TasV

That's really cool!

quoted from http://education.lego.com/en-au/preschool-and-school/secondary/11plus-mindstorms-education/faqs-and-technical-support Apparently the Bluetooth block does it as well if you are using EV3 instead of NXT.

Definitely the NXT mindstorms kits that I bought for my Son last Christmas. Up till then I had lived Lego vicariously through my two Sons with the Lego I had as a kid and loads of Technic kits that we bought them every year. Half the fun was choosing the kits for Christmas and birthdays. My favourite kit that I bought my eldest boy was 9393 tractor kit. I've been using Lego all my working life, too, in my science classes to teach kids about simple machines. Nothing better than the competition to make a Merry-Go-Round that spins the slowest to get across the idea of using gears with the old technics education kits (basically just trays full of technic Lego and motors).

How do yo find the compass sensor? We have a Hitechnic compass sensor and find that every little bit of electromagnetic interference, from things like TVs etc, affects its function resulting in very poor navigation.

I've had a chance to play with the metal caster ball by retro-fitting it into the NXT 2.0 set and have found it really good so long as the robot track is flat. As soon as they start throwing obstacles at you that are 5mm high, or higher, it gets stuck because the socket housing sits down too far over the ball preventing it from being able to roll over it. It can be fixed by attaching suspension to it (not mounted vertically though... it needs to be able to swing up out of the way and snap back into place once over the obstacle) but that's not always possible in robots that have to comply with dimension restrictions such as the RoboCup Junior rules that state the robot can't be more than 18cm high or wide. I have two of the smaller Rotacaster Omniwheels and they are great, BUT, and this is a pretty large BUT for an anal retentive builder like me, it is an odd size that means I can't mount it evenly right in the middle, parallel to the central axis, of the robot without it sitting more to one side than the other. That really bugs me and is why I bought two of them so I can mount them on either side like a car instead of just one at the back. It's also not the same height as any of the standard lego tires which means you need to get creative in levelling the robot/vehicle out. These are the reasons I start looking at making my own pieces. If one is going to design and make 3rd party pieces they should at least made along the same ratios as genuine Lego.

Chorlton, that makes sense. I will check on this. I might be able to give my poor laptop a break instead of trying to render overly complex files.

Mtx, if you would like me to send you the stl files (once the parts have been tested) just let me know.

Nervous now LOL I use CNC routers all the time at work but this is the first time I've had something printed in 3D... I really hope it works. I have plans to design and print a whole robot shell if it works. I'll get the review on the liftarms started by going through the file used to make them. I used Google SketchUp 8 (Just downloaded SU Make and am using that now too) with plugins allowing me to export STL files directly from SketchUp. Each part is made up of two modular parts so that any length piece can be made. They look like this: These two parts are made up of 8230 different faces which is mainly due to trying to get sufficiently high enough resolution in the circles/curves to prevent the facets from being visible in the final product. When combined into a liftarm each piece can therefore be made of up to 80,000ish different faces. I probably don't need to go to this resolution but I wanted the pieces to be as smooth as possible given that 'stepping' can be introduced as an artefact of the printing process. Printing is achieved by laying down layers of material that is sintered by a laser. Because it is printed in layers there may be visible edges between each one, where it changes size, that causes this stepping. The dimensions were based on the image posted on page one of this thread. Each component was made at 100 times the actual size and then scaled down because SketchUp has a really annoying snapping function that can't be turned off (that I am aware of) that turns otherwise straight lines into bent lines in cases where curves intersect with the straight line. Scaling it up, and then scaling it down once finished avoids this.

Only what I see and hear as a casual observer. That's a shame. Still... you have to try I think... might get onto a project with my eldest Son to have a crack myself :) P.S.... I just saw the Make-a-Wish Vampire GT entry on Cuusoo... very noble thing you have done. Kudos.

I guess I'm not trying to make things easier, either. Believe me, the effort needed to design them is by no means easy. It is, instead, a nice way to feed another interest I have that is able to blend nicely with my interest in Lego and my passion for science. I'm not in any way suggesting people should make official MOCs for exhibition purposes at official Lego events. There is a process (Cuusoo) for this to happen that needs to be respected. I think it's strange that people don't consider Technics as Lego. My first kit as a kid was the old 853-1 from the Expert Builders range. I still have all the parts from it 35 odd years later and now my own sons play with them by mixing them with modern studless and Bionicle parts. The only Lego I ever knew as a kid was Technics and now my eldest Son wants to go on the become a robotics engineer and work for Lego. I am actively teaching him about 3D design and the physics of Lego and maybe one day he will be helping to shape the look and feel of official Lego. I digress... I think there is a design process that can be acknowledged here that everyone can benefit from. TLG is not going to go to the expense of making a part unless it is part of a kit. They have a process in place by which people can design parts and MOCs that can be voted on and put into production. If new kits are to be developed then parts also need to evolve and these new parts need to be fully prototyped and tested before anyone should even consider submitting them to Cuusoo, don't you think? Today's Frankenbits are tomorrow's genuine article if that process is followed and respected. Personally, I love your passion for Technics. People like you and Sariel are incredible inspirations to so many, including myself, and I support your cause to mainstream Technics completely (again personally... non-technic Lego bores me (but I love this atm http://lego.cuusoo.com/ideas/view/16897 ) and I don't get minifigs either *shrugs*), but I think things like this actually support your cause, not hinder it, if done properly.

