Blakbird

If you want to build a tractor-trailer, I don't think this would be the truck to start with. It has a long frame chassis and much of the mechanisms are for the wings and lift gate, none of which you would need. You'd end up making a totally different truck.

Hmm, that's probably why the motor doesn't have an axle output. The pulley is the only way to use it and the pulley is not tight enough to stall the motor. However if you stall it with your fingers....

Standard superglue (cyano-acrylate) outgasses as it cures which will leave a white residue on the plastic. To avoid this, buy "foam safe" CA. This is a different formulation made to be safe for foam R/C models. You can get it at any hobby store.

This is not a Technic topic. Moving to "General Discussion".... Several similar articles are already under discussion there. The guy writing the article doesn't seem to know much. The "expert" quoted who says that Meccano is the only way to experience how things really work has apparently never heard of Technic.

I'm not picky about using the full actuator length. I would rather keep the boom rotation point where it is to keep the other kinematics intact and minimize changes. It is true that a completely new superstructure could be more optimized for the actuator, but that is a really large amount of work. I would be happy with the actuator integrated into the existing design. But please do whatever you like! Obviously the point where the rod end of the actuator attaches to the boom needs to move out as well, but that is easy to do.

OK, I guess the other ring fits so tight that I can't install it. Because all of my dimensions seemed to be large, that is probably why I can't even get the smaller ring to slip. The tolerances on 3D printing are still not very good, so it is not too surprising that each result is different. I will try to remember to take a picture tonight.

Oh, I absolutely agree that stalling DC motors in general causing heating and reduced life. I've smoked plenty of R/C motors this way. However with the 9V LEGO motors there doesn't ever seem to be enough current or heat to be noticeable.

I purchased the XL linear actuator and have been playing with it. First off, it took a LOT of sanding before I could get it to work. There was some dust in the threads that needed to be removed (no problem), but also the threads were too tight and would not go together. I removed some outer diameter of the male threads with 80 grit sandpaper, then I filed the thread flanks with a tapered file until everything moved smoothly. I also had to enlarge the axle holes which were too tight to get an axle through. Now that the actuator is working, I have some questions. The design came with 2 different ring gears. One of them seems to be too big and doesn't fit. Why are there 2? The clutch seems very tight and I can't get it to slip before a motor stalls. I know you mentioned that the original clutch was too loose. I really like this actuator and am looking forward to integrating it into a model. I also purchased the Countach wheel covers which look amazing on my Countach.

Sigh. Sometimes it is really frustrating having no talent..... Recently I received the 3D printed linear actuator that Efferman designed. It is huge and powerful and perfect in scale to replace the PF linear actuators in this model. The problem is, I can't figure out how to properly mount it or get power to it. I've mocked up the actuator in LDraw along with a more representative attach location. The trick is to get the power from the pair of bevel gears further back to the single bevel gear at the actuator, and also to brace the support axle for the tremendous weight of the boom. Jurgen and Gerger are clearly 100x (conservative estimate) better than me at this stuff. I've posted the LDraw file. Anyone with skill care to take a crack at it?

Why don't you start by telling us what you'd like to build? It is pretty hard to give feedback if we have no idea what you are doing. As for the rest, each style has merit. What to choose is entirely up to you and what you like. You've identified the differences in cost and weight, so if either of those things is important to your design, then you are already pointed in a certain direction.

In my opinion, the PF system is an improvement over the old 9V in virtually every measurable way. There is a wider variety of motors available, the motors are more powerful, more reliable, and even cheaper. The only things I miss about the old system are the mini motor and the smaller form factor for the wires. Those 4 conductor wires are unnecessary for the motors anyway, and take up a lot of space. I wish they used a 2 conductor version (with the same connector) for motors. I also really liked the old ungeared 9V motor because it ran so fast which allowed some special uses and also made you think more about how to gear it down for other uses (like 8480). I've never noticed any problem with stalling that motor. I think you could stall it indefinitely without damaging anything.

In practice, yes. But I think the point of this topic is that there is no reason Technic needs to be just about vehicles. It seems like a more core concept would be demonstrating how mechanical things work, and from that point of view there is a much wider list of possibilities.

The Eurobricks Technic forum has a group of members with a lot of Technic experience, and who have seen a lot of excellent MOCs. Impressing them is not an easy task. In general, you'll probably find that it is not possible to create "buzz" about a MOC intentionally. Once you've posted your model, you'll find that buzz happens all by itself if the model is worthy of it (and most aren't). Eurobricks is not social media so there are no "likes" or subscribers or other indications of promotional success. A MOC presented here is typically presented for the purpose of sharing with like minded individuals. If you'd also like feedback on your model, you can ask for it but you'll find that people tend to be polite about criticisms so you may not get totally unbiased feedback.

It can go fast in a free fall!

Don't try to upload the pictures directly to Eurobricks. Post the pictures on an image hosting site like Flickr or Bricksafe and then just link them here.

This review topic has got a lot of traffic in it considering there aren't any reviews here yet! (waiting impatiently)

I'd write one but I might be a bit biased.

In general you don't need to ask that question. If there were instructions available, you can bet they would be discussed in the thread.

Well, the brakes are functional in the sense that they really squeeze the rotors and can really provide some resistance, but you wouldn't actually use them to stop the model. Motor braking is plenty for that. So there is no concern about wear. The flat discs you mention do look smoother, but they are also much less than 1x2 stud thick. If you stack two of them together like this there will be a big gap and when you squeeze the rotor you'll just close the gap. You won't get any clamping force. The pulleys work better even with the holes.

This is certainly something I've noticed while compiling Technicopedia. It is virtually impossible to find any official Technic set without tires (or treads). Even the boats have tires. I'd have to think about it, but I'm not sure there has ever been one. If you want include Star Wars and/or Throwbots, then you can find examples with no tires. Some of Nico71's fantastic contraptions don't use tires, like the braiding machine or tachometer. There are also quite a few kinetic sculptures out there.

Looks like another topic that shouldn't be in the Technic forum. There's no doubt that there's much more to LEGO than plastic.

Yes.

I've already posted the full resolution images. Just follow the links to my Bricksafe account. All of my pictures are posted at Bricksafe. Feel free to download as many as you like! I already use them as my screensaver and as my alternating wallpaper and I can confirm it works great.

The phenomenon of full instructions being widely available for Technic models is fairly new. Just a few years ago, you couldn't find any. Now there are dozens. On top of that, the prevalence of social media and the publication of lots of new No Starch Press books has greatly expanded the exposure of these MOCs. The secondary market it just far too small to keep up. There is no doubt that it is a real problem for the future of being a Technic fan. Of course sets from LEGO are still readily available, but if you want to build a model which is vastly more complex than LEGO would ever sell, you either need a large existing collection or a lot of money. The good news is that I think LEGO is listening to a certain extent. There have been a few times in the last couple of years when we fans have been complaining on this very forum about a scarce part (like the red 5x11 panel or the yellow 1x6 thin liftarm) only to have it show up in an official set the next year. I admit that I was really hoping that the 2015 models would be replete with 19L black flex axles and #3 red connectors, but so far no such luck.

This has actually been brought up through the ambassadors (and earlier) many times already. The logistics of selling parts packs and the tiny numbers (compared to their normal sales) that could be expected are just not worth it for a big company like LEGO. There's no reason they couldn't sell every part individually if they wanted to, and AFOLs would buy them, but ir appears only AFOL sellers are willing to spend the labor required to pick an order with 300 assorted LEGO parts costing $0.10 each.