rubber band can be 'tuned' to turn the switch on/off at certain pressures. This allows you to have a replenishing air supply, but not burn out the motor trying to over-pressurize the system.

You can use two battery boxes, and two receivers both set to the same channel so they both receive the same signal. Then each receiver has two motors attached to it. This will also double your batteries so they will last longer, but will be heavier.

There are 5 little holes in these tread pieces. The holes are too small to insert a pin into, but are the correct size to insert a 'bar' (such as a light-saber piece or similar), although I can't remember if there is much 'clutch' with these holes. The holes are also the correct size for the little 'posts' that you find under a 1x6 plate, so these can be attached to the tread piece quite easily.

It looks like you are using a 12t to 24t (2:1 reduction) to rotate the switches (180 degrees of the servo results in 90 degrees at the switch). I have found that a 3:1 reduction seems to work quite well (either 12t to 36t, or 8t to 24t) (180 degrees of the servo results in 60 degrees.at the switch). I like your method of attaching the spare wheel. The two stages with the assistance of gravity is a great idea. In real life it would be quite difficult to lift up a large wheel like that, so I'd like to see it motorized rather than manual.

Nice forklift It looks like it has good maneuverability and can lift quite high. 8843 set uses chains to lift the forks, and uses the Technic chain tread that Lipko mentioned to connect the chain to the forks. More info at Technicopedia: http://www.technicopedia.com/8843.html 8835 and 8872 also used chains, but not in a telescoping motion like 8843 did.

Welcome to Eurobricks Great first MOC It looks like you have a great amount and range of parts to work with. I am also building a tank with two drive motors (connected by a differential) and an extra motor for steering, but I still have a long way to go. Reading about some of your obstacles will no doubt help me when I come across them too. One thing that I have noticed is that your drive-train module is fairly flat. I've found the problem with that is that they can flex too much, and the slightest bit of flex creates a lot of friction on the axles going through the frame. This causes a lot of the torque of the motor to be wasted overcoming this friction. Perhaps a more rigid 3D frame, or some extra bracing and triangulation will help? Please keep us updated with your progress.

I tend to build little modules out of real bricks to make sure they work as expected, such as gearboxes, winches, linkages, etc. Anything that 'moves' can be difficult to visualize within a CAD program, but once I have them worked out in real bricks, I re-create these modules in LDraw so that I can save the designs and refer back to them later, and I can reuse the real bricks for more modules. When it comes to the body work, I tend to use LDraw first, where I can make sure it is to scale and I don't have to worry about building up a supporting structure as I am adding the body - I'm just more concerned with adding the right panels at the right place. I might occasionally pull out real brick/panels just to see how thing look or if I'm not sure that two pieces really fit together. Using LDraw this way, I am able to build from the outside-in and not worry about 'gravity', whereas with real bricks you have to build from the inside-out. Then once I have the modules (gearboxes, winches, linkages, etc) and the body in LDraw, I add a supporting structure/frame/chassis that ties both of them together. One thing that you have to do here is make sure that the frame is rigid enough. Again, this can be difficult to visualize in CAD, but you get used to it after a while, especially after a few failures. Triangulation is usually the key here. Once I have the modules, body, and frame designed, I pull out the bricks again to see if it really works, then tweak things with the real bricks if needed, and recreate those changes in LDraw. I repeat these last steps until everything is just right. By the end of this process, I have the model in real bricks, as well as LDraw ready for creating renders and/or instructions.

Hi efferman, congratulations on being blogged on The Lego Car Blog: http://thelegocarblog.wordpress.com/2013/04/08/g-unit/

Putting anything out onto the internet and into the public domain means that it can easily be copied, especially in this digital age where it is just 1s and 0s. I have come to accept this and not let it bother me too much, but I don't think that it is right. When writing reports/essays/papers at an academic level, we are always told to include a bibliography - to provide the source of any quotes or facts within our work. As the saying goes: "Give credit where credit is due". When I created instructions for my Water Strider, I didn't even think twice about giving credit to Blakbird and Sinner when I used images that they created. I also asked for permission prior to using the images, which both Blakbird and Sinner were happy for me to use, and I think they both appreciated me asking beforehand. I have had people use my photos without permission, which is bad enough by itself, but they also removed my avatar/watermark from the photos. This means that, not only have they stolen my work, they have also removed any accreditation that I was the original author of the work. I think that in a lot of cases the original authors are just looking for some accreditation, and on the internet including a link back to the original source is the least that someone can do.