Well... the way I look at it is that this is just another aspect of what makes Lego appealing to me. You see posts on here all the time from people saying they wished TLG would make such-and-such a part because they can see a need for it. I wanted to see longer linear actuators until I recently worked out a way to use the existing LA as a distance multiplier and now I no longer want to see longer LA... that's another aspect of what makes Lego appealing to me; working out how to make something work. TLG is never going to make them unless they have a need for it and can use it in a set etc... and this is as it should be. It makes sound business sense because it is expensive tooling up for production. The onus then falls back on the individual, who can see a personal need for it, to do it themselves and this, too, is how it should be. One is never going to reach the same level of engineering excellence that TLG has but that is ok because the learning that must take place in order to produce the part and improve on it in the future is an invaluable thing and if other people want to use the pieces that I make then... that's great too. The fact that the unit price is also quite high for custom parts also guarantees they won't be widely used. It is common to hear people say on here that they are purists etc... but I see this as totally incorrect because they are very different concepts. If I'm making a Lego MOC then I will use Lego pieces... by definition if it uses other parts it's not a Lego MOC... it's a MOC. If I want to make a robot that follows a line then who cares what pieces I use to make that happen. Even the rules of RoboCup don't stipulate that the robot must be made from Lego and they even encourage the students to show innovation to construct their own robot parts. In Tasmania, this is supported by the School of Engineering at The University of Tasmania and is a highly sought after accolade which helps students secure pathways into engineering and computing. So... it depends on your motivation and intent. I just hope that people can see this and don't start a 'it's not Lego' bashing...

Very cool! Thanks!

DrJB... check out this YouTube video utilising 3D scanners that integrate with 3D printers: I really don't understand how gearboxes work but I imagine it would be possible to print these. My concern would be how strong the material is and how well the gear teeth would wear. I am trying to get my head around this video to understand how a gearbox works: (trying to work out how to embed YouTube vids here)One thing is for certain... when you start down this 3D design path you want to have a computer with enough grunt to run it. I thought my new laptop had the goods but I'm currently making a 14 and 16 hole liftarm and because I have bumped the resolution of the model right up it took a good 15 minutes just to explode (combine... ironically), all the different parts! The 14-hole liftarm has in excess of 75,000 different faces.

Is there a new version of LDD out that can make these renders or did you do them from screen shots in something like Photoshop? I don't think my LDD (V 4.3) can do such lovely renders.

Yep... knew about it. Just not sure I have the time to put into it. I run the robotics course at Ulvie High which I started because my eldest Son wants to go into robotics, or even work for Lego in their robotics section. I love Lego too, mind you, but being a teacher and owning a small farm with three kids doesn't leave me much time to MOC. I take my robotics class each week and get my Lego fix that way for the time being.

Ahhhhh... ok. I thought you designed it as well. If your offer to test these parts I designed still stands can you please PM me? I will make them available to purchase for a short time and then close them off again. I will reimburse your purchase, in that strong/flexible polished material I think... maybe the high detail stuff... what do you think... and shipping costs via PayPal if you have an account. I refuse to pay nearly $20 postage for $3 parts. It's actually cheaper to have someone in The Netherlands purchase the parts and then have them on-posted to Australia. Check out this part I just found: http://www.shapeways.com/model/994045/air-bottle-cap.html?li=search-results&materialId=6 . Seems like an interesting idea. The issue I have with a lot of these parts is that it is really easy to make the files but so many are untested and remain so until some unsuspecting person buys them and finds they are not up to specifications (as Sanjy found in trying to match Lego's tolerances).

I'm up near Devonport... a teacher at Ulverstone High School :)

Another Tasmanian!!! That makes three of us that I know of!

RE: reading QR codes. This might be able to do it: http://mindsensors.com/index.php?module=pagemaster&PAGE_user_op=view_page&PAGE_id=78 . One of my students was looking into using an iPhone to do line follow work but didn't get very far with it. It was going to have regional visual sensing so it could correlate what it sees and where it sees it with its position and use this to decide which direction it would go (i.e. forward, backward, left or right using proportional steering). On another note... the NXT (not sure about EV3) is based on LabVIEW and in LabVIEW you can do optical sensing. There is a good YouTube video on it but I didn't bookmark it and am struggling to find it again.

Jim, is this you? https://www.shapeways.com/model/156405/lego-test.html?li=user-profile&materialId=6

Even better that you're an Aussie I've made my models private for the time being until they are more fully tested.

I hope they wash all that white powder off them then ;) Those Lego Dogs at the airport would have a field day!

Funny... I'd prefer the default materials LOL

Ok... try this then... it now says I've made it public *shrugs* https://www.shapeways.com/model/1340735/1x4legoliftarm.html?li=my-models&materialId=62 Jim, if you have PayPal send me your email address and I'll reimburse you the cost of buying the parts and shipping. EDIT: Oh.. and I'm not happy about having it public and available for sale like this before testing so if you can please let me know when you've got it I will change the settings back to private until a full assessment is available.

Um... yep... just worked out how to make it public. Try this link: https://www.shapeways.com/model/1340735/1x4legoliftarm.html?li=my-models&materialId=62 I'm not sure why there are lines on the SW render because there are none on the 3D file I made. Maybe they reduce the resolution for web use??? Jim, your review would be excellent. I hope it works because I have this really cool idea for extendable liftarms too. Sanjy... some of my students put me onto Shapeways but your blog is what inspired me to try it for myself. I think what you have done is amazing.