Nazgarot

Hi, I have an idea you could try for a 2 rotor counter rotating construction with only 1 motor. It should have more lift pr motor, and it should be easy to put two of them together to make a quad... replace the red parts with a buggy motor... And the .lxf -ED-

I just noted there is a new rubber tile for the tracks in this picture. Has anyone seen it before? Has anyone seen if it will come in different colors in other sets?

I would love to see some good pictures of your solution. It's hard to see in the video as its all very dark (and most of the parts black). It seems like a very good solution, and it seems quite tight as well. Most of my attempts for push- or pull-rod suspensions have got a lot of play in them... -ED-

Wan't there a problem with the first LAs that came with the 8043 excavator? I think I remember there was a problem with LAs locking up... May it be that one of them is from this early batch? -ED-

Hi, I, as well as others, think it's about time we get a positive spin on this. It's a great opportunity to get a relaunch of old parts, or maybe even new or modified parts. I know the crawler isn't the best base to work from, but there is a lot of cool possibilities. I've added a few pictures to get your wheels turning. I haven't got the set my self (was thinking of waiting for chrismas), but now I will buy it just to enter the competition... Does anyone know if it's only one entry pr person, or can I have several entries? -ED-

I can't see why it shouldn't be possible... Using custom hubs with towballs, and the new lego wishbone this should be quite easy. It will be something like the rear suspention in the pic below. For more about this car please see these links to Nathanael Kuipers fantastic cars. Medium sized car chassis Finished car on a modified version of the same chassis Presentation of Kuipers cars -ED-

Please read the introduction to this topic (first thread). This is not about what you or I find to be illegal or not, but about what would be approved by TLG (the Lego Group). We have already stated that as long as a technique can damage a part, it's illegal. If it makes the parts hard to separate (to hard for a kid), it's dubious if TLG would approve it. Unusual use of part is often something TLG probably will approve. There of the sectioning in the first post. I will continue to update this as new techniques are put in question... -ED-

As I said in the explanation below the pictures it's only a proof of concept, and it is possible to adjust the caster angle by adjusting the wishbones (I did not how ever have the time to do so...): It might very well be that I have a mix up between caster angle and "tow radius", as the Norwegian definitions differ from English... Anyway, you should strive to have an slight angle/offset on both. And it is possible by a slight alteration of this build. You will just have to try. It's a question of clearances, and I can't say what will work without trying. But this should be a good starting point for you... -ED-

This has nothing to do with the discussion. It's simply destructive abuse of Lego, and should be avoided at all cost!! This reminds me of some of my more usable Technic creations before my dark ages. There was actually a few liftarms that was worn through by axels, and that as well without any illegal builds... As for the tank... It seems to simply be a display model, and as such it's ok. But I'm not impressed, as most of what is done could be achieved with unmodified parts. I would be a lot more impressed by a model built under stricter rules, and that is probably the core of it. The rules makes for a more challenging build, thus it's more impressive if it's built by the rules. Only problem is, everyone has their own rules... I usually just avoid making comments if I see a model where I feel the builder has made unnecessary shortcuts, sometimes, how ever, the limitations of these fantastic toys (or ones economy) makes it necessary to break the rules. And in those cases I might be just as amazed by a non purist approach. -ED-