This means that the seller will only sell the piece in multiples of that number. So if it says x100, then you have to order 100, or 200, etc. More information: http://www.bricklink.com/help.asp?helpID=20&q=bulk

While waiting for Eurobricks to implement something like this, I developed my own little 'bookmarklet' that I use. It searches for numbers within posts, and add the set thumbnail image, as well as links to a larger image, Brickset, Bricklink, and Peeron. I do have to activate it on each page that I visit, but I tend to find that there are only certain posts that tend to have lost of set numbers mentioned. This could also be turned into a GreaseMonkey script so that it runs automatically. The Javascript can be found here: http://jsfiddle.net/J9ALL/3/ Info about 'bookmarklets' can be found here: http://en.wikipedia....iki/Bookmarklet Info about GreaseMonkey can be found here: http://en.wikipedia....ki/Greasemonkey Is it perfect? No. Does it incorrectly match prices, piece counts, and years? Yes. Are there other 'false positives'? Yes. But... it works well enough for me. Edit: This forum didn't like the code that I tried to include. Go to the JSFiddle Page to see the code.

You might find the images in this Brickshelf gallery by TechnicWorkshop helpful : http://www.brickshel...rkshop/LiftArt/ There are 68 examples of how liftarms can fit together.

I'm not too excited about the mobile crane, but I am looking forward to the service truck. I've mentioned it before (link), and I'll mention it again - I would like to see a fully RC forklift, which should be possible with the current PF components, and would be great if it had pneumatics with a compressor and an air tank. Omniwheels would be good too. The Brickset Advanced Queries are really useful for looking up this type of information. eg. Technic Sets since 2003 with 1000+ pieces

According to Rebrickable: if you only had 8258, you would have 63% of the parts needed to build 8109 : http://rebrickable.com/build_set?s=8109-1&s1=8258-1&c=1 if you didn't care about colour, you would have 81.8 % of the parts needed : http://rebrickable.com/build_set?s=8109-1&s1=8258-1&c=3 The pieces that you would be missing can be seen at the links above - scroll down the page a little bit. Of course, you could rework the design a little bit...

I think rm8 should at least get his name/initials immortalized somewhere on the model. Perhaps as a printed tile with his name/initials on the number plate, or as a sticker for the doors, or even on the hood or roof.

Your design looks like it is relying upon the resistance of the axle-pins with friction to route the power of the motor between different functions. This can work, however you will be adding extra resistance that the motor then has to overcome, and you may need to play around with different amounts of resistance to get it working just right. I have a proof-of-concept video that also uses resistance to achieve this (a rubber band/belt), but I have never used it in a finished MOC, and it might not be in the correct sequence for your needs. As you can see in the video, I didn't get the resistance just right, so it would have to be tweaked further, especially when a load is put on the linear actuators as the resistance would change. This recent video by Philip Verbeek also shows a system that you might be able to modify for your purposes (jump to about 15 seconds in): It relies upon the motor switching the position of the driving ring, and therefore routing power through a different drive-train. Using a differential, you could route the power of the motor to one output, and when the resistance is too great, it then switches a driving ring to route the motors power to a second output.

Congratulations rm8

While building official sets, I use up to four kitchen drawer sorter trays that I got from Ikea. They are extremely durable, and they only cost a few dollars each: I empty the bags from the sets into the trays, and as the sections of the tray aren't completely closed in, they let me move pieces around within them without having to juggle them from one container to another. When not in use, they nest on top of each other so they don't take up very much room. For the rest of my Lego, I store the pieces in Fischer boxes, which come in a variety of sizes as well as a various number of compartments per box, and various compartment sizes. The compartments have fixed dividers (I don't like the removable dividers), and as others have mentioned, they are almost transparent so you can easily see what is in each box. I then put about a dozen of these Fischer boxes into larger 60L boxes that look something like the one below. This lets me store my Lego away reasonably compactly, and also move large quantities of Lego around quickly (the wheels on the bottom help with this). Lastly, I use the lid from the 60L storage box as a type of 'tray' when making MOCs. I turn them up-side-down, so they have a lip around the edges to stop pieces rolling away, and the lid also has a number of small ridges in it that help me roughly sort the pieces as required.

This should just be a matter of elimination. Remote Controllers - On the remote, you mention that the little green light turns on when you push the levers up/down, so for now we can assume that the remotes are working. Battery Box - When you push the orange switch to either side (not in the middle position), does an LED on the battery box light up? If so, then we can assume the battery box is working. If not, then double check that the batteries in it are ok, and are the correct way around. IR Receivers - If the battery box is ok, it is time to check the IR Receivers. When the receivers are plugged onto the battery box, and the battery box is first switched on, the LED on the IR receivers should light up for a quick moment. IR Communication - As mentioned above, check that the IR Receiver is set to the same channel as the IR Remote Controller using the orange switches on both. For example, set one IR Receiver to position 1, and one Remote to position 1, and the other Receiver and Remote to position 4. Now when you point the Remote at the receiver and push the lever on the Remote, the LED on the IR Receiver should blink. Motors - If the IR Communication is working ok, the next thing to check is the motors. Try isolating the motors by plugging them directly onto the battery box and turning the batter box on (push the orange switch in either direction, just not in the middle). If the motors spin, then you know that they are working ok. If the motor doesn't spin then it may be faulty, so try the other motors to see if they work. If none of the motors work, then I would suspect that the battery box is faulty, but I would double check that the batteries are charged and in the correct orientation. Let us know once you have tried the above steps and it still isn't working.

