DrJB

Guys ... what is this discussion really about? The model is fully/ready in LDD. I'm curious, this ongoing team activity is for ...?

Memorizing for sure (you'll remember them for a while) ... though I'd qualify them as 'mezmerizing' .... i.e., magic :)

The way I did it was as follows ... within LDD 1. Remove the top platter. Build that sub-assembly separately, 2. Flip the base upside down, build the bottom (that are now top) 2 layers 3. flip it back, build the gear-boxes and the whole 'front' of the machine (including gear switching mechanisms) 4. finish off the rear gears and motor area

Not sure you need the old style bushings for this. The new ones will do the trick as we'll ... Unless I am missing something here ...

I have such set and it only came with the CD i.e., no printed instructions. All building steps are 'animated' on the CD. pmichiel must have spent hours putting those together.

I corrected my post. I did not mean to say it was a weak design, not at all ... but some (recent) gears have a smaller clamping force and thus a tendency to slip off their axle. Such is the case for the 12T gear on the 5.5 axle under the gearbox on the left. Also, the bracing I added is to make the design robust enough for kids to play with. All-in-all, a very good/clean design/layout.Trying a math approach here: In the original version (one used to start this thread), there are 3 gearboxes with 4 positions each, and two direction controls for the left/right gears. For any given position of the pen, this MOC can create 4x4x4x2x2= 256 different shapes. To this, we may need to add combinations where none of the gears are engaged, or variation in the pen's position (how it is attached/tilted). Running all 256 possible drawings will for sure take some time ... though it would be fun entertaining kids at some day-long event. I'm thinking a possible mathematical model to draw such shapes ... Stay tuned. Thinking a bit more about this ... all motions must be controlled by the SAME motor, otherwise the path never closes. This explains the intricacy of such beautiful designs.

More 'smaller' parts ... to increase even further the advertised 'part count' on the box ...

Not sure anyone reported on this, but found a new GBC (haven't seen it before) on u-tube.

Agreed, there is no high torque, but possibly some parts were not 'assembled' correctly. That is why I added some 'bracing' to stiffen the frame at some key locations. Also, I used a 'new' 12T gear on a 5.5 axle and it slipped. Possibly, when it did that it locked one of the transmission paths and the gear broke. In the LXF file posted above, the gear that broke is in yellow, and all new 'bracing' is in white. My kids are having a blast trying all sorts of combination. We found 2 more variables we can 'play' with, the radii at which the two suspension parts are attached, and the tilt angle of the pen (how it is attached). The latter can yield very different patterns. Fantastic MOC PG52 ... Thank you for sharing.

I built it and made some changes to the frame to make it 'kid-proof' ... Somehow a 12T gear broke. Went ahead and 'stiffened' the frame and replaced few parts. Sturdier design now. All New/Replaced parts are in WHITE. Broken gear is in yellow. http://www.brickshel...ry.cgi?f=535841 EDIT: Corrected some of my original wording.

For those who do not know what those are ... it is very simple. All Lego stores often display built-up models of their latest sets. When that set is retired, the display model is broken into parts, mixed with other sets, and 'grab' bags are filled with such loose parts. Those bags used to sell for $7.99 in the US and few times I've gotten a pretty good parts assortment. The sad part is, I no longer see those grab bags and was told (by the store manager) that they no longer do this. Apparently, now the stores are required to send all broken-up display models back to Lego Headquarters. 1. Is this true, or is it more likely that the store employees get a first dib at it? 2. Are there grab bags still available at your local Lego store? 3. I still see grab bags now and then, but they are from all those parts that kids picked up from the pick-a-brick bins and got mixed up. I had my eye on an 8043 a while back ... never materialized.

I occasionally see those for sale on eBay ... I asked a large store here if they could sell theirs and they said those technically belong to Lego, and Lego people will take them back in some time. Any idea where one can get them ... at reasonable cost of course?

If you can find one at a decent price, 8258 is a very good assortment of parts. It has only one XL motor though, but a good mix of liftarms, gears, linear actuators, and various connectors. For treads and red curved panels (and many Technic elements), can't beat Bionicle Skopio. Should be able to find one at a decent price. For example: http://www.ebay.com/...=item20da6a14d1 in US or http://www.ebay.com/...=item1e821e3614 in EU Admins: Not sure if posting eBay links is ok. If not, please remove.

Don't be ... you just showed us another useful resource.

Thank You.

Looks very promising ... but expensive as well (shipping). Anyone knows of a local (US) chrome place? On a different note, do you have instructions for such masterpiece?

Good catch, but that is somehow unavoidable with the axles ROTATING about the chassis (axis of rotation is horizontal). What one needs is a King-Pin axis that remains close the vertical at all times (King Pin axis goes goes through top/bottom knuckle connection to lower/upper control arms). To have an always positive caster, you would need an axle that 'translates' up-down relative to the chassis as done on some notorious off-road vehicles such as the old Jeep Grand Cherokee. I must mention the positive caster serves another purpose ... that of positive self-aligning moment i.e., to force the vehicle/tire to go on a straight line ... when no steering is applied (It does get a bit more complicated than that, especially in US vs. EU) ... but that's already getting a bit off-topic. Lastly, beautiful MOC, and I concur, nice color scheme. One question though: Why the mindstorms motors? The PF XL doe not provide sufficient torque?

That's an awesome parts selection ... You know what it means though, right? Well, when can we expect to see/build your next MOC ?

That should be a fairly easy part to 'reproduce' ... i.e., reverse engineer and mass produce in a certain country in Asia ...

Bricklink calls it a 16L flex axle ...

There was a time (very early on) where all you could buy was a 'basic' set consisting of a collection of parts ... and that came with a set of instructions to build few contraptions. Then (about 40 years ago?) Lego started making 'sets' destined to be used for a single specifc model (there was also B/C suggestions). Such 'basic' sets are still available today for the younger generation .... but how about a 'Base Technic' set ... that should include HTF parts. That may be a good CUUSOO proposal .... anyone willing to put a list together for a desired parts list ? EDIT: One can always get the MindStorms add-ons (e.g Resource Sets) from Lego EDU but there, the parts assortment is not always 'balanced'.

EDIT - Removed, started in another thread ... to keep this one on-focus

This came up in a different thread, and thought it deserves its own. The question is: What parts are 'apparently' identical, but really, once you look closer, they are not. I am after very subtle differences, yet very different part numbers. Parts such as 1234a vs. 1234b v. 1234c are rather obvious. Here is one to get started: The large Technic wheels in 32020 vs. 86652 that came in recent sets. How I stumbled upon this: I anted to know how many of such parts I had in my collection, so I simply went to bricklink and tallied up the various sets I had, that included such wheel. The total from Bricklink was lower than was I actually had at home. Upon closer examination, I realized there were in fact two 'flavors' to such parts and the only difference I could note was simply the shape of the axle hole. So, what other parts have you found that, are seemingly identical .... but not once you take a closer look?

Not to go way off-topic ... but a Lego Trivia game is in order here ... 1. L vs. M 2. SNOT vs. MOC 3. Studded vs. Not 4. AFOL vs. AwFOL 5. Jim vs. Ted 6. PF vs. 9V 7. LDD vs. LXF 8. ...

The cargo plane is definitely a must, along with the dump truck AND the snow-mobile for the new suspension/knuckle parts a la 8448, but smaller.