Hi, After about half an hour in the shed I came up with this double wishbone suspension, using the hubs I described earlier. It is of course possible to make an simpler version, but that should be easy to modify for anyone who needs it. This version is very realistic, and fits with both the "normal driven hub", and the "geared hub". I also spent some time drawing them in LDD. Below follows some pics from LDD and an explanation of the setup. The hubs I ended up using, and the complete setup: The red line in this pic shows the toe angle. As you can see it has a slight toe in. This is easy to change by moving the whole steering rack to the other side of the diff. For a front/all wheel drive vehicle (as this hubs are indicating it is) a slight toe out would be preferable. It also archives an Ackermann steering geometry, but because you have an outward angle on the steering rods you might get trouble with the steering becoming unstable at larges steering angles. This is a problem you will have to solve by yourself, as it has nothing to do with the double wishbones and will add a lot of complexity. The next picture shows the caster angle. It can be moved in half stud increases depending on what parts you use, but I would prefer this angle for normal cars. To make the whole setup more complex it is also possible to move one of the wishbones forwards or back to increase or decrease the angle (this will also give you a different "tow radius?", and is often referred to as a combination angle). Here you can see the KPI angle, resulting in the pivot point being at the inside of the tire. For the ungeared hub it will be almost center with a tire of this size. The last pic shows you the camber angle. The red line showing a slight negative camber equals the wheels normal position, and a negative angle here is preferable as the play in the parts will make it a slight positive when weight is applied. As the wheel moves up the camber angle will increase, as the blue line shows (as the wheel extends down from the normal position, the angle will decrease, giving it more negative camber angle). This guarantees that the wheel has optimum surface contact in turns. This model is a proof of concept, and should be seen as such. If anyone wants to include this in a actual model I would recommend using 3 stud liftarms (or similar solution) to make the wishbones more resilient to angular momentum, and using more than one point to connect it to the frame. And you need to give it the correct toe in/out according to what drive setup you have. By playing with the position of the wishbones you can give the setup more or less Caster, and at the same time changes the "tow radius" (I don't know if this is the correct description of it, it's directly translated from Norwegian, but it is decided by the relative position of the wheel center compered to the center of the two wishbones) and thus make the steering more precise and help center the wheels. The steering rack is also placed a bit high compared to the attachment of the steering rod, and this is sure to give bump steer. While this is something to strive for in a rear suspension, it's not at all wanted in the front. It is a problem easily solved how ever... The full LDD file can be found here... Good luck! -ED-

Hi, I've added the techniques that we have discussed, and defined, to the first post. Please feel free to suggest more dubious techniques... I really find this useful, as it helps me a lot to understand what might be required to have a model approved for cuusoo, and Lego competitions. And, thanks for keeping the discussion clean and on topic! -ED-

TLG does...

Hi, A discussion on the unwritten rules of Lego was started a short time ago, and quickly got out of hand. I want to start this topic to answer a legit question: What would Lego allow? I hope this will not be "flamed" the same way that "unwritten rules" was... The thing is, there are some techniques that are considered illegal, and never is used by TLG, but there is also some that would qualify as illegal that are used... I.e. The roof of the Unimog, that stresses parts... I hope this discussion to be a place where people can get answered whether TLG would allow their technique or not. This will be interesting in both this years challenge, and for people who want to get a model through to production on Cuusoo. There was one ,in this aspect, very interesting post on the "unwritten rules" discussion: I think this is a good starting point. Would for example tires stretched to larger wheels, or axles used as torsion springs be allowed in a model? Can plates be used to connect beams? It would be nice if we can keep a clean discussion, without all the flaming. Nobody says you have to follow these rules, but if you want to get a model approved by TLG it would be nice to know what could be accepted. Maybe some of the successful models form Cuusoo can give us some clues... I will update this first post when we agree on things that are questioned (I would also appreciate input on how this post should look). Probable approval by TLG: ========================= *Slight stress on beams (example 8110 Unimog roof) *Cutting of ribbed hoses, pneumatic hoses and 3mm rigid hoses (several older official models employ this) *New use for existing parts (several examples in official models) Possible consideration by TLG: ============================== *New parts that has several uses, and are easy to include in the existing lineup *Uses that will stress parts without damaging them *Attaching 2*n plates to beams (in a way that lets it be removed) Illegal by TLG standards: ========================= *Using axles as torsion springs *Using Driving rings (6539) on a smooth axle joiner (6538c) *Stretching tires to larger rims or other objects -ED- EDIT: Added some new techniques.