From what I remember, 8 tooth gears on axles used to go through plates with holes. The design of the old 8 tooth gears allowed the gear to sit flush with the surface of the plate, whereas the new 8 tooth gear doesn't fit between the studs, so it sits above the studs. An example of this can be seen in the 8090 Technic Universal Set instructions here. In today's studless Technic world, this probably doesn't matter so much.

There are the large sprockets that timslegos linked to: But there are also the smaller sprockets too: If you want to just 'guide' the treads rather than 'drive' the treads, then there are lots of alternatives. Eg: or There are also the smaller treads that you can use too: These are used in some of the smaller sets, such as the 8259 Mini Bulldozer and 9391 Mini Crane. To drive these smaller treads, square edge gears are used, such as the 16t, 24t, or 48t gears. One good way to find the names of parts is to search for a set that has those parts, and look at it's inventory on Bricklink. Eg. The 8043 Motorized Excavator has these larger treads, so you could look through it's inventory here. Edit: If you are in the US, you can also get the treads and sprockets from the Lego Education website: Sprockets (10 large orange sprockets, 12 small black sprockets) = US$12 + shipping Sprockets and Large Treads (10 small black sprockets, 100 large dark grey treads) = US$12 + shipping Large Treads (120 large dark grey treads) = US$15 + shipping Small Treads (36 small black treads) = US$10 + shipping These may be more expensive than Bricklink, but it does allow you to order the parts in bulk.

Great work Barman You've done a great job of getting very natural and fluid movements.

No problem If you want to use multiple PF Lights (LEDs), then yes, they stack on top of each other (within reason). You would have the 9V Small Battery Box, then one of the PF extension wires, then multiple PF Lights (LEDs) stacked on top of each other. If you are making a space base, and have enough space (no pun intended), you could also use one of the PF Battery Boxes to power the PF Lights without the need to use the PF extension wire. If you just want to use the old light bricks, then you don't need to use the new Power Functions (PF) system at all, just use the old 9v components. The blue bulb is just a hollow cover that goes on top of the bulbs in the light bricks. As mentioned by Kevinatorrr, the light bricks use bulbs like older torches, not LEDs, so they give off a slightly yellow light without the bulb cover. The bulb covers were used to create coloured lights. Eg. red and blue for police/fire lights, yellow for construction, green for space (?). Some more information for you... Along the top of the 9V Small Battery Box are two rows of studs with metal electrical contacts on the sides. The light bricks and sound bricks sit on these studs. There are plates that have these same electrical contacts, which can then be stacked upon each other, and can also change direction by 90 degrees. There are also extension wires for this older 9V system in a variety of lengths: So, if you want to light up your space base with 100% Lego parts, I would suggest one of the following options: Use the 9v Small Battery Box with the older 9v Light Bricks, with the older 9v plates and extension wires. As this system has been phased out (last seen in about 2005), you would have to get the parts from Bricklink or similar. Use the 9v Small Battery Box with the PF Extension Wire, and the PF Lights (LEDs). The 9v Small Battery Box was last available in 1998, so you would have to get this from Bricklink or similar. Use a PF Battery Box, and the PF Lights (LEDs). These parts are currently available from Lego directly, or various other sellers (retailers, Bricklink, Ebay, etc). If you don't mind using non-Lego parts, you might want to check out LifeLites which have been used in a number of Lego MOCs with great results. Some LifeLite kits are powered by little 'coin batteries', others by 2xAAA, which makes them very compact. Some of the LifeLite kits also feature lighting patterns (the LEDs turn and and off in specific patterns), and this can add some life to an otherwise static diorama. Check out the LifeLites Flickr Photo Pool. Here is a recent example of a MOC with non-Lego lights: And behind the scenes (click the pics for more info): I hope this information helps. Good luck with your space base.

The battery box that the above posters are referring to is this one: Electric 9V Battery Box Small It was available between 1985 and 1998, in 22 sets, and came in black, white, red, or yellow. These battery boxes were designed to be used with the Electric Light & Sound Bricks and coloured bulb covers, as well as the monorail motor, the older square 9v motors, the micro motor, the fiber optics element, and a few other devices. But if you use a PF extension wire (here or here), you can use this battery box to power the PF Lights (LEDS). It can also power other PF components, but you are somewhat limited by the power of the 9V battery.