No, I was not talking about rim slip. I was considering both better grip (by changing the profile of the tire) and better looks... The question was, is it considered an illegal technique to modify Lego tires by using Lego rims that will stretch the tire? -ED-

First, nice car! Would love to see a video to see how well those XL's work. This is a variant of an "elliptic leaf spring". Se this article for more information. -ED-

I was just wondering, what about using lego tires in ways that stresses them, for example puting a tire on a larger rim then it's made for? I'm thinking both in TR and generally? It would be an illegal build by Lego standards (It stresses the tire), but it's pure Lego, and it may really enhance the grip of some tires... -ED-

All of these will have that if you angle the lower wishbone slightly (i.e. 5 studs between the outer points, and 4 between the inner points). This will give you a slight negative camber that will help make the true camper of the wheel zero degrees when you put a load on it. At the same time it will give you a progressive change of camber angle as the wheel is pushed up. If you don't want this, but want a slight positive camber that increases you can use a longer lower wishbone (It's half a stud longer than this). I'll post some pictures with an example this weekend if you can wait. -ED-

See for your self. Link to LXF file You will need to space the upper and lower wishbones further apart. I recommend putting the lower wishbones at an slight angle (it will make the whole setup tighter), 4 studs from each other at the inner end and 5 at the outer end. The blue parts are possible connections for the steering arms. The best thing about this is that the towballs will allow the wheels to turn at a much greater angle then the traditional Lego hubs. -ED-

Thanks! That was exactly what I was asking for earlier. -ED-

I'm afraid that construction won't work. It will be to far between the pivot point of the steered wheel and the first joint on the axle. The axle will need to expand (or it will pull itself out of the wheel, creating trouble when you try to center it again), and the only part that can help you with that is the CV-joint with the joint axle. There will still be a lot of force playing on the axle, so I would not recommend it. The only viable option would be to use this king pin, or to create one for your self... I have made several such "hubs" if you are interested. One has integrated gearing, and gives you realistic KPI angle as well (I believe I've seen Efferman make something similar). Another one gives you "realistic" caster angle, while still placing the whole hub inside the rim. And I have one very simple that is easy to make, and easy to implement.

I, for one, do... I would be very interested to know what tires you will be using. That is most often the decisive factor when deciding on a scale... -ED-

Yes, that is something I'm wondering about. What are the techniques that makes a build illegal? I use several parts in ways Lego has never used them, but i see that as part of the flexibility in Lego. Every part is designed to fit in many ways. For example the stud of a normal piece will fit in the hole of a beam. But is it legal to use 3x2 plates to lock two studless beams together? Can I use the flex in a axle as a torsion spring? Can I use a column, a piece of string and an axle to make a longer cylinder (like was suggested here a while ago)? Could someone please list the illegal techniques, or at least the criteria for making a technique illegal? -ED-

Welcome back to a great hobby! Yes, this i possible although you will need to use some different gears. The black and grey gears form you pic wouldn't connect. I would how ever recommend putting a differential between the motors, as any difference in speed will result in the faster motor wasting energy to speed up the slower one. That said I have used this setup myself to get more power, and lacking the room to include a differential. Right now I'm working on a model of the Howe and Howe "RipSaw" where I connect two XL motors in this way to get sufficient power. It's a bit harder on the batteries, and the motors develop a little bit more heat, but i have 6 XL motors and have been matching their speed against each other, and have picked out the two that are closest in speed. This can easily be done by connecting two motor running in opposite direction through a differential and measure how much/fast the differential spins. Good luck with your project, and keep us updated! A WIP (Work in progress) blog as a topic here is a good way to get help with your construction. See you around -ED-

This may be interesting to some of us... Researchers at University of Southampton claims to have built a "supercomputer" from Raspberry PI mini computers and lego. This might give some of us (me included) ideas of how to replace the existing NXT brick... It will be cheaper, and more flexible, but a lot more work... Some links for those who wants to build a "supercomputer" for them self. I know this is not exactly Technic, but it should be interesting to those of us who like programming as well as Lego, and that makes me believe this would be the right forum for this. If there already is a tread on this on a different forum, please feel free to close this tread. -ED-

Well... There is one other plane that has a similar scale, and similar functions to yours. The baby Twin Otter. It has an amazing set of functions, but only limited motorization of functions. And... It will never fly. Yours may though, with the right motor/battery combination... -ED-